The Supramolecular Chemistry of Cucurbituril Molecules

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THE SUPRAMOLECULAR CHEMISTRY OF CUCURBITURIL MOLECULES

SUSANA LORENZO

A thesis submitted in fulfilment Of the requirements for the degree of Doctor of Philosophy

School of Chemistry University of New South Wales

March, 2006 Page i

ABSTRACT

The set of molecules cucurbit[n]uril (Qn) are macrocycles composed of n glycoluril monomers linked by methylene groups. These molecules have two oxygen-ringed portals of a diameter slightly smaller than their internal cavity diameter. This thesis describes syntheses, crystallisations, crystal structure determinations, crystal packing analyses and force field calculations exploring the supramolecular chemistry of Qn molecules and their derivatives. Qn acts as a host for guest molecules and at the outset of this project no metal containing molecule had been encapsulated in a Qn molecule. One aim of this project was to prepare such complexes. This was achieved with the synthesis and characterisation of crystalline {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23. Other compounds prepared and characterised crystallographically in the course of this project are: [(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4,

(Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26, (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24,

(Q8)3(PtCl6)4(H3O)8(H2O)x, (Q8)2(PtCl6)3(H3O)6(H2O)18, (Q7)(Cr3O10)(H3O)2(H2O)x and (Q6)(SnCl6)(H3O)2(H2O)x. While the smaller Qn (n = 5–8) retain their circular forms, the larger Qn (n > 8) are less rigid and distort to accommodate larger guests. After analysis of the crystal structures of these Qn compounds and those listed in the Cambridge Structural Database, the principal packing motifs of the Qn molecules were elucidated. The most common is the portal-to-side interaction in which the portal oxygen atoms of one Qn approach the hydrogen atoms around the equator of another Qn. Force-field calculations on guest@Qn complexes were conducted to determine the mechanism for the formation of these complexes. A comparison of the intermolecular interactions of phenylated systems and comparable fluorinated phenyl systems was made using both crystal packing analyses and forcefield energy calculations. Intermolecular energy parameters for these calculations were derived and validated in this work. The principal fluorinated species studied was the – [B(C6F5)4] anion. Examination of its crystal structures found that the substitution of the hydrogen atoms by fluorine atoms is influential enough to alter the predominant Page ii

intramolecular conformation. It is the ‘flipper’ conformer, between pairs of perfluorophenyl groups, that is overwhelmingly the favoured conformation and this has – a strong effect on the types of phenyl embraces that a [B(C6F5)4] anion will form. While the parallel 4PFE, the offset parallel 4PFE and the orthogonal 4PFE are all observed the 6PFE is not. Page iii

ACKNOWLEDGEMENTS

There are many people who have contributed to my project over the years and I would like to take this opportunity to thank them. Firstly to my collaborators at the Australian Defence Force Academy, Dr. Rodney Blanch, Dr. Anthony Day and Dr. Alan White for their introduction to and advice on cucurbituril chemistry. In particular I would like to thank Dr. Anthony Day for the supply of cucurbituril compounds and help with synthetic preparations. Dr. Gareth Lewis, Dr. John McMurtrie, Don Craig and Dr. Peter Turner have provided me with tuition and invaluable assistance in crystallographic techniques. Their help has contributed enormously to this project and I cannot thank them enough. Thanks also to Dr. Jim Hook for his assistance with NMR techniques.

Over the years Dr. Marcia Scudder has acted as a second supervisor to me. She has provided me with instruction in many aspects of my research, from computational to crystallographic techniques and provided a wealth of information on general matters of my research. Marcia has been overwhelmingly generous with her time and so a simple ‘thankyou’ seems too weak a word to express my gratitude. Thankyou anyway.

My supervisor, Emeritus Prof. Ian Dance, is a tremendous role model for any aspiring researcher and I consider it a privilege to have been his student. Along with his extensive knowledge, it is his enthusiasm for his work, his energy and optimism that I consider to be his greatest attributes and those of an excellent supervisor. He applied all his talents with gusto during my PhD and I offer my deepest gratitude for all he has done for me. I wish him all the best in (partial) retirement.

I’d also like to take the time to thank those who have made my time as a PhD student memorable and a lot of fun. They include: Scott Watkins, David Lonnon, Garth Jones, Antonella Petrella, Lakmini Weerakoon, Vanessa Russell, John McMurtrie and Catrin Hasselgren-Harby. Page iv

In particular I’d like to thank Nathan Paris for his long friendship and his genuine encouragement, advice and support, especially in recent times, and also to Doug Lawes for his perpetual kindness and willingness to help out a friend in need.

My family represents a great source of strength for me and I have drawn on this heavily during my student career. I’d like to finish off this page of thankyous by saying how grateful I am to them for the important role they have played in my life. Page v

TABLE OF CONTENTS.

ABSTRACT...... I ACKNOWLEDGEMENTS...... III TABLE OF CONTENTS...... V ABBREVIATIONS ...... XIV

CHAPTER 1: INTRODUCTION TO SUPRAMOLECULAR CHEMISTRY ...... 1 1.1: Supramolecular Chemistry...... 1 1.2: Host-Guest Complexes...... 2 1.3: Supramolecular Devices...... 4 1.4: The Role of Crystallography in the Study of Supramolecular Chemistry...... 5 1.4.1: Crystal engineering...... 6 1.4.2: Polymorphism...... 6 1.5: Conclusion...... 7 REFERENCES...... 9

CHAPTER 2: INTRODUCTION TO CUCURBITURIL CHEMISTRY...... 11 2.1: Introduction...... 11 2.2: Cucurbituril as a Host Molecule...... 13 2.2.1: Interactions between host and guest molecules...... 15 2.2.2: Methods of detection of host-guest complexes...... 18 2.2.3: Altered guest properties due to complex formation...... 19 2.2.4: Chemistry inside the Qn cavity: Qn as a catalyst...... 21 2.2.5: The host-guest complexes of other macrocycles...... 22 2.3: Cation Binding to Portals...... 24 2.4: The Practical Applications of Qn Chemistry...... 26 2.5: The Synthesis of Qns...... 29 Page vi

2.5.1: The synthesis of substituted Qns...... 31 2.6: Computational Studies of Qns...... 33 2.7: Aims of this Project...... 34 REFERENCES...... 35

CHAPTER 3: CRYSTAL STRUCTURE ANALYSIS OF LITERATURE STRUCTURES...... 43 3.1: Introduction...... 43 3.1.1: The crystal packing of the uncoordinated Qn molecules...... 44 3.2: The Metal-Chalcogenide Clusters...... 48 3.2.1: Columns of parallel Qns...... 51 3.2.2: Zig-zag chains of Qns...... 54 3.2.3: Other packing motifs...... 58 3.2.4: Concluding remarks...... 61 3.3: Host-Guest Complexes...... 62 3.4: Metal Complexes not Coordinated to Qn...... 70 3.4.1: Introduction...... 70 3.4.2: The crystal structures...... 70 3.4.3: Concluding remarks...... 75 3.5: 1D Coordination Polymers...... 76 3.6: Metal Cations Coordinated to Qns...... 80 3.6.1: Introduction...... 80 3.6.2: Structures containing portal-to-side interactions...... 82 3.6.3: Short stacks of linked Qns...... 85 3.6.4: Columns of parallel Qns...... 86 3.6.5: Other packing motifs...... 87 3.6.6: Concluding remarks...... 87 3.7: Polyrotaxanes and Molecular Necklaces...... 88 3.7.1: Introduction...... 88 3.7.2: Molecular necklaces...... 91 3.7.3: 1D polyrotaxanes...... 93 3.7.3.1: The zig-zag wave...... 93 Page vii

3.7.3.2: The square wave...... 95 3.7.3.3: The helical chain...... 96 3.7.3.4: The linear chain...... 97 3.7.3.5: Concluding remarks...... 98 3.7.4: 2D polyrotaxanes...... 99 3.7.5: 3D polyrotaxane...... 101 3.8: Functionalised Qns...... 101 3.8.1: Introduction...... 101 3.8.2: The Crystal structures...... 103 3.8.3: Concluding remarks...... 106 3.9: Q5@Q10...... 107 REFERENCES...... 109

CHAPTER 4: EXPERIMENTAL WORK...... 115 4.1: Introduction...... 115 4.1.1: Guest selection...... 118 4.1.2: Templated syntheses...... 119 4.1.3: Blank Experiments...... 120 4.2: Solubilities...... 120 4.2.1: Conditions in which Qns are soluble...... 120 4.2.2: Group 1 metal salt solutions as solvents...... 122 4.2.2.1: Non-aqueous group 1 metal salt solutions...... 122 4.2.2.2: Aqueous metal salt solutions...... 123 4.2.3: Acids as solvents...... 125

4.2.4: Combined Conditions: Q6 + HCl(aq) + NaCl(aq) + transition metal salts.... 126 4.3: Synthesis of Qns...... 128 4.4: Crystallisation Techniques...... 130 4.4.1: Exposure to liquids...... 131 4.4.2: Reduction in temperature of the crystallisation mixture...... 132 4.5: Co-crystallisation of Qns with Various Compounds...... 132

4.5.1: Synthesis of (Q8)3(PtCl6)4(H3O)8(H2O)x...... 133 Page viii

4.5.2: Synthesis of (Q8)2(PtCl6)3(H3O)6(H2O)18...... 133

4.5.3: Synthesis of (Q7)(Cr3O10)(H3O)2(H2O)x...... 134 4.5.3.1: Further work with the Cr(VI) system...... 135 4.5.4: Synthesis of

[(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17...... 137 4.5.4.1: Templated synthesis...... 138

4.5.5: Synthesis of {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23...... 138 4.5.5.1: Guest inclusion and exchange...... 139 4.5.5.2: Alternative acids...... 140 4.5.5.3: Templated synthesis...... 141

4.5.5.4: Additional SnCl4 work...... 142

4.5.6: Synthesis of (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24...... 142

4.5.7: Synthesis of [(Q6)(SnCl6)(H3O)2](H2O)x...... 142

4.5.8: Synthesis of (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26...... 143 4.5.8.1: Attempts at co-crystallisation with iodine...... 143 4.5.9: Iodine...... 144

4.5.10: HgI2...... 146

4.5.11: Molybdenum ring – [Mo12S12O12(OH)12(H2O)6]...... 147 4.5.11.1: Attempts at co-crystallisation with Qn...... 149 4.5.12: Mo-Fe Sphere...... 150

2– 4.5.13: MoO4 anion...... 152 4.5.14: Oxovanadates...... 153

4.5.14.1: Reactions with [Ph4P]3[H3V10O28]H2O...... 158 4.5.14.2: Work with VO2+...... 159 4.5.14.3: Other work with this system...... 159 3– 4.5.15: PO4 anion...... 159 – 4.5.16: [RuCl5(H2O)] ...... 161 4.5.17: Metal Diaminoethane complexes...... 162 z+ 4.5.18: [M(NH3)6] ...... 164 4.5.19: 2– 2– Metal complexes containing the (mnt) ligand (mnt = [S2C2(CN)2] )...... 165 Page ix

z– 4.5.20: The [MCl4] anion...... 167 4.5.20.1: Templated synthesis...... 167 4.5.20.2: Attempts at direct inclusion...... 167 4.5.21: Ferrocene...... 169 4.5.21.1: Templated syntheses...... 169 4.5.21.2: Attempts at direct inclusion...... 170 4– 4.5.22: The [Fe(CN)6] anion...... 170 REFERENCES...... 171

CHAPTER 5: THE CRYSTAL STRUCTURES OF THE NEW COMPOUNDS...... 173 5.1: Introduction...... 173

5.2: The Compound (Q8)3(PtCl6)4(H3O)8(H2O)x...... 175 5.2.1: Crystallographic Information...... 175 5.2.2: The Crystal Packing...... 176 5.2.3: Comparison with literature structures...... 179

5.3: The Compound (Q8)2(PtCl6)3(H3O)6(H2O)18...... 181 5.3.1: Crystallographic Information...... 181 5.3.2: The Crystal Packing...... 182 5.3.3: A comparison with literature structures...... 185

5.4: The Compound (Q7)(Cr3O10)(H3O)2(H2O)x...... 186 5.4.1: Crystallographic Information...... 186 5.4.2: The Crystal Packing...... 187 2– 5.4.3: The occurrence of the Cr3O10 anion...... 191 5.5: The Compound

[(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17...... 192 5.5.1: Crystallographic Information...... 192 5.5.2: The Crystal Packing...... 193 + 2+ 5.5.3: The formation and co-crystallisation of [CoCl(H2O)5] , [Co(H2O)6] and 2– [CoCl4] ...... 198 5.5.4: The Incidence of columnar motifs in Qn structures...... 198 Page x

5.6: The compound {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23...... 199 5.6.1: Crystallographic Information...... 199 5.6.2: Introduction...... 200 5.6.3: The Crystal Packing...... 201 5.6.4:

The reported occurrence of SnCl4(H2O)2 co-crystallised with macrocycles...... 206 5.6.5: Comparison with literature structures...... 207

5.7: The Compound (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24...... 208 5.7.1: Introduction...... 208 5.7.2: Crystallographic Information...... 208 5.7.3: The Crystal Packing...... 209 5.7.4: A comparison with literature structures...... 211

5.8: The Crystal Structure of [(Q6)(SnCl6)(H3O)2](H2O)x...... 212 5.8.1: Introduction...... 212 5.8.2: Crystallographic Information...... 212 5.8.3: The Crystal Packing...... 213 5.8.4: Comparison with literature structures...... 217 5.8.5: Discussion...... 218

5.9: The Compound (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26...... 219 5.9.1: Introduction...... 219 5.9.2: Crystallographic Information...... 219 5.9.3: The Crystal Packing...... 219 5.10: Discussion of the Portal-to-Side Interaction...... 222 REFERENCES...... 225

CHAPTER 6: COMPUTATIONAL STUDIES OF HOST-GUEST SYSTEMS...... 227 6.1: Introduction...... 227 6.1.1: Studies on host-guest complexes in the literature...... 228 6.1.1.1: Studies involving cucurbituril molecules...... 228 6.1.1.2: Studies involving cyclodextrins...... 229 Page xi

6.1.1.3: Studies involving calixarenes...... 230 6.2: Methodology...... 231 6.2.1: Hardware and software...... 231 6.2.2: The energy calculations...... 232 6.2.2.1: The guest molecule...... 232 6.2.2.2: The host molecule...... 233 6.2.2.3: Selection of intermolecular energy terms and other parameters...... 233 6.2.2.4: Limitations to this study: a gas phase versus a ‘soaked’ environment.234 6.2.3: Construction of trajectory profiles...... 235 6.3: Results and Discussion...... 237 2– 6.3.1: PtCl6 @Qn...... 238 2– 6.3.1.1: PtCl6 @Q7...... 238 2– 6.3.1.2: PtCl6 @Q8 ...... 242 6.3.2: Tetrahedral molecules @Qn...... 243 2– 6.3.3: Cr2O7 @Qn...... 253 2– 6.3.3.1: Cr2O7 @Q6...... 253 2– 6.3.3.2: Cr2O7 @Q7...... 256 2– 6.3.3.3: Cr2O7 @Q8...... 258 2– 6.3.4: The guest anion Cr3O10 ...... 261 6.3.5: Benzene@Qn...... 264 6.3.5.1: Benzene@Q6...... 264 6.3.5.2: Benzene@Q7...... 265

6.3.6: SnCl4@Qn...... 266

6.3.6.1: SnCl4@Q6...... 266

6.3.6.2: SnCl4@Q7...... 267 + 6.3.7: NH4 @Qn...... 271 + 6.3.7.1: NH4 @Q5...... 271 + 6.3.7.2: NH4 @Q6...... 276 + + 6.3.8: NH3(CH2)6NH3 @Qn...... 276 + + 6.3.8.1: NH3(CH2)6NH3 @Q6...... 277 Page xii

+ + 6.3.8.2: NH3(CH2)6NH3 @Q7...... 279 + + 6.3.8.3: NH3(CH2)6NH3 @Q8...... 280 6.4: Conclusion...... 286 REFERENCES...... 288

CHAPTER 7: – THE INTERMOLECULAR INTERACTIONS OF THE [B(C6F5)4] ANION. ..291 7.1: Introduction...... 291 7.2: Fluorinated Phenyl rings...... 295 – 7.2.1: The Pf4B anion...... 298 7.2.1.1: The parallel fourfold perfluorophenyl embrace (P4PFE)...... 302 7.2.1.2: The orthogonal fourfold perfluorophenyl embrace (O4PFE)...... 304 7.2.1.3: Other types of embraces...... 305 – 7.2.2: The crystal packing of the structures of the Pf4B anion...... 308 7.2.2.1: Two dimensional networks of P4PFEs...... 308 7.2.2.2: Linear chains of O4PFEs...... 310 7.2.2.3: Chains of embracing anions...... 310 7.2.2.4: Other structures...... 311 7.3: Other Fluorinated Phenyl Compounds...... 313 7.3.1: The six-fold perfluorophenyl embrace (6PFE)...... 313 7.3.1.1: The hexagonal array of 6PFEs...... 313 7.3.1.2: Other packing arrangements of the 6PFE...... 314

7.3.2: E–Pf3 structures without the threefold rotor conformer...... 315 7.4: Discussion...... 316 REFERENCES...... 319

APPENDIX I: CRYSTALLOGRAPHIC INFORMATION FILES...... 323

I.1: (Q8)3(PtCl6)4(H3O)8(H2O)x...... 323 Page xiii

I.2: (Q8)2(PtCl6)3(H3O)6(H2O)18...... 328

I.3: (Q7)(Cr3O10)(H3O)2(H2O)x...... 333

I.4: [(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17 ...... 339

I.5: {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23...... 348

I.6: (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24...... 356

I.7: [(Q6)(SnCl6)(H3O)2](H2O)x...... 365

I.8: (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26...... 369

APPENDIX II: INTERMOLECULAR ENERGY PARAMETERS USED IN COMPUTATIONAL STUDIES...... 379 Page xiv

LIST OF ABBREVIATIONS.

Q cucurbituril Qn cucurbit[n]uril H/h host G/g guest @ at CSD Cambridge Structural Database CCDC Cambridge Crystallographic Data Centre CVFF Consistent Valence force field REFCODE Reference number of structure in CSD MN molecular necklace XRD x-ray diffraction V volume Z number of formula units per unit cell R refinement factor U isothermal parameter iso isotropic TS Transition State Chapter 1: Introduction to Supramolecular Chemistry. Page 1

CHAPTER 1 INTRODUCTION TO SUPRAMOLECULAR CHEMISTRY

This chapter provides a general introduction to Supramolecular Chemistry. Chapter 2 provides a detailed introduction to the cucurbituril molecule and how it can function as a supramolecular host molecule.

1.1: Supramolecular Chemistry.

Supramolecular Chemistry focuses on the interactions between molecules rather than within molecules and on the study of the intermolecular bond rather than the covalent bond[1, 2]. These intermolecular bonds include such attractions and repulsions as van der Waals interactions, dipole-dipole interactions, hydrogen bonding, interactions between ions and S-S bonding. The energies that drive these intermolecular bonds are the basis of molecular recognition: the drawing together of molecules with complementary functional groups. In addition to electronic complementarity there must also be spatial complementarity, that is, molecules should ‘fit’ one another geometrically so that they may ‘bond’ with one another. For example, a host-guest complex cannot form if the guest is too large to pass into the host’s cavity nor will it form if the functional groups of the host and guest molecules repel each other as they approach one another. Cram has called this complementarity “the central determinant of structural recognition”[3]. The self-assembly of molecules through molecular recognition leads to the formation of aggregates, collections of non-(formally)bonded molecules which may be called supramolecules. Self-assembly can then lead to self-organisation, which relates to the formation of aggregates with a higher degree of complexity whose formation results in the display of a function, property or behaviour not seen in the individual molecular components. Self-organisation can be thought of as “ordered self-assembly”[4] and these aggregates as supramolecular devices. Chapter 1: Introduction to Supramolecular Chemistry. Page 2

The fundamental concept of supramolecular chemistry was described as early as 1894 when the ‘lock-and-key’ principle (the idea that molecules should ‘fit’ one another in order to bind) was recognised by Fischer[5]. In the 1930s the discovery of the aggregation of molecules via intermolecular interactions led to the coining of the term ‘Übermoleküle’ (i.e. supramolecule)[6]. Work by Cramer during the 1950s on cyclodextrins[7], by Pedersen in the 1960s on the host-guest complexes of crown compounds[8] and Cram on spherands, cavitands and other container molecules[9, 10] accelerated research in the field of supramolecular chemistry. In 1978, Lehn provided a definition of supramolecular chemistry, summarised in the introductory sentences to this chapter, detailing the importance of the intermolecular bond to the study of this field. In more recent years the link between supramolecular chemistry and other disciplines of science that study interactions between molecules (e.g. receptor-substrate studies in biological systems) was drawn by Lehn, who has suggested the term ‘supramolecular science’ be used to emphasise the breadth of the field[4, 11, 12].

1.2: Host-Guest Complexes.

The formation of a host-guest complex involves molecular recognition between one large molecule that contains a cavity, the host, and a smaller molecule which is able to reside in the cavity, the guest. Alternatively the host may consist of a group of molecules that are able to bond in such a way that a space is formed for a guest to lie in. In order for a complex to form the host molecule must possess converging binding sites while the guest must possess diverging binding sites[9]. Further to this, their binding sites must comprise of complementary groups, i.e. functional groups that are attracted to one another and that ‘fit together’. As mentioned in the previous section, in order for there to be molecular recognition there must be electronic and spatial complementarity between the two binding molecules.

Host-guest complexes fall into two broad categories: cavitates and clathrates. A cavitate is formed by a cavitand, a molecule with a cavity large enough to accommodate a guest molecule. Examples of cavitands include cyclodextrins and calixarenes. Cucurbituril is another example of a cavitand and in chapter 2 its host-guest chemistry Chapter 1: Introduction to Supramolecular Chemistry. Page 3

is discussed at length. A clathrate is formed via the complexation of a guest molecule by a clathrand, an aggregate of two or more molecules that between them form a cavity. Examples of clathrands include the ‘tennis balls’ and ‘softballs’ formed between substituted glycoluril dimers[13], shown in fig. 1.1. These c-shaped molecules come together at right angles to each other to form a sphere-shaped host resembling a tennis ball with seams.

O molecule is bent here O

NHN NHN Ph Ph Ph Ph HN N N NH

O O (a)

(b) Fig. 1.1: (a) A substituted glycoluril dimer used to form the ‘tennis ball’ clathrand (b) a stereo view of the ‘tennis ball’ with H atoms and substituents removed for clarity.

A cavitand is a preorganised host molecule. It is purposely synthesised with a cavity and it exists in much the same form in both the solution and solid phases. Cram has stated that ‘preorganisation governs binding power’[3], that is, highly organised hosts and guests form more stable complexes. So a pre-organised molecule designed with a cavity, and therefore multiple binding sites in close proximity, will generally be able to form more stable complexes than a clathrand, which only exists in the solid phase or only in low concentration in the solution phase. When a host-guest complex forms, particularly a cavitate, encapsulated solvent molecules (which are under strain) are removed from the host cavity by the encapsulation of the new guest and moved into the less organised solvent bulk. This Chapter 1: Introduction to Supramolecular Chemistry. Page 4

entropically favourable process is known as the solvophobic effect and may help to compensate for the drop in entropy caused by the ordering of the many molecules involved in host-guest complex formation[9].

A molecule encapsulated by a host may have its properties significantly altered. If the encapsulation and release of the guest can be controlled these complexes can be put to practical use as supramolecular devices.

1.3: Supramolecular Devices.

A supramolecular device is formed when an aggregate of molecules or a system of molecular components performs a function. This function is carried out at the molecular level rather than through the bulk material. The device provides the observer with a sign that a change has taken place by responding to external stimuli in a manner that can be detected, e.g. colour change or change in redox potential. Lehn and co- workers have investigated this field extensively with examples including photonic, electronic and ionic molecular devices[2, 4, 14]. One example of a supramolecular device is a molecular switch. Just as an ordinary switch has two settings, on and off, a molecular switch moves between two (or more) well defined and easily detected states. Rotaxanes are able to form these molecular switches, or ‘shuttles’, if the position of the threaded macrocycle can be controlled by external stimuli. Such is the case in the example of the pseudorotaxane described by Jun et al. where the position of the cucurbituril molecule is controlled by the pH of the solution. Furthermore, the two states are easily detected via a colour change and differences in fluorescence properties[15]. This particular example is discussed in more detail in § 2.2.1. The complex formed between Eu or Tb with the ligand [bipy•bipy•bipy] is an example of another type of molecular device, one used to effect ‘light conversion’[2]. UV light is absorbed by the ligand and then transferred to the bound cation that emits a luminescent light, a property that the free cations do not posses under the same conditions. Supramolecular devices also include those systems in which two molecular components are covalently bound. One example of such a system involves the intramolecular transfer of an electron from a (porphinato)zinc(II) chromophore to a Chapter 1: Introduction to Supramolecular Chemistry. Page 5

(porphinato)iron(III) complex via a bicyclic bridge. When the (porphinato)zinc(II) chromophore is photoexcited, electron transfer to the (porphinato)iron(III) complex occurs reducing the metal centre to iron(II). This reaction can also proceed without the covalent C-C bonds connecting the two metal-porphyrin complexes, as in the case when a hydrogen bonding interface connects the two groups[16].

In biology, molecular recognition is responsible for enzyme reactions, the functions of neurotransmitters and the replication of DNA, all of which demonstrate high selectivity. The occurrence of these examples of molecular recognition in nature has helped to spur the adoption of molecular recognition by researchers to devise new supramolecular structures in their fields. An example includes the construction of ‘molecular machines’, an alternative to increasingly miniature conventional machines[17]. These ‘molecular machines’ perform functions that mimic those performed by conventional machines and they include such examples as molecular rotors[18] and molecular switches or shuttles as described earlier. This specific area of supramolecular science, focussing on the design and construction of molecular machines and other supramolecular devices, is also referred to as nanoscience or nanotechnology.

The construction of nanoscale supramolecular devices requires an understanding of the subtle balance of the intermolecular forces that occur between molecules. One way that this can be achieved is through the study of the packing of molecules in crystal structures and by the incorporation and testing of the rules of molecular packing via the discipline of crystal engineering.

1.4: The Role of Crystallography in the Study of Supramolecular Chemistry.

Dunitz has called the crystal a ‘supramolecule par excellence’[19] and a co- crystallisation may be considered analogous to the formation of a clathrate[20] as the organisation of molecules in the crystal structure creates cavities that are often filled with guest or solvent molecules. Crystallography can therefore be used to study Chapter 1: Introduction to Supramolecular Chemistry. Page 6

supramolecular chemistry as the interactions between molecules in crystals are the same as those between molecules in supramolecules. Furthermore, as the components of a crystal structure are fixed, interactions and molecular recognition effects can readily be studied.

1.4.1: Crystal engineering. Crystal engineering[21] is the attempt to control the organisation of molecules in crystals by using molecular recognition effects to force certain interactions and orientations. It is accomplished through the design, synthesis and crystallisation of appropriate molecules. If this results in the prediction of the crystal packing and the ability to manipulate molecules in crystalline solids so that a particular orientation and pattern can be achieved reproducibly then this may be extended to the solid state in general where supramolecular devices may also be successfully engineered. It is therefore feasible to use crystal engineering to study the rules that drive supramolecular chemistry.

The ability to control the outcome of crystallisation experiments and specifically the organisation of molecules in a crystalline solid is essential for solid-state reactions. The current state of research in crystal engineering still does not allow the accurate prediction of complete crystal structures for most molecular systems or even of the possible ways in which many pairs of molecules may organise themselves relative to one another. This makes the practical applications of crystal engineering difficult to realise presently but the ‘programming’ of solid-state functions into crystals and solids and the creation of molecular devices remains a goal of supramolecular chemistry.

1.4.2: Polymorphism. A polymorph is a supramolecular isomer, i.e. a crystal structure of the same compound or compounds in which the molecules are organised differently. Polymorphs of the one compound have small free energy differences, so the crystallisation of one structure does not necessarily represent the lowest energy conformer but rather it may be one of many energy minima[22]. Hence, polymorphs can be a useful tool to study supramolecular crystalline structures because they display the ways that molecular recognition can lead to different orientations and interactions in the one system. On the other hand, and for the same reason, they can make the goal of crystal engineering very Chapter 1: Introduction to Supramolecular Chemistry. Page 7

difficult. As there can be many ways for the molecules in some crystal structures to orient themselves a reliable prediction of their packing is very difficult, impeding the ability to design and synthesise solid state architectures. There are, however, examples of some compounds that reliably engage in a particular motif. These motifs are referred to as ‘supramolecular synthons’ and can be used to rank the influence of intermolecular forces and interactions when they are in competition with each other in a crystal structure. Polymorphism is useful then in helping to determine this influence by measuring the prevalence of certain interactions in the various polymorphs of the one compound. Polymorphs are also worth investigating for the reason that they may have different physical and chemical properties despite containing molecules of the same compound. In these cases it is the arrangement of molecules in the solid state that is responsible for the solid-state properties and not the molecules themselves. So by being able to engineer one polymorph in preference to others it becomes possible to produce a supramolecular architecture able to perform a desired function, the defining goal of supramolecular chemistry. Finally, the existence of polymorphs highlights the influence that weak intermolecular forces can have, even so far as to produce two or more different crystal structures, of the same compound, that are very different.

1.5: Conclusion.

With its focus on intermolecular interactions and bonds, supramolecular chemistry sees a move away from more traditional chemistry. In place of the covalent bond, the basis of supramolecular chemistry relies on molecular recognition between groups that are both electronically and geometrically complementary to drive the formation of supramolecular assemblies. The goal of supramolecular chemistry is to increase the organisation and complexity of matter[4] and the formation of self-organised structures able to carry out functions at the molecular level, such as molecular switches, are a clear demonstration of the successes in this field to date. The aim for the future then becomes to expand our understanding of the interactions between molecules to the Chapter 1: Introduction to Supramolecular Chemistry. Page 8

extent that predictions regarding the organisation of molecules can be made and then used to build more elaborate and sophisticated devices. In this chapter a brief outline of some topics relating to supramolecular chemistry was presented. Chapters 2-6 focus on the supramolecular chemistry of the cucurbituril molecule. This will include the crystal packing of this molecule, synthetic experiments and crystallisation experiments with cucurbituril and a computational study on the mechanisms of host-guest complex formation, with cucurbituril as the host molecule. In chapter 7 the intermolecular interactions of perfluorinated tetraphenylborate, – + [(C6F5)4B] , will be compared to those of tetraphenylphosphonium, (C6H5)4P , and the influence of the fluorinated ligands on the crystal packing will be examined. Chapter 1: Introduction to Supramolecular Chemistry. Page 9

REFERENCES

1. Lehn, J.-M., Pure Appl. Chem., 1978, 50, 871. 2. Lehn, J. M., Angew. Chem. Int. Ed., 1988, 27, 89. 3. Cram, D. J., From Design to Discovery., 1990, Washington D.C.: ACS. 4. Lehn, J.-M., Supramolecular Chemsitry: Concepts and Perspectives., 1995, Weinheim: VCH. 5. Fischer, E., Ber. Dtsch. Chem. Ges, 1894, 27, 2985. 6. Wolf, K. L., Frahm, H., and Harms, H., Z. Phys. Chem. Abt., 1937, B36, 17. 7. Cramer, F. and Hettler, H., Die Naturwissenschaften, 1967, 54(24), 625. 8. Pedersen, C. J., J. Am. Chem. Soc., 1967, 87, 7017. 9. Cram, D. J. and Cram, J. M., Container molecules and their guests. Monographs in Supramolecular Chemistry, ed. J.F. Stoddart., 1994, Cambridge: The Royal Society of Chemistry. 10. Cram, D. J., Kaneda, T., Helgeson, R. C., Brown, S. B., Knobler, C. B., Maverick, E., and Trueblood, K. N., J. Am. Chem. Soc., 1985, 105, 3645. 11. Lehn, J.-M., "Perspectives in Supramolecular Chemistry - From the Lock-and- Key Image to the Information Paradigm.", in The Lock-and-Key Principle., J.- P. Behr, Editor., 1994, Wiley: Chichester., vol 1. 12. Lehn, J.-M., Proc. Natl. Acad. Sci. U.S.A., 2002, 99(8), 4763. 13. Hof, F., Craig, S. L., Nuckolls, C., and Rebek, J., Angew. Chem. Int. Ed., 2002, 41, 1488. 14. Lehn, J. M., Angew. Chem. Int. Ed., 1990, 29, 1304. 15. Jun, S. I., Lee, J. W., Sakamoto, S., Yamaguchi, K., and Kim, K., Tetrahedron Lett., 2000, 41(4), 471. 16. de Rege, P. J. F., Williams, S. A., and Therien, M. J., Science, 1995, 269, 1409. 17. Balzani, V., Credi, A., Raymo, F. M., and Stoddart, F. J., Angew. Chem. Int. Ed., 2000, 39, 3348. 18. Dominguez, Z., Dang, H., Strouse, M. J., and Garcia-Garibay, M. A., J. Am. Chem. Soc., 2002, 124(11), 2398. 19. Dunitz, J. D., Pure and Appl. Chem., 1991, 63(2), 177. Chapter 1: Introduction to Supramolecular Chemistry. Page 10

20. Steed, J. W., "Supramolecular Chemistry: Definition.", in Encyclopaedia of Supramolecular Chemistry, J.L. Atwood and J.W. Steed, Editors., 2004, Marcel Dekkar, Inc.: New York., vol. 2, p1401. 21. Schmidt, G. M. J., Pure Appl. Chem., 1971, 27, 647. 22. Desiraju, G. R., Crystal Engineering. The Design of Organic Solids., 1989, Amsterdam: Elsevier. Chapter 2: Introduction to Cucurbituril Chemistry. Page 11

CHAPTER 2 INTRODUCTION TO CUCURBITURIL CHEMISTRY.

2.1: Introduction.

In 1905 Robert Behrend and co-workers were the first to prepare the compound ‘cucurbituril’ and publish an account of its synthesis, an acid catalysed condensation reaction between glycoluril and formaldehyde[1]. The final recrystallised product was . characterised as C10H11N7O4 2H2O but an accurate assessment of the structure of this compound could not be made. The authors recognised the stability of the product in many different solvents and prepared a number of co-crystallisation compounds with species such as KMnO4, CrO3 and H2PtCl6. Years later, Freeman, Mock and Shih repeated the condensation experiment and in 1981 published the first crystal structure of the cucurbituril molecule[2]. The reaction of glycoluril with excess formaldehyde in the presence of a mineral acid

(e.g, HCl, H2SO4) produces the macrocyclic compound commonly known as cucurbituril which is comprised of glycoluril units linked by methylene carbons. The number of glycoluril monomers per cucurbituril molecule can vary from 5–10. This is illustrated in equation 1.

O O

HN NH NN O HCl + (1) H H ' NH NH NN

O O n glycoluril (n = 5 –10)

Freeman et al. dubbed the macrocycle ‘cucurbituril’ due to the resemblance of the molecule’s shape to that of a pumpkin which belongs to the botanical family of Chapter 2: Introduction to Cucurbituril Chemistry. Page 12

cucurbitaceae. In the literature the abbreviation CB[n] is used to denote the differently sized cucurbiturils, where n refers to the number of glycoluril monomers per cucurbituril. In this thesis a different abbreviation is used: Qn, where again n denotes the number of glycoluril monomers per cucurbituril macrocycle. The most commonly reported Qn in the literature is Q6. Structurally, the glycoluril’s carbonyl oxygens line the entrance to the cavity of the macrocycle, the portal. The glycoluril molecule is not planar but rather bent about the middle C–C bond (see fig. 2.1) forcing the carbonyl oxygens to push into the portal. This has implications for the host-guest chemistry of cucurbituril, as will be explained later in this chapter. These carbonyl, or portal, oxygen atoms readily coordinate to metal cations. Qn does not melt but rather the robust molecules decompose above 300 ºC. Qns are soluble in mineral acids and insoluble in all common organic solvents. Hence much of the work conducted in this project was carried out in HCl(aq).

The cavity size of the Qn molecule varies with the value of n. In table 2.1 the sizes of various Qn cavities are listed. Q6 is large enough to contain a benzene molecule while Q10 (which is oval shaped) is large enough to hold a Q5. Q9 has not yet been isolated although it has been detected by NMR[3] and so no details for Q9 appear in the table below.

Table 2.1: The molecular dimensions of the Qn molecules. Q5 Q6 Q7 Q8 Q10a Portal size/Åb 5.1 7.2 8.5 10.4 12.1; 14.1 vdW portal size/Åc 3.4 6.2 7.0 8.9 10.6; 12.6 Cavity size/Åd 8.6 10.6 11.9 13.7 15.5;17.1 VdW cavity size/Åc 7.1 9.1 10.4 12.2 14.0; 15.6

a Both the long and short axes of the oval shaped Q10 are included. b The portal size is the distance between oxygens on opposite sides of the portal. c vdW radii used are: O = C = N = 1.55 Å. d The cavity size is the distance between methine carbon atoms on opposite sides of the cavity. Chapter 2: Introduction to Cucurbituril Chemistry. Page 13

THE GLYCOLURIL MONOMER ATOM COLOUR KEY View from side

NCN - 115Þ C

View from above H

Fig. 2.1(a): The glycoluril monomer.

THE CUCURBITURIL MOLECULE

Oxygen ringed portals

Methine hydrogens

Methylene links

View from side View from above Fig. 2.1(b): The cucurbituril molecule.

Reviews of cucurbituril properties and chemistry by Mock[4], Cintas[5], Lee[6], Lagona[7] and Kim[8] appear in the literature.

2.2: Cucurbituril as a Host Molecule.

The host properties of Qn are obvious from first inspection of the molecule. Its hydrophobic cavity is capable of holding guests of varying sizes and, because of the relative rigidity of this receptor molecule, it generally forms very stable host-guest complexes. Due to the charge distribution on the Qn molecule, which possesses an electronegative portal and an electropositive cavity, a Qn host demonstrates a high Chapter 2: Introduction to Cucurbituril Chemistry. Page 14

specificity for those guest molecules with charge distributions that complement the Qns own charge distribution. An example of an excellent guest molecule is the diaminoalkane. Some typical guests are listed in table 2.2. The guest molecule cis-

SnCl4(H2O)2, encapsulated in Q7 in the course of this project, represents the first metal- halide guest molecule and one of the first metal containing guest molecules to appear in the literature[9]. Its synthesis is described in chapter 4, § 4.5.5 and its crystal structure in chapter 5, § 5.6. The nomenclature used to identify a host-guest complex is guest@host, e.g. [cis-SnCl4(H2O)2]@Q7 denotes that the cis-SnCl4(H2O)2 molecule is inside Q7.

Table 2.2: Some of the guest molecules found inside Qn. Qn GUEST MOLECULES

– Q5 Cl (HCl); He; Xe; CO2; O2; Kr; CH4.

Q6 H2O; diaminoalkanes; benzyl groups; THF, short polypeptides.

Q7 cis-SnCl4(H2O)2; o-carborane; C60; ferrocinium; diaminostilbene.

Q8 Tetrathiafulvalene; naphthalene groups; methylviologen; cyclen; cyclam.

Q10 Q5.

In order for a guest molecule to pass through the portals and into the Qn cavity there must be minimal repulsions between the portal oxygens and the guest molecule. As such there are no reports of guests with a formal negative charge residing in the Qn cavity. The reason for this can be interpreted in terms of repulsions incurred between an approaching anion and the portal oxygens and also due to the hydrophobic nature of the inner cavity. Although there are examples in the literature of crystal structures featuring acid molecules (such as nitric acid and hydrochloric acid) encapsulated in Qn molecules[10][11], it is likely that the complete acid molecule is included rather than just the anions even though the H+ cannot be detected by crystallography.

In an NMR study to determine dissociation constants of Qn complexes, Mock and Shih determined that the rate of host-guest complex formation depends on the ease of passage through the portals rather than the thermodynamic stability of the complex, and that guest molecules appear to be free to rotate inside the cavity[12]. The larger (wider) Chapter 2: Introduction to Cucurbituril Chemistry. Page 15

the guest the longer it takes to pass through the portal of the Qn. There is no correlation between the stability of the complex, once formed, and the length of time taken for it to form as the interactions between host and encapsulated guest stabilise the complex. These interactions are discussed in the following section. Molecular modelling work by Day et al. suggests that to allow easier passage of an appropriate guest molecule through the portal opening of the Qn the carbonyl groups may splay outwards and thereby minimise repulsions[13].

2.2.1: Interactions between host and guest molecules. As mentioned in chapter 1, molecular recognition between a receptor molecule and a substrate molecule depends on the complementarity in size and shape and on the nature of the two molecules involved. In the case of a Qn and a guest molecule the non- covalent electrostatic bonding (present in many cases) and hydrophobic effects are also important. The hydrophobic effects pertain to the fact that most host-guest complexes are formed in aqueous solutions and their formation involves the displacement of strained water moleculesa from the Qn cavity[14]. Hydrogen bonding will contribute to the stability of a host-guest interaction but several authors have suggested it does not appear to be the main driving force behind the formation of host-guest complexes[4, 5]. For instance, in complexes formed between Qn and ammonium alkanes it has been found that replacing the terminal hydrogen of the alkyl chain with a hydroxyl group does not increase the association constant of the Qn complex, whereas replacing it with an ammonium group (to form a diammonium alkane) results in a great increase in the association constant. It is the ion-dipole (electrostatic) interaction between host and guest molecules rather than the hydrogen bonding that drives the formation of these types of complexes. Dispersion forces between host and guest molecules, as in the case of the Xe@Q6 complex[15], also contribute to the formation of an inclusion complex. Electrostatic forces, however, appear to be most important factor in the formation of Qn host-guest complexes. The cavity of the Qn molecule has been found to be a low polarising environment, more akin to the gas phase than the solution phase[16, 17]. This suggests that if not for the

a These water molecules are strained because they are inside the cavity rather than engaged in hydrogen bonding with other water molecules in the bulk solvent. Chapter 2: Introduction to Cucurbituril Chemistry. Page 16

carbonyl oxygen ringed portals, with their partial negative charge, the guest binding ability of the Qn molecule would be vastly inferior.

The one group of guest molecules studied more than any other are the diaminoalkanes and their ammonium mono- and di-cations. Diaminoalkanes thread themselves through the cavity of the Qn so that their amino groups lie level with the oxygen ringed portals. Their amino and ammonium groups engage in both electrostatic and hydrogen bonding with the portal oxygens (see fig. 2.2) and Mock and Shih have shown that the molecule 1, 6-diaminohexane is the optimal length for these types of interactions[18]. As the inner Qn cavity is hydrophobic, displacing water molecules in favour of an alkane chain is thought to further add to the stability of the complex[19]. The resulting host-guest complex is called a pseudorotaxane for the reason that it does not require terminal ‘stopper’ groups to prevent the Qn from slipping off the chain – the interactions between host and guest are enough to keep the Qn in place. In the crystalline state the Qn molecule lies at an angle less than 90º to the diaminoalkane chains so that N- … H Oportal contacts can be maximised and this is particularly evident in the case of the ‘molecular necklace’ supermolecules. Section 3.7 deals in depth with the crystal structures of these complexes and includes diagrams of the many diaminoalkanes that form this type of complex.

G— + Fig. 2.2: The pseudorotaxane formed between Q6 and + + H3NCH2CH2CH2CH2NH3 . The hydrogen bonds are shown as blue and white bonds. The Q6 is shaded grey with the oxygens in red. Hydrogens (other than the amino hydrogens) are omitted for clarity.

Hydrogen bonding between Q oxygens and ammonium hydrogens. Chapter 2: Introduction to Cucurbituril Chemistry. Page 17

The diaminoalkanes’ versatility lies in the ability of their terminal ends to be readily functionalised with other chemical groups. This renders their host-guest complexes with Qns as potentially useful ‘molecular machines’. For example, Mock and Pierpont describe a Q6 based ‘molecular switch’ in which the position of the Q6 along the guest molecule PhNH(CH2)6NH(CH2)4NH2, a functionalised diaminoalkane chain, is dependent on the pH of the solution[20]. Under acidic conditions (pH < 6.7), when all three amino sites become protonated, the Q6 lies over the 6-carbon site. However, under basic conditions (pH = >6.7), when only the aniline group becomes deprotonated and loses its positive charge, the Q6 shifts to engage in electrostatic bonding with the two amino groups on either side of the 4-carbon site. Similarly Jun et al., working with the yellow and fluorescent guest molecule fluorenyltriamine, found that pH can affect the position that the Q6 encapsulates the guest molecule (see fig. 2.3)[21]. Under acidic conditions fluorenyltriamine is encapsulated by Q6 at the diammoniumhexane binding site and retains its yellow colour and fluorescent characteristics. In basic solutions this guest molecule changes colour to violet and loses its fluorescent properties as a result of the deprotonation of the nitrogen near the fluorophore and the subsequent shift of the Q6 to encapsulate the diammoniumbutane site.

Diammoniumhexane binding site: bound under acidic conditions.

+ H2 + N NH3 N + H2

Diammoniumbutane binding site: bound under basic conditions (pH = 8)

Fig. 2.3: The two binding sites of the molecule fluorenyltriamine.

Lee et al. reported the synthesis of a pseudorotaxane comprised of a Q6 threaded onto (4-pyridylmethyl)aminoalkyliminodiacetic acid where the alkyl chain is either 5 or 6 carbon units long. Initially, the pyridylmethyl group resides in the Q6 cavity but upon Chapter 2: Introduction to Cucurbituril Chemistry. Page 18

heating at 60-70 ºC for a few minutes (or standing at room temperature for several days) the Q6 shifts to encapsulate the aminoalkane portion of the guest molecule with which it can engage in electrostatic and hydrogen bonding without the distortion required to accommodate the more bulky pyridyl group. Thus the more thermodynamically stable conformer is formed[22]. In their work on self assembled monolayers (SAMs) of pseudorotaxanes on gold, Kim et al. managed to control the threading and dethreading of the Q6 by simply altering the pH of solution[23].

Host-guest complexes featuring guests other than diaminoalkanes, such as THF[24] and small gas molecules[25], are stabilised by dispersion forces as well as by hydrophobic effects. NMR studies have shown that guest molecules can pass freely through the portals and can exchange readily with other molecules of the same or different type[11][15]. Guests that are small enough to be entirely contained inside a Q6 can be trapped by the coordination of a metal cation to the portal oxygens[24]. A more detailed description of this appears in § 2.3.

It is evident from these examples how important work on host-guest complexes is and the applications that may be derived from their further development. Further discussion on the practical applications of the Qn molecule and its complexes is presented in § 2.4. Several reviews appear in the literature summarising this field of Q chemistry[26-28].

2.2.2: Methods of detection of host-guest complexes. The detection of the presence of an encapsulated molecule is typically performed via NMR. The cavity of the Qn molecule is a magnetic shielding region so the signals due to the species encapsulated in a Qn will undergo an upfield shift. This property can be used to determine not only whether a guest has been encapsulated but also what part of the guest molecule has been encapsulated by the Qn cavity. Mass spectrometry has been used to a lesser extent to detect the existence of host-guest complexes. Day et al. used this technique, in conjunction with NMR, to identify the complex Q5@Q10 and its structure was later confirmed by crystallography[11]. Similarly, MS was used by Buschmann et al. to detect the formation of pseudorotaxanes[29] while Zhang et al. have shown that the complex 1,4-butanediamine@Q6 can survive the electrospray process used in sustained off-resonance irradiation collision induced dissociation[30]. Chapter 2: Introduction to Cucurbituril Chemistry. Page 19

NMR can be used not only to detect the existence of a host-guest complex but also to measure its binding constant. In general host-guest complexes involving Qn are described as being very stable. Studies to determine the guest binding capacity of Qn abounds in the literature with dissociation constants for species ranging from diammonium alkanes[31] to Xe[32]. Alternative and equally popular methods used for this purpose include uv-vis spectrophotometry for guest species such as 4- methylbenzylammonium[33] and diammonium alkanes[34] and calorimetric titrations for guest species such as methylviologen[35], aliphatic alcohols and nitriles[36] and polypeptides[37]. Other less common methods used include fluorescence techniques to measure altered quantum yields of fluorescent guest molecules[38][39][21][40][41] and electrochemical methods such as in the study of the complex methylviologen@Q7[35]. Capillary electrophoresis has been used to study the complexes of Q6 and Q7 with amino compounds[42].

2.2.3: Altered guest properties due to complex formation. As alluded to in the previous section, all of the detection techniques listed function on the basis that the properties of the guest molecule are altered upon being encapsulated in the cavity of a Qn molecule. The cavity provides a shielding region causing the NMR signals of an encapsulated guest to shift upfield. The encapsulation of a guest can also have the effect of depressing its molar absorption making it possible to use UV-VIS absorption spectroscopy to determine binding constants[43][44][35]. Altered fluorescence quantum yields are another result of encapsulation. For instance, the encapsulation of the molecule 2-anilinonaphthalene-6-sulfonate (2, 6-ANS) by Q6 results in the enhancement of its fluorescence[39]. It is thought that only the phenyl ring is incorporated in the cavity and that the ensuing restriction in its rotational mobility relative to the rest of the molecule is the cause of the increase in fluorescence. The close proximity of a pair of encapsulated guest molecules can lead to those molecules exhibiting unusual behaviour. When Kim et al. synthesised the ternary complex (methylviologen)•(2, 6-dihydroxynapthalene)@Q8 they noted that the fluorescence intensity of 2, 6-dihydroxynapthalene decreased and proposed that this was due to the charge transfer between the two guest molecules. This occurs only when both are encapsulated in the Q8 cavity and not when free in solution[45]. Chapter 2: Introduction to Cucurbituril Chemistry. Page 20

An ‘intramolecular charge-transfer complex’ has been synthesised, comprising of a 1:1 complex between Q8 and a long chain guest molecule featuring a 2, 6- dihydroxynaphthalene unit and a terminal viologen unit. The encapsulation results in the viologen group folding back along the chain so that it lies parallel to the naphthalene group within the same Q8 cavity. The viologen group acts as the acceptor and the naphthalene as the donor[46]. The following section, § 2.2.4, lists further examples of modified encapsulated-guest behaviour and how this can be used for the catalysis of reactions.

Encapsulation in a Qn cavity can also have surprisingly little effect on the properties of some molecules. Ong et al. note that the formation of a complex between Q7 and the redox active ferrocenium does not significantly alter the rate constant for the reduction of ferrocinium and they report that this is an uncommon result for encapsulated guests[43]. Also, compared to other host-guest complexes, the stability of Qn complexes is not significantly diminished by the redox conversion of such guests as ferrocinium, cobaltocenium or the methylviologen cation. Furthermore, the redox conversion is found to take place while the guest is still inside the cavity, a very unusual occurrence[35, 43, 44]. Encapsulation does have the effect of changing the current– potential curves for guest molecules however, both diminishing current levels and shifting potentials[35, 44, 47, 48]. When Kim et al. performed CV scans on their [Cu(cyclen)]@Q8 compounds they found that the reduction occurs at a different potential and that in this case the electron transfer rate is reduced[47].

Finally, and importantly for potential practical applications, the formation of a host- guest Qn complex can lead to an increase in the stability of a guest molecule. For instance, phenol blue is protected against hydrolytic decomposition when included in Q6[49]. Jeon et al. reported the formation of the stable complex between the dimer form of the methylviologen cation radical and Q8[50]. The S-dimer of the tetrathiafulvalene cation radical had only ever been recorded at low temperature and in the solid state until Ziganshina et al. synthesised a ternary complex with Q8 at room temperature in aqueous solution[51]. The encapsulation of a rhodamine dye derivative by Q7 leads to an unprecedented stabilisation of the compound[52]. Chapter 2: Introduction to Cucurbituril Chemistry. Page 21

2.2.4: Chemistry inside the Qn cavity: Qn as a catalyst. When a pair of molecules is encapsulated in the Qn cavity they are very often forced into orientations not normally encountered and into close proximity with one another. This has the effect of facilitating interactions between molecules that would not otherwise occur. There are several instances in the literature where chemistry has occurred inside the Qn cavity and these are outlined below. Q6 has been found to catalyse the formation of triazoles from the 1,3-dipolar cycloadditions between alkynes and alkyl azides. Because of the ability of Qn to attract alkylammonium ions into its cavity, researchers have functionalised alkynes and also alkyl azides, where necessary, to take advantage of this property[53-55]. An example of this type of reaction is shown in equation 2. The resulting alignment of the precursor molecules within the one cavity causes the cycloaddition reaction to occur, in some instances where none would have otherwise occurred. The catalytic effect was found to be due to the difference in strain energy between the two host-guest complexes: one containing the two precursors and the other the formed triazole.

CH NH + + 2 3 NH3H2CC CH + –N N (2) + NN N N + CH2CH2NH3 + CH2CH2NH3

The ability of Qn to bring two molecules close together in a particular orientation is further demonstrated by the work done by Jon et al. on the photodimerisation of the (E)- diaminostilbene cation. This cation forms a 1:2 host-guest complex with a Q8 in which the two cations lie parallel to each other in the cavity. Photodimerisation about the olefenic groups occurs after just 0.5 hrs of UV radiation to produce the dimer with a high stereoselectivity. The authors report that this represents a decrease in reaction time and that the high yield of only one isomer is a great improvement over the results achieved by J-CD under similar conditions[56]. Photodimerisation experiments on trans- cinnamic acids encapsulated by Q8 produce dimers not normally seen.[57] The same Chapter 2: Introduction to Cucurbituril Chemistry. Page 22

experiments with Q7 in place of Q8 fail to produce a similar result due to the smaller cavity size.

2.2.5: The host-guest complexes of other macrocycles. Much of the work conducted on Qns is a repetition of experiments first carried out on the other macrocycles that have been available to researchers for a much longer time. All of the rotaxane, polyrotaxane, side-chain polyrotaxane and dendrimer complex work follows from the results first achieved with cyclodextrins and crown ethers. The substitution of Qns for these other macrocycles was an attempt to replicate or improve on the achievements of previous work. The binding constants for Qn host-guest complexes are often reported as being higher or comparable to the complexes of macrocycles such as cyclodextrins (e.g. log K for 4- methylbenxylamine@E-CD is 2.08 while for 4-methylbenxylamine@Q6 log K is 2.67)[58]. The principal reason suggested for this is that as the Qn molecule is rigid it does not distort to accommodate any guest molecules and there is therefore little strain on the Qn. The interactions between host and guest molecules in Qn complexes may also involve stronger forces. For example, as the carbonyl oxygens of a Qn are better electron donors than the ether oxygens of a crown, stronger hydrogen bonding and electrostatic interactions can exist between a guest and the Qn host. Further to this a Qn has twice as many of these oxygen binding sites than a calixarene or crown ether of comparable size.

Qn host-guest complexes can exhibit quite different behaviour to that of the corresponding host-guest complexes involving other macrocycles. For example, Ong et al. report that upon redox conversion of some guest molecules encapulated in E-CDs (such as ferrocene derivatives and viologen) the host-guest complex is destroyed unlike in the case of Qns which usually only undergo a slight drop in the stability of their host- guest complexes[44]. Furthermore Kim et al. have reported that the methylviologen@Q7 complex undergoes direct electron transfer i.e. the complex does not need to dissociate for the guest to undergo reduction. This is in contrast to many of the complexes of other macrocycles in which redox conversion of the guest only occurs when it is not encapsulated[35]. Chapter 2: Introduction to Cucurbituril Chemistry. Page 23

Despite the work and results on Qn host-guest chemistry that has accumulated in recent years, it is outstripped by the amount of research at both the fundamental and, importantly, practical levels that has been carried out on the complexes of other macrocycles. It is the work conducted in these fields that appears to be setting the benchmark for research on the host-guest complexes of Qn. In particular it is the complexes of cyclodextrins and calixarenes that have been developed to the greatest use for a variety of applications.

Cyclodextrins are able to form complexes with molecules ranging from anions, small gas molecules, alcohols, hydrocarbons, organometallics, polypeptides, nucleic acids, [59] C60 and even the small macrocycle, 12-crown-4 . The applications of cyclodextrins as host molecules are equally as varied. They are used for catalytic purposes, for the modification of guest molecule properties[60], for the resolution of enantiomers and can also be bound to the stationary phase of a chromatography column and used for the separation of mixtures[61]. They have uses in the pharmaceutical, food, textiles and environmental protection industries among others.

The versatility of calixarenes as host molecules lies in the ease with which they can be modified to attract and encapsulate a much larger range of molecules. Rebek and co- workers have prepared a great number of ‘capsules’ or ‘deep cavitands’ by building up the sides of this macrocycle[62-64]. These allow larger or more guest molecules to sit inside the cavities and more interestingly, these are able to dimerise so that guest molecules may become trapped. The types of guest molecules that the wide range of modified calixarenes can accommodate include aromatics; C60; alcohols; alkanes; biological compounds such as amino acids, carbohydrates, neurotransmitters, vitamin B12, nucleotides and DNA. They have been found to mimic the binding properties of the natural antibiotic vancomycen; to selectively bind to only one enantiomer of small amino or alcohol based compounds; to modify the properties of guest molecules making them useful sensors and calixarenes can also be used in the multiple forms of chromotography[65, 66]. Chapter 2: Introduction to Cucurbituril Chemistry. Page 24

2.3: Cation Binding to Portals.

The Qn molecule has more than one type of region available for molecular recognition and, as described in § 2.2, its cavity is one such location with a hydrophobic region able to incorporate a range of molecules (see table 2.2). Some of these guest molecules, such as the diammonium alkanes, are drawn into the cavity because of the ion-dipole interactions between the guest’s positively charged ammonium groups and the partial negative charge on the oxygens lining the portals of the Qn. The electrostatic interaction between the host and guest molecules is stabilised further by the hydrogen bonding involving the portal oxygens and the favourable interaction between the hydrophobic cavity of the Qn and the alkane chain of the guest molecule. In contrast, metal cations interact with the Qn via formal coordination bonds to the portal oxygens. Interestingly, this leads to the solubility of Qns in metal salt solutions such as NaCl(aq), a property that can be used to prepare neutral solutions of the otherwise insoluble Qns. A coordinated metal cation has the effect of ‘capping’ (or blocking) the portals of a Qn so that a guest molecule can become trapped. The cations can form either 1:1[67, 68], 1:2[69, 70] or even 1:4[24, 71] Qn-metal (Qn-Mn+) complexes as in some cases two cations can coordinate to the one portal. It is also possible for one metal cation to coordinate to two portals simultaneously, connecting Qn molecules to form a column or 1D coordination polymer[72-74]. In chapter 3, § 3.5 and § 3.6 describe the crystal structures of the Qn-Mn+ complexes while chapter 4, § 4.2 details the solubility of Qn in various metal salt solutions.

The principal methods for measuring the binding constants of Qn-Mn+ complexes are calorimetric and potentiometric titrations[67] and solubility studies conducted in salt solutions[75]. These studies have been conducted on complexes of Q5, Q6 and functionalised Q5 (with methyl groups at the methine positions, known as decamethylQ5). Although the larger Qn do form these types of complexes no work appears in the literature regarding their binding constants. Researchers have compared binding constants of Qn-Mn+ complexes to those of complexes formed between other macrocycles such as crown ethers. The Q6 molecule forms stronger complexes with alkali metal cations than the crown ether macrocycle with log K values up to 2-4 times greater for the Q6 complexes. This is attributed to the Chapter 2: Introduction to Cucurbituril Chemistry. Page 25

greater dipole moment of the carbonyl group compared to that of the ether oxygen[75].In general, a Qn molecule forms complexes with metal cations that are stronger than (in the case of crown ethers) or comparable to other macrocycles, e.g cryptands. Researchers attribute the high favourability of the Qn-Mn+ complexes to the fact that Qn, unlike other macrocycles, is a rigid molecule that cannot distort itself to accommodate a guest or cation at its portals. The strength of the complex depends on the match between the size of the metal cation coordination sphere and the size of the portal ring to which it is complexed. But because the smaller Qns cannot distort their portal size to improve the fit between the ring of donor oxygens and the metal cation, their complexes are not as strong as those macrocycles, such as cryptands, that are able to accommodate differently sized metal cations. However, when a good match is found the complex is likely to be very stable: the value of log K for the complex between decamethylQ5 and Pb2+ is more than twice that for the complex between Q6 and Pb2+. The authors of the paper explain that as the portal of decamethylQ5, at ~ 2.5 Å, is a better fit for the Pb2+ or the Pb(OH)+ cations this is probably the reason for the large difference in binding constants and go on to suggest practical applications for this discovery[67]. Qn-Mn+ complex formation is reversible and can be controlled by simply changing the pH of the solution. When an excess of acid is added to a solution containing Qn-Mn+ the H+ binds competitively with the portal oxygens releasing the bare metal cations. This is the origin of the Qn molecule’s solubility in acid solutions: when H+ cations bind to the portals they impart a charge on the neutral molecule and increase its solubility in aqueous solutions. This property can be useful for the controlled release of a trapped guest in a Qn cavity. Jeon et al. and Whang et al. have shown that by decreasing the pH of a solution containing either a Q6-Na+ or Q6-Cs+ complex they were able to free a trapped THF molecule. This was reversed by increasing the pH to reform the Q6-Mn+ complex, complete with trapped THF molecule[24, 69]. Chapter 2: Introduction to Cucurbituril Chemistry. Page 26

2.4: The Practical Applications of Qn Chemistry.

As already explained the Qn molecule has different types of sites for molecular recognition and a high specificity for particular molecules. The ease with which experimental conditions can be manipulated to achieve the desired metal cation coordination or guest molecule encapsulation and the ease with which these results can be reversed is the basis for all practical uses of the Qn molecule. The potential uses of Qn are diverse and incorporate techniques for waste water management and uses as a detector/sensor for a variety of species. Many of these have already been referred to in § 2.2 and § 2.3. This section will list and elaborate on some of these techniques.

The treatment of wastewater is a possible future use for the Qn molecule’s ability to complex metal cations to its portal oxygens and the solubility of Qn-Mn+ complexes in water has been previously mentioned (§ 2.3). DecamethylQ5 shows a high selectivity for Pb2+ but other Qn molecules also show an affinity for this cation and form more stable complexes with metal cations than do other macrocycles such as crown ethers[75]. The conditions for the removal of reactive dyes from wastewater by Q6 have been investigated but the macrocycles were not found to be of practical use[76, 77].

The catalytic properties of Q6 have been outlined in § 2.2.4 with equation (2) detailing the 1, 3-dipolar cycloaddition of triazoles and alkynes.

But the overwhelming reason for the interest in the potential applications of the Qn molecule is derived from its ability to reversibly encapsulate a guest molecule and in some cases alter its properties. This rigid macrocycle does not distort to accommodate a guest, the way that cyclodextrins do for example, and so it can form very ordered structures even with long chained guest molecules to create pseudorotaxanes. These can readily be utilised as a ‘molecular switch’, several examples of which were described in § 2.2. Kim’s research group has achieved further ordering of the pseudorotaxanes with the construction of pseudopolyrotaxanes: pseudorotaxanes connected end-to-end with metal linkers[78]. Linking individual pseudorotaxanes onto a backbone polymer chain has created side-chain pseudopolyrotaxanes[79-81]. Kim et al. believe that ordering the pseudorotaxanes into such arrays will lead to coherence in their behaviour and the Chapter 2: Introduction to Cucurbituril Chemistry. Page 27

subsequent ability to utilise them in a practical manner[78]. They provide an example of this ordering with the construction of a self-assembled monolayer (SAM) of pseudorotaxanes. The pseudorotaxanes, anchored on to a gold surface by thiol groups, can be easily dethreaded by raising the pH of the solution allowing access to the gold layer by the ions in solution. The conclusion drawn is that this SAM may be behaving as an ion-gate[23]. Other examples of pseudorotaxane based SAMs exist in the literature but all are in the early stages of experimentation[82]. Qn has been used to form inclusion complexes with dendrimers, although a demonstrated use for these complexes has yet to be published[83-85]. Pseudorotaxanes have also been bound to the acridine unit that binds specifically to DNA thus extending the range of potential uses of Qn complexes[86]. Lim et al. have combined these two results with the formation of a ternary complex between DNA, dendrimers and Q6 that acts as a gene delivery carrier[87]. Preliminary work has been conducted by Xu et al. on the use of Q7 as an additive in capillary electrophoresis[88]. The encapsulation of cisplatin by Q7 suggests it may be a potential host for the pharmacological delivery of the drug.[89]

In addition to the mentioned applications, there have been a number of novel discoveries made involving the Qn as a host. The charge transfer host-guest complex (methylviologen)•(2, 6-dihydroxynaphthalene)@Q8[45, 90] was described previously in § 2.2.3 and that work has been expanded to produce a ‘molecular loop’ inside Q8. The complex between Q8 and a guest molecule with a terminal viologen group and a 2, 6- dihydroxynaphthalene unit separated by a three carbon chain (see fig. 2.4(a)) leads to the guest folding back along itself so that the two groups are both included in the one cavity[46]. The same research group provide another example of this type of behaviour. A bisviologen cation with a connecting hexamethylene chain (see fig. 2.4(b)) folds over itself when electrochemically reduced so that the two terminal viologen groups are simultaneously included in the Q8’s cavity[91]. Chapter 2: Introduction to Cucurbituril Chemistry. Page 28

OMe N+ N+Me H3CN N

OO (CH2)6 OMe H3CN N

(a) (b)

Fig. 2.4: The two molecular loops included in Q8. In (a) the naphthalene and the viologen groups are located in the cavity and in (b) the two viologen groups are included in the cavity.

N+

5Q8 + 5

N+

Fig. 2.5: A graphical representation of the pentagonal shaped supramolecule. The mauve patches represent Q8 and the regions of the guest molecule they coincide with are encapsulated in the Q8. Only two Q8 molecules, one guest molecule and one terminal group of two other guest molecules are depicted.

This work follows from the result of the encapsulation of the methylviologen cation radical dimer by Q8[50]. This group have also designed a novel supramolecule formed between five guest molecules and five Q8 molecules. The guest molecule has both a naphthalene and a dipyridyliumylethylene group, both of which are encapsulated in two different Q8 molecules. Each Q8 therefore has both groups in its cavity, each from a Chapter 2: Introduction to Cucurbituril Chemistry. Page 29

different molecule. The resulting complex takes the form of a pentagonal shaped ring[92]. A graphical representation of this is shown in fig. 2.5.

Isaacs et al. have recently published their work on the ‘inverted’ Qn. In this molecule one glycoluril monomer points into the cavity so that its methine H and C atoms are inside the Qn, leaving less room for guest molecules. The authors report that this inverted Qn binds its guests less tightly and that it shows better size and shape selectivity[93].

While the applications just described show genuine potential they are still in the early stages of development. Currently, the restrictions on the environment in which Qn chemistry can be conducted are limiting research but there has been one discovery that is of enormous importance. When the Qn molecule is functionalised at the methine carbon position, to form a substituted Qn, its properties, such as its solubility in water, are altered[94]. This has the consequence of providing many new methods for conducting experimentation, for discovering new uses for Qns and for enhancing and developing the uses already discovered. Section 2.5.1 outlines the synthesis, properties and possible uses for these substituted Qns.

2.5: The Synthesis of Qns.

The research group of Anthony Day, Rodney Blanch and Alan Arnold have studied the synthesis of cucurbiturils at length. Their mechanistic studies have shown that during the acid catalysed condensation of glycoluril with formaldehyde, the glycoluril monomers are connected into long ribbons, or oligomers, by methylene groups which link up to form the circular Qn molecules. They have discovered that the 13C NMR signals for a larger Qn is shifted downfield with respect to the signal for a smaller Qn and have used this property to identify the existence, at least in the solution phase, of Qn molecules as large as Q16[3]. They have detected, but never isolated, Q9 and have only isolated Q10 when occupied by a Q5. Q5 – Q8 have been isolated by several other groups as well[3, 95]. Liu et al. have also isolated Q10 when occupied by a guest and have also isolated free Q10[110]. Before the publication of these results, Day et al. Chapter 2: Introduction to Cucurbituril Chemistry. Page 30

postulated that the larger Qns, where n>8, were not stable and decompose or transform into smaller sized Qns. Their work has involved attempts to elucidate the steps involved in the synthesis of Qns and to find the optimum conditions to produce Qns of different sizes[3, 96, 97].

Equation (3):

O O O O

NN N NH NN NHN O

O RR O 2 O HH HH HH + H2O N N NNH N N N NH

O O O O Ether intermediate

An ether derivative of glycoluril is pictured inset and at right the formation of the oligomers is presented.

The reaction pathway proposed for the formation of the oligomers involves the production of ether derivatives of glycoluril followed by their rapid oligomerisation (see equation 3). However these ethers have never been isolated or even observed in unsubstituted glycoluril monomers. The length of the oligomers determines the size of the Qn molecule, and their formation and closure may be dependent on such things as reaction conditions (concentration of reactants, temperature), acid type and the presence of a guest molecule to template the formation of the Qn. Their extensive research into varying reaction conditions shows that Q6, and to some extent Q5, are the favoured products due to their thermal stability as well as the stability of their precursor oligomers. Day et al. have specifically investigated the ability of metal cations coordinated to the carbonyl oxygens of the precursor oligomers to template the formation of different sized Qns, presumably due to the stabilisation of certain lengths of oligomer ribbons. When the metal cations were added to the glycoluril/formaldehyde/acid reaction mixture they found no correlation between the size of the metal ion radii or their coordination spheres and Qn size. However, when the metal cations were added to the isolated oligomers there was an increase in the yield of Q5 when the smaller cations, such as Li+, were used as templates. This research group also mentions the possibility of anions acting as templates for Qn ring formation as the inner cavity of the oligomers (and Qn) are electropositive regions. Chapter 2: Introduction to Cucurbituril Chemistry. Page 31

It is possible that an anion may be able to determine the size of the Qn if it sits in this region while the oligomer wraps itself around the anion.

2.5.1: The synthesis of substituted Qns. The cucurbituril molecule has limited versatility due to its insolubility in most common solvents. The addition of substituent groups to Qn has been found to increase its solubility thereby rendering it a far more useful compound for the applications outlined in § 2.4. Only one instance of direct functionalisation of an already formed Qn appears in the literature[82]. The low incidence of direct derivatisation of a Qn is presumably due to its very stable and robust, and therefore unreactive, nature. Instead, researchers have focused on substituted glycoluril monomers, with substitution always at the methine carbon position, to synthesise substituted Qns. Substituted glycolurils, their reactivity and behaviour have been studied extensively by the research groups of Isaacs[98-101], Nolte[102-104] and Rebek[63, 105]. As already mentioned, some of the substituted glycoluril monomers have been used successfully to produce Qns with altered properties such as increased solubility and also different encapsulation abilities, as described below.

The first of the substituted Qns to be synthesised was decamethylQ5, which has methyl groups in place of the methine hydrogens[10]. Its properties differ from those of Q5 in that the substituted form is less soluble in dilute acids than the unsubstituted form yet more soluble in water. Zhang et al. have found that decamethylQ5 has a greater affinity for Pb2+ coordination than does Q6, prompting the researchers to describe the substituted Q5 as a highly selective compound for this metal cation[67]. There are differences in the host-guest properties of the substituted form of Q5 as well. Although Q5 pseudorotaxanes have been synthesised by Wego et al., the researchers failed to achieve the same results for decamethylQ5[106] and discovered that decamethylQ5 could not form an inclusion complex with 1,6-diaminohexane, possibly due to it being a more rigid molecule than unsubstituted Q5. However smaller guest molecules such as the nitrate ion/nitric acid molecule and small gas molecules such as

N2, H2, He, Ne, CO2, O2, acetylene and others can be encapsulated in the decamethylQ5 cavity in both the solid state and in aqueous solution[10, 25]. Crystal structure analyses of various decamethylQ5 compounds appear in chapter 3, § 3.8. Chapter 2: Introduction to Cucurbituril Chemistry. Page 32

The synthesis of methyl substituted Q6 has been investigated by Day et al. in the reaction of methyl substituted glycoluril ethers with unsubstituted glycoluril monomers[107]. They reported that only the partially substituted Q6, hexamethylQ6, formed as a major product and that only the symmetrically substituted isomer formed i.e. that composed of alternating substituted and unsubstituted glycoluril monomers. This new compound is soluble in acetonitrile, DMSO and trifluoroethanol but only when water was added to the organic solvents.

The compound (Ph)2Q6 is synthesised using five moles of glycoluril for every one mole of phenyl substituted glycoluril. Isobe et al. chose to attempt this synthesis after repeated attempts at synthesising the dodecasubstituted form failed, probably due to steric strain. The authors then also formed a pseudorotaxane by threading a [108] diaminoalkane through (Ph)2Q6 .

Qn derivatives that are soluble in water are sought as they may be useful for the removal of pollutants from waste or contaminated water. Their solubility in water is also of particular use in the determination of the binding constants of the Qn-Mn+ complexes in the absence of H+, which competes for coordination to the portal oxygens. The first compound synthesised that exhibited a high degree of solubility in water was 1,2-cyclohexylQn, n = 5, 6[94]. This compound is also soluble in methanol and DMSO and partly soluble in ethanol, DMF and acetonitrile but they are most soluble in water. An analysis of the crystal structures of 1,2-cyclohexylQ5 and Q6 appears in chapter 3, § 3.8.

As mentioned earlier there is one instance in the literature of direct functionalisation of a Qn. The reaction of K2S2O8 with Qn gives the (OH)2nQn (n = 5 – 8) compound that reacts further to form alkyl ether substituted and thioether substituted Qns amongst others[82]. This is depicted in scheme 2.1. A potential use for this derivative has already been demonstrated with the anchoring of an alkyl ether substituted Q6 onto a glass surface and the subsequent formation of anchored pseudorotaxanes with added spermine modified with a fluorophore group. Liu et al. have been successful at grafting [109] (OH)12Q6 to silica gel for use as a chromatographic stationary phase . The Chapter 2: Introduction to Cucurbituril Chemistry. Page 33

compound (OH)2nQn is soluble in DMSO and partly soluble in DMF. A crystal structure analysis of this compound appears in chapter 3, § 3.8.

Scheme 2.1

O O 1.NaH, DMSO 2. Alkyl bromide N N N N K2S2O8 H H HO OH NN NN Photoinitiated O O n n reaction with

n = 5-8 CH3(CH2)4SH

O S (CH2)3 (CH2)4CH3

(CH2)3 (CH2)4CH3 O S

2.6: Computational Studies of Qns.

The computational studies in the literature involving Qn molecules focus on two things: firstly the stability of Qn molecules and their derivatives and secondly the optimisation and energy calculations of host-guest complexes. Only one study conducted on the mechanism of host-guest complex formation appears in the literature. The methods used in these computational studies include DFT, ab initio, semiempirical and molecular mechanics calculations. These are discussed in more detail in chapter 6, § 6.1.1.1. Chapter 6 also presents the molecular mechanics calculations conducted in the course of this project. 2.7: Aims of this Project. Chapter 2: Introduction to Cucurbituril Chemistry. Page 34

There are three main aims of this project:

1. At the onset of this project the literature provided only examples of organic guests encapsulated in Qn, there were no examples of metal containing guests and this area of investigation appeared to be absent from the literature. Because of the effect that encapsulation can have on a guest molecule, the attempt to include a metal containing molecule and small inorganic molecules became a primary focus of this project. The properties of a metal guest that may be altered include changed redox chemistry as well as enhanced stability of the metal containing guest. Expanding the range of species that can be included in the Qn cavity will necessarily expand the type of chemistry available for Qns. Chapter 4 describes the experimental work conducted and the results produced during this project.

2. The literature contains a large number of Qn crystal structures yet there exists no detailed analysis of the types of interactions Qns engage in nor an overview of which interactions dominate these structures. Chapter 3 presents the analyses of the crystal structures of Qns in the literature and chapter 5 presents the analyses of the crystal structures of the Qn compounds prepared in the course of this project.

3. Finally, very little published literature focuses on the mechanism of host-guest complex formation. Computational studies can help researchers develop a picture of how guests approach the Qn, how their passage through the portal occurs and thus how a host-guest complex is formed. In this work the method of molecular mechanics was used to try to achieve this aim and in chapter 6 these calculations are presented. Chapter 2: Introduction to Cucurbituril Chemistry. Page 35

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108. Isobe, H., Sato, S., and Nakamura, E., Org. Lett., 2002, 4(8), 1287. 109. Liu, S.-M., Xu, L., Wu, C.-T., and Feng, Y.-Q., Talanta, 2004, 64, 929. 110. Liu, S., Zavalij, P. Y., and Isaacs, L., J. Amer. Chem. Soc., 2005, 127, 16798. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 43

CHAPTER 3 CRYSTAL STRUCTURE ANALYSIS OF LITERATURE STRUCTURES.

ATOM COLOUR KEY FOR CHAPTER 3

H Co Nb In W C Pt N Ni Mo Cs O Hg Cu Pd Al La Fe Rb P Ag Ce S Bi Sr Cd Cl Gd U

3.1: Introduction.

The oxygen ringed portals of the Qn molecule coordinate well with many groups, either directly with bare metal cations, through hydrogen bonding to water molecules or via electrostatic attractions with partially charged groups such as ammonium groups. A study of the crystal structures of Qn molecules in the literature reveals that the type of molecule coordinated to the portal can restrict the types of interactions in which a Qn molecule can engage and can therefore affect the crystal packing of a compound. This chapter will analyse these interactions and present the trends in the different classes of Qn structures. These classes include: metal-chalcogenide clusters; host-guest complexes, metal complexes not coordinated to Qn; 1D coordination polymers; metal Chapter 3: Crystal Structure Analysis of Literature Structures. Page 44

cations coordinated to Qn; polyrotaxanes and molecular necklaces and Q5@Q10. In order to gauge the effect that the coordination of the portal has on the crystal packing of a Qn molecule, a brief summary of the packing of Qn molecules without coordinated portals follows. The majority of the crystal structures analysed in this chapter are drawn from the Cambridge Structural Database(CSD)[1-4]. Each structure has a six-letter reference code, or Refcode, and these are listed alongside the compound formulas in this work. In cases where structures are new to the CSD and have not been assigned a Refcode they are instead given a CCDC number (CCDC = Cambridge Crystallographic Data Centre).

3.1.1: The crystal packing of the uncoordinated Qn molecules. An uncoordinated Qn molecule is defined here as one that does not engage in formal coordination bonds, hydrogen bonding or any electrostatic interactions with any species in the crystal structure with the exception of small neutral solvent molecules that are usually encapsulated in its cavity. Although most crystal structures feature coordinated Qn molecules, there are examples in the literature of uncoordinated Qn molecules. [5] The first example is of the compound [(H2O)2@Q5](H2O)2 (Refcode = LIRTEL) . The packing of this crystal structure features the Q5 molecules arranged in a herringbone array. In order for this packing style to occur, the Q5 molecules are engaged in “portal-to- side” interactions with each other, that is, the portal oxygens of one Q5 point to the methine and methylene hydrogens on the outer side of another. This interaction leaves no room for solvent water coordination to the portal oxygens. Instead there are two water molecules located inside the cavity separated by an O…O distance of 2.5 Å. The other two water molecules in this structure occupy the cavities in the crystal structure. Figure 3.1 depicts a layer of this packing and a detailed representation of the “portal-to- side” interaction. [5] The compound [THF@Q7](H2SO4)4(H2O)19 (Refcode = LIRTIP) also features layers of Qn molecules in a herringbone array. However, the Q7 molecules are not centred over the portals of their neighbouring Q7s, leaving some of the portal oxygens free to hydrogen bond with solvent water as shown in fig. 3.2. The sulfate anions are located between the layers of Q7 molecules. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 45

Fig. 3.1: The packing in the compound LIRTEL. The blue dashed lines represent O…C–H bonds; typical distances are 2.3 Å.

x Fig. 3.2: The packing in the compound LIRTIP. The view on the left shows the solvent water situated over the portals. The blue dashed lines indicate O…C–H hydrogen bonding between Q7 molecules. Typical O…C–H distances are 2.5 Å. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 46

[6] The compound [(4-MePyH)@Q6](NO3)(H2O)4 (Refcode = LACGOM) engages in the herringbone packing arrangement in a similar fashion to LIRTIP. The guest does not interfere with this pattern as it does not protrude from the cavity. As in the previous example, the Q6 molecules in this structure are in off-centre portal-to-side interactions. As a result, the guest’s pyridinium group is able to engage in hydrogen bonding with solvent water found over the portal.

As in the previous examples, the compound Q8(H2SO4)2(H2O)30 (Refcode = LIRTOV)[5] engages in off-centre portal-to-side interactions with solvent water covering part of the Q8 molecules’ portals and the sulfate anions surrounding the outside edges of the Q8. Unlike the previous two examples however, this compound does not feature the herringbone interaction. Instead, this compound crystallises in the space group I41/a with the Q8 molecules organised in chains running down the c-axis separated by O…H-C distances of 2.4 Å. A view of this is shown in fig. 3.3, in stereo, to highlight the portal-to-side interactions present in this structure.

KEY

41 axis =

(a) (b)

Fig. 3.3: (a) The crystal packing of LIRTOV viewed down the c-axis. The location of one 41-screw axis is highlighted and inset in (b) a stereo view of the chain is depicted, side-on. All solvent molecules, anions oxygens and hydrogens have been omitted for clarity. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 47

The compounds [(CH2CH2NH)4@Q8](HCl)4(H2O)19.67, (Refcode = YAVQIV), [(CH2

CH2NH- CH2 CH2 CH2NH)2@Q8](HCl)4(H2O)18 (Refcode = YAVQOB) and [7] [{Cu(CH2CH2NH)4 (H2O)}@Q8](NO3)2(H2O)16, (Refcode = YAVQUH) all – crystallise in the high symmetry space group R3. As in the case of LIRTOV these compounds feature Q8 molecules in off-centre portal-to-side interactions, however the off centring is more pronounced in these structures allowing one portal of a Q8 molecule to interact with two Q8 sides (fig. 3.4). Despite this, there is room for solvent water to hydrogen bond with the portals of the Q8 molecules. As in the crystal packing of LIRTOV there is no herringbone pattern featured in this structure.

Fig. 3.4: A stereo view of the off-centre portal-to-side interactions between the Q8 molecules in YAVQIV. Hydrogens and guest molecules omitted for clarity.

The portal-to-side interaction appears to be a favourable one for the Qn molecule to engage in and, as will be explained, is disrupted only by the more favourable interactions involving hydrogen bonding. In the following sections, in particular § 3.2, the various alternative interactions that Qn molecules engage in will be presented and the effects these have on the overall packing of Qn structures will be explained. The rest of this chapter will describe the motifs seen in the crystal structures of the various classes of cucurbituril compounds. A representative set of examples from each class will be used to describe the disruptive influence that coordination of the portal oxygen atoms can have on the formation of the portal-to-side interaction. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 48

3.2: The Metal-Chalcogenide Clusters.

This class of Qn structures contain metal-chalcogenide clusters that feature multiple water-ligands. The cucurbituril molecule, being symmetrical, can organise itself in different ways in order to achieve maximum stability of the crystal structure. The best way to achieve this in a metal-chalcogenide cluster structure is via hydrogen bonding between the cluster’s water-ligands and the Qn portal oxygens. Consequently, the principal interaction in the crystal packing of most of these structures involves the positioning of the clusters directly over the portal and orientated in such a way that their water ligands point towards the portal oxygens. They are drawn to these positions not only by the possibility of hydrogen bonding but also by the electrostatic attraction between the positive charge on the clusters and the partial negative charge on the portal oxygens. Because of this positioning, the uninterrupted herringbone array between Qn molecules does not feature in this class of crystal structures.

A typical cluster contains S or Se bound to transition metals such as Mo and W and can contain up to 9 water ligands. All the clusters in the literature to date are cations with only five examples of an anion and four examples of a neutral cluster. The chemical formulas and charges of these clusters are listed in table 3.1.

Table 3.1: The metal-chalcogenide clusters co-crystallised with Qn molecules. COMPOUND CLUSTER REFCODE and Reference 2- [8] Q6(H3O)4[W3S7Cl6](H2O)18 [W3S7Cl6] VIFWIQ 0 [9] (Q8)3[W3S4(H2O)5Cl4]2(H2O)35 [W3S4(H2O)5Cl4] KANNOD + [10] (H9O4)Q6[W3S4(H2O)6Cl3]2Cl3 [W3S4(H2O)6Cl3] ARIBEI (H2O)16.15 2+ [11] {Q6[W3S4(H2O)7Cl2]}Cl2(H2O)10 [W3S4(H2O)7Cl2] QIMPUX 3+ [12] (PyH@Q6)[W3S4(H2O)8Cl]Cl4 [W3S4(H2O)8Cl] MEGZAZ (H2O)15.5 + [13] [PyH@Q6] [W3Se4(H2O)6Cl3]2 [W3Se4(H2O)6Cl3] LACNUZ Cl3(H2O)18 3+ [14] Q6[W3Se4(H2O)8Cl]2 Cl6(H2O)12 [W3Se4(H2O)8Cl] MAYBOD 2+ [15] Q6[Cl3InW3S4(H2O)9]2Cl4 [Cl3InW3S4(H2O)9] MUFPAE (H2O)28 Chapter 3: Crystal Structure Analysis of Literature Structures. Page 49

+ [16] Q6[W3(CuCl)S4(H2O)6Cl3]2Cl2 [W3(CuCl)S4(H2O)6Cl3] EWEJUL (H2O)12 + [10] Q6[W3(SbCl3)S4(H2O)6Cl3]2 [W3(SbCl3)S4(H2O)6Cl3] ARIBIM (SbCl6)2/3(H2O)12 4+ [17] Q6[W3(Ni(HP(OH)2))Se4(H2O)9] [W3(Ni(HP(OH)2))Se4(H2O)9] WUMGIU Cl4(H2O)11 4+ [14] Q6[{W3Se4(H2O)7Cl2}2Hg]Cl4 [{W3Se4(H2O)7Cl2}2Hg] MAYBUJ (H2O)14 4+ [14] Q6[{Mo3S4(H2O)7Cl2}2Hg]Cl4 [{Mo3S4(H2O)7Cl2}2Hg] MAYBET (H2O)14 4+ [14] Q6[{Mo3Se4(H2O)7Cl2}2Hg]Cl4 [{Mo3Se4(H2O)7Cl2}2Hg] MAYBIX (H2O)14 0 Q6[Mo2O4(H2O)2Cl4] (H2O)10.5 [Mo2O4(H2O)2Cl4] No Refcode[18] + [19] {Q6[Mo3O4(H2O)6Cl3]2}Cl2 [Mo3O4(H2O)6Cl3] UCAROF (H2O)14 2.5– [9] (Q8)(H3O)8Cl(PdCl4) [Mo3S4(H2O)2.5Cl6.5] KANNAP [Mo3S4(H2O)2.5Cl6.5]2(H2O)29 2– [9] (Q8)3(H3O)4 [Mo3S4(H2O)3Cl6] KANNET [Mo3S4(H2O)3Cl6]2(H2O)68 2– [9] (Q8)(H3O)6Cl2 [Mo3S4(H2O)3Cl6] KANNIX [Mo3S4(H2O)3Cl6]2(H2O)12 + [11] (PyH@Q6)[Mo3S4(H2O)6Cl3] [Mo3S4(H2O)6Cl3] , QIMQAE 2+ [Mo3S4(H2O)7Cl2]Cl4 [Mo3S4(H2O)7Cl2] (H2O)17 + [20] Q6[Mo3S4(H2O)6Cl3](H3O)2Cl3 [Mo3S4(H2O)6Cl3] HUGZOY (H2O)9 2+ [21] Q6[Mo3S4(H2O)7Cl2]Cl2(H2O)10 [Mo3S4(H2O)7Cl2] NAMYAC – [22] (H3O)2Q6 [Mo3Se4(H2O)4Cl5] IKITUR [Mo3Se4(H2O)4Cl5]2(H2O)15 3+ [22] Q6[Mo3Se4(H2O)8Cl]2Cl6 [Mo3Se4(H2O)8Cl] IKITOL (H2O)16 + [23] Q6[Mo3S4Ni(H2O)7Cl3]Cl [Mo3S4Ni(H2O)7Cl3] XEMQAH (H2O)13 2+ [23] (PyH@Q6) [Mo3S4Ni(H2O)8Cl2] XEMQEL [Mo3S4Ni(H2O)8Cl2]Cl3(H2O)14.5 + [24] (H2O@Q6) [(OH)3PPdMo3S4(H2O)6Cl3] QUQLOD [Mo3PdP(OH)3S4Cl3(H2O)6]2Cl2 (H2O)19 + [24] Q6[(OH)3AsPdMo3S4(H2O)6Cl3]2 [(OH)3AsPdMo3S4(H2O)6Cl3] QUQLUJ Cl2(H2O)19 Chapter 3: Crystal Structure Analysis of Literature Structures. Page 50

0 [25] [PyH@Q6] [(ClPd)Mo3S4(H2O)6Cl3] NOSZOK [(ClPd)Mo3S4(H2O)6Cl3]Cl (H2O)14 + Q6[(ClPd)Mo3Se4(H2O)7Cl2]Cl [(ClPd)Mo3Se4(H2O)7Cl2] No Refcode[26] (H2O)7 0 [13] Q6[Cl3SnMo3Se4Cl3(H2O)6] [Cl3SnMo3Se4Cl3(H2O)6] , LACPAH + [Cl3SnMo3Se4Cl2(H2O)7]Cl [Cl3SnMo3Se4Cl2(H2O)7] (H2O)26 [20] Q6Cl2.61(H2O)15 [Mo3(Ni(PhSO2))S4Cl1.17 HUGZEO 1.83+ [Mo3(Ni(PhSO2))S4Cl1.17 (H2O)7.83] (H2O)7.83] [Mo3(Ni(PhSO2))S4Cl2.22 0.78+ [Mo3(Ni(PhSO2))S4Cl2.22 (H2O)6.78] (H2O)6.78] [20] Q6Cl2.59(H2O)11 [Mo3(Pd(PhSO2))S4Cl1.12 HUGZIS 1.88+ [Mo3(Pd(PhSO2))S4Cl1.12 (H2O)7.88] (H2O)7.88] [Mo3(Pd(PhSO2))S4Cl2.29 0.71+ [Mo3(Pd(PhSO2))S4Cl2.29 (H2O)6.71] (H2O)6.71] 4+ [27] {Q6[Nb2S4(H2O)8]}Cl4(H2O)15 [Nb2S4(H2O)8] GUQCEA

Figure 3.5 shows a typical Qn-cluster complex. Typical distances between the cluster water oxygens and the Q6 portal oxygens are between 2.6 - 2.9 Å.

90º

+ Fig. 3.5: The Q6-[Mo3S4(H2O)6Cl3] complex as found in the structure QIMQAE. The blue lines represent hydrogen bonding. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 51

All the positively charged clusters and some of the neutral clusters cap the Q6 molecules’ portals. As seen in table 3.1, the compound IKITUR contains an anionic – cluster, [Mo3Se4(H2O)4Cl5] , possessing water ligands which theoretically could engage in hydrogen bonding with the portal oxygens. However, this bonding does not occur. The cluster does not cap the portal in this structure because of the overall repulsion between the formal negative charge on the cluster and the partial negative charge on the portal oxygens. In the case of the compound VIFWIQ, as the anionic cluster contains no water ligands it cannot engage in hydrogen bonding and so it does not cap the Q6 portals (see fig. 3.13). This leaves the Q6 molecules free to engage in the herringbone array. The neutral clusters, on the other hand, can hydrogen bond with the Qn molecules and so, with the exception of KANNOD (see § 3.2.3), engage in the typical portal capping interactions. Therefore, it can be concluded that it is the absence of a negative charge in combination with the presence of water ligands able to engage in hydrogen bonding that will draw a metal-chalcogenide cluster to “cap” the Qn portal.

The remainder of this section describes the various crystal packing motifs featured in the crystal structures of compounds containing metal-chalcogenide clusters and Qn molecules.

3.2.1: Columns of parallel Qns. The first motif described here features Q6 molecules arranged parallel to one another in columns.

The compound {(PyH@Q6)[Mo3S4(H2O)6Cl3][Mo3S4(H2O)7Cl2]Cl4(H2O)17 (Refcode = QIMQAE) is an example of the simplest type of cluster structure in which the Q6 molecules lie parallel to one another in columns. Figure 3.6 shows a view of its packing and a detailed view of one parallel column showing that, as there is a cluster capping each portal, there are two clusters between each pair of Q6s. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 52

90Þ

+ Fig. 3.6: The crystal packing of QIMQAE featuring the cluster [Mo3S4(H2O)6Cl3] that has its six water ligands on one side and the three chlorides on the opposite. Hydrogens, solvent water and anions have been omitted for clarity.

This differs from the columns seen in the compound {Q6[Nb2S4(H2O)8]}Cl4(H2O)15 (Refcode = GUQCEA) where only one cluster lies between two Q6s (see fig. 3.7). This occurs because the cluster molecules in the compound QIMQAE have their water ligands pointing in one direction only (see fig. 3.6) and can only engage in hydrogen bonding with one portal at a time. In the compound GUQCEA, where the cluster’s water ligands point in two opposite directions (see fig. 3.7(a)), simultaneous H-bonding can occur with two portals. Another difference between the two compounds is that the Q6 molecules of the one column in GUQCEA do not overlap each other as they do in QIMQAE. This offset maximises the number of short hydrogen bonds in this structure. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 53

4+ Fig. 3.7(a): A side view of the column found in the structure GUQCEA. The clusters, [Nb2S4(H2O)8] , have water ligands pointing in both directions allowing each cluster to interact with two portals.

90Þ

Fig. 3.7(b): One cluster interacting with a pair of Q6 molecules in the compound GUQCEA. The cucurbiturils are offset from one another in order to maximise hydrogen bonding. The fine blue lines indicate these hydrogen bonds.

Fig. 3.8(a): A side view of the column in the crystal structure MAYBET containing the cluster 4+ [{Mo3S4(H2O)7Cl2}2Hg] . Chapter 3: Crystal Structure Analysis of Literature Structures. Page 54

90º

Fig. 3.8(b): A pair of Q6 molecules with a metal-chalcogenide double cluster from the compound MAYBET. The blue lines indicate hydrogen bonding.

In the compound {Q6[{Mo3S4(H2O)7Cl2}2Hg]}Cl4(H2O)14 (Refcode = MAYBET), another simultaneous Q6-cluster-Q6 interaction is found. This crystal structure contains “double” clusters, in which two Mo-S clusters are connected by a central Hg atom. As in the previous example (GUQCEA) this enables the cluster to hydrogen bond with the portals of two Q6 molecules simultaneously. In this structure, the Q6 molecules of the one column do overlap one another as shown in fig. 3.8(b).

The compounds (Q8)(H3O)6Cl2[Mo3S4(H2O)3Cl6]2(H2O)12 (Refcode = KANNIX) and

(Q8)(H3O)8Cl(PdCl4)[Mo3S4(H2O)2.5Cl6.5]2(H2O)29 (Refcode = KANNAP) both contain anions and therefore the clusters to not cap the portals due to electrostatic repulsions. Instead the packing of these structures feature parallel but offset Q8 molecules with gaps created for the anionic clusters. There are few interactions between water ligands and Q8 portal oxygens.

3.2.2: Zig-zag chains of Qns. An alternative arrangement to the columns of parallel Qn molecules sees the molecules lying at an angle to one another. This still allows hydrogen bonding between the Qn Chapter 3: Crystal Structure Analysis of Literature Structures. Page 55

portals and the clusters but, as will be explained in this section, it also allows for the clusters to interact with the Qn molecules situated at their sides. This is possible because most of the clusters have water ligands pointing outwards to the side with which they can engage in hydrogen bonding with the neighbouring Qn molecules’ portal oxygens. An example of one such cluster is shown in fig. 3.9(a). It should be noted however that not all the structures featuring zig-zag chains contain clusters with water ligands pointing outwards to the side.

Water ligands point down and out to the side

Water ligands point down only

(a) (b)

2+ Fig. 3.9: (a) The cluster [W3S4(H2O)7Cl2] has a water ligand pointing outwards allowing it to interact + with two Q6 molecules whereas (b) the cluster [Mo3S4(H2O)6Cl3] only has water ligands pointing downwards (in the figure). Hence, it only interacts with one Q6.

The compound {Q6[W3S4(H2O)7Cl2]}Cl2(H2O)10 (Refcode = QIMPUX) features a simple packing motif with the Q6 molecules in a zig-zag chain and a cluster molecule capping only one portal of each Q6. This leaves the other portal free to engage in hydrogen bonding with the water ligands of a nearby cluster: O…O = 2.6 Å and 2.8 Å. In fig. 3.10 a single layer of the crystal structure is shown. The compound

Q6[Mo3S4(H2O)7Cl2]Cl2(H2O)10 (Refcode = NAMYAC) packs in a similar fashion.

The crystal structure of (PyH@Q6)[Mo3S4Ni(H2O)8Cl2]Cl3(H2O)14.5 (Refcode = XEMQEL) also features a zig-zag chain and again each Q6 molecule has a cluster over just one of its portals. In this structure, however, the Q6 molecules engage in the portal- to-side motif with H…O distances of 2.8 Å. Due to the portal-to-side interactions there is limited interaction between the cluster molecules and neighbouring Q6 molecules. This is illustrated in fig. 3.11. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 56

2+ Fig. 3.10: A view of a layer of the crystal structure QIMPUX (cluster = [W3S4(H2O)7Cl2] ) featuring the zig-zag chain of Q6s and one cluster per Q6. The fine blue lines indicate hydrogen bonding.

2+ Fig. 3.11: In the compound XEMQEL, with the cluster [Mo3S4Ni(H2O)8Cl2] , the portal-to-side interactions do occur. The fine blue lines indicate hydrogen bonding. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 57

SIDE ABOVE

Fig. 3.12: One of the zig-zag chains in the structure of MEGZAZ featuring the cluster 3+ [W3S4(H2O)8Cl] . The fine blue lines represent hydrogen bonding.

The compound (PyH@Q6)[W3S4(H2O)8Cl]Cl4(H2O)15.5 (Refcode = MEGZAZ), crystallises with only half of the Q6 molecules capped with a cluster over each portal, allowing the Q6 molecules to engage in good portal-to-side interactions with each other (see fig. 3.12). Every second Q6 molecule is centred over the portals of both its neighbouring Q6s in the chain, with resulting O…H-C distances of 2.2 Å. The cluster molecules also engage in hydrogen bonding with their neighbouring cucurbiturils with O…O distances of 2.7 Å.

The compound Q6(H3O)4[W3S7Cl6]2(H2O)8 (Refcode = VIFWIQ) contains one of only five examples of an anionic cluster in this series of Qn structures. As it has no water ligands it does not hydrogen bond to the portals. Instead, the clusters lie between the layers of Q6 molecules orientated so that their chlorine ligands point towards the sides of the Q6s. Because of the absence of a Q6-cluster complex, the Q6 molecules are arranged in a herringbone array with the stabilising O…H-C contacts seen in the Chapter 3: Crystal Structure Analysis of Literature Structures. Page 58

structures described in § 3.1.1 (see fig. 3.13). These portal-to-side interactions feature H…O distances of 2.4 and 2.5 Å.

(b)

(a)

(c)

Fig. 3.13: (a) The herringbone array featured in VIFWIQ; (b) a portal-to-edge interaction; hydrogen bonding is represented by the blue lines and (c) the arrangement of the anionic clusters about the Q6 molecule.

3.2.3: Other packing motifs. The following three crystal structures feature packing motifs that differ from those described in the previous examples.

In the compound {(H2O@Q6)[Mo3PdP(OH)3S4Cl3(H2O)6]2}Cl2(H2O)19 (Refcode = QUQLOD) the clusters cap both portals of the Q6 but there are no parallel stacking or zig-zag chains formed in this crystal structure. Instead the Q6-cluster complexes lie at angles to one another to form layers with large cavities as pictured in fig. 3.14. There are no interactions between the Q6 molecules. The -P(OH)3 terminal group is rare. A search of the CSD found only three structures featuring this group when not part of the very common phosphoric acid, OP(OH)3. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 59

SIDE

ABOVE

Fig. 3.14: A layer of the crystal structure of QUQLOD and a detail of the Q-cluster complex.

Fig. 3.15: The crystal structure of UCAROF. The inset shows the staggered arrangement of the complexes in this crystal structure. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 60

In the crystal structure of {Q6[Mo3O4(H2O)6Cl3]2}Cl2(H2O)14 (Refcode = UCAROF) similar Q6-cluster complexes exist and are staggered as shown in fig. 3.15. This results in each Q6 being surrounded by four clusters. This packing style is unique to this structure.

The compound {Q6[W3(CuCl)S4(H2O)6Cl3]2}Cl2(H2O)12 (Refcode = EWEJUL) – crystallises in the rhombohedral space group R3m. This is another example of a Qn structure in a high symmetry space group but this structure differs markedly from any previously described. Figure 3.16 features a stereo view of the packing of the Q6 molecules in this structure, each of which has a cluster capping both portals. Although the Q6s are parallel they do not stack directly over one another and instead a cubic close packing arrangement is adopted.

Fig. 3.16: A stereo view of the packing of the Q6 molecules in the crystal structure of

{Q6[W3(CuCl)S4(H2O)6Cl3]2}Cl2(H2O)12. Hydrogens have been omitted for clarity.

The structures of (Q8)3[W3S4(H2O)5Cl4]2(H2O)35 (Refcode = KANNOD) and

(Q8)3(H3O)4[Mo3S4(H2O)3Cl6]2(H2O)68 (Refcode = KANNET) also crystallise in a – high symmetry space group: R3. The structures are similar to that of

(Q8)3(PtCl6)4(H3O)8(H2O)x (chapter 5, § 5.2.2) where the Q8 molecules are in a Chapter 3: Crystal Structure Analysis of Literature Structures. Page 61

‘spoked wheel’ array. In KANNOD and KANNET the clusters lie between the layers of Q8 molecules but do not cap the Q8 portals.

3.2.4: Concluding remarks. As mentioned in the introduction, the overriding crystal packing feature in the metal- chalcogenide cluster class of structures is the hydrogen bonding of the cluster to the Qn. In all cases the cluster is centred over the portal to evenly distribute and maximise these hydrogen bonds between the Qn portal oxygens and the cluster’s water ligands. The ubiquity of this motif suggests that the Qn-cluster interaction is favourable to the Qn- solvent water interaction. This possibly due to the multiple hydrogen bonds that exist between a Qn and a cluster. There are few Qn structures (of any kind) in the literature where a ring of waters lies over the portal even where there are no competing species in the compound; a more typical scenario involves two or three water molecules engaged in hydrogen bonding with the portal oxygens and also with each other. Substituting these few free waters for a cluster with multiple water ligands, with the possibility that each can hydrogen bond with more than one portal oxygen, is therefore a favourable option. Furthermore, the water ligands in question are all coordinated to a metal and as this makes them more electropositive than free water molecules they can be expected to form stronger hydrogen bonds with the portal oxygens. All the clusters with water ligands directed sideways are engaged in zig-zag chains in order to maximise the hydrogen bonding between portal oxygens and water ligands. There are also examples of structures which feature the zig-zag chain even though their clusters do not have sideways pointing waters and this is presumably also to maximise interactions between Qn molecules and metal-chalcogenide clusters.

The formation of a Qn-cluster complex is the driving force behind the general packing motifs of the metal-chalcogenide cluster structures, so much so that its presence can interfere with the formation of portal-to-side interactions. The hydrogen bonding between clusters and Qn portals is more favourable than the hydrogen bonding between Qns and so this interaction dominates the packing. As a result the portal-to-side interaction has been limited to just one portal of a Qn (resulting in the zig-zag chains) or has been eliminated (as in the case of parallel columns). The Qn-cluster complex disrupts the herringbone array and other typical patterns of Qn packing. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 62

In table 3.1 the metal-chalcogenide cluster compounds are organised so that those with similar clusters are positioned close together. It could be suggested that the similarities in cluster types might be reflected in the similarities in packing patterns of their crystal structures. This is borne out to some degree; the compounds

(H2O@Q6)[Mo3PdP(OH)3S4Cl3(H2O)6]2Cl2(H2O)19 (Refcode = QUQLOD) and

Q6[(OH)3AsPdMo3S4(H2O)6Cl3]2Cl2(H2O)19 (Refcode = QUQLUJ) are isostructural as are the pair Q6Cl2.61(H2O)15[Mo3(Ni(PhSO2))S4Cl1.17(H2O)7.83][Mo3(Ni(PhSO2))S4

Cl2.22(H2O)6.78] (Refcode = HUGZEO) and Q6Cl2.59(H2O)11[Mo3(Pd(PhSO2))S4Cl1.12

(H2O)7.88][Mo3(Pd(PhSO2))S4Cl2.29(H2O)6.71] (Refcode = HUGZIS). In both cases, the only difference between the compounds of a pair is the type of metal atom. The number of water, chloride and other ligand groups are the same (or almost the same). These four structures have a very similar packing pattern (fig. 3.14). They each feature a cluster with a bulky metal ligand group attached to the top of the cluster that prevents any possibility of the formation of parallel columns (see detail of fig. 3.14). The crystal packing rules appear to be the same with the simpler clusters –those crystal structures with clusters that differ only by the type of metal or chalcogenide atom pack similarly. In contrast, varying the number of waters, or chloride ligands, can change the crystal structure completely. This result is not so surprising as there are a large number of orientations and packing motifs available to these types of compounds (as has just been described in § 3.2.1-3). So, when the periphery of the cluster, which is directly involved in interacting with the Qn molecule, changes, the arrangement of the molecules in a crystal structure can also be expected to change to maximise the hydrogen bonding that is so important to this class of structures.

3.3: Host-Guest Complexes.

This class of structures feature inclusion complexes involving a guest molecule that protrudes from the Qn cavity and may interfere with the portal-to-side interactions and disrupt the herringbone array and other typical packing motifs. It does not include the long chain pseudorotaxanes or ‘molecular necklaces’ complexes that will be discussed in a § 3.7. Some host-guest complexes with small guests will also be discussed here. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 63

At the start of this project no examples of metal containing guest molecules existed in the literature and one aim of this project was to crystallise complexes with these guest molecules. This was achieved with the synthesis and crystallisation of {[cis- [28] SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 . Its crystal structure is presented in chapter 5, § 5.6. There are only thirteen crystal structures of host-guest complexes in the literature and in table 3.2 their guest molecules are pictured. The crystal structures of the structures REQNEG and REQNAC are not presented for analysis here, as the crystallographic data is not available.

Table 3.2: The Host-Guest complexes. FORMULA Refcode and and Reference GUEST MOLECULE [6] [Guest@Q6]NO3(H2O)4 LACGOM

where Guest = 4-methylpyridinium

+ HN CH3

[29] [Guest@Q6](HCl)2(H2O)10 CISWOQ

where Guest = p-xylylenediamine

+ H3N + NH3 [30] [Guest@Q8]2I3.33Cl0.67(H2O)34.63 No refcode

where Guest = NMe3

Me3N [30] [Guest@Q8] I2.4(H2O)13.2(H3O)0.4 No refcode Chapter 3: Crystal Structure Analysis of Literature Structures. Page 64

where Guest = O HN N

HN N NH

H2NNH2 [31] [2Guest@Q10]I4(H2O)32.94 No refcode

where Guest = O HN N

HN N NH

H2NNH2 [Ferrocene@Q7] No refcode[32] [33] [Guest@Q6]Br2(H2O)10 WUKTOL

where Guest = protonated pyridylmethylamine

+HN + NH3 [34] [Guest@Q8]2SO4(H2O)51 OBIPUK

where there are two Guest molecules:

N+ N+ OH

HO O 2,6-dihydroxynapthalene HO [5] [Guest2@Q8](HCl)2H2SO4(H2O)30 LIRTUB

where Guest = Chapter 3: Crystal Structure Analysis of Literature Structures. Page 65

+ NH 2 NH

[35] [Guest@Q6] (H2O)8.5 TUBWAO

where Guest =

N MnCl (H O) + 3 2 NH2

+ H2N N (OH2)Cl3Mn

[36] [Guest@Q6] (C2H6O)0.86(C3H7NO)4(ClO4)2(H2O)4 REQNEG

where Guest = O2N NO2 + + NH-(CH2)3-NH2 -(CH2)4-NH2 -(CH2)3-NH O N 2 NO2 [36] [Guest@Q6](H2O)14.37 REQNAC

where Guest =

H — — H + NCO2 O2C N H2N N + H2 [37] [Guest@Q8]Cl2(H2O)16 KANXED

where Guest =

NN Ni2+ N N

[37] [Guest@Q8]Q8Cl2(H2O)42 KANXIH

where Guest = trans-[Cu(en)2(H2O)2] [37] [Guest@Q8]Cl2(H2O)17 XAJXOW

where Guest = trans-[Cu(en)2(H2O)2] Chapter 3: Crystal Structure Analysis of Literature Structures. Page 66

This discussion begins with those host-guest complexes containing small guest molecules. In these structures the portal-to-side interaction is not hindered.

In the compound [(4-MePyH)@Q6]NO3(H2O)4 (Refcode = LACGOM) the herringbone array is not disrupted mainly because the guest molecule is small and does not protrude from the cavity. This is shown in fig. 3.17.

Fig. 3.17: The Q6 molecules are able to engage in the herringbone array in LACGOM due to the inclusion of a small guest molecule, shown here in pink.

The portal-to-side interaction is slightly offset to enable the pyridinium hydrogen to hydrogen bond with a water molecule (O…H = 1.8 Å) and for water molecules to lie over the portal and engage in hydrogen bonding with the portal oxygens. In the structure featuring two guest molecules inside a Q10 cavity (see table 3.2), the herringbone pattern is also present.

The structure of the compound ferrocene@Q7 features two different conformers of the host-guest complex. In one the ferrocene is horizontal inside the cavity, parallel to the

C2 axis, while in the other it is almost vertical. These are shown in fig. 3.18. These two conformers alternate in the chains formed in this structure with portal-to-side interactions between the Q7s. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 67

Fig. 3.18: A chain of ferrocene@Q7 molecules. The two different forms of this host-guest molecule are shown inset.

In the crystal structures of KANXED, KANXIH and XAJXOW the guest molecules are also small enough to allow the portal-to-side interactions to form. The packing of

KANXED is similar to that of (Q7)(Cr3O10)(H3O)2(H2O)x described in chapter 5, § 5.4.2. The packing of KANXIH and XAJXOW, which are isostructural, is similar to that of (Q8)2(PtCl6)3(H3O)6(H2O)18 described in chapter 5, § 5.3.2.

The typical portal-to-side interactions are disrupted in the compounds

[(NH2CH2(C6H4)CH2NH2)@Q6](HCl)2(H2O)10 (Refcode = CISWOQ) and [(HNC5H4-

CH2NH3)@Q6]Br2(H2O)10 (Refcode = WUKTOL). The amino groups of the guest molecules protrude far enough out of the Q6 cavity to repel the methylene and methine hydrogens of other Q6 molecules. As a consequence alternative packing motifs are adopted: in the structure CISWOQ (fig. 3.19) the Q6s of the one layer do not overlap each other to any significant degree and similarly in WUKTOL (fig. 3.20) there is little interaction between Q6s. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 68

Fig. 3.19: A single layer of the packing in the compound CISWOQ. The guest molecule, which is coloured light blue, can be seen protruding slightly from the cavity. Hydrogens have been omitted for clarity.

90Þ

Fig. 3.20: The crystal packing of WUKTOL. The guest molecules are in pink; hydrogens have been omitted for clarity.

In contrast, the compound [(HO-C10H6-OH)(C19H17N2O2)@Q8]2SO4(H2O)51 (Refcode = OBIPUK) is able to participate in portal-to-side interactions because although one of its guest molecules protrudes from its cavity it does so only from one side of the Q8 leaving the other cavity unencumbered. In fig. 3.21 a stereo view of the packing of this structure is shown. As can be seen only one side of each Q8 is involved in a portal-to- Chapter 3: Crystal Structure Analysis of Literature Structures. Page 69

side interaction resulting in the formation of zig-zag chains of Q8 molecules. This interaction appears to involve only the Q8 molecules with no contribution from the guest molecules. Although the chains of the one layer eclipse one another they are still far apart; however, the larger guest molecules of the one chain do interact with the Q8s

of the next chain.

Fig. 3.21: A stereo view of the crystal packing of OBIPUK. The larger guest molecule is shown in light blue for clarity; hydrogens have been omitted for clarity.

In the final two structures described in this section, the portal-to-side interactions are not possible because the guest molecule protrudes from both portals. The compound LIRTUB contains discreet layers of host-guest complexes engaged in minimal interactions with each other. In the structure of TUBWAO all the host-guest complexes lie parallel and the pyridine ring of the guest lies over a 5-memebered ring of a neighbouring Q6 with C…C and C…N distances around 3.5 Å.

As expected, the portal-to-side interaction is disrupted by the presence of a guest molecule that protrudes from the cavity or has a positively charged terminal group (such + as NH4 ) that repels the methylene and methine hydrogens of neighbouring Qns. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 70

3.4: Metal Complexes not Coordinated to Qn.

3.4.1: Introduction. This class of structures feature metal complexes containing water ligands that are able to hydrogen bond to the Qn portal oxygens. The Qn molecules remain uncoordinated to any metal atom however, distinguishing them from those structures presented in § 3.6. When this hydrogen bonding occurs the portal-to-side interactions are disrupted and the better the coverage of the portal by the metal complex, due to more hydrogen bonds, the more disrupted the portal-to-side interaction. In five examples presented here the Qn molecules all lie parallel to one another – the portal-to-side packing motif has been completely eliminated in favour of portal oxygen to water ligand hydrogen bonding. Table 3.3 lists the compounds that will be discussed in this section.

Table 3.3: Qn crystal structures featuring uncoordinated molecules. REFCODE COMPOUND Reference [38] GUMWEQ (Q6)2[InCl4(H2O)2]3(H3O)3(H2O)17 [38] GUMWIU Q6[In(H2O)6](NO3)3(H2O)9 [38] GUMWOA Q6[Al(H2O)6]Cl3(H2O)18 [39] ITUTEW Q6[Ni(H2O)6]2(SO4)2(H2O)16 [39] ITUTIA Q6[Cr(H2O)6](NO3)3(H2O)13 [40] WAKSOR Q6(H)2[Y((H2O)8]2(NO3)8(H2O)13 [38] GUMWAM Q6[InCl2(H2O)4]3Cl3(H2O)4 [41] LUHMIK [(H2O)@Q6][(UO2)4O2Cl4(H2O)6](H2O)4 [42] XAVXAN Q6(GaCl4)2(H7O3)4Cl2(H2O)2

[43][73] UCANOB Q6(FeCl4)2(H7O3)4Cl2(H2O)3

3.4.2: The crystal structures.

In the structure of compound (Q6)2[InCl4(H2O)2]3(H3O)3(H2O)17 (Refcode = – GUMWEQ) the presence of the [InCl4(H2O)2] anion, that does not lie centred over the portal due to electrostatic repulsions, results in good portal-to-side interactions; typical Chapter 3: Crystal Structure Analysis of Literature Structures. Page 71

distances are O…N, C, O = 3.0-3.3 Å; O…H = 2.7, 2.8 Å. Figure 3.22(a) shows one layer of Q6s, displaying the herringbone array, that is separated from the next layer by the anions; fig. 3.22(b) shows the position of these anions over the portals.

SIDE VIEW

TOP VIEW

(a) Fig. 3.22: (a) The structure GUMWEQ features portal-to-side – interactions as the anion,[InCl4(H2O)2] only covers part of the portal (b) The blue and white striped lines represent hydrogen bonding. All hydrogens omitted for clarity. (b)

The Q6 molecules are tilted so that they can engage in hydrogen bonding with the anions occupying the spaces between the Q6 layers.

The structure of Q6[In(H2O)6](NO3)3(H2O)9 (Refcode = GUMWIU) features a cation able to cover a greater portion of the portal. As a result there is greater deviation from the ideal portal-to-side interaction and the herringbone array, and this is reflected in the distances between the Q6 molecules: O…O = 3.5 Å and O…H = 2.6-2.9 Å. The packing of this structure is pictured in fig. 3.23. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 72

SIDE VIEW

TOP VIEW

(a)

Fig. 3.23: (a) The crystal packing of the Q6s in GUMWIU (b) 3+ the cations, [In(H2O)6] , lie entirely over the portals. Hydrogen bonds are shown in blue and white striped bonds. All hydrogens have been omitted from (a) for clarity. (b)

CATION 1

SIDE TOP CATION 2

(a)

Fig. 3.24: (a) The packing of one layer in GUMWOA. (b) 3+ views of both Al(H2O)6 cations hydrogen bonding with portal oxygens as indicated by the blue and white striped lines. One of the cations is disordered over two orientations. SIDE TOP (b) Chapter 3: Crystal Structure Analysis of Literature Structures. Page 73

The cation in the structure of Q6[Al(H2O)6]Cl3(H2O)18 (Refcode = GUMWOA) lies centred over the portal and this prevents the formation of the herringbone array and the Q6s are almost parallel to one another. There are still a number of interactions between the Q6 molecules but fewer involving the portal oxygens; distances include O…C = 3.4 Å, C…N = 3.2 Å, O…H = 2.7, 2.9 Å and N…H = 2.7 Å. The crystal packing is illustrated in fig. 3.24(a) and the hydrogen bonding between the two crystallographically independent cations and the portal oxygens is shown in fig. 3.24(b). One of these cations is disordered over two orientations.

The structure of Q6[Cr(H2O)6](NO3)3(H2O)13 (Refcode = ITUTIA) is similar to that of 3+ GUMWOA. There is a [Cr(H2O)6] cation between each pair of Q6s which are arranged parallel to one another and are arranged in a way similar to that shown in fig.

3.24. The structure of Q6[Ni(H2O)6]2(SO4)2(H2O)16 (Refcode = ITUTEW) also has columns of parallel Q6s but each pair is separated by two cations. To avoid repulsions 2+ between the two [Ni(H2O)6] cations, the Q6s of the one column lie in a staggered formation rather than eclipsing one another.

The crystal packing of the structure of Q6[InCl2(H2O)4]3Cl3(H2O)4 (Refcode = GUMWAM), which crystallises in the high symmetry space group P6/mmm, is somewhat different from the previous three. Instead of two cations hydrogen bonding to each Q6 there are twelve arranged above and below the rim of the portals as shown in fig. 3.25(a). This enables a greater number of hydrogen bonds to form in the structure but this occurs at the sacrifice of all Q6-Q6 interactions: all Q6 molecules are exactly parallel to one another in this structure. Instead of being offset from each other, as in the previous structure ITUTEW, the Q6s all lie in the same plane with the layers of cations lying between the Q6 layers. This results in only the Q6 methine hydrogens pointing to each other but these are well separated. The compound

Q6(H)2[Y((H2O)8]2(NO3)8(H2O)13 (Refcode = WAKSOR) packs similarly with all Q6s parallel to each other but with no hydrogen bonding between the cations and Q6s, an unusual feature among this set of compounds. The cations instead engage in hydrogen bonding with the nitrate anions. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 74

90Þ

(a) Fig. 3.25:(a) A layer of Q6 molecules in GUMWAM + surrounded by the InCl2(H2O)4 cations; inset is a side view of 12 cations surrounding one Q6 (b) a side view of one cation and a Q6; hydrogen bonds are indicated by the blue and white (b) lines.

Similarly, the structure of [(H2O)@Q6][(UO2)4O2Cl4(H2O)6](H2O)4 (Refcode = LUHMIK) features the Q6s lying parallel to one another but here the neutral

[(UO2)4O2Cl4(H2O)6] species lies over the portals (fig. 3.26(b)). In addition there are further interactions between the methylene and methine Q6 hydrogens and the side oxygens and chlorines of the neighbouring [(UO2)4O2Cl4(H2O)6] molecules (fig. 3.26(c)). As in the structure of ITUTEW the Q6s lie in an offset arrangement so that there are some Q6-Q6 interactions with distances of O…N = 3.3, 3.5 Å and O…H = 2.8, 2.9 Å.

90Þ

Fig. 3.26(a): Here a single layer of [(UO2)4O2Cl4(H2O)6] molecules in LUHMIK is shown interacting with one layer of Q6 molecules. All hydrogens, chlorines and solvent water omitted for clarity. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 75

90Þ

Fig. 3.26(b): A Q6 molecule engaged in hydrogen bonding with two neutral molecules in the structure LUHMIK and (c) a Q6 molecule surrounded by four neighbouring molecules. Hydrogen bonds are represented by blue and white lines and Cl…C, N<3.4 Å are represented by red and white striped lines.

The structure of Q6(GaCl4)2(H7O3)4Cl2(H2O)2 (Refcode = XAVXUN) features its Q6 + portal oxygens hydrogen bonded to the H3O7 cation in favour of portal-to-side interactions. The structure of Q6(FeCl4)2(H7O3)4Cl2(H2O)3 (Refcode = UCANOB), 2+ isomorphous to XAVXUN, features the cyclic [H14O6] species hydrogen bonded to its portals. Hence the Q6s lie parallel to each another with no Q6-Q6 interactions as they are separated from each other by the anions. The favourable coordination of the + 2+ H3O7 and [H14O6] cations to the portal oxygens disrupts the herringbone pattern, as this hydrogen bonding is more stabilising than the portal-to-side interaction.

3.4.3: Concluding remarks. As discussed in § 3.2 and further confirmed by the structures described in this section, hydrogen bonding between the portal oxygens and the water ligands of cocrystallised metal complexes disrupts the portal-to-side interactions. When this occurs, the herringbone pattern is replaced by the arrangement of parallel Qn molecules in the crystal packing. This is accompanied by a decrease in the involvement of the portal oxygens in any Qn-Qn interactions. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 76

3.5: 1D Coordination Polymers.

In this class of structures one or more metal cations are coordinated to two Qn portals simultaneously so that long chains or columns of bound Qn molecules are formed. This makes any portal-to-side interactions impossible. There are twelve examples of these columnar structures in the literature. These are listed in table 3.4.

Table 3.4: Structures featuring 1D coordination polymers. REFCODE COMPOUND Reference [44] MAPWUV Q6[Rb2(P-OH)2(P-CH3OH)2(H2O)2](H2O)17 [45] XAGXEI THF@Q6[K2(P-OH)2](H2O)18 [46] UCALEP Q6[Ca(H2O)3(HSO4)(CH3OH)]2(HSO4)2(H2O)4 [47] IBAZER Q6[Zr4(OH)8(H2O)16]Cl8(H2O)16 [47] IBAZIV Q6[Hf4(OH)8(H2O)16]Cl8(H2O)16 [48] IWUVOL Q6[Th(H2O)5Cl]2Cl6(H2O)13 [49] IMOBOB Q6[Sr4(H2O)12(NO3)4](NO3)4(H2O)3 [49] IMOBUH Q8[Sr2(H2O)12][Sr(H2O)3(NO3)2]2(NO3)4(H2O)8 [48] IWUVEB [Q6Sm(H2O)5(SO4)][Sm(H2O)5(SO4)2](H2O)17 [50] CCDC - (Q6)2[Na4(H2O)16]Cl4(H2O)6 257203 [50] CCDC - [(Q6)Na2(H2O)2][Cu(I2sal)(Hqs)](H2O)6.5 257204 where I2 sal = 3, 5-diiodosalicylate; Hqs = 8- hydroxyquinoline-5-sulfonate [50] CCDC - [(Q6)Na2(H2O)2][Cu(Ibz)(Hqs)Cl](H2O)5.5 227936 where Ibz = 3-iodobenzoate

In the compound Q6[Rb2(P-OH)2(P-CH3OH)2(H2O)2](H2O)17 (Refcode = MAPWUV) each portal is bound to a cluster consisting of two Rb atoms that are linked by two bridging hydroxides and two methanol groups that point into the Q6s’ cavities. Each Rb atom is additionally bound to a water molecule. The Rb atoms, bridging hydroxides and water ligands are disordered over three sites, whereas the methanol ligands are not. The arrangement of the columns leads to the formation of hexagonal shaped channels filled by solvent water, which was located during the structure solution and refinement Chapter 3: Crystal Structure Analysis of Literature Structures. Page 77

and is well defined. Neighbouring columns are offset from each other by half a unit cell so that the high symmetry structure can pack more efficiently (space group = P63/mmc). In this way the Q6 molecules of one column lie beside the Rb-OH clusters of the next. This is shown in fig. 3.27.

90Þ

Fig. 3.27: Hexagonal channels feature in the crystal structure of MAPWUV and the columns are offset from each other as shown in the detail at right.

The columns of six other compounds, THF@Q6[K2(P-OH)2](H2O)18 (Refcode =

XAGXEI), Q6[Ca(H2O)3(HSO4)(CH3OH)]2(HSO4)2(H2O)4 (Refcode = UCALEP),

Q6[Zr4(OH)8(H2O)16]Cl8(H2O)16 (Refcode = IBAZER),

Q6[Hf4(OH)8(H2O)16]Cl8(H2O)16 (Refcode = IBAZIV), Q6[Th(H2O)5Cl]2Cl6(H2O)13

(Refcode = IWUVOL) and (Q6)2[Na4(H2O)16]Cl4(H2O)6 (Refcode = CCDC-257203) adopt a close packing arrangement instead of the hexagonal array of columns seen in MAPWUV, but these structures still feature the offset columns.

The structure of Q6[Sr4(H2O)12(NO3)4](NO3)4(H2O)3 (Refcode = IMOBOB) differs from the structures discussed so far as its columns are not straight but rather feature Q6s in a staggered formation, as pictured in fig. 3.28(b). Each Q6 has two + [Sr4(H2O)12(NO3)4] cations bound to each portal and these are connected to the next pair of cations (rather than directly to the Q6 portal oxygens) via shared water ligands i.e. there are four Sr atoms separating every two Q6s. The columns of the one layer lie parallel and without being offset from one another unlike the columns in MAPWUV. This is unnecessary in IMOBOB as the columns are themselves staggered and are Chapter 3: Crystal Structure Analysis of Literature Structures. Page 78

therefore able to lie side by side with minimal repulsions. As seen in the stereo view in fig. 3.28(a) the columns of neighbouring layers lie at an angle to each other.

(a)

Layer 1 Layer 2

Fig. 3.28: (a) A stereo view of the crystal packing of IMOBOB showing the differences between layers of columns; (b) a view of a single column showing the coordination of four Sr atoms per Q molecule. (b)

(b) Chapter 3: Crystal Structure Analysis of Literature Structures. Page 79

x y

z z

(a) (b)

Fig. 3.29: (a) A view of the xz plane of IMOBUH and (b) a view of the yz plane of IMOBUH. Hydrogens and solvent water omitted for clarity.

The structure of Q8[Sr2(H2O)12][Sr(H2O)3(NO3)2]2(NO3)4(H2O)8 (Refcode = IMOBUH) is similar, but not identical, to IMOBOB in both molecular structure and crystal packing. Here, again, there are two Sr atoms coordinated to each Q8 portal and each of these pairs is linked by water ligands to the next pair. All the Q8 molecules of the one column are staggered and all the columns lying in one layer, that parallel to the xz plane, lie parallel to each other and run along the z axis (fig. 3.29(a)). There are some portal-to-side interactions with O…H distances of 2.4-2.6 Å between columns in adjacent layers (columns related by c-glide planes at y = 1/4, 3/4). The structure of the compound [Q6Sm(H2O)5(SO4)][Sm(H2O)5(SO4)2](H2O)17 ((Refcode = IWUVEB) also features these columns of staggered Qs.

In all the previous examples of 1D coordination polymers the Qns of the one column are parallel. In the columns of the structures of

[(Q6)Na2(H2O)2][Cu(I2sal)(Hqs)](H2O)6.5 (Refcode = CCDC-257204) and

[(Q6)Na2(H2O)2][Cu(Ibz)(Hqs)Cl](H2O)5.5 (Refcode = CCDC-227936) this is not the case. Figure 3.30 shows how the Q6s of the columns in the structure of

[(Q6)Na2(H2O)2][Cu(Ibz)(Hqs)Cl](H2O)5.5 are not parallel. Furthermore, the two Chapter 3: Crystal Structure Analysis of Literature Structures. Page 80

columns pictured are not identical but are the inverse of one another. The structure of the compound [(Q6)Na2(H2O)2][Cu(I2sal)(Hqs)](H2O)6.5 does not contain this last feature i.e. only one type of column exists.

Fig. 3.30: Two of the 1D coordination polymers of [(Q6)Na2(H2O)2][Cu(Ibz)(Hqs)Cl](H2O)5.5. Hydrogens have been omitted for clarity.

3.6: Metal Cations Coordinated to Qns.

3.6.1: Introduction. This class of structures features a metal cation coordinated to the oxygens lining the portals of the Qn molecule. In addition the metals, mainly alkali metals and lanthanides with a high affinity for oxygen, have multiple water ligands and are occasionally coordinated to groups such as chlorides, nitrates and sulfates. The coordination number of the metals range from 5 (e.g Na) to 10 (e.g Cs). In the main there is normally one such metal complex bound to each portal but there is one example in this class where two metal complexes are bound to one portal and several examples of a metal complex bound to two Qns at once. The metal cation is rarely centred over the portal but rather coordinates to two or three portal oxygens and so covers only a portion of the cavity entrance. There is some variation in the extent to which the cavity is covered in this class of structures and as a result, portal-to-side interactions are possible and occur Chapter 3: Crystal Structure Analysis of Literature Structures. Page 81

frequently. However, as will be shown in the following examples, this pattern of crystal packing is readily disrupted in favour of hydrogen bonding to water ligands. As there are similarities between the molecular structures of the Qn-metal complexes of this class and the Qn-cluster complexes of the metal chalcogenide class, a comparison of their crystal packing motifs will also be made. In table 3.5 the compounds in this class are listed.

Table 3.5: Compounds featuring a metal cation bound to the Qn portal. REFCODE COMPOUND Reference [51] NEXRAJ THF@Q6[CsCl(H2O)2](H2O)5 [52] IPASOH Q8[Q8BiNO3(H2O)5][Bi(NO3)3(H2O)4]2[Bi(NO3)5]2 (H2O)19 [53] HUGQAB Q6[La(H2O)6SO4]NO3(H2O)12 [54] XIVXEA Q6[K(CH2CH2PtCl3)]2(H2O)2 [53] HUGQEF (Q6)3[Gd(H2O)4]2Br6(H2O)45 [55] LACPEL (Q6)3[Sm(H2O)4]2Br6(H2O)44 [53] HUGQIJ (Q6)3[Ce(H2O)5]2Br6(H2O)26 [53] HUGPII Q6[Gd(H2O)4NO3](NO3)2(H2O)7 [53] HUGPOO Q6[Gd(H2O)3NO3(C2H5OH)](NO3)2(H2O)5.5 [53] HUGPUU Q6[Yb(H2O)4NO3](NO3)2(H2O)6 [51] NEXQUC (H2O)@Q6[Cs2(H2O)6]Cl2(H2O)2 [56] NALLIV [(H2O)3@Q6][Na4(H2O)10](SO4)2(H2O)10 [56] NALLOB [THF@Q6][Na4(H2O)10](SO4)2(H2O)10 [48] IWUVIF Q6[Sm(H2O)5(NO3)]2(NO3)4(H2O)6.5 Chapter 3: Crystal Structure Analysis of Literature Structures. Page 82

3.6.2: Structures containing portal-to-side interactions.

Fig. 3.31: A layer of the structure NEXRAJ is shown here and a view of the portal-to-side interactions is shown on the right. The pink lines represent Cl…C, N < 3.2 Å and the blue lines represent O…C, N < 3.3 Å. Hydrogens have been omitted for clarity.

In the first example presented here, THF@Q6[CsCl(H2O)2](H2O)5, (Refcode = NEXRAJ), only one portal of each Q6 is coordinated to a metal cation and hence it is possible for the Q6s to engage in portal-to-side interactions as shown in fig. 3.31. The resulting portal-to-side interaction involves considerable coverage of the portal with O…H distances of 2.3 Å and Cl…O distances of 2.8 Å. Even though the Cs atom is coordinated to all six oxygens and lies centred over the portal there are interactions … between the [CsCl(H2O)2] species and a nearby Q6 (Cl C, N < 3.2 Å, pink lines in fig. 3.31) therefore extending the interaction to both sides of the Q6 and allowing the herringbone pattern to form. Although there is the possibility of parallel columns of Q6s forming (see § 3.2.1) driven by the hydrogen bonding between the waters of [CsCl(H2O)2] and the portal oxygens of another Q6, this does not occur. The Cl ligand may be repelling the oxygen ringed portal of nearby Q6s and hence the herringbone pattern forms. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 83

90º

Fig. 3.32: A single layer of the compound IPASOH is shown here along with a stereo view of the portal-to-side interaction (one Q8 is coloured blue). All hydrogens, solvent and non- coordinated species are omitted for clarity.

In the compound Q8[Q8BiNO3(H2O)5][Bi(NO3)3(H2O)4]2[Bi(NO3)5]2(H2O)19 (Refcode = IPASOH), there are two types of Q8 molecules, one with a Bi atom coordinated to each portal and the other remaining unbound. The Bi atom is additionally coordinated to four waters as well as a nitrate group pointing up and outwards, away from the Q8. As in the previous example (NEXRAJ) portal-to-side interactions are able to occur and are pictured in fig. 3.32. The inset shows a stereo view of the degree of overlap in the interaction. In addition to the Bi-O coordination bonds within the complex, there are also hydrogen bonds between water ligands and the portal oxygens: O…O distances = 2.6 Å. The 2– [Bi(NO3)3(H2O)4] and [Bi(NO3)5] species lie between the layers of coordinated Q6s. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 84

Fig. 3.33: A layer of the compound HUGQAB and inset a view of the portal-to-side interaction. The blue line indicates hydrogen bonding and the pink lines represent other H…O contacts < 2.4 Å.

The Q6 in the compound {Q6[La(H2O)6SO4]}NO3(H2O)12 (Refcode = HUGQAB) has only one of its portals coordinated to a metal cation. Although not shown in fig. 3.33, the bulky sulfate group protrudes outwards and away from the Q6 thus allowing the + portal-to-side interaction to occur in this structure. However, as the [La(H2O)6SO4] cation covers a large part of the portal, only the uncoordinated portal is involved in this interaction. The interaction features one Q6 lying side-on and centred over another Q6’s portal. The first Q6 is tilted so that the water ligands of the coordinated cation engage in hydrogen bonding with the portal oxygens of the second Q6, with O…O distances of 2.8 Å (see inset of fig. 3.33). Between the Q6s there are H…O distances of 2.2 and 2.3 Å. The coordinated sulfate does not contribute to this interaction.

+ – + The structure Q6[K (CH2CH2PtCl3) ]2(H2O)2 (Refcode = XIVXEA) has a K(H2O) cation located over each portal but they are off-centred so that much of the portal opening is free to engage in portal-to-side interactions: C-H…O = 2.3 Å. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 85

3.6.3: Short stacks of linked Qns. These crystal structures are similar to those presented in § 3.5 insofar as they involve the linking of one Qn to another by a bridging metal cation. They differ in that they feature a finite number of Qns bound together rather than an infinite 1D coordination polymer.

(b)

(a) Fig. 3.34: (a) The packing of the structure HUGQEF and (b) two views of the portal-to-side interaction.

The Qn-metal complex in the structure {(Q6)3[Gd(H2O)4]2}Br6(H2O)45 (Refcode = HUGQEF) is unusual in that it involves two cations bound to three Q6s, a structural feature labelled as a ‘three-deck sandwich’ by Samsonenko et al.[53]. These complexes are still able to engage in portal-to-side interactions as seen in fig. 3.34(b) with C-H…O 3+ distances of 2.2 and 2.3 Å. The [Gd(H2O)4] cation is not involved in this interaction which differs from the next example, {(Q6)2[Ce(H2O)5]2}Br6(H2O)26 (Refcode = 3+ HUGQIJ), also featuring a connecting metal cation. Here two [Ce(H2O)5] cations coordinate to the portals of two Q6s i.e. each portal is bound to the same two metal cations. This is illustrated in fig. 3.35(a). Portal-to-side interactions are formed when these complexes lie perpendicular to one another (as in HUGQEF) and these interactions involve the metal complexes as much as they do the Q6 molecules. The complexes are oriented in such a way that the two cations lie centred over the unbound portal of a nearby complex and so hydrogen bonding occurs between the water ligands of one complex and the portal oxygens of the other (fig. 3.35(b)). The C-H…O Chapter 3: Crystal Structure Analysis of Literature Structures. Page 86

distances between the three Q6s is 2.3 Å despite there being minimal coverage of the portal of one Q6 by the other two Q6s. The structure LACPEL is isostructural with HUGQEF.

90Þ

(a) (b) Fig. 3.35: (a) Two of the Q6-Ce complexes in HUGQIJ and (b) an end on view of the portal-to-side interaction showing the degree of overlap of one Q6 portal (in pink) by a neighbouring complex.

3.6.4: Columns of parallel Qns.

The structures {Q6[Gd(H2O)4NO3]}(NO3)2(H2O)7 (Refcode = HUGPII),

{Q6[Gd(H2O)3NO3(C2H5OH)]}(NO3)2(H2O)5.5 (Refcode = HUGPOO) and

{Q6[Yb(H2O)4NO3]}(NO3)2(H2O)6 (Refcode = HUGPUU), all isostructural and isomorphous, each only have one portal bound to a cation leaving the other free to engage in portal-to-side interactions. However, in place of this motif the packing features parallel Q6s stacked in columns so that the water ligands of one Q6-metal complex can hydrogen bond with the oxygens of the free portal of the next Q6, reminiscent of the metal chalcogenide structures described in § 3.2.1. This type of interaction is probably the most stabilising in this class of structures, as it involves hydrogen bonding, but it does not occur in the three structures described in § 3.6.2. The reason that the Q6-metal complexes can stack end to end in the three structures HUGPII, HUGPOO and HUGPUU is that the nitro and ethanol ligands point out to the sides instead of upwards and towards any neighbouring Q6 portal. Therefore repulsions between complexes are less significant in HUGPII, HUGPOO and HUGPUU than in NEXRAJ, IPASOH and HUGQAB. All Qn-Qn interactions are sacrificed in order to achieve the favourable parallel stacking of the Qn-metal complexes. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 87

3.6.5: Other packing motifs.

The structures [(H2O)3@Q6][Na4(H2O)10](SO4)2(H2O)10 (Refcode = NALLIV) and

[THF@Q6][Na4(H2O)10](SO4)2(H2O)10 (Refcode = NALLOB), which are isostructural, and (H2O)@Q6[Cs2(H2O)6]Cl2(H2O)2 (Refcode = NEXQUC) feature either two cations or a very large cation over both Q6 portals making portal-to-side interactions and parallel Q6 stacks impossible. The structure of the compound

Q6[Sm(H2O)5(NO3)]2(NO3)4(H2O)6.5 (Refcode = IWUVIF) also features a large cation over each portal disrupting the portal-to-side interaction. However, each Sm atom is coordinated to a nitrate ligand and the Q6s are oriented in this structure to interact with the nitrate ligands of neighbouring complexes. The O…C, N distances are in the range of 3 – 4.5 Å.

3.6.6: Concluding remarks. Just as in the metal chalcogenide complexes (§ 3.2), these Qn-metal complexes feature either one or both Qn portals ‘capped’ by a compound that can hinder the ability of the Qn to engage in portal-to-side interactions. In the Qn-metal complexes, however, the capping compound is not always centred over the portal or large enough to cover the entire portal, and so the disruption to the herringbone pattern is not always complete. In the example of NEXRAJ it is able to exist albeit with the involvement of the Cs water ligands. Therefore the general packing rules of this class of structures appear to follow those governing the metal chalcogenide structures as well as the uncoordinated metal-ligand complex structures (§ 3.4): the portal-to-side interaction exists only if the more favourable hydrogen bonding between water ligands and free portal oxygens cannot exist. In general, it is the herringbone pattern versus the columns of parallel Qn molecules. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 88

3.7: Polyrotaxanes and Molecular Necklaces.

3.7.1: Introduction. + + As mentioned in chapter 2, the n-diaminoalkane carbon chain ( NH3(CH2)nNH3 ) is optimal for insertion into the Qn cavity as it is not a bulky molecule and allows for ion- dipole attractions and hydrogen bonding to occur between the amino groups and the portal oxygens. In this class of structures the 1,4-diaminobutane and 1,5- diaminopentane chains are linked to enable multiple Qns to be threaded onto the one long chained molecule, much like beads threaded onto a string. Thus a pseudorotaxane is formed. Unlike a traditional rotaxane these do not require bulky terminal groups to prevent the loss of the threaded molecules or ‘beads’. When the ends of one ‘string’ are joined, a ‘molecular necklace’, or MN, is formed. When the ends of the ‘string’ are not linked but rather extend as 1D polymers a polyrotaxane is formed. The terminology used to name MNs, [n]MN, reveals the number of Qn molecules on a necklace: n = number of Qn molecules + 1, as the necklace itself is included in the count. Diagrams of the various ‘string’ units found in the crystal structures described here are shown in fig. 3.36. A polyrotaxane or molecular necklace is constructed when individual pseudorotaxanes are connected together with a metal atom. There are no examples of mixtures of different string units or different metal atoms within a single polyrotaxane or molecular necklace in the literature. The shape of the strings will sometimes affect the shape of the final polyrotaxane or molecular necklace and therefore the arrangement of the Qn molecules relative to each other in the crystal structure. In all cases the herringbone pattern is impossible but there are still numerous portal-to-side interactions and it may be speculated that these drive the orientations that the pseudorotaxanes adopt. In table 3.6 the formulas of the compounds in this class of structures are listed. The table explains which string unit and metal atom connector are present and whether a polyrotaxane or molecular necklace is formed. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 89

N N N + + + NH2 NH2 NH2 N + + + H2N H2N H2N (3) + NH2 N N N + (4) N N H2N N + + N H2N H2N + H2N + + NH2 NH2 N + (5) (1)N (2) H2N

N N

+ CO – H2N + – 2 NH2 CO2 + NH2 +H N +H N 2 2 + (6) H2N (8) N (7) CO – – 2 O2C

Fig: 3.36: The various string units used to construct the polyrotaxane and molecular necklace structures.

Table 3.6: Structures featuring polyrotaxanes or molecular necklaces. COMPOUND String unit; Metal-ligand REFCODE connector; and Reference [n]MN or polyrotaxane. [57] Q6[((6)@Q6)Pt(en)]3 (6); Pt(en); [4]MN. XIGXOA (NO3)12(H2O)70 [57] [((3)@Q6)Pt(en)]4(CH3CH2OH)8 (3); Pt(en); [5]MN. XIGXIU (NO3)16(H2O)59 [58] [((4)@Q6)Pt(en)]3 (4); Pt(en); [4]MN. SEWSES (NO3)12(H2O)87 Chapter 3: Crystal Structure Analysis of Literature Structures. Page 90

[59] [((1)@2Q6)Cu(H2O)3Cu]2 (1); Cu and [Cu(H2O)3]; JUWQIB (NO3)14(H2O)76 [5]MN. [59] [((1)@2Q6)(Ni(H2O)4)2] n (1); Ni(H2O)4; JUWQOH (NO3)14 n(H2O)82 n 1D polyrotaxane. [60] [((4)@Q6)Cu(H2O)3]n (4); Cu(H2O)3; TUBVUH (NO3)4n(H2O)14n 1D polyrotaxane. [61] [((3)@Q6)(Co(H2O)4)]2n (3); Co(H2O)4; ADOFAA (NO3)8n(H2O)30n 1D polyrotaxane. [61] [((3)@Q6)(Ni(H2O)4)]2n (3); Ni(H2O)4; ADOFEE (NO3)8n(H2O)30n 1D polyrotaxane. [62] {((2)@2Q6)2[Cd(H2O)4]2 (2); Cd(H2O)4 and Cd(H2O)2; YAPNUZ double-chained 1D [Cd(H O) ]} (NO ) (H O) 2 2 n 3 14n 2 78n polyrotaxane. [63] [((2)@2Q6)(Ni(H2O)4)2]n (2); Ni(H2O)4; IGOPEZ (NO3)8n(H2O)21n 1D polyrotaxane. [63] [((2)@2Q6)(Zn(H2O)4)2]n (2); Zn(H2O)4; IGOPID (NO3)8n(H2O)20.5n 1D polyrotaxane. [61] [((4)@Q6)(Co(H2O)4)]n (4); Co(H2O)4; ADOFII (NO3)4n(H2O)13n 1D polyrotaxane. [61] [((4)@Q6)(Ni(H2O)4)]n (4); Ni(H2O)4; ADOFOO (NO3)4n(H2O)13n 1D polyrotaxane. [61] [((5)@Q6)(Cd(H2O)3(NO3))]2n (5); Cd(H2O)3(NO3); ADOFUU (NO3)7n(H2O)18n 1D polyrotaxane. [64] [((5)@Q6)Ag]n(NO3)3n(H2O)12n (5); Ag; 1D polyrotaxane. PAPQUS [65] [((4)@Q6)Ag]n (4); Ag; 1D polyrotaxane. REKHOE (CH3C6H4SO3)3n(H2O)11n [62] [(2)@2Q6]n[Co(H2O)4]2n (2); Co((H2O)4 ; YAPPAH (NO3)8n(H2O)30n 1D polyrotaxane. [61] [((3)@Q6)2nAg] (3); Ag; 2D polyrotaxane. ADOGAB (CF3SO3)5n(H2O)20n [61] [((3)@Q6)2nCu(H2O)] (3); Cu(H2O); ADOGEF (NO3)6n(H2O)23.5n 2D polyrotaxane. [65] [((4)@Q6)3Ag2]n (4); Ag; 2D polyrotaxane. REKHIY (NO3)8n(H2O)40n [66] [((3)@Q6)Cu(ox)(H2O)2]n (3); Cu(ox)(H2O)2; WOWLAV (NO3)3n(H2O)20n 2D polyrotaxane. [67] [((8)@Q6)3n(Tb(H2O)3)2n] (8); Tb(H2O)3; WIYMIA (NO3)6n(H2O)28n 2D polyrotaxane. [67] [((7)@Q6)3n(Tb2(H2O)2)2n] (7); Tb2(H2O)2; WIYMOG [((7)@Q6)]n(NO3)4n(OH)4n 3D polyrotaxane. (H2O)20n Chapter 3: Crystal Structure Analysis of Literature Structures. Page 91

3.7.2: Molecular necklaces. There are only two examples of a [4]MN structure in the literature; the first of these is found in the compound Q6[((6)@Q6)Pt(en)]3(NO3)12(H2O)70 (Refcode = XIGXOA). In fig. 3.37 a single [4]MN is shown along with the interactions of the MNs with each other and with the free Q6 molecules in the structure. The [4]MNs stack on top of one another while the free Q6 molecules lie over the corners of the triangular [4]MN so that there are two Pt(en) groups between a pair of free Q6s. These Pt(en) groups lie over the free Q6 portals and point towards their oxygens with C…O distances of 3.2-3.4 Å; N…O = 2.8, 3.0 Å and a Pt…O = 3.4 and 3.5 Å. In addition to this the free Q6 molecules also interact with the nearby pyridyl groups of the [4]MN with C…O distances of 3.2 Å. Because of the size and shape of the [4]MN the Q6s are forced into portal-to-side interactions although the degree of overlap is not as great as in typical interactions of this type. The shortest O…H distances are 2.5 and 2.6 Å.

The only other [4]MN is found in the compound [((4)@Q6)Pt(en)]3(NO3)12(H2O)87

(Refcode = SEWSES) which crystallises in the space group P63/m. Here the action of the screw axes results in the arrangement of the [4]MNs seen in fig. 3.38. When viewed down the z-axis this arrangement gives the appearance of a ‘spoked wheel’, with six Q6 molecules forming the spokes of the wheel although the six are not actually in the same layer.

The compound [((1)@2Q6)Cu(H2O)3Cu]2(NO3)14(H2O)76 (Refcode = JUWQIB) contains [5]MNs (see fig. 3.39(a)). The [5]MN is square shaped and two of the Cu atoms coordinate to both the phenanthroline groups and to two of the Q6 molecules’ portals. As a result of the square shape of the [5]MN, the Q6s have better portal-to-side interactions with a greater degree of overlap than in the previous example, XIGXOA. Typical distances are O…C = 3.0-3.2 Å; O…N = 2.9, 3.4 Å and O…O = 3.4 Å. These [5]MNs pack in layers with the phenanthroline groups of neighbouring [5]MNs overlapping (see fig. 3.39(b)). Typical C…C distances are 3.4, 3.5 Å. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 92

Free Q

(a) 4[MN]

Fig. 3.37: (a) The [4]MN found in XIGXOA and (b) the packing of the [4] MNs (without Q6s) and the free Q6s. (b) Hydrogens omitted for clarity.

Fig. 3.38: The packing of the [4]MNs in SEWSES results in the formation of‘spoked wheels’. Only two of the MN chains are shown, coloured in pink and yellow. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 93

90º

(a)

Fig. 3.39: (a) The [5]MN in the compound JUWQIB. Q6s are in pink for clarity; (b) the overlapping phenanthroline groups of different MNs, C…C distances are 3.4, 3.5 Å (b)

3.7.3: 1D polyrotaxanes. The most common type of polyrotaxane, the 1D polyrotaxane, can adopt four basic shapes: the zig-zag wave, the square wave, a helical chain and a linear chain and with one exception they are all infinite chains.

This one exception is found in the compound [((1)@2Q6)(Ni(H2O)4)2](NO3)14(H2O)82 (Refcode = JUWQOH). The crystal packing of this structure is remarkably similar to JUWQIB and as in that structure there are overlapping phenanthroline groups with C…C = 3.3-3.5 Å.

3.7.3.1: The zig-zag wave.

In the compound [((4)@Q6)Cu(H2O)3]n(NO3)4n(H2O)14n (Refcode = TUBVUH) the coordination of two (4) string units at the cis position of the Cu(H2O)3 group brings about a zig-zag shaped polyrotaxane that allows the favourable portal-to-side interaction to occur. The zig-zag shaped polyrotaxanes are aligned with one another so that their pyridyl rings engage in offset face-to-face interactions. Distances between the carbon atoms of these pyridyl rings are 3.6-3.9 Å. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 94

While there are no portal-to-side interactions between the Q6s of different polyrotaxanes there are between Q6s of the same polyrotaxanes with fair coverage of … 2+ the portal. There are methylene/methine C O distances of 3.2-3.4 Å. The Cu(H2O)3 group of one polyrotaxane lies over the rim of a Q6 portal of an adjacent polyrotaxane with O…O = 2.8 and 2.9 Å. All these interactions can be seen in fig. 3.40.

Fig. 3.40: Two of the zig-zag waves found in TUBVUH. All hydrogens have been omitted for clarity.

The structures of ADOFAA and ADOFEE, which are isostructural, also feature zig-zag shaped 1D polyrotaxanes. To complete this section, the structure of the compound (Refcode = YAPNUZ) is described. This 1D polyrotaxane, pictured in fig. 3.41, features a double chain, connected by a Cd(H2O)2 group. The phenanthroline groups of neighbouring chains overlap one another, reminiscent of the interactions between the molecular necklaces of JUWQIB and the 1D polyrotaxane of JUWQOH. Just as in JUWQOH the C…C distances between the overlapping phenanthroline groups in the structure YAPNUZ are 3.3 and 3.5 Å. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 95

Fig. 3.41: The double chained 1D polyrotaxane featured in YAPNUZ. Two chains are shown here (one is coloured pink) to emphasise the overlap of neighbouring chains.

3.7.3.2: The square wave. The square shaped 1D polyrotaxanes in the structure of

[((2)@2Q6)(Ni(H2O)4)2]n(NO3)8n(H2O)21n (Refcode = IGOPEZ) also feature overlapping groups between adjacent polyrotaxanes. These are shown in fig. 3.42(b). The shape of the polyrotaxanes (see fig. 3.42(a)) precludes any portal coverage and Q6- Q6 interactions are limited to C…C distances of 3.5 Å or greater. The extensive degree of overlap between the phenanthroline groups of neighbouring polyrotaxanes results in C…C distances of between 3.3-3.6 Å, while the pyridyl groups do not have any C…C < 4 Å. 2+ The Ni(H2O)4 group of one polyrotaxane lies over the rim of a Q6 portal of an adjacent polyrotaxane with O …O = 2.7 and 2.8 Å. H2O portal Chapter 3: Crystal Structure Analysis of Literature Structures. Page 96

(a)

Fig. 3.42: (a) The square shaped 1D polyrotaxane in IGOPEZ, Qs are in pink for clarity; (b) shown below are sections of two overlapping polyrotaxanes (one coloured pink); distances between chains are listed in the text.

(b)

The structure IGOPID, which is isostructural to IGOPEZ, and the structures of ADOFII and ADOFOO, isostructural to one another, all possess square shaped 1D polyrotaxanes in their structures.

3.7.3.3: The helical chain. Figure 3.43 shows two views of the helical chain found in the compound

[((5)@Q6)(Cd(H2O)3(NO3))]2n(NO3)7n(H2O)18n (Refcode = ADOFUU). The oval shaped cross-section of the chain can be seen when it is viewed end on (top part of fig. 3.43). Chapter 3: Crystal Structure Analysis of Literature Structures. Page 97

90Þ

Fig. 3.43: The helical shaped polyrotaxane of the structure ADOFUU. The Q6 molecules are coloured pink and the hydrogens are omitted for clarity.

The Q6 molecules on the one polyrotaxane do not engage in portal-to-side interactions because they are too far apart and similarly neither do the Q6 molecules of adjacent polyrotaxanes. The structure PAPQUS also features a helical 1D polyrotaxane and the shape of this helix does allow for Q6-Q6 interactions of between 3.0 and 4.0 Å.

3.7.3.4: The linear chain.

The compound [((4)@Q6)Ag]n(CH3C6H4SO3)3n(H2O)11n (Refcode = REKHOE) is the only structure in the CSD with a linear 1D polyrotaxane. Although this polyrotaxane is not perfectly straight it does not possess a clear and obvious shape as the other 1D polyrotaxanes described so far. As these chains do not have sharp bends, as the zig-zag chains do, the Q6 molecules of the one chain cannot interact with one another. Adjacent polyrotaxanes are positioned so that the Q6 molecules of different polyrotaxanes can interact, with C…C distances = 3.4 Å; C…N = 3.6, 3.7 Å and C…O = 3.2 and 3.6 Å. This positioning also results in the overlap of some of the pyridyl groups with C…C = 3.9 Å and interactions between a Q6 molecule and a neighbouring chain with C…C = 3.5 Å; C…N = 3.3, 3.4, 3.6 Å; N…N = 3.5 Å and a silver atom in close proximity to a portal oxygen: Ag…O = 2.8 Å. In addition, six p-toluenesulfonate anions crystallise with their rings parallel and almost face-to-face to six of the 5-memebered rings of each Q6 molecule, with distances of Chapter 3: Crystal Structure Analysis of Literature Structures. Page 98

C…C = 3.4, 3.5 Å; C…N = 3.6, 3.7 Å and C…O = 3.4 Å. Another two p- toluenesulfonate anions point their -SO3 groups directly over two 5-membered rings resulting in O…N = 3.1, 3.4, 3.6 Å; O…O = 3.1, 3.5 Å and O…C = 2.9, 3.1, 3.3-3.6 Å. As well as interacting with Q6 molecules some of these anions also lie parallel to the polyrotaxane pyridyl groups with C…C = 3.3, 3.5 Å and C…N = 3.4, 3.6 Å. The packing of this structure and the interactions described above are shown in fig. 3.44.

(a) (b)

Parallel Q and benzyl rings

Parallel pyridyl rings

Fig. 3.44: (a) The crystal packing of the structure REKHOE is shown with two of the interactions – described in the text highlighted; (b) six of the (CH3C6H4SO3) anions surrounding each Q6 lie with their benzyl rings parallel to a 5-membered ring while two point their –SO3 groups towards the Q6. Q6s are coloured pink and benzylsulfanate groups are in blue.

3.7.3.5: Concluding remarks. It is clear that as there is only one example of a linear polyrotaxane in the literature all the other shapes are preferred for polyrotaxanes. Zig-zag, square and helical shaped polyrotaxanes can allow portal-to-side interactions between the Qns of the one polyrotaxane and there can also be interactions between Qns of different chains. In fact, the only example of a linear polyrotaxane, REKHOE, is unable to adopt any geometry other than a linear form as it involves Ag bound to a pyridyl ring with its methylene carbon attached at the 4-position. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 99

The geometry at the metal connector can alter the shape of the polyrotaxane. For example, the structures of TUBVUH and ADOFII feature the same string units but

TUBVUH has a trigonal bipyramidal geometry about the Cu(H2O)3 connector while

ADOFII has octahedral geometry about its connecting Co(H2O)4 group. The result is that TUBVUH has a zig-zag shaped polyrotaxane while ADOFII has a square shaped one. The geometry about the connecting metal atom normally involves the coordination of the string unit at the cis position, despite the inherent steric hindrance, possibly so that a non-linear geometry can be adopted and so that portal-to-side interactions may occur.

In general, it appears that where possible the 1D polyrotaxane that enables the best portal-to-side (or any Qn-Qn) interactions to occur is formed.

3.7.4: 2D polyrotaxanes. A 2D polyrotaxane has more than two string units connected to each metal atom and extends out into two dimensions. There are five structures in the literature which have 2D polyrotaxanes, two featuring a square grid and the other three hexagonal grids.

The compound [((3)@Q6)2nAg](CF3SO3)5n(H2O)20n (Refcode = ADOGAB) contains the square grid shown in fig. 3.45. It forms square shaped cavities in which the anions sit and because of this shape the Q6 molecules are actually able to engage in good portal-to-side interactions with O…H = 2.5, 2.9 Å. Each layer of this structure contains just one 2D polyrotaxane and neighbouring layers eclipse one another. The structure ADOGEF is isostructural with ADOGAB.

The other structures feature hexagonal grids in place of square shaped ones.

In the compound [((4)@Q6)3Ag2]n(NO3)8n(H2O)40n (Refcode = REKHIY) the hexagonal grid is formed when three string units are linked to one another by the triply bound Ag atoms. When viewed side on these hexagonal units are S-shaped, as seen in fig. 3.46. This curvature allows for the interlocking of the hexagons. There are some poor quality portal-to-side interactions between the Q6 molecules in this structure with only partial coverage of the portals despite the close proximity of the Q6s with one another due to the interlocking of the 2D polyrotaxanes. Nonetheless typical Chapter 3: Crystal Structure Analysis of Literature Structures. Page 100

distances between Q6 molecules are good with O…C = 3.0, 3.2, 3.6 Å; O…N = 3.2 Å, O…O = 3.2 Å and C…C = 3.4 Å.

Fig. 3.45: A portion of the square grid 2D polyrotaxane in ADOGAB.

Fig. 3.46: The hexagonal grid of REKHIY which due to its curvature is able to interlock with others. Only one hexagon is shown for clarity. 90Þ

The structure of WIYMIA is similar to REKHIY as they both contain interlocking 2D polyrotaxanes made up of curved hexagons. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 101

The structure of [((3)@Q6)Cu(ox)(H2O)2]n(NO3)3n(H2O)20n (Refcode = WOWLAV) differs somewhat from the previous examples. Although it does contain hexagonal units these are not directly connected to one another but rather are connected by the bridging oxalate groups bound to each Cu connector. These grids do not interlock but they overlap one another, so that channels are formed.

3.7.5: 3D polyrotaxane. The only example in the literature of a 3D polyrotaxane is featured in the structure of

[((7)@Q6)3n(Tb2(H2O)2)2n][((7)@Q6)]n(NO3)4n(OH)4n(H2O)20n (Refcode = WIYMOG). The string units of this 3D polyrotaxane are organised into a rectangular prism with the linking Tb atoms at the corners and each edge of the prism threading a Q6 ‘bead’. The prisms are connected via the Tb atoms and hence a 3D rectangular grid is formed. The Q6s are unable to engage in good portal-to-side interactions but they do have O…N distances of 3.2 Å and O…C distances of 3.1-3.5 Å.

3.8: Functionalised Cucurbiturils.

3.8.1: Introduction. Functionalised cucurbiturils have substituted groups in place of their methine hydrogens. In the literature there are structures with three types of substituent groups, although many others are possible: methyl groups[68], hydroxyl groups[69] and cyclohexane rings[70]. Work by various groups to synthesise these functionalised Qns has stemmed from the problem of cucurbituril’s insolubility in most solvents, particularly traditional organic solvents. This problem seems to have been overcome with the synthesis of the cyclohexane functionalised Q6 as it is soluble in water, methanol, DMSO and partly soluble in ethanol, DMF and acetonitrile. The hydroxyl functionalised Q6 is soluble in DMSO and partly soluble in DMF. The first step in preparing these compounds is to obtain the substituted glycoluril molecule, followed by a normal Qn synthesis. In one case, (UKUQIA), the substitution of the methine hydrogens occurs after the formation of the Q6[69]. It appears that Q5 is the more readily functionalised of all the Qns and this is because the substituted groups encounter less hindrance when attached to the smallest Qn. As there is a smaller angle Chapter 3: Crystal Structure Analysis of Literature Structures. Page 102

between glycoluril monomers in the Q5 molecule there is more room on the outer side of the molecule for larger groups. These functional groups extend outwards along the Qn molecule’s equatorial plane and because of this normal portal-to-side interactions cannot occur. Instead, most of the functionalised Qn structures feature parallel or nearly parallel Qns. There are twelve crystal structures featuring functionalised Qns in the CSD and these are listed in table 3.7.

Table 3.7: Functionalised Qn structures. COMPOUND FUNCTIONAL GROUP REFCODE and Reference [68] [HNO3@(CH3)10Q5](HNO3)2(H2O)6 CH3 LAHBAX [70] [(CH2CH2CH2CH2)5Q5](H2O)25 Cyclohexyl IDEBAU [70] [(CH2CH2CH2CH2)6Q6](H2O)18 Cyclohexyl IDEBEY [71] [(CH3)10Q5](NH2(CH2)6NH2)(H2O)11.5 CH3 XIGBIY [69] [THF@(OH)12Q6](K2SO4)2(H2O)16 OH UKUQIA [72] [(CH3)10Q5](NH4)2(Cl)2(H2O)4 CH3 LOZMOC [72] [(CH3)10Q5](H2O)13.66 CH3 LOZMUI [72] [(CH3)10Q5](CH4)0.5(H2O)13.28 CH3 LOZNAP [72] [(CH3)10Q5](O2)0.12(H2O)12.68 CH3 LOZNET [72] [(CH3)10Q5](CO2)0.76(H2O)12 CH3 LOZNIX [72] [(CH3)10Q5]Kr0.42(H2O)12.94 CH3 LOZNOD [72] [(CH3)10Q5]Xe0.52(H2O)12.68 CH3 LOZNUJ

3.8.2: The Crystal structures.

The first of the functionalised cucurbiturils to be synthesised was [HNO3@(CH3)10Q5]

(HNO3)2(H2O)6 (Refcode = LAHBAX).

The (CH3)10Q5 (decamethylQ5) molecules all lie parallel to one another in this structure in layers that eclipse each other. This is illustrated in fig. 3.47 along with a view of a single layer. The figure shows how far the (CH3)10Q5 molecules are from Chapter 3: Crystal Structure Analysis of Literature Structures. Page 103

… one another with only their –CH3 groups pointing towards one another, with one C C distance = 3.4 Å. The molecules of nitrate lie above and below the layers of (CH3)10Q5 molecules.

90Þ

Fig. 3.47: Two views of the crystal packing of

[HNO3@(CH3)10Q5](HNO3)2(H2O)6 (LAHBAX) and inset a single layer of

the (CH3)10Q5 molecules showing the substituted methyl groups pointing towards each other.

[72] Miyahara et al. measured the capacity of the (CH3)10Q5 cavity to absorb a series of small molecule gases. When these tests were performed in the aqueous state crystals of the included compounds precipitated and seven of these had their crystal structures determined. One of these, LOZMOC, is isostructural with LAHBAX while the other six (LOZMUI, LOZNAP, LOZNET, LOZNIX, LOZNOD and LOZNUJ) are isostructural with each other. The structure of [(CH3)10Q5](H2O)13.66 (Refcode = LOZMUI) is pictured in fig. 3.48. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 104

90Þ

Fig. 3.48: A layer of the structure of [(CH3)10Q5](H2O)13.66 (LOZMUI) showing the degree of overlap of the (CH3)10Q5 molecules.

A single layer of the structure LOZMUI consists of (CH3)10Q5 molecules offset from one another by half a unit cell allowing the methyl groups of one (CH3)10Q5 to lie near the portal oxygens of another. This results in C…O distances of 3.4, 3.7 Å and H…O distances of 2.5 Å. As in the previous structure, LAHBAX, all (CH3)10Q5 molecules are parallel to one another. The structure of IDEBAU is similar to that of LOZMUI.

The functionalised Qn in the compound [(CH2CH2CH2CH2)6Q6](H2O)18 (Refcode = IDEBEY) features a cyclohexane ring in place of the methine hydrogens (see fig. 3.49).

Its crystal structure is almost identical to that of LOZMUI, however the (CH3)10Q5 molecules are not exactly parallel to one another. Despite this, the portal-to-side interaction does not occur in this structure. The overlap of the portals by the substituent groups of neighbouring Qns occurs to a greater degree in this structure with C…O distances of 3.2-3.7 Å. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 105

Fig. 3.49: The functionalised Q6 in

[(CH2CH2CH2CH2)6Q6](H2O)18 (IDEBEY).

In the compound [(CH3)10Q5](NH2(CH2)6NH2)(H2O)11.5 (Refcode = XIGBIY) the

(CH3)10Q5 are too far separated for any interactions to occur. They are separated by the 1, 6-diaminohexane chains that reside on the outside of the Qs rather than passing through their cavity. Its amino groups point into the portals to give O…N = 2.8, 2.9 Å. Figure 3.50 shows one of the layers in the structure. Because of this interaction portal-to-side interactions are impossible. There is little overlap between the functionalised Q5s, unlike in the case of IDEBEY, but there are still recorded distances of 3.4-3.6 Å between portal oxygens and the substituted methyl carbons. There are also C…C distances = 3.4, 3.5 Å between these methyl carbons and the 1, 6 - diaminohexane chains.

The (CH3)10Q5 molecules in this structure are almost parallel with each other.

Fig. 3.50: A layer of the structure

[(CH3)10Q5](NH2(CH2)6NH2)(H2O)11.5 (XIGBIY). Each pair of functionalised Q5s is separated by a diaminohexane that points into the Q5 portals. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 106

90Þ

Fig. 3.51: The zig-zag layer featured in [THF@(OH)12Q6](K2SO4)2(H2O)16 (UKUQIA). Hydrogens and potassium cations omitted for clarity.

The compound [THF@(OH)12Q6](K2SO4)2(H2O)16 (Refcode = UKUQIA) is different to all the others as it contains the (OH)12Q6 molecules in zig-zag chains as illustrated in fig. 3.51. There are two potassium cations coordinated to each Q6 portal, interrupting any typical portal-to-side interactions. Some of the –OH substituent groups of the Q6 … engage in hydrogen bonding with the sulfate anions with HO Osulfate distances = 2.6 Å. … Between the (OH)12Q6 molecules there are HO O distances of 2.8, 3.5 and 3.6 Å; HO…OH = 3.4 Å; HO…C = 3.2, 3.3 Å and C…O = 3.2 Å.

3.8.3: Concluding remarks. The functionalisation of the Qn molecule at the methine position inhibits the formation of any portal-to-side interactions and there are no examples of a herringbone pattern in this class of structures. The main type of interaction here involves parallel (or nearly parallel) Qns overlapping one another so that the substituent groups of one functionalised Qn may lie over the portals of another. The only example where there is significant deviation from this occurs where the substituting group, a hydroxyl, is one that can readily engage in hydrogen bonding with the portal oxygens (UKUQIA). Yet because of the coordination of potassium cations to the (OH)12Q6 portals there are minimal interactions of this type. This allows the hydroxyl groups to hydrogen bond with each other, the sulfate anions and other atoms of the (OH)12Q6 molecule. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 107

So, in addition to the coordination of a Qn portal by a metal or metal cluster, the substitution of the methine hydrogens for bulkier groups can also disrupt the portal-to- side interaction and the traditional herringbone array.

3.9: Q5@Q10.

In the ordinary synthesis of the cucurbituril molecule, a range of different sized Qns are formed in the reaction mixture and it is possible for a larger sized Qn to incorporate a smaller sized Qn. The only example of this found in the literature is the compound

[(Cl@Q5)@Q10](HCl)11(H2O)25.75 (Refcode = IDEWEX), formed when a Q5 moves into the cavity of the larger, oval shaped Q10. NMR studies have shown that the Q5 is able to rotate and precess freely inside the Q10 and also to leave and enter the Q10 although the rate of exchange is slow on the NMR scale. In the crystalline state, however, the Q5 is static, lying at an angle of 64q to the Q10 axis, with distances between the C, N and O atoms of the Q5 and the Q10 starting from 3.4 Å. Two views of this molecule are shown in fig. 3.52(a). Each Q5 has a water molecule at each portal opening with O…O = 2.6-2.9 Å. Additionally there is a chloride/HCl at the centre of each Q5 cavity.

Overlapping Q5 rings

(b) (a)

Fig. 3.52: (a) A single molecule of Q5@Q10 and (b) a view of the packing of this structure. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 108

All of the Q5@Q10 complexes lie parallel in the crystal packing, as shown in fig. 3.52(b). They are arranged so that pairs of Q5@Q10 lie with the five membered rings of their Q5 molecules overlapping. Distances between these rings are: C…C = 3.5 Å, C…N = 3.7 Å, O…C = 3.6 Å and N…N = 3.7 Å. There is a multitude of chlorides surrounding the Q5@Q10 molecule, congregating in particular about the electropositive equatorial plane of the Q10. Each Cl anion lies centred over either one of the glycoluril rings or one of the eight membered rings, although not all of the Q10 rings are covered in this way. Most Cl…C and Cl…N distances fall within the range of 3.3 – 3.7 Å and Cl…H § 2.9 Å. Similar interactions do not occur with the exposed portions of the Q5 ring. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 109

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48. Samsonenko, D. G., Sokolov, M. N., Geras'ko, O. A., Virovets, A. V., Lipkowski, J., Fenske, D., and Fedin, V. P., Russ. Chem. Bull., Int. Ed., 2003, 52(10), 2132. 49. Gerasko, O. A., Virovets, A. V., Samsonenko, D. G., Tripol'skaya, A. A., Fedin, V. P., and Fenske, D., Russ. Chem. Bull. Int. Ed.,, 2003, 52(3), 585. 50. Zheng, F., Yajima, T., Li, Y.-Z., Xu, G.-Z., Chen, H.-L., Liu, Q.-T., and Yamauchi, O., Angew. Chem. Int. Ed., 2005, 44, 3402. 51. Whang, D., Heo, J., Park, J. H., and Kim, K., Angew. Chem. Int. Ed., 1998, 37(1), 78. 52. Sokolov, M. N., Mit'kina, T. V., Geras'ko, O. A., Fedin, V. P., Virovets, A. V., and Llusar, R., Z. Anorg. Allg. Chem., 2003, 629, 2440. 53. Samsonenko, D. G., Lipkowski, J., Gerasko, O. A., Virovets, A. V., Sokolov, M. N., Fedin, V. P., Platas, J. G., Hernandez-Molina, R., and Mederos, A., Eur. J. Inorg. Chem., 2002(9), 2380. 54. Zhang, Y. and Coppens, P., Private Communication to CSD, 2002. 55. Samsonenko, D. G., Gerasko, O. A., Lipkowski, J., Virovets, A. V., and Fedin, V. P., Russ. Chem. Bull. Int. Ed., 2002, 51(10), 1915. 56. Jeon, Y.-M., Kim, J., Whang, D., and Kim, K., J. Am. Chem. Soc., 1996, 118(40), 9790. 57. Park, K.-M., Kim, S.-Y., Heo, J., Whang, D., Sakamoto, S., Yamaguchi, K., and Kim, K., J. Am. Chem. Soc., 2002, 124(10), 2140. 58. Whang, D., Park, K.-M., Heo, J., Ashton, P., and Kim, K., J. Am. Chem. Soc., 1998, 120(19), 4899. 59. Roh, S.-G., Park, K.-M., Park, G.-J., Sakamoto, S., Yamaguchi, K., and Kim, K., Angew. Chem. Int. Ed., 1999, 38(5), 638. 60. Whang, D., Jeon, Y.-M., Heo, J., and Kim, K., J. Am. Chem. Soc., 1996, 118(45), 11333. 61. Park, K.-M., Whang, D., Lee, E., Heo, J., and Kim, K., Chem. Eur. J., 2002, 8(2), 498. 62. Park, K.-M., Lee, E., Roh, S.-G., Kim, J., and Kim, K., Bull. Korean Chem. Soc., 2004, 25(11), 1711. 63. Park, K.-M., Roh, S.-G., Lee, E., Kim, J., Kim, H.-J., Lee, J. W., and Kim, K., Supramol. Chem., 2002, 14(2-3), 153. Chapter 3: Crystal Structure Analysis of Literature Structures. Page 113

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CHAPTER 4 EXPERIMENTAL WORK.

4.1: Introduction.

In this chapter the experiments attempted in the course of this project are outlined. Many experiments listed here were devised as initial trials, conducted to see if promising results might eventuate. In this way, a broad range of experiments was conducted relatively simply and quickly, although in some cases it was many months before any change was recorded. Some of these trial experiments were further developed but some results were not deemed positive (insofar as no crystal structure was obtained). As these results helped to develop an understanding of the characteristics of the Qn molecule they are still mentioned in this chapter as important observations and to emphasise the general principles of Qn chemistry. Where possible, some rationale is offered as to why the experiments did not succeed. This unconventional approach to experimental work is reflected in the layout of this chapter. Much of this chapter describes the trial experiments and the results obtained. Often there is no characterisation other than single crystal x-ray diffraction of the products for the reasons outlined below. In § 4.5 the experiments involving classes of similar anions or cations are loosely grouped together.

A key goal in this work was the synthesis of a host-guest complex with a Qn as the host and a metal containing species as the guest. The preparation of x-ray quality crystals and the determination of their structures is the ideal method of characterising any such compounds as it can conclusively show whether inclusion has occurred. Although other characterisation techniques (IR in particular) can be used to confirm the presence of a Qn in a solid sample, they can not be used to determine if that sample contains an inclusion compound. The NMR of solutions, on the other hand, would be useful in this regard and other workers have used this technique successfully for this purpose, examples of which appear in chapter 2. Chapter 4: Experimental Work. Page 116

There were some limitations to the use of NMR in this work and the foremost was the issue of solubility. As discussed in chapter 2, Qns are not soluble in the traditional solvents used for NMR but solutions of Qn can be obtained in other solvent systems such as HCl and NaCl(aq). These solutions were used for NMR measurements despite line broadening effects due to the high concentration of ions. The NMR spectrum was measured for the relevant metal nucleus (that of the metal in the guest) and peaks assigned due to the species existing inside and outside the Qn cavity. Other atoms in the guest would have been suitable for the identification of a host-guest complex e.g. C or N, however the metal was used rather than any atoms in the ligand because the peaks due to the metals were likely to be uncomplicated and easy to assign - one peak for the guest inside the cavity and one for the guest outside. This leads on to the second problem with the use of NMR in this work: not all metals are suitable for NMR. However there are many that can be used and in this work, the 119Sn nucleus was used most successfully. An extensive description of this work appears in § 4.5.5. Finally, the issue of comparing the spectrum obtained with those in the literature was found to be a significant hurdle. This involved trying to deduce the identity of the guest and then finding examples of NMR spectra conducted on this species under the same conditions (both solvents and concentrations) in order to obtain the ppm range in which a peak due to the guest may appear. In the course of this project this procedure was performed on the Q7 + SnCl4 system under aqueous conditions and this experiment is explained in detail in § 4.5.5. However, due to the formation of an insoluble product, NMR could not provide an indication that a host-guest complex had formed. The insolubility of many products was the major reason why NMR was not used as an identification tool in this project.

Therefore, as crystallisation was heavily relied on for the identification of host-guest complexes, x-ray quality crystals were needed. In many instances during this project non-crystalline material formed as the Qns are insoluble in a wide range of solvents. When a recrystallisation was attempted on some of these solids ‘dissociation’ of the solid would occur. If it can be assumed that these solid samples comprise of two parts, the first the colourless Qn and the second the potential guest that is often coloured, then when a solid sample was placed in a solvent the guest portion would move into solution Chapter 4: Experimental Work. Page 117 leaving an undissolved white powder – the Qn – behind: the solid had ‘dissociated’ (Equation (2)). The following equations describe the types of dissociations considered in this work:

G@Q(solution) o G(solution) + Q(solution) (1)

G@Q(s) + solvent o G(solution) + Q(s) (2)

[G+Q adduct](s) + solvent o G(solution) + Q(solution) (3)

[G+Q adduct](s) + solvent o G(solution) + Q(s) (4) where G = guest and [G+Q adduct](s) represents a solid product containing both the Q and the potential guest molecule but no host-guest complex.

The dissociations described by equations (2) and (4) proved to be the most problematic, as once the Qn and the guest were in different states the formation of a host-guest complex became impossible. The Qns will not go back into solution as (2) and (4) are irreversible reactions in all cases. Equations (1) and (3) represent dissociations that are probably reversible as the guest molecules can still pass through the portals of the Qns and crystallise in a host-guest complex. It was these systems that were sought after in this work and great efforts were made to find the appropriate solvent systems. After researching this area it appears that the mineral acids (e.g. HCl, H2SO4), with their ability to dissolve many compounds, probably provide the best solvating conditions. As described later in this chapter the host-guest compound cis-SnCl4(H2O)2@Q7 was synthesised in a highly acidic environment and all but one of the crystal structures described in chapter 5 were prepared in acid. This does not, however, rule out the use of any other solvent system and whenever a recrystallisation was performed the full range of solvents and aqueous metal salt solutions were tested for their ability to dissolve the sample to be recrystallised. What was often seen was that samples were most soluble and less likely to dissociate in acids as these conditions would drive the Qns into solution and provide the opportunity for slow crystal formation. A negative outcome of working with acids as solvents was that the harsh acidic environment restricted the choice of potential guests and these restrictions formed the boundaries of this research. Chapter 4: Experimental Work. Page 118

4.1.1: Guest selection. The main criterion when selecting a guest was its size complementarity with the Qn cavity and the portal diameter. This latter criterion was a lesser concern, as there is evidence that the portal oxygens are able to splay outwards and allow molecules into the cavity that would otherwise encounter repulsions from the portal oxygens. Computer modelling studies were routinely conducted to determine which Qn cavity a particular guest would fit inside. The principal consideration used to guide the selection of a guest for direct insertion into a Qn (i.e. through the portals) was its likely interaction with the portal oxygens. These carry a partial negative charge and to date no guests with a formal negative charge have been included in the cavity of a Qn, almost certainly due to the repulsions between the carbonyl oxygens and the negatively charged guest. However, guests containing groups with a partial negative charge may be included, even if those groups inhabit the outer sphere of the guest. The host-guest complex prepared in this work, and described in chapter 5, § 5.6, involves a cis-SnCl4(H2O)2 group inside a Q7. This guest is included despite the partially negative charges on the Cl ligands. Despite the unlikelihood of the inclusion of guests with a formal negative charge, experiments were 2– nonetheless conducted with these molecules, e.g. PtCl6 . Some host-guest complexes are stabilised by the attractions between the portal oxygens and the ligand groups on the guest molecule. The attractive force involved is predominantly hydrogen bonding and examples from the literature are presented in chapter 2. In order to take advantage of these forces some of the guests chosen for potential inclusion contained functional groups with the capability of hydrogen bonding z+ z+ with the carbonyl oxygens, e.g. [M(NH3)6] and [M(en)nLm] . During this project, preparations for new compounds synthesised under acidic conditions appeared in the literature. One example is [Mo12S12O12(OH)12(H2O)6], a ring shaped molecule formed at pH ~ 1[1]. Some of these compounds were unsuitable for guest inclusion, usually due to their size, but the co-crystallisation of these compounds with Qns was attempted primarily because of the limited number of compounds that could be used successfully in this work. Chapter 4: Experimental Work. Page 119

Apart from those already listed previously, some other types of molecules selected for possible inclusion were neutral species such as SnCl4, I2 and various oxometallate species, e.g. the oxovanadates.

4.1.2: Templated syntheses. In chapter 2 the mechanism of Qn formation and cyclisation is discussed in detail. The first step in this process involves the condensation of the glycoluril monomers by formaldehyde and the formation of oligomers, of various lengths, made up of the methylene linked glycoluril monomers. The ends of an oligomer then join together to form the circular Qns. The order of precipitation of the Qns is Q5, Q6, Q8 and Q7. A set of reactions were performed in this work attempting to utilise a potential guest to template the formation of a Qn about it. Guests were chosen on the basis of their size (small enough to fit inside a Qn cavity) and on their ability to withstand strongly acidic conditions without decomposing. The aim was to see if a guest molecule could promote the formation of a Qn about it. Few experiments using the principle of templated synthesis were attempted because most guests could not survive the extreme conditions necessary for the synthesis of Qns (strong acid and prolonged heating). In the instances when the guest molecule did not decompose, obtaining a final product from which good crystals could form was often fairly difficult, as is described in § 4.5. If a mixture was formed it would be filtered and the filtrate left to develop crystals but the solid product was not worked with any further. The rationale behind this was that if any solid that formed during the reaction or upon cooling did contain a host-guest compound, then any recrystallisation procedure may change the composition of this host-guest compound, either through the changed concentrations of reagents and solvents and also through the increased exposure to heat during the recrystallisation. As stated in the previous paragraph, the aim was to see if the synthesis of Qns in the presence of a potential guest could alone template the formation of a Qn about it. For this reason most non-crystalline solids that formed during templated syntheses were left with no further work performed on them. The filtrate was left to crystallise to see if a host-guest complex had formed during the synthesis. Little success was had with this methodology and the direction of synthetic work was steered towards guest insertion through the portal cavities of already formed Qns. Chapter 4: Experimental Work. Page 120

4.1.3: Blank Experiments. Blank experiments were carried out in which an experiment was replicated with the Qn absent while all other reagents were included. If a solid formed only while the Qn was present, it would indicate that there was an interaction occurring between the Qn and a reagent, with the possibility that a host-guest compound had precipitated. When this occurred, particular emphasis was placed on trying to recrystallise these solids. These blank experiments appear in this chapter alongside their Qn containing counterparts.

4.2: Solubilities.

As mentioned previously in chapter 2, the literature lists that Qns are soluble only in aqueous acids, and group 1 metal salt aqueous solutions. In this project, other metal salt solutions were found to solubilise Qns. It is the high affinity of these metal cations for the carbonyl oxygens lining the portals that leads to their coordination to the Qns with the result of an increased solubility. It may be postulated that the Qns’ solubility in acids is similarly due to the complexation of the portal oxygens by H+. The solubility of Qns in only a limited range of solvents proved to be a limiting factor in the scope of work that could be conducted. Part of this research involved finding new conditions in which to carry out experiments with Qns and a large amount of information regarding the solubility of Qns in different solutions was amassed. This is presented here along with the principles behind many of the experiments listed in § 4.5.

4.2.1: Conditions in which Qns are soluble. During the course of this project the following solutions and solvent mixtures, along with commonly used acids (e.g. HCl, HBr, HI, H2SO4), were used to dissolve Qns in the experiments described in § 4.5. Q5 is the least soluble of the Qns and will not dissolve appreciably in some of the solvents listed below, whereas Q7 is significantly more soluble in these solvents. For the purposes of this work, soluble is defined as when 0.05 g of a substance dissolves completely in ~ 5 mls of a solvent with or without heating; partly soluble as when only part of that amount of solid dissolves and insoluble when no appreciable amount of solid dissolves in boiling solvent. Chapter 4: Experimental Work. Page 121

Acids: TFA/H2O (in a ratio of 3:1), glacial CH3COOH/H2O (in a ratio of 2:3);

Bases: NaOH(aq) and KOH(aq) (concentrations as low as 10% will partially dissolve Q6 and Q7). The Qns are not soluble in solutions of aqueous ammonia.

HBr(aq) was used to dissolve Q6 with heating and good quality, orange, hexagonal crystals were grown at a temperature of 70 ºC. These crystals did not diffract well and there was some indication of twinning. As a consequence no solution of the structure from the diffraction data was found.

Q5 did not form crystals in HBr(aq). Q5@Q10 came out of solution as a white powder. Q7 developed crystals but they were not suitable for crystallography. Aqueous solutions of group 1 metal salts will dissolve the Qns. Concentrations as low as 0.1 M are effective at dissolving Q7. The Qns are not as soluble in transition metal (Cu2+, Co2+, Ni2+) salt solutions but Q7 is fairly soluble in the concentrated (1 M) aqueous solutions of these salts. All counter ions are simple anions, e.g. the halides, nitrate, sulfate etc. + The Qns are soluble in 0.1 M NH4Cl(aq) and this is due to the coordination of NH4 to the Qns via hydrogen bonding between the hydrogens of the cation and the portal oxygens.

Q7 is also soluble in 0.1 M aqueous solutions of Et4NCl and partly soluble in

Me4NCl and Bu4NBr. This may be due to the attraction between the cations and the partial negative charge on the carbonyl oxygens – a weaker interaction than hydrogen bonding. This may account also for its solubility in aqueous solutions of

Ph3PMeBr. However, as Q6 is generally less soluble than Q7, it does not exhibit

solubility in 1 M Me4NCl(aq). Q5@Q10 is soluble in fewer solutions than the other Qns. It is not soluble in 0.1 M

NaOH(aq), 0.1 M NaBF4(aq) or 1.8 M H2SO4(aq), only partly soluble in 0.1 M

NaCl(aq) and 2.5 M HCl(aq) and 5 M CH3COOH(aq).

Q5@Q10 is readily soluble in the more concentrated acids such as 5 M HCl(aq), 18

M H2SO4(aq), TFA/H2O (ratio of 3:1) and glacial CH3COOH/H2O (ratio of 2:3). In

contrast, Q7 is not soluble in the CH3COOH/H2O solvent mixture. Chapter 4: Experimental Work. Page 122

4.2.2: Group 1 metal salt solutions as solvents. 4.2.2.1: Non-aqueous group 1 metal salt solutions.

The solubilities of various group 1 metal salts in solvents other than H2O was tested along with the ability of these solutions to dissolve Qns:

A 0.1 M NaI(MeCN) solution did not dissolve the Qns. The solids instead turned yellow due to the presence of iodine. As with most experiments involving iodine, recrystallisations were hampered by the loss of iodine to the atmosphere. When these yellow coloured solids were recrystallised from various concentrations of HCl (2.5 M – 10 M) they did not develop good quality crystals.

The salts KBr, NaBr, K2SO4 and Na2SO4 were found to be soluble in acetonitrile with a small amount of water added to the solvent e.g: NaBr (0.505g) was dissolved in a minimum amount of water at room temperature and then made up to 50 mls with acetonitrile to give a 0.1 M solution. However Q7 was not readily soluble in these solutions. NaBr is soluble in DMSO and DMF and KBr is soluble when heated. NaCl is less soluble in DMSO and not at all in DMF. Q7 was found to be partly soluble in a

0.1M solution of NaBr(DMSO) but insoluble in a 0.1 M solution of NaBr(DMF).

K2SO4 is soluble in pyridine while NaBr, KBr and NaCl are insoluble in pure

pyridine. 0.1 M K2SO4(pyridine) does not dissolve any of the Qns. NaBr was dissolved in a minimum amount of methanol and made up with DMSO but this solution did not dissolve Q7. Adding a larger amount of MeOH did not improve the solubility of Q7.

Q7 is slightly soluble in a 1 M NaBr(MeOH) solution.

0.1 M KBr(DMSO) did not dissolve Q7 or Q5.

A useful method of recrystallisation is to layer a solution of the sample with a high temperature boiling liquid in which the sample is not soluble. As the solution and the liquid mix, the solubility of the sample is reduced. DMSO and DMF do not dissolve Qns and these were used to this effect.

0.1 M NaBr(aq) was used to dissolve Q5 and then small portions of DMSO and DMF added to try and encourage slow crystal formation but cloudy solutions formed.

Similar results were encountered with 0.1 M NaCl(aq). Chapter 4: Experimental Work. Page 123

When these experiments were repeated with Q7 no solid precipitated upon the

addition of DMSO or DMF and a similar result was recorded in 0.1 M KBr(aq). Eventually, as water evaporated, a non-crystalline solid formed. Hence, this method alone is not enough to produce crystalline material and, as further recrystallisations are necessary, this method was not developed or utilised in this project.

4.2.2.2: Aqueous metal salt solutions. Many experiments in this project took advantage of the solubility of Qns in aqueous salt solutions so that a broader range of potential guest molecules could be used. Several qualitative experiments were initially conducted. In many instances colourless crystals formed. These are likely to be complexes of Qn with a group 1 metal coordinated to its portal and, as many of these complexes appear in the literature, no characterisation of the colourless crystals in this project was conducted. The qualitative experiments are outlined below:

Q6 was dissolved in NaBr(aq) and CoCl2/H2O added. Colourless crystals formed from the bulk solution and a portion layered with ethanol produced colourless crystals aswell.

Q6 was dissolved in NaBr(aq) and NiSO4/ H2O added. Colourless crystals formed.

Q6 was dissolved in NaBr(aq) and CuBr2/ H2O added. Colourless crystals formed

Q6 was dissolved in NaCl(aq) and CuBr2/ H2O added. Colourless needles formed.

Q6 was dissolved in NaCl(aq) and CuCl2/ H2O added. Green crystals formed.

Q6 was dissolved in NaCl(aq) and solid CoCl2 added. Deep blue crystals formed. (This was developed further and details appear in § 4.5.4). Similar crystals formed

when this experiment was conducted in NaBr(aq).

Q7 (approx. 0.3 g) was dissolved in 1 M aqueous solutions of Ni(NO3)2, CoSO4,

CuBr2, NiCl2, Cu(NO3)2, CuSO4, CuCl2 and NiSO4. These mixtures were exposed to various solvent vapours.

A portion of Ni(NO3)2(aq) + Q7 exposed to pyridine turned blue and developed a non-crystalline solid after one month. This solid was collected and

dissolved in 0.1 M Ni(NO3)2(aq) solution with additional pyridine added. No x-ray quality crystals formed. Chapter 4: Experimental Work. Page 124

A portion of CoSO4(aq) + Q7 was exposed to acetone and this developed a pink hygroscopic solid that was unsuitable for crystallography. A portion

exposed to ethanol had similarly unsuitable crystals. When 1 M CoSO4(aq) alone was exposed to ethanol for three weeks a non-crystalline solid formed.

A portion of CuBr2(aq) + Q7 was exposed to pyridine and this turned green and developed a dark green solid. The solid is soluble in water but this aqueous solution soon developed a colourless powder. A blank experiment, where 1 M

CuBr2(aq) alone was exposed to pyridine, resulted in the formation of a royal

blue solution but no solid. The sample of CuBr2(aq) + Q7 left exposed to the atmosphere developed a brown solid that was not suitable for crystallography.

A blank experiment, where 1 M CuBr2(aq) was left exposed to the atmosphere for three weeks, led to no change.

A portion of NiCl2(aq) + Q7 was exposed to pyridine and developed badly formed blue crystals. These are unstable in air. Some of this solid was

dissolved in a 0.1 M NiCl2(aq) solution and pyridine added. No suitable

crystals formed. A blank experiment, where 1 M NiCl2(aq) was exposed to pyridine vapour, led only to the development of a light blue solution from an initial green solution.

A portion of Cu(NO3)2(aq) + Q7 exposed to pyridine developed a blue powder.

This is not readily soluble in 0.1 M Cu(NO3)2(aq) and instead a light blue precipitate formed. A blank version of this experiment, where 1 M

Cu(NO3)2(aq) was exposed to pyridine vapour, caused a royal blue solution to form but no solid precipitated.

The portion of CuSO4(aq) + Q7 exposed to THF, acetone and ethanol developed a feathery blue solid that is air stable and water soluble to give a

blue solution. The portion of CuSO4(aq) + Q7 exposed to pyridine developed a light blue powder that was collected and the following day the filtrate had developed a white powder. When blank versions of this experiment where conducted different results were noted: exposure to pyridine vapour only caused a royal blue solution to Chapter 4: Experimental Work. Page 125

form; exposure to acetone and ethanol led to the formation of light blue

crystals and 1 M CuSO4(aq) was exposed to THF and no change was recorded.

A portion of CuCl2(aq) + Q7 was exposed to pyridine and developed a sky blue

solid. This solid is not soluble in 1 M CuCl2(aq), and in water the complex fragments (i.e. a white powder forms while the soluble portion goes into solution). This can be reversed by the addition of pyridine that causes all the solid to redissolve. When pyridine is added to a sample of the sky blue solid

in 1 M CuCl2(aq) a copious amount of light blue solid precipitates. This solid

dissociates in water, CuCl2(aq) and other solvents as well as being insoluble in a range of other solvents. It does dissolve in MeCN to produce a light khaki solution and when recrystallised very thin, long crystals form that are not suitable for crystallography. Better quality crystals could not be produced despite various attempts at recrystallisation. Recrystallisation from other solvents such as THF failed to generate good quality crystals.

A blank experiment was carried out: 1 M CuCl2(aq) was exposed to pyridine vapour and a royal blue solution formed along with a pale blue powder. These results are similar to those observed for the equivalent Q7 experiment described in the previous paragraph and could indicate that Cu(II) is being reduced to form the colourless and insoluble CuCl.

4.2.3: Acids as solvents. The formation of the colourless crystals described in § 4.2.2.2 indicates that the group 1 metal cation is complexing to the Qn. Few crystals containing any coloured transition metals are being formed. In the cases where coloured crystals did form, crystallography showed that the group 1 metal had complexed to the portals and the transition metal was unassociated with the cavity of the Qn, such as in the case of CoCl2 in 1 M NaCl(aq) with Q6 (see 4.5.4). This is due primarily to the higher affinity of alkali metals for oxygen compared to the transition metals. Group 1 metal salt solutions were replaced with HCl (and TFA to a lesser extent) and some of the qualitative experiments conducted are outlined below:

Q6 was dissolved in hot HCl and an aqueous solution of CoCl2 was added to produce a reddish purple solution. When various solvents, such as acetone and Chapter 4: Experimental Work. Page 126

ethanol, were added, coloured powders formed. After 5 days, the initial reaction mixture developed a pink powder that is insoluble in dilute acidic solutions.

Q6 was dissolved in hot 10 M HCl and solid CoSO4 was added until the solution was saturated. Very small blue crystals formed soon after and these were recrystallised from 10 M HCl to give larger crystals that were not well formed and unsuitable for crystallography.

Q6 was dissolved in TFA/H2O (ratio of 3:1) at room temperature and solid CoCl2 was added until the solution was saturated. The solution was filtered while hot.

The following day a fine pink powder formed that was recrystallised in TFA/H2O but this failed to form crystals and instead a pink powder formed again. Recrystallisation was attempted a second time with the same result.

Q6 was dissolved in boiling 2 M HCl and Cu(NO3)2 added as a solid. A few days later only a white powdery solid had formed that is likely to be Q6 coming out of solution.

Q6 was dissolved in boiling 2 M HCl and CuCl2 was added as a solid. A few days later a white powdery solid had formed that is likely to be Q6 coming out of solution.

Q6 was dissolved in boiling 2 M HCl and CuBr2 was added as a solid. Two weeks later the dark brown solution had developed a dark coloured solid as well as some very fine yellow-brown needles. These were not suitable for crystallography. This experiment was repeated but x-ray quality crystals were not produced. . CdCl2.2 5H2O (0.1946 g, 0.852 mmol) in 10 M HCl (2 mls) was added to Q7 (0.0988 g, 0.085 mmol) dissolved in 10 M HCl (5 mls). No solid precipitated. After 3 months crystals formed but these were unsuitable for crystallography.

4.2.4: Combined Conditions: Q6 + HCl(aq) + NaCl(aq) + transition metal salts. In an attempt to overcome the problem of poor crystal formation, HCl and group 1 metal salts were used simultaneously. The concentration of H+ was kept low with the aim of promoting good crystal growth but high enough to offer some competition to the group 1 metal cations for the coordination sites on the Qn portals. Described here are a series of qualitative experimental trials designed to observe the trends in this type of reaction. Chapter 4: Experimental Work. Page 127

The following solution was prepared: Q6 was dissolved in 10 mls of 0.1 M NaCl(aq) and then 1ml of 1 M HCl was added. This represents an equivalent molar amount of Na+ and H+. The following salts were dissolved in aliquots of this solution:

CoCl2, CuBr2, CuCl2, NiCl2, NiSO4, CoSO4, Ni(NO3)2, Cu(NO3)2, Co(NO3)2 and

CuSO4.

Two days later the CuBr2 and Ni(NO3)2 samples had developed colourless crystals.

One week later the Co(NO3)2 sample also had colourless crystals.

Two months later the CuCl2 sample had developed dark green crystals that lose their sheen in water and eventually dissolve. They are air stable.

Three months later, the CuSO4 sample had developed green, block shaped crystals from a green solution. These are stable.

The Cu(NO3)2, CuCl2 and CuSO4 crystallisations were repeated on a larger scale.

Q6 (0.0955 g, 0.096 mmol) was dissolved in 30 mls of 1 M NaCl(aq) with stirring and heating. 6 mls of 1 M HCl was added followed by solid . Cu(NO3)2.2 5H2O (11.6 g, 0.05 mol). Although the majority of all solids dissolved, the solution was filtered. This solution developed well formed, blue, block shaped crystals after two weeks of exposure to the atmosphere.

Q6 (0.0746 g, 0.075 mmol) was dissolved in 30 mls of 1 M NaCl(aq) with stirring and heating. 6 mls of 1 M HCl was added followed by solid

CuCl2.2H2O (11.6 g, 0.068 mol). Although the majority of all solids dissolved, the solution was filtered. This solution was set aside exposed to the atmosphere but no crystalline material formed, only a white powder, likely to be Q6. This experiment was repeated using half (5.8 g) and a quarter (2.9 g) of the

amount of CuCl2.2H2O. Large emerald green crystals appeared 10 weeks later. The other sample developed pale blue, needle-like crystals unsuitable for crystallography.

Q6 (0.1153 g, 0.116 mmol) was dissolved in 30 mls of 1 M NaCl(aq) with stirring and heating. 6 mls of 1 M HCl was added followed by solid

CuCl2.2H2O (12.6 g, 0.07 mol). Although the majority of all solids dissolved, the solution was filtered. This solution developed small blue crystals. Chapter 4: Experimental Work. Page 128

4.3: Synthesis of Qns.

The following is the description of a large scale synthesis conducted at ADFA with the assistance of Dr. Anthony Day. All NMR scans were conducted at room temperature using conc. HCl as the solvent and D2O as the lock solvent. Glycoluril (50 g, 0.35 moles) and paraformaldehyde (21.1 g) were mixed by hand in a round bottom flask. 10 M HCl (70 mls) was cooled in an ice bath and then added to the solid mixture and stirred by hand. Cooling the acid in ice helped to reduce the amount of heat generated when it was added to the solid mixture, and also to slow down the rate of gel formation to give a longer mixing time and, therefore, a more consistent mixture. After approximately 20 mins a thick tan coloured gel had developed. After 30 mins the flask (with a rubber stopper) was placed in an oil bath and heated to 110 ºC for three hours. After one hour of heating a white crust like solid formed around the surface of the solution. This was removed from the sides of the flask and redissolved in the reaction mixture. After a further hour a white solid began to precipitate and so the temperature was lowered to 100 ºC for the final hour of reaction to slow the precipitation of any more solid. A sample of the reaction mixture was taken for 13C NMR and the spectrum is shown in fig. 4.1.

After cooling overnight, the mixture was filtered and 13C NMR on the solid showed that the major product was Q5. The filtrate was then heated to boiling followed by the addition of a minimum amount of water until a solid precipitated. This was allowed to cool and 13C NMR showed it to be almost pure Q6. The filtrate was rotary evaporated until a wet solid remained. This remaining wet solid contained Q7 and some Q6 that had not precipitated in the previous fractional crystallisations. This was dissolved in a minimum amount of boiling conc. HCl and boiling water added until the remaining Q6 (as confirmed by NMR) precipitated. The final filtrate was found to contain approx. equal parts of Q7 and Q6 and so further fractional crystallisations were continued until a relatively pure sample of Q7 was isolated. The 13C NMR spectrum of this product is shown in fig. 4.3. Chapter 4: Experimental Work. Page 129

Q6 Q6

Q8 Q5 Q8 Q5

Fig. 4.1: The 13C NMR spectrum of the synthesis mixture reveals the product distribution. The peaks at 50-55 ppm are due to the methine C; at 70-75 ppm due to the methylene C and at 155-160 ppm due to carbonyl C. All peaks are labelled except for the Q5, Q7 and Q8 carbonyl peaks that are not well resolved.

Fig. 4.2: The 13C NMR spectrum of Q7 donated by Dr. Anthony Day. As can be seen it is contaminated with small amounts of Q5 (peaks indicated with arrows). The peak at 155 ppm is due to the carbonyl Cs, the peak at 70 ppm is due to the methylene Cs and the peak at 51 ppm is due to the methine Cs. Chapter 4: Experimental Work. Page 130

It was somewhat difficult to obtain pure samples of any Qn using this method of separation and it is common to have samples partly contaminated with other Qns. The 13C NMR spectra shown in figs. 4.2 and 4.3 show how the samples of Q7 used in this research were both contaminated by small amounts of Q5 and Q6.

Fig. 4.3: The 13C NMR spectrum of the final fraction of the fractional crystallisation shows the predominant product to be Q7. As can be seen from the spectrum the sample is relatively pure with only a small amount of impurities.

Most of the Qn used in this project was prepared from the synthesis described above. Q5@Q10 was synthesised and kindly donated by Dr. Anthony Day, as was a sample of Q7. These samples were used without further purification.

4.4: Crystallisation Techniques.

Several techniques were used to obtain crystals suitable for single crystal x-ray diffraction. These are explained in some detail below and will be referred to in the rest of this chapter. Some of these techniques have already been referred to in § 4.2. The simplest technique involved dissolving a sample in a suitable solvent and exposing this crystallisation mixture to the atmosphere to allow for evaporation and slow crystal Chapter 4: Experimental Work. Page 131 growth. Heating was also employed to aid the dissolution of the sample and upon cooling, crystal growth could also occur. Covering the reaction flask and boring a small hole through the cover or lid can be used to slow the rate of evaporation. In this way the formation of any crystals is slowed and this will generally lead to better quality crystals.

4.4.1: Exposure to liquids. Quite often the process described above did not yield any solid material or any crystalline material. This failure to produce any solid may be due to the use of a high boiling solvent that does not evaporate readily. A way to force precipitation is to expose the crystallisation mixture to a second liquid in which the sample is not soluble. There are four ways this can be carried out. The first way involves mixing two liquids. The sample is dissolved in one liquid and the second liquid, in which the sample is less soluble, is added and the two liquids are mixed. When the sample comes into contact with the second liquid precipitation occurs. A variation of this technique involves the sample being dissolved in a solvent that is more volatile than the second liquid. As the more volatile solvent evaporates, the concentration of the second liquid increases and causes the sample to precipitate. The third method, known as liquid diffusion/infusion, involves layering the second liquid directly on top of the recrystallisation mixture. When this second liquid slowly diffuses into the recrystallisation mixture precipitation should occur. The fourth method again involves selecting a second liquid in which the sample is insoluble but in this method the sample is only exposed to its vapour. This is known as vapour diffusion/infusion. Both the crystallisation mixture and the second liquid are placed together in a closed container but not in direct contact. This is usually done by placing about 1-2 mls of the crystallisation mixture into a 4.5 mls sample tube with a 1.2 cm diameter and approximately 3-4 mls of the second liquid into a 45 mls sample tube. The vapour of the second liquid slowly diffuses to change the composition of the liquid phase, effecting crystallisation. The rate of vapour diffusion can be controlled by increasing the temperature of the second liquid and also by increasing or decreasing the exposure of the sample to the vapour of the second liquid; this is achieved by increasing or decreasing the size of the surface area of both the sample and the second liquid. Chapter 4: Experimental Work. Page 132

4.4.2: Reduction in temperature of the crystallisation mixture. Dissolving the sample in a suitable solvent is commonly achieved by heating the mixture. A sudden reduction in the temperature of this crystallisation mixture can result in non-crystalline solid or small crystal formation that is unsuitable for x-ray diffraction. The conventional way to circumvent this problem is to gradually reduce the temperature of the crystallisation mixture. This method was commonly employed in this project with some success. A covered flask containing the heated crystallisation mixture was placed in an oil bath at approximately the same temperature as the mixture. The temperature of the oil bath, which was monitored with a thermometer, was gradually lowered over the course of several hours or longer. Attempts were made to determine the optimum cooling gradient and to obtain good quality crystals for each sample. A side effect of maintaining crystallisation mixtures at elevated temperatures for prolonged periods is that a further reaction can occur and alternative products may form. This was taken advantage of in the attempt to increase the occupancies of the guests in the compound cis-SnCl4(H2O)2@Q7 (see § 4.5.5). When these side effects needed to be avoided, maintaining a sample at a high temperature could not be employed. However, because of the high insolubility of many of the products formed in this project often there was no alternative but to use the technique of temperature reduction to try and obtain the elusive good quality single crystal. Nonetheless, the possibility that this method could be destroying the very complex that this research was trying to produce and isolate was always a threat.

4.5: Co-crystallisation of Qns with Various Compounds.

Initially, templated syntheses were conducted (see § 4.1.2) but as these had limited success they were abandoned in favour of direct insertion of potential guests into Qns under suitable conditions. As described in the § 4.1.1, guests were chosen for their size complementarity with the Qn cavities. One of the main problems encountered while performing these experiments was the tendency of any precipitated product to ‘dissociate’ when certain solvents were added, Chapter 4: Experimental Work. Page 133 particularly those in which Qns are not soluble (see § 4.1, equations (2) and (4)). This entailed the guest portion of the compound going into solution leaving a white solid, the Qn, undissolved. This further highlights the difficulties faced in this project and the importance of finding and maintaining the correct conditions for conducting these reactions.

All experiments were conducted at room temperature unless otherwise stated. All reagents were used without further purification. Where starting material had to be synthesised, details of those syntheses appear in the corresponding sections.

4.5.1: Synthesis of (Q8)3(PtCl6)4(H3O)8(H2O)x. This synthesis followed an experiment first published by Behrend[2]. In the original paper PtCl4 is used in place of Na2PtCl6.6H2O, as follows: A sample of Q (2 g) was dissolved in 20 mls of conc. HCl and 20 mls of water and poured into a solution of

PtCl4 (2.4 g dissolved in 100 mls of H2O). A yellow crystalline solid precipitated immediately. The preparation described below was carried out at ADFA with the assistance of Dr. Anthony Day. All reagents were kindly donated by Dr. Anthony Day. Q8 (0.020 g, 0.02 mmol) was dissolved at room temperature in 10 M HCl (4 mls) and

H2O (4 mls) was added to Na2PtCl6.6H2O (0.024 g, 0.05 mmol) in 10 mls of H2O. The very fine orange powder that formed was dissolved in conc. HCl with heating and the solution was allowed to evaporate to dryness. After redissolving in conc. HCl, crystals were grown from the supernatant liquid. This produced light orange hexagonal shaped crystals that degrade at room temperature within a few minutes of being removed from the mother liquor and exposed to the atmosphere. The compound was characterised by single-crystal XRD and details appear in chapter 5, § 5.2.

4.5.2: Synthesis of (Q8)2(PtCl6)3(H3O)6(H2O)18. The crystals of this compound formed following a recrystallisation of the previous compound (§ 4.5.1) from conc. HCl. When these block-shaped crystals are exposed to the atmosphere they become dull as they lose solvent. After the crystal structure had been determined there was insufficient sample of this and (Q8)3(PtCl6)4(H3O)8(H2O)x Chapter 4: Experimental Work. Page 134

(§ 4.5.1) to run further characterisation studies. Details of the single-crystal XRD appear in chapter 5, § 5.3.

4.5.3: Synthesis of (Q7)(Cr3O10)(H3O)2(H2O)x. This synthesis followed from an experiment first published by Behrend[2] where a sample of Qn (2 g) was dissolved in 20 mls of conc. H2SO4 and 20 mls of water and added to a solution of CrO3 (1.5 g in 100 mls of H2O). The mixture was heated for an hour in a water bath during which red crystals began to form. More formed upon cooling the solution. The preparation described below was carried out at ADFA with the assistance of Dr. Anthony Day. All reagents were kindly donated by Dr. Anthony Day.

CrO3 (0.75 g, 7.5 mmol) was dissolved in 50 mls of H2O and Q7 (1 g, 0.9 mmol) dissolved in 10 mls of 18 M H2SO4 and 10 mls of H2O was added. An orange-red precipitate formed immediately. This was dissolved with heating and then placed in an oil bath at 70 ºC and the temperature was gradually reduced to 25 ºC over several hours to produce poor quality needles. A portion of the mixture was redissolved with heating and layered with an equivalent amount of water and in this way long, orange, needle- like crystals formed. These crystals were used for single-crystal XRD and details of the structure appear in § 5.4. They are stable for long periods (months) in solution but on exposure to the atmosphere at room temperature begin to decompose and discolour almost immediately. For this reason, other than crystal structure determination at low temperature, characterisation of this compound was not possible.

The reaction described above was varied with different acids.

CrO3 (0.1662 g, 1.7 mmol) dissolved in 10 mls of water was added to Q7 (0.2286 g, 0.2 mmol) dissolved in 2 mls of 10 M HCl and 2 mls of water and a light orange coloured solid formed. This was filtered and a portion was dissolved in boiling water but overnight a yellow/white precipitate formed, a sign that the Q7 had dissociated from the Cr species (see § 4.1, equations (2) and (4)). No crystalline material was obtained from this experiment.

Q7 (0.1990 g, 0.2 mmol) dissolved in 2 mls of a TFA/H2O (ratio of 3:1) was added

to CrO3 (0.1535 g, 1.5 mmol) dissolved in 10 mls of water. A fine, light orange Chapter 4: Experimental Work. Page 135

precipitate formed. It was filtered and this solid was found to be soluble in the

TFA/H2O, mixture, partly soluble in H2O but not soluble in acetonitrile. A

recrystallisation from H2O was attempted but only a non-crystalline material formed. Vapour diffusion experiments were conducted with the original filtrate but this led to all samples of the orange solution turning green due to the formation of Cr3+, as the solvents were oxidised by the Cr(VI) species.

The crystal structure of this compound comprises six Q7 molecules organised in a ring formation (see chapter 5, § 5.4). The cavity of this ring is filled only with water despite having dimensions large enough to fit a Q6. The potential for the cavity to be filled with other solvent molecules could not be explored by exposing the crystalline product to liquid vapour due to the instability of these crystals out of the reaction mixture. Any addition of another liquid to the reaction mixture would similarly cause degradation of the solid sample. In addition, the Cr(VI) oxidised many solvents, as just described. Hence, the crystallisation experiment was only repeated in the presence of Q6, with the aim of filling the large cavity in the crystal structure.

Q7 (0.2139 g, 0.2 mmol) and Q6 (0.0318 g, 0.03 mmol) were dissolved with heating in

3 mls of 18 M H2SO4 and 3 mls of H2O. CrO3 (0.1501 g, 1.5 mmol) dissolved with heating in 10 mls of water was added and no solid formed. The mixture was placed in an oil bath initially set at ~ 50 ºC and the temperature was lowered overnight. No crystalline material formed, however.

Adamantane and PNP+Cl– were also trialed as potential ring cavity guests but due to their insolubility in acid the experiments did not proceed.

4.5.3.1: Further work with the Cr(VI) system.

Solid Q6 was added to an aqueous solution of K2Cr2O7 and a yellow powder formed. This powder was collected and left exposed to the atmosphere overnight during which it decomposed to an olive green colour as the Cr(VI) was reduced to Cr(III). Obtaining good quality crystals from the filtrate proved to be difficult as the same decomposition was observed for the recrystallisation samples. Chapter 4: Experimental Work. Page 136

The following experiments first appeared in the original cucurbituril publication by Behrend[2]. In this paper experiments describing potassium dichromate and potassium chromate combined with Qns under a variety of solvent conditions are outlined. These experiments were repeated in this project and are described below. Blank experiments were also performed, as described.

Q7 (0.0997 g, 0.09 mmol) dissolved in HNO3 (1 ml, 15 M) and 1 ml of water was

added to K2Cr2O7 (0.1104 g, 0.4 mmol) dissolved in 3 mls of water and a large amount of light orange solid immediately precipitated out. This was filtered and the filtrate developed orange crystals that were later recrystallised. Some of the crystals

were dissolved in HNO3 and this solution was layered with water but good quality crystals did not form.

A blank experiment was performed: 15 M HNO3 (1 ml) and water (1 ml) was added

to K2Cr2O7 (~ 0.14 g, 0.48 mmol) dissolved in 4 mls of water. No solid formed immediately or after 4 weeks of exposure to the atmosphere. Hence, it is likely that

2– the solid that formed in the previous experiment contained both Q7 and the Cr2O7 anion and so further experimentation was aimed at trying to prepare crystals of this product. The previous experiment was repeated under slightly more dilute conditions. Q7

(0.1012 g, 0.09 mmol) dissolved in HNO3 (1 ml, 15 M) and 2 mls of water was

added to K2Cr2O7 (0.1049g, 0.4 mmol) dissolved in 4.5 mls of water but a powder still formed. A portion of the mixture was taken and, as an attempt to dissolve it in

boiling water failed, boiling HNO3 was added in order for it to dissolve. Poor

quality crystals formed. The remainder of the Q7/HNO3/ K2Cr2O7 mixture was set aside for 9 months after which good quality, dark yellow, hexagonal crystals formed. Crystallography was attempted but the crystals did not diffract well and the structure could not be solved.

This was repeated with more HNO3 and less H2O. Q7 (0.1001 g, 0.09 mmol)

dissolved in HNO3 (2 mls, 15 M) was added to K2Cr2O7 (0.1016 g, 0.4 mmol) dissolved in 1.5 mls of water. A cloudy solution formed that cleared upon heating. No crystals formed from this mixture. Chapter 4: Experimental Work. Page 137

Behrand also conducted experiments under basic conditions and these were also repeated in this project. The details are presented below.

Q7 (0.0955 g, 0.08 mmol) dissolved with heating in 2 mls of 10% KOH(aq) and 1 ml

of H2O was added to K2CrO4 (0.1056 g, 0.5 mmol) in 3 mls of H2O. A yellow cloudy solution formed immediately. Two weeks later more powder had formed along with two large yellow crystals with smaller ones soon following. None of these crystals were suitable for crystallography.

A blank experiment was conducted: 2 mls of 10% KOH(aq) and 1 ml of H2O were

added to K2CrO4 (~ 0.1 g, 0.5 mmol) in 3 mls of H2O. No solid formed immediately but one week later a large amount of yellow solid had formed. Further work was then conducted on the Q7 containing experiments to try and obtain crystals in order to determine if an inclusion compound had formed. The experiment was repeated but the mixture was filtered while warm. Q7 (0.1109

g, 0.1 mmol) in 2 mls of boiling 10% KOH(aq) was added to K2CrO4 (0.1106 g, 0.6

mmol) in 2 mls of H2O. The mixture was boiled in order to dissolve the solid that formed upon mixing. This was filtered and the filtrate was placed in an oil bath at 70 ºC and the temperature gradually decreased. Despite this, a fine precipitate still developed. This was repeated but this time the mixture was allowed to cool before being

filtered. Q7 (0.0995 g, 0.1 mmol) in 1 ml of 10% KOH(aq) and 1 ml of water was

added to K2CrO4 (0.1053 g, 0.5 mmol) in 1 ml of H2O. This mixture was heated to dissolve most of the solid that formed upon mixing. However, when it cooled the solid reformed. Four days later this mixture was filtered. This filtrate developed small crystals. These were left to grow but good quality crystals did not eventuate.

4.5.4: Synthesis of

[(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17. This crystalline compound was prepared in the course of conducting the solubility tests outlined in § 4.2.2.2. Q6 (0.1097g, 0.1 mmol) was dissolved with repeated boiling in aqueous NaCl (30 mls,

0.1 M). Solid CoCl2.2H2O (5.9 g, 0.04 moles) was added and while the deep purple solution was still hot it was filtered to remove any solid impurities. The solution was Chapter 4: Experimental Work. Page 138 allowed to stand and after 4 months large, deep blue, rectangular crystals formed. These crystals are stable out of solution but in water they turn white and the solution pale pink. These crystals were suitable for single-crystal XRD and details of the crystallography appear in § 5.5.

4.5.4.1: Templated synthesis.

A templated synthesis of Qns in the presence of CoCl2 was attempted early on in this project. Glycoluril (1.5 g, 1.5 mmol), CoCl2 (1.5 g, 5 mmol), formaldehyde and 10 M HCl (7mls) were mixed together to give a clear blue gel. This was left for two hours and then refluxed at 100 ºC. This was repeated using paraformaldehyde in the place of glycoluril. Again the deep blue gel formed. After refluxing, the mixture formed a deep blue crust instead of individual crystals. As there was no way of determining whether this blue crust contained a host-guest complex no further work was done (see reasoning outlined in § 4.1.2).

cis 4.5.5: Synthesis of {[ -SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23. Q7 (0.1038 g, 0.09 mmol) was dissolved in a minimum amount of 10 M HCl and added dropwise to SnCl4.5H2O (0.3 g, 0.9 mmol) dissolved in 2 mls of 10 M HCl. A white solid immediately formed which was found to be very insoluble in all but boiling concentrated acids. This solid was dissolved with boiling in 10 M HCl and layered with water to form colourless to pale yellow, long, rectangular crystals. These crystals are air stable. At temperatures above 220 ºC they start to turn pink and above 300qC they turn brown. The white powder behaves similarly.

Alternative crystallisation experiments were performed in TFA/H2O (ratio of 3:1) but no crystalline material was produced even after vapour diffusion with a range of solvents. The crystal structure of this compound showed that there are two crystallographically distinct guest@host complexes in this structure with occupancies of 50% and 75%. This is presented in more detail in chapter 5, § 5.6. Chapter 4: Experimental Work. Page 139

4.5.5.1: Guest inclusion and exchange. In order to determine the rates of guest inclusion and exchange and elucidate the factors governing them, 119Sn NMR studies were conducted. The general NMR experiment involved repeating the synthesis of {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 on a much smaller scale inside an NMR tube and measuring the peaks due to

SnCl4(H2O)2 in different states - both as a guest inside the Q7 cavity and when free in solution (with the included state having a peak upfield to that of the free SnCl4(H2O)2 due to the shielding effects of the Q7). The rate of change in peak area indicated how quickly the equilibrium between the two states was established and indeed even if an equilibrium existed.

– 2– The peaks due to any other species in solution, such as SnCl5(H2O) and SnCl6 , were – also monitored. These form when SnCl4 coordinates with another one or two Cl ions contributed by the solvent in which the NMR experiment is conducted, e.g. HCl. The possibility that the equilibrium established in the solution phase might reflect the composition in the crystalline phase was considered. Problems arose due to the insolubility of the product: the amount of compound necessary for detection by NMR required a large amount of solvent to keep it in

2– solution. It was postulated that the formation of the large SnCl6 , in all concentrations of HCl, was the cause of the insolubility of the solid so the possibility of conducting these NMR experiments in other solvents was investigated. HCl was also avoided for the reason that Taylor et al. have reported signal broadening in their studies of Sn(IV) chloride and, in preliminary experiments with SnCl4 and Q7 in 3 M HCl, a similar result was recorded in their work[3]. Taylor et al. went on to conduct their investigations in aqueous LiCl. A similar approach was adopted in this work but again the problem of insolubility arose and this was attributed to the presence of Cl– ions and the formation

2– of SnCl6 . When SnCl4 is dissolved in either 4 M LiCl, or 3 M HCl, three signals appear: a small signal at 624.2 ppm (in 4 M LiCl) and 628.6 ppm (in 3 M HCl) due to

3+ SnCl3(H2O) ; a large peak at 643 ppm (4 M LiCl) and 644 ppm (3 M HCl) due to

SnCl4(H2O)2 and a medium sized peak at 674 ppm (4 M LiCl) and 675 ppm (3 M HCl)

– 2– due to SnCl5(H2O) . Despite the absence of a peak for SnCl6 in these spectra, the formation of a precipitate when the SnCl4 solution was mixed with the Q7 solution was Chapter 4: Experimental Work. Page 140

2– still attributed to the formation of SnCl6 . This was primarily because of its presence in the crystal structure.

2– To avoid the formation of SnCl6 , chloride ions had to be eliminated from the sample solutions. For this reason, aqueous 4 M LiNO3 was trialed. Neither of the reagents was entirely soluble in this without the addition of a small amount of conc. HCl but the same signals were observed in this solvent: a peak for SnCl4(H2O)2 occurs at 643.4 ppm and – for SnCl5(H2O) at 674.6 ppm when SnCl4, 4 M LiNO3 and conc. HCl are mixed.

When HNO3 was substituted in place of HCl a solid still formed upon mixing the two

2– reagents, SnCl4 and Q7. This result suggests that it is not the SnCl6 anion that is the cause of the high insolubility of this compound and that it is probably the host-guest complex that drives the formation of the solid. Experiments conducted in 1 M

LiNO3(aq) also produced precipitates.

The use of aqueous NaOH as an NMR solvent led to the precipitation of Sn(OH)4 even under dilute conditions. In addition to this Q7 is not completely soluble in aqueous

NaOH hence no NMR was conducted in this solution. Although the TFA/H2O (ratio of 3:1) solvent mixture was able to keep all reagents and products in solution, with no NMR data on Sn(IV) chloride species in TFA present in the literature this experiment was not conducted.

4.5.5.2: Alternative acids.

This preparation of {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 described in § 4.5.5 was repeated in a number of different acids in an attempt to avoid the formation of an insoluble product and therefore enable NMR studies of this system to be conducted:

Q7 (0.1 g, 0.09 mmol) was dissolved with heating in 2 mls of 18 M H2SO4 and

added to SnCl4.5H2O (0.3 g, 0.9 mmol) in 1 ml of 18 M H2SO4 and 5 mls of H2O. A fine suspension formed that would not dissolve in excess acid or with heating.

This solid was collected and a portion dissolved in conc. H2SO4 but after 3 months only a powder had formed.

Q7 (0.1322 g, 0.10 mmol) was dissolved in 3 mls of TFA/H2O (3:1 ratio) and added

to SnCl4.5H2O (0.3069 g, 0.9 mmol) in 5 mls of TFA/H2O (3:1 ratio). Extra water was added to each sample prior to mixing to completely dissolve the solids. When Chapter 4: Experimental Work. Page 141

the two solutions were mixed a white precipitate formed. The solid was filtered and

found to be sparingly soluble in excess amounts of the TFA/H2O solvent mixture. The filtrate was exposed to the atmosphere but only a powder and no crystals formed. Q7 (0.1120 g, 0.10 mmol) was dissolved in 2 mls of 90% formic acid and 1 ml of

H2O and added to SnCl4.5H2O (0.2994 g, 0.9 mmol) in 2 mls of 90% formic acid

and 1 ml of H2O. A white solid formed immediately which was partly soluble when excess formic acid and water (in a ratio of 2:1) was added. The filtrate failed to produce crystals. The white powder was also partly soluble in conc. HCl with heating but again the filtrate did not produce any crystals, only a powder. The previous experiment was repeated under less concentrated conditions: Q7 (0.1121 g, 0.10 mmol) was dissolved in 5.5 mls of 90% formic acid with heating

and added to SnCl4.5H2O (0.3061 g, 0.9 mmol) dissolved in 4 mls of 90% formic acid. A white solid formed and this was partly soluble in 15 mls of a formic acid and water mixture (in a ratio of 2:1).

2– These results further demonstrate that it is unlikely that the formation of the SnCl6 anion causes the precipitation of a solid but rather it is the formation of the host-guest complex itself.

4.5.5.3: Templated synthesis.

SnCl4.5H2O (5.5 g, 0.02 moles) and glycoluril (1.5 g, 0.01 moles) were placed in a round bottom flask and 7 mls of 10 M HCl was added with stirring. Formaldehyde (1.5 mls) was added and the mixture placed in an oil bath and heated at 100qC for approx. 3 hours. During this time most of the solid dissolved. When the temperature of the mixture had lowered to 80 ºC, a solid precipitated that would not dissolve when an additional 5 mls of boiling conc. HCl was added. This was filtered and the solid was found to be very insoluble even in conc. boiling HCl. The filtrate did not develop any crystals, probably because the products had already precipitated and been collected in the previous filtration step. Chapter 4: Experimental Work. Page 142

4.5.5.4: Additional SnCl4 work. Q5@Q10 (0.0901 g, 0.036 mmol) was dissolved in boiling HCl (5 M, 7 mls) and added to SnCl4.5H2O (0.1577 g, 0.450 mmol) dissolved in boiling HCl (5 M, 3 mls). A white solid immediately formed that was only soluble in excess boiling 10 M HCl. After 2 days large colourless crystals formed from this recrystallisation mixture and these degrade after one hour of exposure to the atmosphere. Low temperature crystallography was attempted on one of these crystals but the structure could not be solved.

4.5.6: Synthesis of (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24.

After {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 was crystallised and its structure determined, the following experiment was devised as an attempt to try and increase the occupancies of the guest molecules inside the Q7 cavity. A sample of the white powder initially formed in the synthesis of {[cis-

SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 (described in § 4.5.5) was dissolved in boiling 10 M HCl and kept at a temperature of 65-70 ºC for one hour. After this it was removed from the heat and left uncovered for two days during which it developed colourless hexagonal plates. These crystals were used for single-crystal XRD and details of the structure appear in chapter 5, § 5.7. The crystallography shows that instead of increased occupancy of the Q7 molecule there is a different compound of the formula (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24 featuring the smaller Q5, Q6 and no Q7. No host-guest complex exists in this compound. As mentioned in § 4.4, Qn samples are often contaminated with different sized Qns and the NMR of the original Q7 showed small peaks for Q5 and Q6. It is likely that this contamination is the source of the Q5 and Q6.

4.5.7: Synthesis of [(Q6)(SnCl6)(H3O)2](H2O)x. This experiment also led on from the result of § 4.5.5; here Q7 is replaced by Q6. Q6 (0.2024 g, 0.3 mmol) dissolved in ~ 9 mls of boiling 5 M HCl was added to

SnCl4.5H2O (0.9822 g, 2.8 mmol) dissolved in 10 mls of boiling 5 M HCl and a white solid immediately formed. A portion of the mixture was redissolved in boiling 5 M HCl and several days later small colourless crystals had formed. As these crystals were Chapter 4: Experimental Work. Page 143 unsuitable for crystallography a portion of the hot recrystallisation mixture was placed in an oil bath with the temperature fixed at 30 ºC. This process generated crystals suitable for x-ray diffraction and a description of the structure is presented in chapter 5, § 5.8. These crystals are unstable in air and they lose their sheen and degrade overnight. A melting point test caused the crystals to lose their crystallinity above 240 ºC and char as the higher temperatures were reached. A portion of the solid was dissolved in 5 M HCl and exposed to various liquid vapours. Those exposed to TFA and petroleum ether developed crystals after one day. Crystallography on those crystals formed after exposure to petroleum ether vapour showed them to be the same as the original structure. The experiment was repeated in 50% formic acid. Q6 (0.0933 g, 0.1 mmol) was dissolved in 4-5 mls of 50% formic acid and added to SnCl4.5H2O (0.5011 g, 1.4 mmol) also dissolved in 4-5 mls of 50% formic acid. A white/pink powder formed instantly that does not readily dissolve in additional 50% formic acid or in 100% formic acid.

4.5.8: Synthesis of (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26.

A sample of (Q5@Q10)(HCl)10(H2O)23.75 was kindly donated by Dr. Anthony Day. While trying to find conditions in which Q5@Q10 is soluble, crystals of

(Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26 formed after (Q5@Q10)(HCl)10(H2O)23.75 was dissolved with heating in CH3COOH/H2O (ratio of 2:3). These colourless, square shaped plates formed with no need for further recrystallisation. They lose their sheen at temperatures above ~ 140 ºC and melt above 320 ºC. These crystals were used for single-crystal XRD and further details appear in chapter 5, § 5.9.

4.5.8.1: Attempts at co-crystallisation with iodine.

A sample of (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26 was exposed to I2 vapour and they turned a yellow colour. This colour was deemed too pale to contain any

significant amount of I2 in the structure and so crystallography was not attempted.

I2(s) was placed in contact with these crystals while still in the mother liquor. Although they turned a dark yellow-brown colour, crystallography revealed that this

compound had the same unit cell as (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26 Chapter 4: Experimental Work. Page 144

crystallised from CH3COOH/H2O (ratio of 2:3) and was, therefore, almost certainly not a different compound.

4.5.9: Iodine.

Iodine is known to form chains made up of I2 molecules that associate closely with one another. These polyiodide chains form in particular circumstances, such as the iodine- starch reaction, and can thread themselves into the cavity of the starch molecule and other molecules such as cyclodextrins. Modelling has shown that these polyiodide chains are also able to fit inside the cavity of the Qns and the neutral charge on the chain makes it a suitable potential guest. Although iodine is partly soluble in acids such as HCl, it readily sublimes, making recrystallisation experiments difficult to control and often unsuccessful, leaving behind a colourless mixture. This is described in the following experiments. Solid Qn was added to an iodine saturated aqueous solution. The solid turned a pale rose pink colour after being mixed for a short time. This pink solid is stable in air. When it was dissolved in acid and left to recrystallise, the pale pink colour disappeared as a result of the iodine subliming. When the pink solid was added to other solvents, a white solid formed (the Qn) while the iodine dissolved into the solvent.

Q6 (0.0870 g, 0.1 mmol) and I2 (0.4051 g, 1.6 mmol) were ground together to produce a dark brown solid that rapidly loses iodine and decolourises. This solid

dissolves in water to give a tan coloured solution and in TFA/H2O to give a pink solution. Both these solutions readily decolourise.

10 mls of an I2 saturated solution of TFA/H2O (dark pink in colour) was filtered and

added to Q7 (0.1267 g, 0.1 mmol) dissolved in a minimum amount of TFA/H2O.

The dark pink solution was stoppered to try to prevent the loss of I2 to the

atmosphere but I2 loss eventually occurred and no crystals formed.

Q7 (0.1007 g, 0.09 mmol) was boiled in 10 mls of 1 M NaCl(aq) and 20 drops of 10

M HCl and then filtered. A saturated solution of I2 in 1 M NaCl(aq) was added and a cloudy pink-brown mixture formed that is soluble in 10 M HCl. This solution was

exposed to the atmosphere causing all the I2 to sublime and colourless block shaped Chapter 4: Experimental Work. Page 145

crystals to form. A portion that was left in a stoppered sample tube retained its

colour although the lid turned pink, indicating a loss of I2.

I2 (0.1017 g, 0.4 mmol) was dissolved in 7 mls of 2 M KI(aq) and added to Q5

(0.1092 g, 0.1 mmol) dissolved in 10 mls of boiling 2 M KI(aq). A brown solid formed immediately. A portion was filtered and the filtrate exposed to the atmosphere. Soon after, the flask was covered and 10 months later black crystalline material formed. These crystals were unsuitable for crystallography.

I2 (0.0955 g, 0.4 mmol) was dissolved in 5 mls of 2 M KI(aq) solution and added to

Q6 (0.1249 g, 0.1 mmol) dissolved in 35 mls of boiling 2 M KI(aq) solution. A brown solid formed immediately. A portion was filtered and placed in a stoppered sample tube. After two days this filtrate developed a non-crystalline solid. The original reaction mixture was covered and 10 months later a red-brown powder had formed.

I2 (0.0947 g, 0.4 mmol) was dissolved in 5 mls of 2 M KI(aq) solution and added to

Q7 (0.1411 g, 0.1 mmol) dissolved in 10 mls of boiling 2 M KI(aq) solution. A brown non-crystalline solid formed immediately and this was the only product.

10 mls of an I2 saturated solution of 1 M NaOH(aq) was added to Q7 (0.0645 g, 0.06

mmol) dissolved in 25 mls of NaOH(aq). A colourless, cloudy solution formed but no crystalline material followed.

10 mls of 2 M NaCl(aq) saturated with I2 was added to Q5 (0.1102 g, 0.1 mmol) in

30 mls of boiling 2 M NaCl(aq). A gold-orange coloured solution formed. Within a few minutes very small gold coloured crystals formed. As these crystals were too

small for XRD they were recrystallised from a solution of 2 M NaCl(aq) and exposed to the atmosphere. After several days the solution had decolourised indicating loss

of I2.

10 mls of 2 M NaCl(aq) saturated with I2 was added to Q6 (0.1003 g, 0.1 mmol) in 3

mls of 2 M NaCl(aq). A tan coloured solution formed. This was covered with a watchglass and in two days large garnet coloured crystals had formed. A repeat of the experiment produced these large dark red crystals again. These crystals lose their crystallinity when exposed to the atmosphere for several hours. One of these crystals was used for low temperature single-crystal XRD but the structure did not Chapter 4: Experimental Work. Page 146

contain any iodine despite the crystals being coloured. It is probable that there is just a trace amount of iodine in the compound and this is supported by the fact that the crystals are so light in colour and not black, as they would be if appreciable amounts of iodine were present.

10 mls of 2 M NaCl(aq) saturated with I2 was added to Q7 (0.1316 g, 0.1 mmol) in 4

mls of 2 M NaCl(aq). A dark pink coloured solution formed and a yellow solid formed after a few days. The filtrate eventually decolourised.

Q7 (0.1125 g, 0.1 mmol) was dissolved in 6 mls of 2 M KCl(aq) solution. 6 mls of 2

M KCl(aq) saturated with I2 was added and after one day a yellow powder started to form but no crystalline material developed.

Q5@Q10 (0.1078 g, 0.04 mmol) was dissolved in ~ 30 mls of CH3COOH/H2O

(ratio of 2:3) and 15 mls of the same solvent mixture saturated with I2 was added. A reddish tan coloured solution formed and three days later fine, needle-like orange/tan crystals developed from this solution. Attempts at recrystallising these resulted in colour loss and exposure of the filtrate to the atmosphere only yielded a red powder.

4.5.10: HgI2

2– In the presence of excess halide, the species HgX4 forms from HgX2, where X is a halide. Modelling studies show that this tetrahedral anion fits inside the cavity of Q7.

HgI2 (0.4109 g, 0.88 mmol) was dissolved in boiling HCl (20 mls, 10 M) and Q7 (0.1023 g, 0.09 mmol) dissolved in HCl (5 mls, 10 M) at room temperature was added. A mustard yellow precipitate formed. This solid is not soluble in ethanol,

MeCN, acetone, TFA/H2O or 5 M HCl. The solid was filtered and the filtrate, pale yellow/green in colour, was set aside. The solid dissolved only after boiling in conc. HCl, however a fine suspension formed when the solution cooled. After 24 hours this had transformed to a yellow solid with dark-red flakes through it under a yellow solution. When this mixture was reheated the yellow solid readily dissolved to leave just the red flakes. During this time, the original filtrate had turned from pale yellow/green to dark yellow and also had developed dark-red flakes. These dark-red flakes are amalgamates of very small crystals and therefore unsuitable for crystallography. Chapter 4: Experimental Work. Page 147

This experiment was repeated but in a 1:1 molar ratio. HgI2 (0.0436 g, 0.1 mmol) was dissolved in boiling HCl (2 mls, 10 M) and added to Q7 (0.1054 g, 0.09 mmol) in 0.5 mls of conc. HCl at room temperature. As a yellow precipitate formed immediately, excess conc. HCl was added and the mixture boiled until a rose pink solution formed. When it was left to cool, a precipitate formed. Ten days later there were small red crystals that were unsuitable for crystallography.

4.5.11: Molybdenum ring – [Mo12S12O12(OH)12(H2O)6]. Cadot and co-workers reported the synthesis of a ring shaped molecule of the formula

2+ [1] [Mo12S12O12(OH)12(H2O)6] (shown in fig. 4.4), comprised of the [Mo2S2O2] unit . The synthesis is carried out in acidic solutions making this compound suitable for this work. The ring molecule has a diameter of 15.3 Å and a cavity diameter of ~ 11Å. Its dimensions make it impossible for the ring to form a host-guest complex with any of the Qns so a co-crystallisation was aimed for instead.

(a) (b)

Fig. 4.4: (a) [Mo12S12O12(OH)12(H2O)6] (b) Q7. Mo is shown in magenta, O in red, S in yellow and N in green. H atoms are omitted for clarity.

The preparation of this annulus and the precursor compounds is described here along with the efforts to co-crystallise the annulus with Q7, pictured alongside it in fig. 4.4.

[4] Synthesis of (NH4)2[Mo2(S2)6].2H2O :

MoO3 + 2(NH3) + H2O o (NH4)2MoO4

(NH4)2MoO4 + (NH4)2Sx o (NH4)2[Mo2(S2)6] Chapter 4: Experimental Work. Page 148

MoO3 (4 g, 0.03 moles) was stirred in conc. NH3(aq) (85 mls) heated to 60 ºC. This was filtered to remove any undissolved MoO3 and a 10% solution of (NH4)2S (80 mls) was added. The deep red solution was kept at ~ 80 ºC for 19 hrs and the flask covered with a watch glass. Five days later a red solid formed: (NH4)2[Mo3S13]. This was filtered and an additional 20 mls of 10% (NH4)2S was added to the filtrate and the flask stoppered. Two days later more red solid had developed in the filtrate which was again filtered and a further 40 mls of 10% (NH4)2S added. Two days later, black crystals of

(NH4)2[Mo2(S2)6].2H2O had formed. These were collected, washed in water and left to air dry. Solid sulfur precipitates as a byproduct at each step of this synthesis.

[5] Synthesis of (Me4N)2[Mo2O2S6] :

2– – 2– [Mo2(S2)6] + 2OH o [Mo2O2S6]

(NH4)2[Mo2(S2)6] (0.7 g, 1.1 mmol) was added to 75 mls of 28% NH3 and a dark brown/black solution formed immediately. This was covered with a watchglass and stirred for 1 hr and then left standing, covered, for a further 23 hrs. A light brown solid formed and this was filtered. The red-tan coloured filtrate had Me4NCl (1.2 g, 0.01 mol) in 40 mls of water added to it and a light tan coloured solid formed immediately. This was collected, washed with a little water and dried.

[1] Synthesis of [Mo12S12O12(OH)12(H2O)6] :

(Me4N)2[Mo2O2S6] ( 0.2543 g, 0.45 mmol) was suspended in an aqueous solution of KI

(0.7 M, 1.5 mls). I2 (0.2333 g, 0.9 mmol) and KI (0.4118 g, 2.5 mmol) were dissolved in 1.8 mls of 1 M HCl and then added to the Mo suspension. This was heated at 50 ºC and stirred for 10 mins during which a red solution and solid formed. This was filtered, the filtrate placed in ice and then filtered again. This insoluble portion is S and Me4NI.

4 M KOH(aq) was added dropwise to the filtrate until the solution was at a pH ~ 1 and then cooled in ice. An orange-yellow solid formed that was collected and washed in ethanol and ether (0.11 g, 0.05 mmol, 60% yield). Chapter 4: Experimental Work. Page 149

4.5.11.1: Attempts at co-crystallisation with Qn.

The following experiments attempt to synthesise [Mo12S12O12(OH)12(H2O)6] in the presence of Q7.

I2 (0.1 g, 0.4 mmol) and KI (0.16 g, 1 mmol) were dissolved in HCl (0.7 mls, 1 M).

(Me4N)2[Mo2O2S6] (0.1 g, 0.177 mmol) was suspended in an aqueous solution of KI (0.6 mls, 0.7 M) and the iodine solution was added slowly with stirring. The mixture was heated to 60 ºC for 10 mins and then filtered. The filtrate was then placed in ice and filtered again. A solution of Q7 (0.25 g, 0.22 mmol), dissolved in 2.5 M HCl (6 mls), was added and an orange-yellow powder formed that was cooled in ice and filtered. The filtrate was set aside (see next paragraph). When this orange-yellow solid was added to any solvent in which the Qns are not soluble (e.g. ethanol, water) the Mo ring compound went into solution but a white solid (possibly the Q7) remained. The orange-yellow coloured solid dissolved in 5 M HCl to give a colourless solution. It was partly soluble in MeCN to give a yellow solution but an orange solid remained undissolved. This undissolved orange solid is slightly

soluble in TFA/H2O to give a pale yellow solution. No crystals formed from the filtrate (which was initially yellow but turned orange) but a non-crystalline solid did form. The solid was collected and dissolved in 5 M HCl to give a pink solution that failed to produce any crystals, only a red powder. The filtrate from this last step produced crystals after two days but these were too small for crystallography.

This experiment was attempted again in a variety of ways. The first method involved the preparation of [Mo12S12O12(OH)12(H2O)6] first, followed by its co-crystallisation with Q5@Q10.

[Mo12S12O12(OH)12(H2O)6] (0.0143 g, 0.006 mmol) (synthesis outlined at the start of § 4.5.11.1) was heated in 5 M HCl and Q5@Q10 (0.0198 g, 0.008 mmol) in 5 M HCl was added. Not all of the Mo ring solid dissolved but the mixture was left unfiltered. Initially an orange solid formed but a few days later badly formed orange crystals appeared and they were recrystallised from conc. HCl. This did not lead to x-ray quality crystals however. Chapter 4: Experimental Work. Page 150

The second method involved the preparation of [Mo12S12O12(OH)12(H2O)6] with the addition of the Q7 at an earlier stage of the synthesis. A suspension of Q7

(0.1410 g, 0.12 mmol), KI (0.6344 g, 3.8 mmol) and I2 (0.3704 g, 1.5 mmol) in HCl

(1 M, 2.8 mls) (not all dissolved) was added to (Me4N)2[Mo2O2S6] (0.3954 g, 0.7 mmol) in an aqueous solution of KI (2.4 mls, 0.7 M) and heated and stirred for 10 mins. A dark brown mixture formed. This was filtered and over the weekend the solid blackened. The filtrate was cooled in ice until a yellow/white solid

precipitated (according to Cadot et al. this is S and Me4NI but in this work it could also be Q7) and this was filtered. Aqueous KOH (4 M, ~ 1.5 mls) was added dropwise to the filtrate which was then placed in ice for 48 hrs. This filtrate developed the familiar orange-yellow coloured solid in this time and that was collected. The resultant filtrate developed a white powder the following day. One week later the filtrate had a fine red powder but also colourless block shaped crystals (likely to be Q7 alone). The orange-yellow solid is not soluble in water or 4 M KOH but is soluble in 5 M HCl. A recrystallisation in this solvent did not yield any crystals.

4.5.12: Mo-Fe Sphere. Müller and co-workers published the synthesis of a Mo-Fe spherical capsule, with a 21

Å diameter, containing a Keggin type cluster of the formula: [HxPMo12O40 [6] H4Mo(IV)72Fe(III)30(CH3COO)15O254(H2O)98] . This is pictured in fig. 4.5 alongside Q7. As with the Molybdenum ring (§ 4.5.11), co-crystallisation, rather than host-guest complex formation, was sought in these experiments. Chapter 4: Experimental Work. Page 151

(a) (b)

Fig. 4.5: (a) The Mo-Fe capsule (formula listed in text) with the Keggin cluster omitted. Mo is shown in magenta, Fe in orange and O in red. (b) Q7. H atoms omitted for clarity.

Müller et al. described the synthesis as follows: NaH2PO4.2H2O (0.21 g, 1.35 mmol) was added to the mixture FeCl2.4H2O (1.0 g, 5.03 mmol), Na2MoO4.2H2O (5.0 g, 20.66 mmol), H2O (75 mls) and glacial acetic acid (10 mls). Concentrated HCl (3 mls) was added until the pH ~ 2.0 and the mixture was stirred for 15 mins at room temperature and then filtered. This filtrate was exposed to the atmosphere for a week after which thin green plates formed. These were collected, washed with water and dried at room temperature.

In the synthesis by Müller et al. just described, the reaction mixture is acidified to a pH of 2 in the final step. It was at this stage that Q7 was added in this work.

FeCl2.4H2O (0.6354g, 3.2 mmol) was added to Na2MoO4.2H2O (5 g, 0.02 mmol) dissolved in 75 mls of water and a red-brown precipitate formed immediately. After 10 mls of glacial acetic acid was added to this mixture a deep blue solution formed.

Solid NaH2PO4.2H2O (0.285 g, 1.8 mmol) was added, followed by the dropwise addition of Q7 (0.3699 g, 0.32 mmol) dissolved in 3 mls of 10 M HCl. A blue-grey solid formed and after 15 mins of stirring the solid and the solution had turned a deep green colour. This is the colour of the Mo-Fe sphere as described in the original paper. A portion of this mixture was filtered. After 6 weeks the filtrate contained a mustard yellow solid and large colourless block shaped crystals. The addition of concentrated HCl resulted in the mixture turning green. The original Chapter 4: Experimental Work. Page 152

unfiltered portion remained green and was filtered to give a khaki coloured filtrate and a grey-green solid. This filtrate developed an olive green/yellow powder and small yellow crystals a few days later. The preceding procedure was repeated with Q5@Q10 in place of Q7 and small, green plates formed. However, elemental analysis showed that no Q5@Q10 was contained in these crystals.

2– 4.5.13: MoO4 anion.

2– 6– In acidic conditions the MoO4 anion will form polyanions such as [Mo7O24] ,

4– [Mo8O26] and larger in the solution phase. Many others form upon crystallisation under the correct conditions.

Na2MoO4.2H2O (0.1216 g, 0.5 mmol) was dissolved in 2 mls of boiling conc. HCl and Q5@Q10 (0.0831 g, 0.03 mmol) dissolved in 4 mls of boiling conc. HCl was added. A white solid formed instantly and the flask was placed in an oil bath set at 75 ºC for 2 hours. The solid was collected and redissolved in conc. HCl but only a white powder formed. This solid is not soluble in other solvents but will dissolve in 5 M HCl. Attempts were made to form better quality crystals by layering the recrystallisation mixture with water but only poorly formed crystals appeared.

The experiment was repeated under less concentrated conditions. Na2MoO4.2H2O (0.1449 g, 0.6 mmol) was dissolved in 10 mls of boiling conc. HCl and added to a solution of Q5@Q10 (0.0881 g, 0.04 mmol) dissolved in 10 mls of boiling conc. HCl. No solid formed initially, and the mixture was placed in an oil bath set at 75 ºC. The next day, a small amount of solid was present in the flask. This reaction only produced a white powder instead of good quality crystals.

Na2MoO4.2H2O (0.1454 g, 0.6 mmol) was dissolved in 10 mls of boiling conc. HCl and Q5@Q10 (0.0989 g, 0.04 mmol) dissolved in 10 mls of boiling conc. HCl was

added. After the solution had cooled, 20 mls of H2O was added and a fine precipitate formed which dissolved after 20 mls of conc. HCl was added and the mixture boiled. Three weeks later, cloudy white crystals formed. Some of these were dissolved in boiling conc. HCl but no crystals formed from this recrystallisation. A portion of the mother liquor from which the cloudy white crystals had formed was filtered off and left exposed to the atmosphere. A month Chapter 4: Experimental Work. Page 153

later, small crystals had formed but due to their size they were unsuitable for crystallography. Eventually a white powder formed.

4.5.14: Oxovanadates.

What follows here is a description of the work involving V2O5 as a starting material, and the adjustment of the pH of its solutions to control the products formed.

There is a complicated equilibrium involved in the chemistry of V2O5 and although it has been studied extensively there are still many unclear areas. One of the reasons for these uncertainties is the lengthy amount of time required for some of the species to form and the equilibria to be established. According to Greenwood and Earnshaw[7] the best model to describe this chemistry states that, in an alkaline solution, V2O5 will form

3– the colourless orthovanadate ion, VO4 , regardless of the concentration of V(V). As the pH is lowered, various orange coloured oxovanadates form at concentrations of V(V) higher than 0.32 mmol. At high concentrations ([V] > 0.1 mmol) the

3– decavanadates, eg. H3V10O28 , form in the pH range 2-6. As the pH is lowered further + to ~ 2 the yellow dioxovanadium anion, VO2 , is the predominant species but at high concentrations ([V] > 0.1 M) V2O5 exists at this pH. V2O5 can be reduced by hydrohalic acids to V(IV) and from this the blue vanadyl ion, VO2+, forms in acidic

2– media and the yellow/brown V4O9 forms in alkaline solutions. Initially, the aim of this set of experiments was to co-crystallise the multiple oxovanadates with a range of the Qns. These experiments were considered ideal as the species present in solution could be controlled simply by altering the pH and vanadium concentration. The main obstacle to achieving successful results with this work was that non- crystalline material always formed instantaneously and conducting successful recrystallisations at the same pHs these solids initially formed proved difficult. In the descriptions of the experimental procedures listed below, the species that are believed to have formed (according to pH, vanadium(V) concentration and colour of solid or solution) appear listed in parentheses. When crystals were obtained they were invariably large, colourless, block shaped crystals (almost certainly Qns with Na+, as the larger oxovanadates are all strongly coloured compounds) which developed amidst a Chapter 4: Experimental Work. Page 154

khaki coloured mixture, likely to be V2O5 forming at high concentrations of V(V) and low pHs attained after the evaporation of solvents.

V2O5 was firstly used to try and template the synthesis of Qns. Glycoluril (1.5 g, 1.5 mmol), paraformaldehyde (0.633 g), HCl (7 mls, 10 M) and

V2O5 (1.13 g, 6.2 mmol) were placed together in a round bottom flask. When the reactants were first mixed the colour remained rust-orange but after heating at 90 ºC on the following day it gradually turned to a dark blue solution with no solid. This is due to the formation of VO2+ due to the reduction of V(V) by formaldehyde, which is readily oxidised. No crystals formed from this solution. Adding EtOH to the solution caused a light blue/white solid to form and the addition of NaOH

2– caused a brown solid to form, possibly a salt of V4O9 that forms under basic conditions. This previous experiment was repeated and similar results were recorded – no crystals formed.

Templated synthesis was replaced by direct insertion as an alternative method of creating a host-guest complex.

V2O5 (0.0993 g, 0.55 mmol) was stirred in 50 mls of water for 1 hr at 45 ºC and Q7 (0.0981 g, 0.08 mmol) in HCl (1.5 mls, 5 M) added. A caramel coloured mixture formed immediately and this gradually lightened to dark yellow. After the colour changed the mixture was filtered. The filtrate was yellow and the solid light brown. Three weeks later this filtrate developed a tan coloured solid. The main species in + this yellow filtrate was probably VO2 and, as the solvent evaporated and the

concentration of V(V) increased, V2O5 may have formed.

The above experiment was repeated but this time the V2O5 solution was filtered

before the addition of Q7 in HCl. V2O5 (0.0986 g, 0.55 mmol) was stirred in 50 mls of water for 20 mins at ~ 45 ºC and then filtered. Q7 (0.1112 g, 0.1 mmol) in HCl (1.5 mls, 5 M) was added to the filtrate. A yellow precipitate formed and the filtrate + was colourless. The solid may have contained both Q7 and VO2 . No crystalline material formed. Chapter 4: Experimental Work. Page 155

A blank experiment was performed where V2O5 (~ 0.1 g) was stirred in water (25 mls) at 50-60 ºC for 40 mins, then filtered and 5 M HCl (1.5 mls) added dropwise until the pH ~ 1. A colourless/pale-yellow solution formed with no solid appearing. This contrasts with the previously described experiment (in which Q7 is included as a reagent) where a yellow solid precipitates immediately, suggesting that those solids did contain Q7.

V2O5 (0.1023 g, 0.6 mmol) was dissolved in NaOH(aq) (25 mls, 1 M) at room temperature and then 5 M HCl was added dropwise until the pH ~ 1. As this

3– occurred the colour of the solution changed from colourless (VO4 ) to an + orange/yellow (the oxovanadates) to finally yellow (VO2 ). Q6/8 (0.0944 g) dissolved in 5 M HCl was added dropwise but no solid formed. After this solution was exposed to the atmosphere to evaporate, non-crystalline solid formed on the side of the flask. After seven weeks of exposure to the atmosphere, the solution turned green and block shaped colourless crystals formed. In the presence of hydrohalic acids, V(V) can be reduced to V(IV) and species such as the blue VO2+ may form. The green colour may have been due to the partial reduction of V(V)

2+ + resulting in a mixture of VO and VO2 .

V2O5 (0.1017 g, 0.6 mmol) was dissolved in NaOH(aq) (25 mls, 1 M) at 50 ºC. Q6/8

(0.1022 g) dissolved in NaOH(aq) (25 mls, 1 M) at 50 ºC was added dropwise. As soon as 5 M HCl was added to lower the pH to ~ 1 a yellow solid under an orange solution formed (oxovanadates) and as more HCl was added, the solution turned yellow. This was filtered and 2.5 weeks later the light yellow filtrate developed large, colourless, block shaped crystals (probably Q7 with Na+ coordinated to the portals). An oxovanadate is unlikely to have been present in these colourless crystals as the oxovanadates are all highly coloured species.

The previous experiment was repeated but left unfiltered for one week. V2O5

(0.114 g, 0.6 mmol) was dissolved in NaOH(aq) (25 mls, 1 M) at 50qC. Q6/8 (0.1022

g) dissolved in NaOH(aq) (25 mls, 1 M) at 50˚C was added dropwise. 5 M HCl was added until the pH ~ 1 and a yellow solid formed. One week later the mixture was filtered as no change had been noted. The light orange coloured solid was dissolved in boiling 5 M HCl and the resulting mixture turned green indicating that VO2+ and Chapter 4: Experimental Work. Page 156

+ VO2 were being formed as V(V) is reduced to V(IV) and the concentration of V(V) drops.

A blank version of this experiment was performed: V2O5 (~ 0.1 g) was dissolved in

NaOH(aq) (1 M, 25 mls) to give a colourless solution and 5 M HCl was added until the pH ~ 2. At this point the solution was yellow and no solid had formed, indicating that the presence of Q7 was causing a solid to form. After one week, an orange precipitate had formed in the blank and after another three weeks this solid

had turned to an orange/brown colour, probably due to the formation of V2O5 after the evaporation of solvent and increase in the concentration of V(V). The previous experiment was repeated again but less HCl was added and the

solution left basic. V2O5 (0.1221 g, 0.7 mmol) was dissolved in NaOH(aq) (25 mls, 1

M) at 50 ºC. Q6/8 (0.1024 g) dissolved in NaOH(aq) (25 mls, 1 M) at 50qC was added dropwise. Approximately 2 mls of 5 M HCl was added dropwise to this

3– mixture over 2 hours. The supernatant liquid was colourless (VO4 ) while the solid was orange/yellow (oxovandates). One week later it was filtered as no change had been noted. When the solid was dissolved in NaOH with boiling it gave a

3– colourless solution due to the formation of orthovanadate, VO4 , at a high pH. + When 1 M HCl was added to this solution a yellow powder formed (due to VO2 or

3– H3V10O28 ) and this was boiled to give a colourless solution again. Apart from

NaOH and HCl the solubility of the orange/yellow solid was tested in NH3, acetone, acetonitrile, DMF and DMSO and it was found to be insoluble in all these solvents.

V2O5 (0.1084 g, 0.6 mmol) dissolved with heating in 1 M HCl gave a colourless

solution to which Q6/8 (0.1049 g) in NaOH(aq) (25 mls, 1 M) was added. 5 M HCl was added dropwise with stirring and heating and a yellow solid formed. The + yellow mixture (VO2 ) was filtered. Ten days later the filtrate had large colourless opaque crystals (likely to be Q7 with Na+ bound to the portals).

A blank experiment was conducted: V2O5 (~ 0.1 g) was dissolved in 5 M HCl (15 mls) to give a yellow solution. No solid formed after one month of exposure to the atmosphere, indicating that the presence of Q7 led to the precipitation of a solid. Chapter 4: Experimental Work. Page 157

V2O5 (0.2368 g, 1.3 mmol) in NaOH(aq) (25 mls, 1 M) at 45 ºC was acidified to pH ~ 4 and the solution darkened to a yellow colour (the decavanadates form at this pH). Q7 (0.3090 g, 0.27 mmol) was added as a solid and an orange-yellow

precipitate formed immediately. The solid was filtered and washed with H2O. The filtrate was layered with acetone and a few days later orange crystals had formed. These were found to be hygroscopic. Some of the original filtrate was placed on a watch glass and overnight colourless block shaped crystals formed. The exposure to acetone was repeated with the same results but the crystals were not suitable for crystallography.

V2O5 (0.2348 g, 1.3 mmol) in NaOH(aq) (25 mls, 1 M) and Q7 (0.2922 g, 0.3 mmol)

in NaOH(aq) (25 mls, 1 M) were heated to boiling and mixed. 5 M HCl was added dropwise until the pH ~ 3. An orange solid under an orange solution formed (possibly decavanadate). Four days later the solid was collected. Portions of the filtrate were exposed to various solvents (pyridine, TFA, ethanol, methanol, acetone, THF, acetonitrile, toluene, ethyl acetate and dietheyl ether) but in almost all cases an orange/brown/green mixture formed. A repeat of the experiment yielded the same results. The orange solid dissolves in 5 M HCl to give a light green solution due to the low + concentration of V(V) and the high pH resulting in the formation of the VO2 ion along with the reduction of V(V) to give VO2+. When NaOH is added to this solution it turns yellow-green and a light yellow solid formed. This was not soluble

in H2O or TFA. Eventually, colourless block shaped crystals formed from this reaction mixture.

The V2O5, Q7 and NaOH experiment was repeated but this time the filtrate was

placed in the dark. V2O5 (0.2395 g, 1.3 mmol) in NaOH (25 mls, 1 M) and Q7 (0.3069 g, 0.3 mmol) in NaOH (25 mls, 1 M) were heated to boiling and mixed. 5 M HCl was added dropwise over a period of 5 hours until the pH ~ 3. A yellow solid formed that was insoluble in HCl (pH = 3) but did dissolve in 10 M HCl with a

+ 2+ resultant green solution: VO2 (yellow) and VO (blue). The filtrate was placed in the dark and eventually turned a brown-green (as the solvent evaporates the

concentration of V(V) increases and V2O5 forms). No crystals formed from the filtrate. Chapter 4: Experimental Work. Page 158

4.5.14.1: Reactions with [Ph4P]3[H3V10O28]H2O.

The decavanadate, [Ph4P]3[H3V10O28].H2O, was synthesised and co-crystallisation experiments with Q5@Q10 were carried out.

V2O5 (0.9 g, 4.95 mmol) in 25 mls of 1 M NaOH(aq) was heated to 60 ºC and then filtered to give a pale yellow solution. 5 M HCl was added dropwise over a period of 3 hours while maintaining the temperature of the solution. When the pH was ~ 2, 25 mls of a 0.1 M PPh4Br solution was added and a copious amount of yellow precipitate,

[Ph4P]3[H3V10O28].H2O, formed which was immediately filtered, washed with water and air dried. If this solid is exposed to pH < 2, such as when it is dissolved in conc. HCl, the decavanadate decomposes to V2O5 and a brown solid forms.

[Ph4P]3[H3V10O28].H2O (0.0187 g, 0.009 mmol) dissolved in 10 mls of 5 M HCl was added to Q5@Q10 (0.0124 g, 0.005 mmol) in HCl (approx. 6 mls, 5 M) and

3– after two months the mixture had turned a blue/green colour (H3V10O28

2+ + decomposing to VO and VO2 ) and contained yellow crystals that were not of x- ray quality. With the discovery that Q5@Q10 was soluble in a 2:3 mixture of glacial acetic acid and water (pH ~ 3), the decavanadate experiment was repeated in this solvent mixture. Q5@Q10 (0.0495g, 0.02 mmol) was dissolved in a minimum amount of

boiling CH3COOH/H2O. [Ph4P]3[H3V10O28].H2O (0.0806 g, 0.04 mmol) is partly

soluble in the CH3COOH/H2O mix. This suspension was filtered and the Q5@Q10 solution was added to the filtrate. A very fine, yellow precipitate formed that would

not dissolve when additional CH3COOH/H2O was added and boiled. No crystals formed.

+ 4.5.14.2: Work with VO2 .

The reaction of V2O5 with concentrated H2SO4 generates the yellow dioxovanadium + anion, VO2 . A series of experiments were conducted where V2O5, dissolved in

H2SO4, was mixed with Qns of different sizes. Chapter 4: Experimental Work. Page 159

Q7 (0.1298 g, 0.11 mmol) was dissolved in 5 mls of 4 M H2SO4 and was added to

V2O5 (0.1025 g, 0.60 mmol) in 25 mls of 4 M H2SO4.

Q6 (0.1057 g, 0.11 mmol) was dissolved in 5 mls of 4 M H2SO4 and was added to

V2O5 (0.1122 g, 0.6 mmol) in 25 mls of 4 M H2SO4.

Q5 (0.0986 g, 0.12 mmol) was dissolved in 5 mls of 4 M H2SO4 and was added to

V2O5 (0.1161 g, 0.63 mmol) in 25 mls of 4 M H2SO4.

Q5@Q10 (0.2347 g, 0.09 mmol) was dissolved in 20 mls of 4 M H2SO4, filtered

and added to V2O5 (0.1099 g, 0.60 mmol) in 30 mls of 4 M H2SO4. All of the mixtures listed above were originally a light yellow colour due to the + presence of VO2 . Three months later, portions of these samples were exposed to different liquid vapours that led to the solutions turning a blue colour and to the formation of non-crystalline solids. Eventually all the original solutions turned blue, indicating the presence of VO2+.

4.5.14.3: Other work with this system.

(NH4)3VO4 (0.1965 g, 1.7 mmol) was dissolved in aqueous NH3 (25 mls, 28%) at 40 ºC and solid Q7 (0.1717 g, 0.15 mmol) was added. This did not dissolve with heating or overnight stirring. No crystals formed from this preparation.

V2O5 (0.2305 g, 1.3 mmol) dissolved in HCl (25 mls, 5 M) at 40 ºC was mixed with

Q7 (0.3361 g, 0.29 mmol) in 5 M HCl. Aqueous NH3 (28%) was added dropwise and initially a yellow solid formed. This solid then turned a brown/green colour and

3– then finally turned colourless (VO4 ), while a light grey solid formed.

3– 4.5.15: PO4 anion. The ability to conduct these experiments in an acidic environment made this anion an attractive guest to work with. Furthermore, polyphosphate chains may form where the neighbouring PO4 tetrahedra share a corner oxygen. Modelling studies have shown that these chains are able to fit inside the Qn cavity.

Na3PO4.10H2O (0.1114 g, 0.3 mmol) was dissolved in a minimum amount of water and Q6/8 (0.0959 g) added as a solid. The Q6/8 did not dissolve even with boiling and overnight stirring. This was unexpected, as the presence of Na+ cations that can Chapter 4: Experimental Work. Page 160

coordinate to the portal oxygens should have led to the solubilisation of Q6/8. However, the presence of the phosphate anion could alter the solubility of Qns even in the presence of Na+.

Na3PO4.10H2O (0.1065 g, 0.3 mmol) was dissolved in conc. H3PO4 (~ 5 mls) in

4– order to form P2O7 or larger polyphosphate anions. Q6/8 (0.1018 g) was added as a solid and it dissolved after heating. No change was noted and so, after six months, a small amount of water was added. Large colourless crystals formed a week later. Diffraction data on one of these crystals was collected at 150 K and, although the data was good, the solved structure did not show the presence of phosphorus so further refinement was not continued.

P2O5 (13 g, 0.09 mol) was dissolved in 10 mls of conc. H3PO4 and Q7 (2.3 g, 1.98 mmol) added. Most of the Q7 dissolved to give a pale brown/off-white coloured mixture but no crystals formed. Q5@Q10 (0.099 g, 0.04 mmol) was dissolved with heating in 5 mls of 10 M HCl

and added to Na3PO4.10H2O (0.1469 g, 0.4 mmol) dissolved in 15 mls of hot 10 M HCl. Two weeks later large, badly formed crystals appeared as well as smaller needles. A portion of the mixture (crystals and mother liquor) was recrystallised from 10 M HCl. Crystals formed upon cooling and one week later they were well formed rectangular prisms. These crystals diffracted weakly and so a diffraction data collection was not attempted. A more dilute acid was used. Q5@Q10 (0.0634 g, 0.03 mmol) was dissolved with

heating in 7 mls of 10 M HCl and added to Na3PO4.10H2O (0.1400 g, 0.4 mmol) dissolved in 10 mls of hot 0.04 M HCl. A week later, very small colourless needles had formed. A sample of this was recrystallised from a minimum amount of conc. HCl. Large cloudy crystals developed after two days. Attempts to recrystallise these did not produce good quality crystals.

– 4.5.16: [RuCl5(H2O)] . – [RuCl5(H2O)] is able to survive in an acidic environment and can therefore be used in this research. [NH4][RuCl5(H2O)] was synthesised by Prof. Ian Dance.

[NH4][RuCl5(H2O)] (0.0964 g, 0.3 mmol) was dissolved in 20 mls of 5 M HCl to give a red solution. Q7 (0.1145 g, 0.1 mmol) dissolved in 1 ml of 5 M HCl was Chapter 4: Experimental Work. Page 161

added to it and a red-orange powder formed immediately. This solid was dissolved in boiling 5 M HCl and left to cool. After several days the powder formed again. Some of the reaction mixture was filtered and the filtrate left to evaporate. This too developed a red-orange powder. Another portion of the filtrate was placed in a freezer but no solid formed. Recrystallised portions of the reaction mixture (dissolved in conc. HCl) were exposed to various solvents with either no change recorded (in the cases of acetonitrile, toluene and benzene) or the formation of a red- orange powder (in the cases of THF, acetone, ethanol and ether). The red-orange powder itself is paste-like and is only slightly soluble in acetonitrile and DMSO. The DMSO solution is initially orange but turns yellow, then green. The solid is partly soluble in 2.5 M HCl but no crystals form from this solution.

A blank experiment was performed: [NH4][RuCl5(H2O)] (0.0796 g, 0.249 mmol) was stirred in HCl (5 M, 20 mls) and the mixture filtered. After 10 days of exposure to the atmosphere no solid formed, indicating that Q7 needs to be present for the red-orange powder, described in the previous paragraph, to appear. The experiment was repeated under more dilute conditions and at an elevated

temperature. [NH4][RuCl5(H2O)] (0.128 g, 0.400 mmol) was dissolved in 35 mls of 5 M HCl with heating. Q7 (0.1102 g, 0.1 mmol) dissolved in 25 mls of 5 M HCl with heating was added. No solid formed initially but after a few days a red powder formed. A portion of the reaction mixture was filtered and the filtrate left to evaporate but no solid formed.

A blank experiment was performed: [NH4][RuCl5(H2O)] (0.127 g, 0.400 mmol) was dissolved in hot HCl (5 M, 60 mls) and left covered for several days. The cover was then removed and the solution exposed to the atmosphere for a week. No solid formed in this time indicating that the presence of Q7 is necessary for the formation of the red powder described in the previous paragraph.

The experiment was repeated in 2 M NaCl(aq). [NH4][RuCl5(H2O)] (0.1048 g,

0.300 mmol) was dissolved in 40 mls of 2 M NaCl(aq). Q7 (0.0936 g, 0.08 mmol)

was dissolved in 15 mls of 2 M NaCl(aq). Both solutions were filtered and then

mixed. A dark red powder formed that was not soluble in excess 2 M NaCl(aq). To a 5 mls portion of this mixture, 5 mls of conc. HCl was added and the mixture Chapter 4: Experimental Work. Page 162

heated, dissolving the solid and producing a bright red solution; this did not lead to crystal formation. Some of the original reaction mixture was filtered and exposed to various solvents but no crystals eventuated. A portion of the original reaction mixture exposed to the atmosphere eventually formed colourless crystals under a red-orange solution.

A blank experiment was conducted: [NH4][RuCl5(H2O)] was dissolved in aqueous NaCl (2 M, 55 mls) and heated. This was filtered and HCl (5 M, 5 mls) was added to the filtrate. This filtrate was left exposed to the atmosphere for 10 days. No solid formed, unlike in the experiment containing Q7.

The experiment was repeated in dilute HCl. [NH4][RuCl5(H2O)] (0.1013 g, 0.3 mmol) was dissolved in 55 mls of 1 M HCl with heating. Q7 (0.1017 g, 0.09 mmol) dissolved in 15 mls of 1 M HCl and 3 mls of 10 M HCl with heating was added to the first solution. A fine precipitate formed. Boiling conc. HCl was added to a portion of this and the mixture was then filtered but the filtrate only developed a red powder.

4.5.17: Metal Diaminoethane complexes.

Metal diaminoethane complexes such as [Co(en)2Cl2] have the potential to hydrogen bond with the portal oxygens via the amino groups on the en ligand. This bonding can act as a stabilising force for host–guest compounds between the metal diaminoethane complexes and Qns. In fig. 4.6 a model of one such compound is pictured with the hydrogen bonds highlighted. Subsequent to this work, Mit’kina et al. published the crystal structures of compounds containing the host-guest complex {trans- [8] [Cu(en)2(H2O)2]}@Q8 . Chapter 4: Experimental Work. Page 163

(a) (b)

Fig. 4.6: A model of trans - Co(en)2Cl2 inside the cavity of Q7. (a) shows the view from above and (b) the side-on view. The red and white striped bonds indicate short H…O distances. Q7 is shaded grey, Co is coloured light blue and Cl is orange.

The diaminoethane complexes used in these experiments were prepared using standard literature procedures. Diaminoethane complexes are destroyed in concentrated acids and so alternative solvents, such as methanol, water and dilute acids were used. As methanol and water are unable to dissolve Qns, increased stirring times were employed to try and improve the likelihood of guest inclusion.

Solid Q6 (0.1104 g, 0.1 mmol) was added to a solution of Ni(en)2Cl2 (0.0902 g, 0.36 mmol) in 10 mls of methanol and was left to stir overnight and then filtered. The pale blue filtrate was left exposed to the atmosphere but no crystalline material formed.

A solution of trans-Co(en)2(NO2)2 (0.1044 g, 0.3 mmol) in HCl (20 mls, 0.2 M) was mixed with Q7 (0.112 g, 0.1 mmol) in HCl (10 mls, 0.2 M) and stirred, covered, overnight. A yellow solution with a little undissolved solid formed and this was filtered. Portions of the filtrate were layered with the following solvents:

methanol, THF, toluene, ether, TFA/H2O as well as being exposed to the atmosphere. After one day a colourless solid (Q7) had formed in the cases of methanol, THF and ether. No solid formed in the other samples.

A solution of [CoCl2(en)2]NO3 (0.0937 g, 0.3 mmol) in TFA/H2O (20 mls, in the

ratio of 3:1) was added to a solution of Q7 (0.1162 g, 0.1 mmol) in TFA/H2O (10 mls) and left to stir, covered, overnight. No positive result was recorded.

Solid Q7 (0.1132 g, 0.1 mmol) was added to a solution of Co(en)2SO4 (0.1068 g,

0.39 mmol) in 10 mls of H2O and left to stir for about 16 hrs during which most of Chapter 4: Experimental Work. Page 164

the Q7 appeared to dissolve. It was filtered and a fine purple precipitate appeared in the filtrate. This was repeated: solid Q7 (0.1039 g, 0.09 mmol) was added to a solution of

Co(en)2SO4 (0.1018 g, 0.37 mmol) in 10 mls of H2O. This was stirred overnight and then filtered. No solid material formed from the purple filtrate.

z+ 4.5.18: [M(NH3)6] . z+ The [M(NH3)6] species was considered for inclusion because, as a cation, it will encounter attractive forces from the partial negative charges on the portals. Furthermore, in the same way as diaminoalkanes hydrogen bond to the portals, the z+ ammonia hydrogens of [M(NH3)6] can engage in hydrogen bonding with the portal oxygens and thereby help to stabilise any host-guest complex that forms. Molecular modelling shows that this species fits inside the cavity of Q7. Acids could not be used as solvents, as they destroy these amine complexes and convert + the ammonia ligands to NH4 that coordinate to and cap the portals, preventing the formation of a host-guest complex. Hence, alternative solvents were employed as z+ described below. The [M(NH3)6] complexes were synthesised according to literature preparations and also in situ in some of the following reactions.

The addition of 28% NH3 to an aqueous solution of CoCl2.6H2O (0.1044 g, 0.44 mmol) gave a green/blue solid. Q7 (0.1207 g, 0.1 mmol) was added and left to stir overnight covered with a watchglass. The Q7 appeared to dissolve in the mixture. The mixture was filtered and the blue/green solid was collected and washed with EtOH causing it to yellow a little. The filtrate was a pale pink colour indicating an octahedral complex had formed.

28% NH3 was added to the pale pink filtrate causing the solution to turn yellow/brown and a brown powder to form. This solid was dissolved in conc. HCl – and the resultant solution was light blue (tetrahedral complex – [CoCl4] ). When

2+ NH3 was added to this it turned pink (octahedral complex- [Co(NH3)6] ). Chapter 4: Experimental Work. Page 165

A blank experiment was performed. As the colour changes appear to be similar to those observed in the Q7 containing experiment it is difficult to determine the importance of the presence of Q7. No further work was done with this system.

NiCl2.6H2O (0.121 g, 0.51 mmol) was dissolved in water and 28% NH3 was added dropwise until a royal blue colour developed. Solid Q7 (0.1081 g, 0.1 mmol) was added and the mixture was left to stir covered overnight. This was filtered and a portion was exposed to the atmosphere to crystallise. A white powder (Q7) precipitated out from this filtrate overnight.

Ni(NH3)6I2 (0.1056 g, 0.25 mmol) was dissolved in DMSO and solid Q7 (0.0510 g, 0.04 mmol) was added with stirring. No crystals formed from the filtrate and it is unlikely that Q7 dissolved in the DMSO.

2– 2– 4.5.19: Metal complexes containing the (mnt) ligand (mnt = [S2C2(CN)2] ). The mnt compounds were selected because they are planar molecules that fit inside Q7 with no steric hindrance as shown in fig. 4.7. However, they are all negatively charged leading to expected electrostatic repulsion between the carbonyl oxygens of the host and the formal negative charge on the guest.

(a) (b) – Fig. 4.7: A model of [Ni(mnt)2] @Q7 viewed from (a) side on and (b) above. Q7 is shaded grey, Ni is in light blue and S in yellow. Hydrogens have been omitted for clarity.

As these anionic complexes dissociate under acidic conditions no templated syntheses were attempted. Instead the direct inclusion approach was adopted and the experiments were conducted in solvents in which the potential guests are soluble, e.g. methanol, acetone and dichloromethane. The Qns do not dissolve in these solvents, so all reagents Chapter 4: Experimental Work. Page 166 were stirred for prolonged periods to maximise the solubilisation of the Qns and facilitate the formation of host-guest complexes. All the mnt compounds were synthesised by Prof. Ian Dance.

(Bu4P)[Ni(mnt)2] (0.2634 g, 0.44 mmol) and Q7 (0.5206 g, 0.45 mmol) were stirred together in 50 ml of methanol overnight. A dark brown solution formed instantly, as the metal complex is soluble in methanol. A grey solid remained (likely to be undissolved Q7) and this was collected the following day and the filtrate left aside. After one week the filtrate had transformed to a black solid under a yellow-brown solution. This was filtered and the solid was found to be soluble in methanol and its melting point (120-130 ºC) found to be similar to that of the starting material (130 ºC). The original grey solid has a melting point greater than 320 ºC (therefore likely to contain Q7). This grey solid is not soluble in water or 5 M HCl, is sparingly soluble in acetone and ethanol (possibly a dissociation {see equation (2) and (4)}

with the (Bu4P)[Ni(mnt)2] portion going into solution) but is soluble in DMSO and DMF to give a red/brown solution over a red solid. No crystalline material formed from these solutions.

(KOS)2[Zn(mnt)2] (0.2513 g, 0.37 mmol) and Q7 (0.5101 g, 0.44 mmol) were mixed in acetone and stirred. A creamy coloured solid remained that is insoluble in water, acetone, DMF and DMSO but is soluble in 5 M HCl and is therefore highly likely to be undissolved Q7. (KOS = 1-ethyl-4-carbomethoxypyridinium).

(Bu4P)[Co(mnt)2] (0.2618 g, 0.44 mmol) was dissolved in 100 mls of methanol and the insoluble portion filtered off. Q7 (0.5223 g, 0.45 mmol) was added to the filtrate and left to stir. The Q7 appeared to remain undissolved. As the results recorded for this experiment were similar to the two previous experiments, a different solvent was selected and the experiment repeated.

(Bu4P)[Co(mnt)2] (0.261 g, 0.44 mmol) was dissolved in 70 mls of CH2Cl2 and Q7 (0.4909 g, 0.42 mmol) was added to the filtrate. A black solid formed and an extra 20 mls of solvent was added. This was filtered and the black crystalline solid that was collected on the filter paper quickly turned to a grey powder and then a black

oil that is not soluble in CH2Cl2, MeCN, THF or acetone. The oil is partly soluble in DMSO when warmed, to give a light yellow solution. Acetone dried out the oil so that the resultant solid could be collected. This black solid has a mp > 300 ºC. Chapter 4: Experimental Work. Page 167

z– 4.5.20: The [MCl4] anion. Templated syntheses were attempted in the first instance but, as no crystals formed this way, mixing the anions with already formed Qns was attempted. The metal tetrachloro species used in these experiments were prepared following standard literature procedures.

4.5.20.1: Templated synthesis.

Solid [Me4N][FeCl4] (0.3627 g, 1.33 mmol), glycoluril (1.5 g, 10.6 mmol) and paraformaldehyde (0.633 g) were mixed in a round bottom flask followed by the addition of 7mls of conc. HCl. This mixture was stirred until a thick gel formed. After 1.5 hours the mixture was placed in an oil bath set at ~ 100 ºC and set to reflux. The gel liquefied and some undissolved solid was noted. After 40 mins of heating a yellow solid precipitated. This was collected and found to be slightly

soluble in 10 M HCl and insoluble in H2O – when it was placed in water a white

solid formed indicating the dissociation of the Qn + [Me4N][FeCl4] compound (see equations (2) and (4)). This solid is also insoluble in a wide range of other solvents. Portions of the filtrate from the original reaction mixture were taken and exposed to various solvents. Exposure to ethanol, methanol, THF and acetone caused a white powder to form. Exposure to pyridine caused the solution to become cloudy and exposure to acetonitrile did not cause any solid to form nor was any other change noted.

4.5.20.2: Attempts at direct inclusion.

Q6 dissolved in HCl was mixed with an aqueous solution of [Et4N][FeCl4] and filtered. The filtrate was allowed to stand overnight during which large yellow block shaped crystals formed. As they were not suitable for crystallography they were boiled in the mother liquor where they lost their sheen but did not dissolve. This sample was filtered and the solid was dissolved in HCl while the filtrate was put aside. This filtrate developed small yellow crystals. The experiment was

repeated and crystals acquired. The crystal structure of Q6[FeCl4]2(H7O3)4.3H2O

2– was subsequently published by Virovets et al., featuring the FeCl4 crystallised [9] outside the Q6 . The synthesis described in the paper involves FeCl3 dissolved in a Chapter 4: Experimental Work. Page 168

solution of Q6 in HCl (2 M). Yellow crystals of Q6[FeCl4]2(H7O3)4.3H2O formed after 5 days of exposure to the atmosphere.

Solid Q7 (0.102 g, 0.09 mmol) was added to [Et4N][FeCl4] (0.0966 g, 0.3 mmol) dissolved in 10 mls water and the mixture was left to stir for 21 hours. The undissolved solid was filtered to leave a light yellow coloured filtrate, portions of which were exposed to various solvents. The portion exposed to EtOH developed a powder that was dissolved in HCl and re-exposed to EtOH but no crystalline material formed; the samples exposed to the atmosphere and THF both developed a white powder; the sample exposed to MeCN did not develop a solid and in the case

of TFA/H2O (ratio of 3:1) only a small amount of non-crystalline solid formed.

A blank experiment was conducted in which [Et4N][FeCl4] (~ 0.1 g, 0.3 mmol) was dissolved in 10 mls of water and portions of this were exposed to the following

solvents: ethanol, THF, acetonitrile and TFA/H2O (ratio of 3:1). After one month orange-yellow powder formed in the samples exposed to ethanol, acetonitrile and the atmosphere. No change was noted for the other samples. The differences recorded in these blank experiments to those reported in the previous experiments suggest that the presence of Q7 does alter the results. However, as no crystalline material formed the presence of a host-guest complex could not be verified.

[Me4N][FeCl4] (0.1082 g, 0.40 mmol) was dissolved in a minimum amount of boiling 10 M HCl. When Q7 (0.1075 g, 0.09 mmol) was added as a solid to the warm solution, a yellow-orange solid formed. A portion of this mixture was dissolved in additional boiling conc. HCl but upon cooling a fine precipitate formed that would not readily dissolve. This was subsequently filtered but no crystals formed from the filtrate.

The previous experiment was repeated. [Me4N][FeCl4] (0.1013 g, 0.37 mmol) was dissolved in a minimum amount of boiling 10 M HCl to give a dark yellow solution. Q7 (0.0951 g, 0.08 mmol) dissolved in boiling 10 M HCl was added. A yellow solid precipitated out immediately. A portion of this mixture was dissolved in additional 10 M HCl. Six months later, bright yellow crystals that exhibit dissociation when placed in water (see equations (2) and (4)) had formed.

A blank experiment was conducted whereby [Me4N][FeCl4] (~ 0.1g) was dissolved in concentrated HCl and left exposed to the atmosphere. As no solid had formed Chapter 4: Experimental Work. Page 169

after one month, it may be suggested that the formation of the yellow solid described in the previous paragraph is dependent on the presence of Q7 and also that it contained Q7 as evidenced by the dissociation results in water.

[Et4N][FeCl4] (0.1029 g, 0.31 mmol) was dissolved in a minimum amount of boiling 10 M HCl and was then filtered. Q7 (0.1019 g, 0.09 mmol) dissolved in boiling 10 M HCl was added to this but no precipitate formed.

A blank experiment was conducted whereby [Et4N][FeCl4] (~ 0.1g) was dissolved in concentrated HCl and left exposed to the atmosphere. After one month no solid had formed.

[Et4N]2[CuCl4] (0.0954 g, 0.21 mmol) was dissolved in 5 M HCl and Q7 (0.1600 g, 0.18 mmol) was added. Two months later the solution was exposed to various solvents as no crystals had yet formed. The sample exposed to acetonitrile developed yellow crystals that dulled when exposed to the atmosphere over a 10 day period. This experiment was repeated and the sample exposed to acetonitrile but within 24 hours it had gone cloudy. Three weeks later, badly formed yellow crystals appeared.

4.5.21: Ferrocene. Ferrocene is small enough to fit inside the cavity of Q7. It is stable in acid and reacts with sulfuric acid to form the ferricinium cation. This cation is also stable in acid and, being attracted to the partial negative charge on the portal oxygens, may also be included inside Q7. Initially a templated synthesis was attempted in the presence of ferrocene. This was followed by an attempt at direct insertion into the cavity of Q7. Recently, Jeon et al. have observed the inclusion of ferrocene and ferrocene substituted compounds in Q7[10].

4.5.21.1: Templated syntheses. Ferrocene (0.28 g, 1.5 mmol) was added to a mixture of glycoluril (1.5 g, 1.5 mmol) and sulfuric acid (18 M) followed by the addition of formaldehyde. A black mixture formed immediately that was difficult to filter and work with. Ferrocene (0.28 g, 1.5 mmol), glycoluril (1.5 g, 1.5 mmol), HCl (5 M, 6.9 mls) and formaldehyde (1.5 mls) were mixed until the orange mixture set. After 3 hours this mixture was heated to ~ 100 ºC and after one hour of heating it had turned a deep Chapter 4: Experimental Work. Page 170

blue colour due to the formation of the ferricinium cation. Heating was continued for another three hours and after cooling it was noted that the colour of the mixture was dark brown. This mixture was difficult to filter and work with.

4.5.21.2: Attempts at direct inclusion.

Ferrocene dissolved in CHCl3 was layered over Q7 dissolved in HCl which caused the acidic layer to turn a light green colour. When the aqueous layer was placed on a watch glass light green crystals formed. When another portion of the aqueous

layer was exposed to more CHCl3, green crystals formed in the aqueous layer. This solution eventually darkened. As chlorinated solvents can cause unwanted side

reactions, the experiment was repeated with DMF in place of CHCl3. Ferrocene dissolved in DMF was layered over a suspension of Q7 in water. A creamy yellow solid under a green solution formed. Any attempt to dissolve the solid in a range of solvents caused the solid to turn white and the liquid to turn green – an indication that ferrocene and Q7 were dissociating (see equations (2) and (4)). This experiment was repeated and the creamy yellow solid was left in DMF. No crystals formed in this experiment.

4– 4.5.22: The [Fe(CN)6] anion.

10% KOH(aq) (30 mls) was used to try and dissolve Q7 (0.4982 g, 0.43 mmol). The mixture was filtered and 30 mls of water was added to the filtrate. This was poured

into an aqueous solution of K4[Fe(CN)6] (0.5739 g, 1.55 mmol in 10 mls of water). A white powder precipitated from a pale yellow solution after several hours. A few days later, rust-coloured crystals appeared. Six days later, the solution had pale yellow crystals and an orange powder. The crystals were not of a high enough quality to use for single crystal x-ray diffraction. Chapter 4: Experimental Work. Page 171

REFERENCES

1. Cadot, E., Salignac, B., Halut, S., and Secheresse, F., Angew. Chem. Int. Ed., 1998, 37(5), 611. 2. Behrend, R., Meyer, E., and Rusche, F., Liebigs Ann. Chem., 1905, 339, 1. 3. Taylor, M. J. and Coddington, J. M., Polyhedron, 1992, 11(12), 1531. 4. Müller, A., Bhattacharyya, R. G., and Pfefferkorn, B., Chem. Ber., 1979, 112, 778. 5. Müller, A., Krickemeyer, E., and Reinsch, U., Z. Anorg. Allg. Chem., 1980, 470, 35. 6. Müller, A., Das, S. K., Kogerler, P., Bogge, H., Schmidtmann, M., Trautwein, A. X., Schunemann, V., Krickemeyer, E., and Preetz, W., Angew. Chem. Int. Ed., 2000, 39(19), 3414. 7. Greenwood, N. N. and Earnshaw, A., Chemistry of the Elements., 1984, Oxford: Butterworth-Heinemann Ltd. 8. Mit'kina, T. V., Naumov, D. Y., Geras'ko, O. A., Dolgushin, F. M., Vicent, C., Llusar, R., Sokolov, M. N., and Fedin, V. P., Russ. Chem. Bull., 2004, 53(11), 2519. 9. Virovets, A. V., Samsonenko, D. G., Dybtsev, D. N., Fedin, V. P., and Clegg, W., J. Struct. Chem., 2001, 42(2), 319. 10. Jeon, W. S., Moon, K., Park, S.-H., Chun, H., Ko, Y. H., Lee, J. Y., Lee, E. S., Samal, S., Selvapalam, N., Rekharsky, M. V., Sindelar, V., Sobransingh, D., Inoue, Y., Kaifer, A. E., and Kim, K., J. Am. Chem. Soc., 2005, 127, 12984. Chapter 5: The Crystal Structures of the New Compounds. Page 173

CHAPTER 5

THE CRYSTAL STRUCTURES OF THE NEW COMPOUNDS.

5.1: Introduction.

This chapter describes the crystal structures of the compounds prepared in this research project. The syntheses of these compounds are outlined in chapter 4, § 4.5.

A Bruker-AXS SMART 10003 three-circle CCD diffractometer was used for single crystal XRD. All crystals were coated in Paratone oil to prevent crystal decomposition and all data collections were conducted under a liquid nitrogen stream set at a temperature of 150 K to minimise dynamic disorder and to prevent crystal decomposition. The data was integrated using SAINT[1]. SADABS[2] was used for absorption correction. Reflection merging and scaling was performed with XPREP[1]. This produced a .ins (instruction) file. For the structures described in sections 5.2, 5.3, 5.4, 5.5 and 5.8, the .ins file was used as input for the structure solution program SIR97[3]. SHELX97[4] was used for the refinement of the structures; the graphical interface of WINGX[5] was used to view the results of the refinement cycles in these cases. The use of the Bruker-AXS SMART diffractometer and the data integration and subsequent solution and refinement of structures was carried out with the assistance of Dr. Peter Turner. Dr. Gareth Lewis and Dr. John McMurtrie also rendered assistance. The structures described in sections 5.6, 5.7 and 5.9 were solved using SIR92[6] and refined using RAELS[7] by Mr. Don Craig. The structures described in § 5.4 and § 5.8 feature channels filled with a large amount of disordered solvent water. In order to deal with the adverse effect this had on their refinement, the SQUEEZE technique was applied. This technique, run via the PLATON program[8], eliminates the contributions to the structure factors of the disordered component of the structure (as determined by the user) to obtain modified structure factors. It does this through the back-Fourier transformation of the electron density in Chapter 5: The Crystal Structures of the New Compounds. Page 174 the disordered region of the structure. The refinement of the remainder of the structure then proceeds with these new structure factors. The end result is an improved R factor, not due just to the elimination of the contribution from the disordered component of the structure, but also due to the improved thermal parameters of the ordered component of the structure. The SQUEEZE function also calculates the volume of the disordered area and the number of electrons in this volume whose contributions were eliminated. The refinement program RAELS performs the same function. Specific details on the application and results of these techniques are given with the relevant descriptions of each crystal. In all cases, only the disordered solvent + water/H3O was classed as the disordered component when using PLATON SQUEEZE and not the Qn molecules or any ions.

Some of the crystal structures did not refine to give low R factors. This is in part due to the amount of disordered solvent (and other disordered components) present in these Qn structures. It is also in part due to the extremely weak diffraction intensities of some of the crystals and the instability of these crystals out of their acidic mother liquor. However, we are confident that the non-solvent components of these structures are correct. Other researchers working with the Qn molecule have also experienced similar problems and regular reports of disordered solvent appear in the literature. The structure of ESOSIS (see § 2.4) was unable to be refined and was published with R = 20% and with parts of the structure missing.

All the figures presented in this chapter were produced using CrystalMaker v.5.1.3 and the atom colours used in the figures in this chapter are shown in the atom colour key. Chapter 5: The Crystal Structures of the New Compounds. Page 175

ATOM COLOUR KEY FOR CHAPTER 5

C Cl Pt Sn O

N Co Cr Na

5.2: The Compound (Q8)3(PtCl6)4(H3O)8(H2O)x.

The synthesis of this compound is described in chapter 4, § 4.5.1.

5.2.1: Crystallographic Information. – The compound crystallises in the trigonal space group R3. The cell dimensions are: a = b = 22.006 Å and c = 53.323 Å; V = 25822 Å3; Z = 3. The hexagonal shaped orange crystals were not stable for long when removed from solution and their diffraction pattern was weak. The diffraction was carried out at 150 K to minimise dynamic disorder and, importantly, to prevent the decomposition of the crystal over the ~ 20 hrs of data collection. During the refinement of the structure it became evident that the data was flawed, possibly due to twinning, and that another diffraction experiment should be carried out on a different crystal. However this was not possible because the original small scale synthesis of this compound had been carried out in another laboratory and only a low yield of crystalline material was obtained. The starting materials could not be obtained and the experiment could not be repeated. The structure reported here is the final refinement of the flawed data and has R = 0.36. PLATON SQUEEZE was not applied to this structure as this is usually used as a final step to deal with disordered solvent in an otherwise well refined structure. An analysis of the structure proceeded for two reasons. Firstly, the thermal parameters for the Q8 atoms are reasonable and secondly, the bond lengths of the Q8 molecule are Chapter 5: The Crystal Structures of the New Compounds. Page 176 not very different from those of well refined structures. In this structure the maximum C-N = 1.52 Å, max. C-O = 1.26 Å and max. C-C = 1.64 Å. In the structure

[(Q6)(SnCl6)(H3O)2](H2O)x (§ 5.8) the maximum bond lengths are C-N = 1.46 Å, C-O

= 1.23 Å and C-C = 1.60 Å; in (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24 (§ 5.7) the maximum bond lengths are C-N = 1.50 Å, C-O = 1.27 Å and C-C = 1.61 Å and in

[(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17 (§ 5.5) the maximum bond lengths are C-N =1.47 Å, C-O = 1.24 Å and C-C = 1.56 Å. The anions are disordered with high thermal parameters. One anion, containing Pt1, is disordered over two sites, and the deviation of the Cl-Pt-Cl angles from the typical 90º – and 180º is due to the disorder. The other platinum atom, Pt2, lies on a 3 site. A

+ – water/H3O oxygen atom also lies on a 3 site. Many of the solvent oxygens were also + disordered. Because of this disorder most of the water/H3O oxygen atoms were not identified (only three are listed in the cif). However, in order to balance the charges in + the asymmetric unit, four H3O cations appear in the formula of this compound. An undetermined number of waters also appear in the formula. Q8 hydrogens were assigned geometrically idealised positions (C–H = 1.00 Å) and constrained to Uiso(H) = 1.2Ueq(C).

A cif containing the refined and acceptable portion of this structure appears in Appendix I and an electronic version is available on the CD provided with this thesis.

5.2.2: The Crystal Packing.

This crystal structure of (Q8)3(PtCl6)4(H3O)8(H2O)x features discrete layers of Q8 2– molecules separated by layers of PtCl6 (Pt1) dianions. All the Q8 molecules of the one layer lie in the same plane (see fig. 5.2)– there is no staggering of the Q8s relative to one another as seen in (Q7)(Cr3O10)(H3O)2(H2O)10.3 (§ 5.4). One such layer of Q8 molecules is pictured in fig. 5.1, illustrating how the Q8s are arranged somewhat like the spokes of a wheel. Each Q8 molecule is involved in portal-to-side interactions with four neighbouring Q8 molecules, the maximum number possible for a Q8 molecule. Each Q8 points to the portals of two other Q8s and has two Q8s pointing to each of its portals. The portal-to-side interactions in this structure are excellent with very good Chapter 5: The Crystal Structures of the New Compounds. Page 177 coverage of the portals and distances between the Q8 molecules of: O…C, N, O = 3.0 – 3.5 Å. This result, along with the crystallisation of the compound in a high symmetry space group, once again demonstrates the high favourability of the portal-to-side interaction in the crystal structures of Qn compounds. This ‘spoked wheel’ arrangement is uninterrupted by the interactions of the anions with the Q8s. The ‘spoked wheel’ pattern produces circular and triangular cavities in the layer whose – centres are on the 3-fold rotation axes and the 3 roto-inversion axes (see fig. 5.3). The circular gaps, or ‘hubs’ of the wheel, are about 9.8 Å in diameter and are occupied by 2– the other PtCl6 (Pt2) dianions. The edges of the triangular cavities are approximately 8.5 Å in length and are calculated to fit 2-3 waters, using the soak command of InsightII®[9].

xy Circular cavity, diameter = 9.8 Å.

Triangular cavity

Fig. 5.1: A layer of the Q8 molecules in the crystal structure of (Q8)3(PtCl6)4(H3O)8(H2O)x, viewed here 2– down the z-axis. A PtCl6 anion lies at the centre of each circular cavity. Anions, hydrogens and solvent oxygens have been omitted for clarity. Chapter 5: The Crystal Structures of the New Compounds. Page 178

Circular cavity

Triangular cavity

z Four different layers of Q8 molecules. Circular cavity

Fig. 5.2: This stereo figure shows the alternating layers of Q8 molecules. The spaces between the layers, occupied by the anions, are evident. Hydrogens have been omitted for clarity.

KEY 3 axis =

31 axis =

Fig. 5.3: Three layers of Q8 molecules viewed down the z-axis with the locations of the symmetry elements included. Molecules of the one layer are shown in the same colour. As can be seen the triangular cavities of one layer lie over the circular cavities of another to create channels which are filled 2– with PtCl6 anions and solvent (not shown). These channels run along the z-axis. Chapter 5: The Crystal Structures of the New Compounds. Page 179

The layers of Q8s are separated by layers of Pt1 anions, however these anions crystallise near the sides of the Q8s and not over the circular or triangular cavities. As can be seen in fig. 5.3, the layers of Q8 molecules do not eclipse each other but rather they are shifted half a unit cell, along the x and y axes, relative to one another. As a consequence the circular cavities of one layer overlap the triangular cavities of another, forming channels with hexagonal cross sections (filled with the Pt2 anions) that run down the z-axis, as pictured in fig. 5.3.

As described earlier, the Pt1 anions lie in layers between the layers of Q8 molecules while the Pt2 anions lie within the layers of Q8 molecules. The Pt2 anion is located in the circular cavities in these layers, surrounded by six Q8 molecules. Although one of the Cl ligands of the Pt2 anion lies over a five membered glycoluril ring, the shortest Cl…N distance is 3.5 Å. Figure 5.4 shows a detailed view of the anions and their positions over a ‘spoked wheel’ of Q8 molecules.

Pt1 anions

Pt2 anion

90Þ

Pt1 anions (a) (b)

Fig. 5.4: A top view (a) and a side view (b) of the positions of the anions in relation to the Q8 molecules. The Q8s are coloured in blue and all oxygens and hydrogens atoms have been omitted for clarity.

5.2.3: Comparison with literature structures. The ‘spoked wheel’ pattern in this structure is reminiscent of the crystal packing of SEWSES (§ 3.7). This structure also has the ‘spoked wheel’ pattern but this is comprised of sets of three Q6s overlapping each other and therefore not lying in the Chapter 5: The Crystal Structures of the New Compounds. Page 180 same plane. Furthermore, each set of three Q6s is part of a [4]MN (molecular necklace) and the three are locked into this arrangement by the connected threading ‘string’ units.

In (Q8)3(PtCl6)4(H3O)8(H2O)x, the Q8s are only drawn into this arrangement by the favourable high quality portal-to-side interactions.

Another structure in the literature, 5[(CH3-py-CHCH-py-CH2-naphth)@Q8] (Refcode = ESOSIS) (see § 2.4, fig. 2.5), also features the ‘spoked wheel’ pattern, this time with five Q8 molecules all lying in the same plane. The structure contains a host-guest complex featuring a guest with a terminal naphthalene group connected via a methylene bridge to a dipyridyliumylethylene group. The terminal naphthalene group and the terminal methylpyridyl group of the one guest molecule reside inside the cavities of two Q8 molecules. Each Q8 molecule has the opposite terminal ends of two guest molecules in its cavity and so a chain of linked host-guest complexes is able to form. Five of these complexes link up into a pentagonal supramolecule which the authors have identified as the first [6]MN. The authors reported that good quality diffraction data was difficult to obtain and only an incomplete structure, missing most of the guest molecule atoms, was submitted to the CSD. As in the case of SEWSIS, the structure ESOSIS relies on interactions other than the portal-to-side motif to produce the ‘spoked wheel’ motif.

The crystal structures of the compounds (Q8)3[W3S4(H2O)5Cl4]2(H2O)35 (Refcode =

KANNOD) and (Q8)3(H3O)4[Mo3S4(H2O)3Cl6]2(H2O)68 (Refcode = KANNET) (see chapter 3, § 3.2.3) are similar to (Q8)3(PtCl6)4(H3O)8(H2O)x. They also rely on the portal-to-side interactions alone to bring about the ‘spoked wheel’ pattern, with the – metal-chalcogenide clusters found lying on the 3 sites between the layers of Q8 molecules.

In contrast to other structures featuring the chloride ligand (such as {[cis-

SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 described in § 5.6;

(Q6)(SnCl6)(H3O)2(H2O)12 described in § 5.8 and [(Cl@Q5)@Q10](HCl)11(H2O)25.75 described in § 3.9), (Q8)3(PtCl6)4(H3O)8(H2O)x does not feature many instances of the chloride ligand positioned over the glycoluril rings. As such the favourable portal-to- Chapter 5: The Crystal Structures of the New Compounds. Page 181 side interaction is able to organise into the pattern of the ‘spoked wheel’ in a high symmetry space group.

5.3: The Compound (Q8)2(PtCl6)3(H3O)6(H2O)18.

The synthesis of this compound is presented in chapter 4, § 4.5.2.

5.3.1: Crystallographic Information.

The compound crystallises in the tetragonal space group I41/a. The cell dimensions are: a = b = 28.362 Å and c = 21.855 Å; V = 17582 Å3; Z = 4. An irregularly shaped orange crystal of approximate dimensions 0.38 x 0.42 x 0.61 mm was used for the diffraction measurement. The crystal began to decompose immediately when removed from the acidic mother liquor but this decomposition was slowed down by coating the crystal with oil. This enabled crystal selection and mounting without visible decomposition of the crystal. The diffraction was carried out at 150 K to minimise dynamic disorder and, importantly, to prevent the decomposition of the crystal over the ~ 20 hrs of data collection. The crystal did not diffract strongly and the structure was found to be twinned. The Q8 atoms are well defined and the anions are also well defined, albeit with large thermal parameters. The solvent oxygens are not well defined however, and this combines with a large amount of residual electron density to give a high final R = 0.21. The use of PLATON SQUEEZE was not possible due to twinning. A total of nine water oxygens were located, three were assigned full occupancy and six half occupancy. + In order to balance charges, four of these oxygens are defined as H3O cations although no identification can be made. No attempt was made to locate the water hydrogens, while the Q8 hydrogens were placed in geometrically idealised positions (C–H = 1.00

Å) and constrained to Uiso(H) = 1.2Ueq(C).

The space group is I41/a. There is one Q8 molecule located on a centre of inversion, 2– + two PtCl6 anions, four H3O cations and an indeterminate number of water molecules

2– – (as explained above). One of the PtCl6 anions (containing the Pt1 atom) lies on a 4 Chapter 5: The Crystal Structures of the New Compounds. Page 182 site located on a twofold axis. The octahedron is generated from Cl2 on the twofold 2– axis and Cl1 on a general position (Cl1 is cis to Cl2). The other PtCl6 anion (containing the Pt2 atom) has its Pt atom on an inversion centre and this octahedron is completed with Cl3, Cl4 and Cl5 on general positions. + All water/ H3O oxygens are in general positions.

The cif for this structure appears in Appendix I and an electronic version is available on the CD provided with this thesis.

5.3.2: The Crystal Packing.

In fig. 5.5, the crystal packing of (Q8)2(PtCl6)3(H3O)6(H2O)18 is shown. In fig. 5.5(a) – the locations of the 41 screw axes and 4 rotatory-inversion axes are indicated and in fig. 5.5(b) and (c) the molecules related by these symmetry elements are depicted in stereo from a side on view. As can be seen in fig. 5.5(b) and (c), there are a myriad of portal- to-side interactions in this structure with excellent portal coverage by neighbouring Q8 molceules. The Q8 molecules are separated by O…H distances in the range of 2.4 - 2.7 Å. These Q8-Q8 interactions dominate this structure and the dianions, which cannot lie over the portals due to electrostatic repulsions, are left to fill the vacant gaps generated by the Q8 motifs. Chapter 5: The Crystal Structures of the New Compounds. Page 183

KEY 4 axis =

41 axis =

SPACE GROUP = I41/a

y z (a)

– Fig. 5.5: The crystal packing of (Q8)2(PtCl6)3(H3O)6(H2O)18. (a) a view of the 4 and the 41 axes viewed – down the z-axes. The atoms Pt1 and Cl2 lie on the 4 site. (b) a view of the 41 screw axis in stereo and (c) – a view of the 4 axis in stereo. Chapter 5: The Crystal Structures of the New Compounds. Page 184

Only the Pt2 anion is included in the spiral of Q8 interactions generated by the 41 screw 2– shown in fig. 5.6(a). As can be seen in fig. 5.6(a), there is one PtCl6 at the side of each Q8 molecule with one Cl pointing towards a carbonyl carbon. Typical Cl…C, N = 3.5 – 3.9 Å.

y y

x x

(a) (b) 2– Fig. 5.6: The distribution of the PtCl6 dianions about (a) the 41 screw axis (in stereo) - Pt2 anions and – (b) about the 4 axis – Pt1 surrounded by Pt2 anions.

Figure 5.6(b) shows how the anions are clustered between the groups of four Q8 – molecules about the 4 axis. There are four Pt2 anions and one Pt1 anion in this cluster and each type occupies a different position and interacts differently with the Q8s. Half of the eight triangular faces of the Pt1 anion lie mainly over the glycoluril rings of the four surrounding Q8 molecules, with Cl…C, N = 3.3-3.8 Å. The other four faces Chapter 5: The Crystal Structures of the New Compounds. Page 185 interact with the chlorine ligands of the Pt2 anions via Cl…Cl = 3.9 Å. The four surrounding Pt2 anions behave differently – individual chlorine ligands rather than the triangular faces point at the glycoluril rings with longer Cl…C, N = 3.7-3.8 Å. The interactions between the chlorine ligands and the Q8 molecules in this structure are similar to those seen in the compounds [(Cl@Q5)@Q10](HCl)11(H2O)25.75 (§ 3.9) and … in Q6(SnCl6)(H3O)2(H2O)x (§ 5.8), albeit with somewhat longer distances. The Cl Cl distances are also longer in this structure than in previously reported structures. Some of these interactions are shown below in fig. 5.7.

Fig. 5.7:(a) The interaction between the Pt1 anion and Q. One triangular face is outlined and lies parallel over a glycoluril ring. Cl…Q distances are listed in the text. (b) The interaction between Pt1 (centre) and four surrounding Pt2 anions. Cl … Cl distances = 3.9 Å are shown in pink and white. One (a) triangular face is outlined and is seen pointing towards a Pt2 anion. (b)

There are two half water oxygens residing inside each portal of the Q8 with O …O = 2.9, 3.2 and 3.3 Å. Another two oxygens are located above the portal H2O portal with O …O = 2.6 and 2.8 Å. The rest of the oxygens surround the outer edges H2O portal of the portals and the equatorial region of the Q8 with O …O = 3.2-3.5 Å and H2O portal O …H = 2.6 and 2.8 Å. These water oxygens are engaged in a hydrogen bonding H2O Q8 network separated by O…O distances of 2.4-3.0 Å.

5.3.3: A comparison with literature structures. There are three other Qn structure in the literature that crystallise in the space group 2– I41/a. In the structure of Q8(H2SO4)2(H2O)30 (Refcode = LIRTOV) the SO4 2– molecules occupy similar positions to the PtCl6 anions in Chapter 5: The Crystal Structures of the New Compounds. Page 186

(Q8)2(PtCl6)3(H3O)6(H2O)18, although none lie on a symmetry site. The Qn-Qn interactions are almost identical with similar portal coverage and O…H distances. It is not surprising that the two structures should have very similar crystal structures as they both possess anions and this allows the Qns to engage in the highly favourable portal- to-side motif as the portals remain uncovered.

The compounds {trans-[Cu(en)2(H2O)2]@Q8}Q8Cl2(H2O)42 (Refcode = KANXIH) and {trans-[Cu(en)2(H2O)2]@Q8}Cl2(H2O)17 (Refcode = XAJXOW) also crystallise in the space group I41/a with similar interactions.

Of course this compound, (Q8)2(PtCl6)3(H3O)6(H2O)18, can also crystallise in a different packing arrangement. These crystals formed following the recrystallisation of the compound (Q8)3(PtCl6)4(H3O)8(H2O)x (§ 5.2). Although both compounds,

(Q8)2(PtCl6)3(H3O)6(H2O)18 and (Q8)3(PtCl6)4(H3O)8(H2O)x, feature the same species – they crystallise in different space groups (I41/a versus R3) but they both feature portal- to-side interactions and importantly both compounds crystallise in high symmetry space groups, further demonstrating the high favourability of the portal-to-side interaction.

5.4: The Compound (Q7)(Cr3O10)(H3O)2(H2O)x.

The synthesis of this compound is described in chapter 4, § 4.5.3.

5.4.1: Crystallographic Information. – This compound crystallises in the trigonal space group R3. The cell dimensions are: a = b = 57.678 Å and c = 13.706 Å; V = 45597 Å3; Z = 18. A long thin orange crystal of dimensions 0.12 x 0.13 x 0.73 mm was used for the collection. The collection was carried out at 150 K to minimise dynamic disorder. After an initial trial, the refinement converged to R = 0.123 despite a large amount of disordered solvent and residual electron density. The Q7 and the anions were well defined with most atoms having + good to moderately good thermal parameters but only four solvent water or H3O oxygens were equally well defined. Therefore, the PLATON SQUEEZE function was Chapter 5: The Crystal Structures of the New Compounds. Page 187 employed to complete the refinement of this structure. The contribution to the intensity data from 1851 electrons, equivalent to 185 water molecules per unit cell, was eliminated to give a final R = 0.075. All trichromate anions are crystallographically equivalent and all Q7s are also equivalent. Neither the Q7 nor the trichromate anion has any higher symmetry themselves. All the atoms in the Q7 and trichromate molecules were given full + occupancy and made anisotropic. When the four solvent water/H3O oxygens in the asymmetric unit were given half occupancies their thermal parameters became acceptable. In order to balance the charges in the asymmetric unit there must be two + H3O cations, likely to be found near the portal oxygens. Therefore the formula of the compound is (Q7)(Cr3O10)(H3O)2(H2O)x. All hydrogens on Q7 were placed in geometrically idealised positions (C–H = 1.00 Å) and constrained to Uiso(H) =

1.2Ueq(C). Some thermal parameters are large for the well defined portion of this structure. However, as these atoms have full occupancy (none are situated on a symmetry site) and the other atoms in the same molecule have full occupancy with acceptable U values, no further work was done to try and improve these large thermal parameters.

The cif for this structure appears in Appendix I and an electronic version is available on the CD provided with this thesis.

5.4.2: The Crystal Packing. – The structure crystallises in the high symmetry space group R3 despite neither Q7 nor the trichromate anion having high symmetry themselves. As seen in fig. 5.8(a) the Q7s are arranged into rings lying in the xy plane and comprised of six Q7s surrounding a 17 Å diameter cavity filled with solvent water. Using the InsightII® Soak command it has been calculated that 100 waters fit in the cavity of one ring. When viewed down the z-axis, the rings of one layer eclipse those of the layers above and below leading to the formation of large channels, running down the z–axis, that are filled with disordered solvent water. As described in § 5.4.1, most of these solvent molecules cannot be located. The Q7 molecules lie parallel to those in the layers above and below but there is little hydrogen bonding between these Q7s. Instead, the rings Chapter 5: The Crystal Structures of the New Compounds. Page 188 have enough space between them to accommodate solvent molecules and the only + solvent water/H3O oxygen atoms located in this structure are found in these regions. Of these four, only one is located in the portal of the Q7 and the other three surround the Q7 molecule as shown in figs. 5.8(a) and (b). The distances between these oxygens and the Q7 portal oxygens are 2.9 Å.

The six Q7s of the one ring lie in a puckered formation and they engage in hydrogen bonding with each other and they are angled so that their portals are partly covered by their neighbour’s side. Although the portal-to-side coverage is not good, there are H…H distances = 2.1 Å and H…O distances = 2.3, 2.6, 2.7 Å involving both methylene and methine hydrogens. Each ring has eighteen trichromate anions in close proxmity, six in the same plane as the Q7s and six above and below the plane. Figure 5.8(b) illustrates how these anions are positioned near the Q7s and away from the channels with typical distances of 2.4 and 2.6 Å between the Q7s’ hydrogens and the trichromate oxygens.

In addition, the terminal CrO3 groups of the anions lie over the 5-membered rings of the Q7 molecules with C…O = 3.0-3.3 Å ; N…O = 3.1, 3.2, 3.3, 3.5 Å and O…O = 3.2 Å. The rings belonging to adjacent channels are offset from one another: fig. 5.8(c) shows how one channel is shifted a third of a unit cell along the z–axis so that one ring will lie in the groove created by the two rings of the adjacent channels. There are a number of Q7-Q7 interactions due to this positioning: C…O = 3.1, 3.4, 3.5, 3.6 Å; N…O = 3.4 Å.

A 3-fold rotatory inversion axis lies at the centre of each of the rings and a 31 screw axis lies between rings. Their locations are depicted in fig. 5.9. The stereo view in fig. 5.9 shows 3 pairs of parallel Q7s from three different rings. As mentioned earlier, the Q7s of neighbouring channels do not lie in the same plane but lie offset by a third of a unit cell as a result of the action of the 31 screw axis. Figure 5.9 also illustrates (in stereo view) how the Q7s and the eclipsing rings of the one channel are parallel to each other while the Q7s of neighbouring rings lie at an angle to one another. Chapter 5: The Crystal Structures of the New Compounds. Page 189 Chapter 5: The Crystal Structures of the New Compounds. Page 190

KEY 3 axis = z

31 axis =

Fig. 5.9: The crystal packing of (Q7)(Cr3O10)(H3O)2(H2O)x viewed down the z–axis (top) with the roto- inversion and screw axes indicated. A stereo view of the molecules related by the screw axis is pictured inset. The anions, solvent and hydrogens have been omitted for clarity.

This crystal structure of (Q7)(Cr3O10)(H3O)2(H2O)x features a metal complex uncoordinated to a Qn, more examples of which appear in chapter 3, § 3.4. This structure, (Q7)(Cr3O10)(H3O)2(H2O)x, follows the packing trends of these and other Qn structures, that is, as there is no possibility of any species in this structure coordinating to and capping the portals, the Q7 molecules are free to engage in portal-to-side interactions. It is one of only two structures among the new compounds to feature a 31 – or 3 axis (the other being (Q8)3(PtCl6)4(H3O)8(H2O)x described in § 5.2) and is one of – only a handful of Qn compounds that crystallise in the high symmetry space group R3, Chapter 5: The Crystal Structures of the New Compounds. Page 191 allowing every Q7 molecule in this structure to engage in the favourable portal-to-side interaction.

The compound {[Ni(cyclam)]@Q8}Cl2(H2O)16 (Refcode = KANXED) (chapter 3, § 3.3) also has a similar crystal structure with channels formed by the eclipsing rings of

Q8 molecules. However, unlike in (Q7)(Cr3O10)(H3O)2(H2O)x, neighbouring rings of Q8 molecules are not offset but rather lie in the same plane.

While there are multitude of Q7-Q7 attractive interactions in this structure, they do not provide the stability to prevent decomposition of the crystals out of solution. These crystals are extremely unstable and decompose within minutes, losing their solid form and their colour. If kept under the preparative solution they last for only several months, until the crystals and the mother liquor darken. This instability is almost certainly driven by the large solvent filled channels of the crystal structure. The colour change (from orange to blue/green) that accompanies the fast decomposition out of solution implies that the trichromate anion is oxidising some species, possibly Q7. Q7 is the only compound available to be oxidised under these conditions and this is in keeping with the observation that the crystals appear to be deliquescent, indicating that the Q7 may be decomposing.

2– 5.4.3: The occurrence of the Cr3O10 anion. The trichromate anion is generally synthesised from an aqueous solution containing an excess of CrO3, chromium trioxide. There are many examples in the literature of the crystallisation of this dianion with a simple monoatomic cation and there are no other instances of co-crystallisation with a macrocycle. This anion can exist in both the angular and extended forms (fig. 5.10) and in this structure it exists in the angular form so that it can fit well to the curved sides of the Q7s in order to maximise the interactions described previously.

It is likely that the dichromate anion forms first and then reacts with a further CrO3 unit 2– to become Cr3O10 . Little information appears in the literature on the stability, uses or properties of this [10] anion. Behr et al. report that the salt (Bu4N)2(Cr3O10) can be recrystallised from water undecomposed, lending weight to the argument that it is the large solvent filled Chapter 5: The Crystal Structures of the New Compounds. Page 192 channels in the structure that lead to the instability of the crystals rather than a sensitivity of the trichromate to moisture. Although the trichromate anion could fit inside the cavity of Q7 it is not included due to the repulsion between the portal oxygens and the trichromate oxygens that both carry partial negative charges.

(a) (b) Fig. 5.10: The two forms of trichromate are pictured above; (a) is the angular form found in (Q7)(Cr3O10)(H3O)2(H2O)x and (b) is the linear form found in the compound FURNIP (dipyrazinium trichromate).

5.5: The Compound [(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17.

Details of the synthesis of this compound appears in chapter 4, § 4.5.4.

5.5.1: Crystallographic Information.

The compound crystallises in the monoclinic space group P21/c. The cell dimensions are: a = 25.76 Å, b = 21.85 Å and c = 29.42 Å, E = 91.36q; V = 16559 Å3; Z = 4, final R = 0.046. An irregularly shaped, deep-blue crystal of dimensions 0.22 x 0.31 x 0.69 mm was used for the data collection. The Q6 complex, all the anions and the solvent water are well defined. Four waters per asymmetric unit were assigned half occupancy in order to improve their thermal parameters and the overall refinement of the structure.

There are two unique Na–H2O clusters that lie between pairs of Q6s in this structure. As only the oxygen atom was located (and not the hydrogens) it cannot be determined crystallographically whether the clusters involve hydroxides or waters. However, when the charges of the known components are balanced it was determined that the bridging ligands of the Na clusters are neutral and therefore waters. Chapter 5: The Crystal Structures of the New Compounds. Page 193

Each Na is bound in an octahedral geometry to four water oxygens and two portal oxygens. One cluster involves three Na cations, bridging water oxygens and non- bridging water ligands. All atoms in this cluster were given full occupancy. The other cluster features six disordered Na cations and eight disordered and four fully occupied bridging water oxygens. Further details appear in § 5.5.2. All hydrogens were placed in geometrically idealised positions (C–H = 1.00 Å) and constrained to Uiso(H) = 1.2Ueq(C). No attempt was made to locate any water hydrogens. The cif for this structure appears in Appendix I and an electronic version is available on the CD provided with this thesis.

5.5.2: The Crystal Packing.

The structure [(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17 contains a 1D coordination polymer, such as those described in chapter 3, § 3.5. As it features columns of Q6s connected via the Na cations coordinated to their portals, the Q6s cannot engage in portal-to-side interactions. The columns run along the y-axis with

+ 2+ 2– – the [CoCl(H2O)5] and [Co(H2O)6] cations, the [CoCl4] and Cl anions and the water molecules arranged around the columns. Some of the Q6 cavities contain water molecules as will be explained later. The packing of this structure is shown in fig. 5.11 with one column shown in detail. There are two distinct types of columns in this structure but they have several features in common: each Na is coordinated to two portal oxygens and additionally bound to four water ligands.

The structure contains alternating layers of these columns. The columns of the one layer lie side by side in the direction parallel to the z-axis but columns of neighbouring layers are displaced so that the Q6s of one column lie near the Na–H2O clusters of the other. This is illustrated in fig. 5.12.

Chapter 5: The Crystal Structures of the New Compounds. Page 194

z x

90Þ

Layer 2

Layer 1

Fig. 5.11: The crystal packing of [(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17 with a detail of one column shown at right. The two distinct columns occupy different layers of the structure as indicated in the figure above. Na is light green, Co is light blue and Cl is gold.

Layer 1

Fig. 5.12(a): At left are three columns from the same layer (layer 1). The Q6s lie side by

side as do the Na–H2O clusters. The columns are separated by the various cations and anions. Hydrogens, waters and chloride anions have been omitted for clarity.

Na is coloured light green; Co is coloured light blue and Cl is coloured gold. y

z Chapter 5: The Crystal Structures of the New Compounds. Page 195

Fig. 5.12(b): At right are three columns from neighbouring layers. The columns are shifted relative to one another so that the bulge of one column fits into the groove of its neighbour. The columns are 2– separated by the CoCl4 , 2+ Co(H2O)6 , + – CoCl(H2O)5 and Cl ions. y Hydrogens, waters and chloride anions have been omitted for clarity. Layer 1Layer 2 Layer 1

Neighbouring columns of the same layer are related by the action of the c-glide planes normal to b, at y = 1/4, 3/4, as illustrated in fig. 5.12(a). The cations and anions surrounding the columns prevent any interactions between Q6s of different columns of either layer.

The columns of layer 1 feature a well defined Na–H2O cluster, of formula Na3(P-

H2O)4(H2O)4, and all atoms have full occupancy (see fig. 5.13(a)). Two Na atoms are bound to two portal oxygens (bond length = 2.3 – 2.4 Å), three bridging oxygens (2.3 – 2.5 Å) and a water molecule (2.5 Å). The third Na atom is bound to two portal oxygens (2.3 Å), two bridging oxygens (2.3 – 2.5 Å) and two water ligands (2.4 – 2.5 Å). The Q6 molecules of this column contain a water molecule assigned half occupancy in their cavities. One singly bound water ligand protrudes into the Q6 cavity and engages in hydrogen bonding with one portal oxygen, with an O…O distance of 2.9 Å. It does not hydrogen bond with the water molecule inside the Q6 cavity. A bridging oxygen shared by two of the Na atoms also protrudes into the Q6 cavity but does not engage in hydrogen bonding. Chapter 5: The Crystal Structures of the New Compounds. Page 196

Fig.5.1 3:(a) All the atoms of the cluster of column 1 have full occupancy. Each Q6 in this column has a water molecule in its cavity; (b) In contrast, all the atoms in the cluster of column 2 are disordered with the exception of four water ligands. Only every second Q6 in this column has a water in its cavity (disordered over two sites).

(a) (b)

The columns of layer 2 feature a disordered Na–H2O cluster of formula Na3(P-(H2O)8 (see fig. 5.13(b)). The three Na cations are disordered over two sites as are four of the bridging water oxygens. The other four bridging water oxygens were assigned full occupancy. Each Na is coordinated to two portal oxygens with bond lengths varying from 2.1 – 2.5 Å. The Na–Obridging bond lengths vary from 2.1 – 2.6 Å. The columns of layer 2 are composed of two crystallographically unique Q6s. Each of these has an inversion site at its centre but only one contains a water molecule disordered over two sites. As for column 1, there are bridging waters protruding into the Q6 cavity. They also engage in hydrogen bonding with the portal oxygens as well as the disordered water molecule in the cavity, with O…O distances as short as 2.4 Å between the water molecule and a nearby disordered bridging water.

2– Although the Q6 molecules of column 1 are surrounded by four [CoCl4] anions, the Cl ligands do not point directly to the five membered glycoluril rings as occurs in other structures. Instead they lie about the equatorial region of the Q6, away from the portals and the partial negative charge they carry. There are Cl…H distances = 2.9 Å. Four Cl– anions also surround the Q6s but, as these are close to the plane of the portal … oxygens, there are few Cl Q6 interactions. The Na–H2O clusters are surrounded by Chapter 5: The Crystal Structures of the New Compounds. Page 197

2– 2+ two [CoCl4] anions and also by four [Co(H2O)6] cations. Two of these cations engage in hydrogen bonding with the water ligands of the cluster. The chloride anions also lie near these cations with O…Cl distances of 3.1 Å and 3.2 Å. A few of the water molecules engage in hydrogen bonding with the cluster oxygens (O…O = 2.9 Å). The Q6 molecules of column 2 have a different arrangement of anions and cations about

2– 2+ them. About the equator of the Q6s lie four [CoCl4] anions and two [Co(H2O)6]

2– cations. As for column 1, the Cl ligands of the [CoCl4] do not point to the faces of these Q6s but rather they point towards the equatorial plane of the Q6 with Cl…H distances < 2.8 Å. The four chloride anions again lie level with the carbonyl groups.

2– 2+ The Na–H2O cluster is surrounded by two [CoCl4] anions and four [CoCl(H2O)5]

2+ cations. The water ligands of the [CoCl(H2O)5] cations point towards the cluster but despite this only two of these cations engage in hydrogen bonding with the cluster’s oxygens (O…O = 2.8 Å). The Cl– anions lie near the clusters with a Cl…O of 3.1 Å. There is no hydrogen bonding between the water molecules and the cluster oxygens in column 2.

Column 2 KEY Column 1 Column 1

21 axis =

Fig. 5.14: The locations of

the 21 screw axes are indicated on the figure at left. One of these axes runs down the centre of column 1, parallel to the y axis; the other axis runs between z columns of type 2.

x Chapter 5: The Crystal Structures of the New Compounds. Page 198

In fig. 5.14 the locations of the 21 screw axes are presented. The views of columns 1 and 2 in fig. 5.12(b) show the action of the 21 screw axis symmetry element on the molecules.

+ 2+ 5.5.3: The formation and co-crystallisation of [CoCl(H2O)5] , [Co(H2O)6] and

2– [CoCl4] . + The incidence of the [CoCl(H2O)5] cation in a crystal structure is rare with no cases reported in the CSD and there are no other examples of all three ions co-crystallising.

2– 2+ The presence of both [CoCl4] and [Co(H2O)6] in the same crystal structure is also rare - only one example exists in the CSD. Originally, the crystallisation mixture in this work was a deep purple colour indicating a mixture of octahedral and tetrahedral species. Over the months it took for the crystals to form, the crystallisation mixture

2– turned blue indicating the prevalence of the tetrahedral [CoCl4] anion. Studies by Zeltmann et al.[11] and by Pan et al.[12] show that there is a very narrow Cl– concentration range where all three ions can coexist. In studies measuring the + absorption spectra of Co(II) species, Pan et al. concluded that the [CoCl(H2O)5] species was the most energetically favoured of the possible octahedral cobalt-chloride complexes but as the Cl– concentration is increased the more highly chlorinated species

2– – form, leading to the formation of the [CoCl4] anion at high Cl concentrations. This + – may explain why the [CoCl(H2O)5] is so rare – the condition of low Cl concentration is rarely encountered in experimental work as it is often a counter anion and carries a single charge. It is postulated that the presence of the highly insoluble Q6 drove the crystallisation and that the various Co species were trapped in the crystalline phase.

5.5.4: The Incidence of columnar motifs in Qn structures. There are twelve other crystal structures in the literature that feature Qn molecules organised in columns, connected via the coordination of metal cations to their portal oxygens. The structures and crystal packing of these twelve are described in detail in chapter 3, § 3.5. In seven of the structures, MAPWUV, XAGWEI, UCALEP, IBAZER, IBAZIV, IWUVOL and CCDC-257203, the columns run parallel to one another but are Chapter 5: The Crystal Structures of the New Compounds. Page 199 shifted such that the groove of one column lies beside the bulge of a neighbouring column to minimise repulsions. This motif is also featured between columns of different layers in the structure described here (see fig. 5.12(b)). In the other three structures, IMOBOB, IMOBUH and IWUVEB, the columns are staggered so that each of the metal clusters does not lie centred over both Qn portals. This enables the columns to lie side by side with minimal repulsions.

Of the twelve 1D coordination polymer structures, [(Q6)(Na3(H2O)8)]2[CoCl4]4

[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17 is the only one to feature three metal atoms between a pair of Qn molecules. It most closely resembles XAGWEI due to its close packed crystal structure and the similarity in the shape of the columns.

cis 5.6: The compound {[ -SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23.

The synthesis of this compound is described in chapter 4, § 4.5.5.

5.6.1: Crystallographic Information. The compound crystallises in the orthorhombic space group Fdd2. The cell dimensions are: a = 47.180 Å, b = 71.699 Å and c = 18.939 Å; V = 64066 Å3; Z = 16. A long, thin, colourless crystal of dimensions 0.09 x 0.09 x 0.74 mm was used for the data collection. The collection was carried out at 150 K to reduce dynamic disorder. Although there was a large amount of disordered solvent, the complex and the anions are well defined with R = 0.061. The crystal structure solution and refinement were performed by Mr. + Don Craig. There are 30 water oxygens, six of which have been labelled as H3O cations to balance charges. Only two of these water oxygens have half occupancy, one of which lies on a two-fold rotation axis. No attempt was made to locate any water hydrogens. Other hydrogens were placed in geometrically idealised places (C-H = 1.0 Å) and constrained to Uiso(H) = Ueq(C).

The cif for this structure appears in Appendix I and an electronic version is available on the CD provided with this thesis. Chapter 5: The Crystal Structures of the New Compounds. Page 200

5.6.2: Introduction.

This structure contains the host-guest complex [cis-SnCl4(H2O)2]@Q7 formed by the co-crystallisation of SnCl4 and Q7 under acidic conditions. It is the first example of a metal halide compound entering the cavity of a Qn. There are two crystallographically unique Q7s in the compound {[cis-

SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23. One has a guest with 50% occupancy (1) and the other with 75% occupancy (2).

Fig. 5.15: The two unique inclusion complexes are pictured above. The diagrams depict the intermolecular contacts between host and guest (blue and white bonds represent hydrogen bonding and the red and white bonds the Cl…Q7 interactions). Space filling views of the two complexes show how the guest fits inside the cavity and does not protrude out of the portals.

The Q7s are slightly differently shaped, as are the Sn–O (water) bonds in each guest molecule, leading to different intermolecular bonding. The host-guest complex is stabilised by the hydrogen bonding between the guests’ water hydrogens and the portal Chapter 5: The Crystal Structures of the New Compounds. Page 201 oxygens that are less than 2 Å apart. In order for these short contacts to occur, the guest molecule is offset from the Q7’s equatorial plane by 0.9 Å. Despite this, the guest fits in neatly and entirely within the Q7, with no protrusions, as shown in fig. 5.15.

It is likely that the tetrahedral SnCl4 passes through the portal of the Q7 and, once inside, coordinates to two water molecules to form cis-SnCl4(H2O)2. A molecular modelling study on the passage of SnCl4 through the portal of Q7 was conducted and the results appear in chapter 6, § 6.3.6.2. The study shows that the formation of the complex SnCl4@Q7 is favourable.

5.6.3: The Crystal Packing. The packing of the structure is depicted in fig. 5.16 and, as for many other Qn structures, portal-to-side interactions feature prominently.

z y 1 2

Fig. 5.16: One unit cell viewed down the z–axis. The zig-zag chains extend down the x–axis (featuring molecules of 1) and the z–axis (featuring molecules of 2). Only the Q7s are shown in the figure and their hydrogens have been omitted for clarity.

The packing involves the two unique [cis-SnCl4(H2O)2]@Q7 complexes each engaged in a unique zig-zag chain, with chains of 1 running along the x–axis and chains of 2 running along the z–axis. In addition, molecules of 1 border the zig-zag chain composed of molecules of 2. The portal-to-side interactions between molecules of 2, Chapter 5: The Crystal Structures of the New Compounds. Page 202 involving significant degrees of portal overlap, are further stabilised by the attractive interactions between the methylene hydrogens of one Q7 and the waters of the guest of the neighbouring Q7. This is highlighted in detail in fig. 5.17.

90Þ

Fig. 5.17: The zig-zag chain involving molecules of 2. The blue and white bonds represent the contacts between the guest waters of one complex and the Q7 of a neighbouring complex. The purple lines indicate the other stabilising interactions between the Q7s.

The interaction depicted in fig. 5.17 involves a methylene hydrogen of one Q7 in close proximity to both waters of the guest molecule of a neighbouring Q7, with H…O = 2.6 Å (blue and white lines in fig. 5.17). The arrangement also features H…O = 2.4, 2.5, 2.6 Å between the atoms of two neighbouring Q7s (purple lines in fig. 5.17). Unlike the packing motifs involving 2, there are no equivalent interactions between the Q7s of type 1. The only notable interaction is an H…H distance of 2.3 Å. The guest molecules do not contribute to any stabilising packing motifs. Figure 5.18 shows the chains and layer made up of molecules of 1. As can be seen in the figure, the chains are 2– separated by the SnCl6 anions.

There is a number of H…O interactions between 1 and 2 although the guest molecules do not contribute to any stabilising interactions as they do in the case of interactions between the Q7s of type 2. Typical H…O distances between the Q7s of 1 and 2 are 2.3 – 2.5 Å. Chapter 5: The Crystal Structures of the New Compounds. Page 203

90Þ x

2– Fig. 5.18: The zig-zag chain involving the type 1 complex. The chains are separated by the SnCl6 dianions.

2– Fig. 5.19: The arrangement of SnCl6 anions about 1 and 2. The pink and blue striped lines represent Cl…Q7 distances of Cl…H = 2.6, 2.7 Å and Cl…C, N = 3.2, 3.3 Å and the purple lines represent Cl}Cl distances of 3.7 and 3.8 Å.

2– The Q7s in this structure are surrounded by SnCl6 anions, giving rise to multiple Cl…Q7 interactions and these are highlighted in fig. 5.19. The interactions between the anions and the Q7 molecules here are similar to those described in § 3.9 (Q5@Q10) ,with the chloride ions pointing to the glycoluril rings of the Q10. As expected, the Chapter 5: The Crystal Structures of the New Compounds. Page 204

2– SnCl6 anions do not crystallise over the portals due to the electrostatic repulsions between the portal oxygens and the chloride ligands. This factor, in combination with the guest molecules’ ability to stabilise Q7-Q7 interactions, ensures that the portal-to- side motif occurs prolifically in the crystal structure of {[cis-

SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23, more so than in many other Qn containing structures described in chapter 3.

The bond lengths in the cis-SnCl4(H2O)2 complex are similar to those found in the literature. Both 1 and 2 have Sn–Cl bonds = 2.3, 2.4 Å; 1 has Sn–O bonds of 2.0 and 2.3 Å while 2 has Sn–O bonds of 2.1 Å. These bond lengths are typical of the cis-

SnCl4(H2O)2 complex and it therefore does not undergo distortion, via bond length shortening, in order to fit inside the Q7 cavity. In fact, the Sn–O bond of 2.3 Å is longer than the average of 2.1 Å and this bond lengthening is probably an attempt to maximise the hydrogen bonding between host and guest molecule. The hydrogen bonding between the water ligands and the portal oxygens involve O…O distances = 2.7, 2.8, 2.9 Å (molecule 1) and 2.7, 2.8 Å (for molecule 2). The Cl…Q7 interactions, represented by red and white stripes in fig. 5.15, include Cl…C, N distances < 3.3 Å. In molecule 2, the guest is orientated so that three of the Cl ligands each point towards glycoluril rings. In molecule 1, only one Cl ligand points towards a glycoluril ring. As already mentioned, the Sn atom of each cis-SnCl4(H2O)2 complex is located at a distance of 0.9 Å from the equatorial plane of the Q7 in order to maximise hydrogen bonding.

The locations of the symmetry elements in the space group Fdd2 are highlighted in fig.

5.20. The zig-zag chains of 2 are formed by the action of the 21 screw axis while a water molecule lies on the two-fold site. The diagonal glide planes lie parallel to both the yz planes (x =1/8, 3/8, 5/8 and 7/8) and the xz planes (y = 1/8, 3/8, 5/8 and 7/8). Chapter 5: The Crystal Structures of the New Compounds. Page 205

KEY

2-fold rotation axis = y

21 axis = x

Fig. 5.20: The positions of the 21 screw and the two-fold axes in the space group Fdd2 are indicated above. The positions of the glide planes have been omitted for clarity. Water molecules and hydrogen atoms have been omitted for clarity.

Although not included in any diagrams in this section so far, water features prominently in this crystal structure. As expected, it crystallises near the portal oxygens with a heavy concentration over the portal housing the chlorinated end of the guest molecule. Due to the off-centring of the guest molecule there is more space near this portal. This … is clearly shown in fig. 5.21. Typical Owater Oportal distances are in the range 2.6–2.9 … Å. Typical Owater HQ7 distances lie in the range 2.5–2.9 Å. A part of the extended network of hydrogen bonded water is shown in fig. 5.21. Chapter 5: The Crystal Structures of the New Compounds. Page 206

1 2

Fig. 5.21: The arrangement of water molecules about the complexes 1 and 2. The blue and white bonds represent hydrogen bonding and other short O…H distances. The Q7 is shown in grey for clarity.

5.6.4: The reported occurrence of SnCl4(H2O)2 co-crystallised with macrocycles. Other macrocycles such as calixarenes, cyclodextrins and crown ethers are able to include SnCl4(H2O)2 as a guest and a search of the CSD was performed to find if such complexes existed. The interactions between these macrocycles and the guest molecule

SnCl4(H2O)2, in the crystalline phase, were examined. There are no instances in the CSD of a co-crystallisation of the tin complex with cyclodextrins or calixarenes and only four with the 18-crown ether, with one instance of a SnCl4 molecule directly bound to the oxygens of this macrocycle.

Of the structures containing SnCl4(H2O)2, only two exhibit the hydrogen bonding between the water ligands and the ring’s oxygens as seen in {[cis-

SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23.

In the compound 2(cis–SnCl4(H2O)2)(18-crown-6)2(CH3CN)2[CH3(CH2)4CH3](H2O)4

(Refcode = XIHNEH), a cis–SnCl4(H2O)2 points its water ligands to two crown ethers in order to maximise the favourable hydrogen bonding. This leaves room for a water molecule to lie over each side of the ring and these also engage in hydrogen bonding … … with the cis–SnCl4(H2O)2 complex, with H O distances of 1.7 and 1.9 Å (O O = 2.5 and 2.7 Å). This is depicted in fig. 5.22. Chapter 5: The Crystal Structures of the New Compounds. Page 207

Fig. 5.22: The interaction between cis-SnCl4(H2O) and the crown ether in XIHNEH. The blue and white bonds indicate the hydrogen bonding with H…O distances of 1.7 and 1.9 Å

The compound (cis–SnCl4(H2O)2)(18-crown-6)(CHCl3)2(H2O)2 (Refcode = COCLUB) … … has an identical arrangement with the OSn Ocrown = 2.6 Å and the OSn Owater = 2.6 Å.

5.6.5: Comparison with literature structures. The literature contains four other examples of a Qn crystal structure featuring a metal containing guest. Section 3.3 describes the packing of these host-guest complexes. The guest molecules include ferrocene (Refcode not available), trans-[Cu(en)2(H2O)2] (Refcode = KANXIH, XAJXOW) and [Cu(cyclam)]2+ (Refcode = YAVQUH). In that complex, the ligand cyclam (1,4,8,11–tetraazacyclotetradecane) or cyclen (1,4,7,10– tetraazacyclododecane) is first encapsulated in the cavity of Q8 followed by its

2+ coordination to Cu . In {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23, the formation of the complex is believed to occur via the insertion of SnCl4 followed by its coordination of two waters.

The compounds YAVQUH and {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 are also the only two examples of Qn structures in which the guest molecule is involved in the portal-to-side interaction, adding further stability to the prolific motif. Chapter 5: The Crystal Structures of the New Compounds. Page 208

5.7: The Compound (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24.

The synthesis of this compound is described in chapter 4, § 4.5.6.

5.7.1: Introduction. The compound described in the previous section, § 5.6, formed from a recrystallisation mixture that had been heated to boiling for approximately 10 minutes. Although this led to the formation of the inclusion compound [cis-SnCl4(H2O)2]@Q7, the occupancies of the host cavities were only 50% and 75%. The possibility of incomplete inclusion being caused by the slow passage of the guest molecule through the portal was considered and so the recrystallisation was repeated with the mixture kept at an elevated temperature for a longer time. However, instead of a Q7 cavity with full occupancy this experiment led to the formation of a new compound,

(Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24 and its crystal packing is described below. Of all the Qn structures in the CSD this is the only structure containing a mix of Qns, with the exception of Q5@Q10. It is unlikely that the Q7 of the original recrystallisation mixture decomposed to Q6 after being kept at a higher temperature for an extended period. Day et al. have reported that although the higher Qns will decompose to the more stable Q6 under these conditions, Q7 appears stable enough to resist this transformation[13]. It is probable that the Q5 may have been present as a trace impurity in the original batch of Q7, a common occurrence, and this may also be the case for the Q6 present.

5.7.2: Crystallographic Information.

The compound crystallises in the monoclinic space group P21/n. The cell dimensions are: a = 21.339 Å, b = 32.811 Å and c = 21.579 Å, E = 95.77q; V = 15109 Å3; Z = 2. The collection was carried out at 150 K to eliminate dynamic disorder. Colourless hexagonal plates, with one elongated axis, of dimensions 0.29 x 0.29 x 0.23 x 0.07 mm were used for the collection. The solution and refinement of this structure was performed by Mr. Don Craig using RAELS with the final R factor = 0.088. One of the 2– + SnCl6 anions is disordered over two sites. Not all water/H3O oxygens were assigned full occupancy (4 have half occupancy) and no attempt was made to locate any water Chapter 5: The Crystal Structures of the New Compounds. Page 209 hydrogens. Other hydrogens were placed in geometrically idealised places (C-H = 1.0

Å) and constrained to Uiso(H) = Ueq(C).

A cif for this structure appears in Appendix I and an electronic version is available on the CD provided with this thesis.

5.7.3: The Crystal Packing. This compound contains molecules of both Q5 and Q6, the only known example of such a compound. Each Q5 contains a chloride ion almost centred in its cavity (0.3 Å from the equatorial plane) and an oxygen at both portals directly in line with the chloride ion, in the same fashion as the Q5 molecule of Q5@Q10. These oxygens are + likely to be H3O cations attracted to this position by the partial negative charge about the portal oxygens, and possibly by the negative charge on the Cl–. There are four of these Cl@Q5 complexes for every Q6. In chapter 3, and in other chapters in this thesis, the unlikelihood of an anion being encapsulated in a Qn is discussed. The crystal structure discussed here features a Cl– inside a Q5. Due to the Cl– anion’s almost centred location in the cavity and the presence of two waters symmetrically located at each Q5 portal, it is unlikely that an HCl is contained in the Qs. Hence, this structure features a rare example of a single small anion encapsulated in a Qn. The Qn molecules in this compound are not coordinated and are therefore free to 2– engage in portal-to-side interactions. The SnCl6 anions do not approach the portal oxygens, due to electrostatic repulsions, but rather crystallise about the sides of the Q5 and Q6 molecules. As a result there are portal-to-side interactions, but only between the Q5 and Q6 molecules and not between the Q5 molecules. The Q6 molecules are situated too far apart to interact with each other. The crystal packing consists of layers of Q5s separated by layers of widely dispersed Q6 molecules. In fig. 5.23(a) a single layer of Q5 molecules is shown with the positions of the 21 screw axes highlighted. Figure 5.23(b) shows a view of the same layer with the Q6 molecules (in pink and blue) included on both sides of the Q5 layer. Chapter 5: The Crystal Structures of the New Compounds. Page 210

KEY

21 axis =

(a) (b)

Fig. 5.23: (a) A view of the xz plane showing the layer of Q5 molecules and the positions of the 21 screw axes and (b) a view of the same layer with the Q6 molecules included in pink and blue. The different colours represent Q6s of different layers.

As can be seen in fig. 5.23(b), the Q6 molecules of the one layer are widely separated from each other and in fig. 5.24 it is obvious why this is so: each is situated in a square 2– cavity of the grid of SnCl6 anions that lies between the layers of Q5 molecules. These anions are separated by Cl…Cl distances of 3.3-3.6 Å and from the Q6 molecules by Cl…C = 3.5-3.7 Å; Cl…N = 3.4-3.5 Å and Cl…H = 2.7-2.9 Å. There are no Cl…O interactions less than 3.7 Å, which is as expected between two partially negative atoms.

Fig. 5.24: The Q6 molecules are imbedded in the cavities of the 2– layer of SnCl6 anions. Chapter 5: The Crystal Structures of the New Compounds. Page 211

The Q5 molecules, meanwhile, are organised into zig-zag chains but curiously do not engage in portal-to-side interactions (see fig. 5.25). Despite the lack of these interactions there are still O…C, N, O < 3.5 Å between the Q5 molecules. The result of this is that the portals are left free to interact with the Q6 molecules instead and it is here that the familiar portal-to-side interaction is encountered.

Fig. 5.25: The Q5 molecules are arranged in a zig-zag chain in this structure.

Each Q6 engages in portal-to-side interactions with six of the eight Q5 molecules surrounding it, lying partly over their portals. Typical distances are O…C = 3.1 – 3.5 Å and O…N = 3.1 – 3.6 Å. Both portals of each Q5 interact with a Q6 in this manner as can be seen in fig. 5.23(b) where both a blue and a pink Q6 lie over most Q5s. Another two Q5s lie almost parallel with each Q6, directly over and below it so that it is eclipsed, but they are far from the Q6 due to the electrostatic repulsions between the portal oxygens. These Q5s engage in portal-to-side interactions with other nearby Q6 molecules.

+ As expected, the water/ H3O oxygens crystallise in close proximity to the Qn portal … + oxygens with O O distances of 2.8 and 2.9 Å. These water/ H3O oxygens are separated from each other by distances in the range of 2.3-2.8 Å. + … The Q6 has a water/ H3O oxygen inside each of its portals with Oportal Owater = 2.9- + 4.1 Å. Another two water/ H3O oxygens lie over the portals, 2.4 Å apart from these guest water oxygens and 2.7 Å apart from one portal oxygen.

5.7.4: A comparison with literature structures. A comparison of this structure to those in the literature reveals that there are none that are isostructural or isomorphous with (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24 and, as mentioned in the introduction, no literature structures feature both Q5 and Q6. Chapter 5: The Crystal Structures of the New Compounds. Page 212

+ Despite being prepared in conc. acid there are no rings of hydrogen bound H3O cations above the portal oxygens as seen in XAVXUN and UCANOB (chapter 3, § 3.4.2) and therefore portal-to-side interactions can and do occur. In addition, just as in the — example of GUMWEQ, featuring the anion [InCl4(H2O)2] (chapter 3, § 3.4.2), the anion in this structure does not lie centred over the portal leaving it free to interact with other Qns. This results in a structure with multiple portal-to-side interactions and similar Qn-Qn distances to those seen in GUMWEQ, even though the crystal packing is quite different.

5.8: The Crystal Structure of (Q6)(SnCl6)(H3O)2(H2O)x.

The details of the synthesis of this compound appear in chapter 4, § 4.5.7.

5.8.1: Introduction. In § 5.6 of this chapter the structure of the host-guest compound {[cis-

SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 was described and the partial occupancy of its host molecule was mentioned. To try and understand what drove the inclusion of the guest in that instance, the synthesis was repeated with Q6 in place of Q7. Unlike the structure containing Q7, no host-guest complex was formed in this experiment and a possible explanation for this is discussed in § 5.8.5.

5.8.2: Crystallographic Information. The compound crystallises in the monoclinic space group C2/c. The cell dimensions are: a = 26.966 Å, b = 20.624 Å, c = 13.457 Å, E = 115.445(5)q, V = 7484(3) Å3, Z = 4. A colourless, block shaped crystal of dimensions 0.11 x 0.17 x 0.26 mm was used for the diffraction. The collection was carried out at 150 K to reduce dynamic disorder, particularly of water molecules. This structure was well refined with a final R = 0.059 after the PLATON SQUEEZE function was applied. The use of SQUEEZE was necessary, as there were solvent waters with high thermal parameters and significant residual electron density. A total of 56 water oxygens per unit cell could be refined but an additional 10 (approx.) water oxygens could not be refined. These unrefined waters Chapter 5: The Crystal Structures of the New Compounds. Page 213 lie in the channels of this structure (described in § 5.8.3). All the Q6 molecules and anions are crystallographically equivalent and the Sn atoms lie on a two-fold axis. All the non-hydrogen atoms (except for some water oxygens) were given full occupancy. + In order to balance the charges, two of the solvent oxygens are classed as H3O . All Q6 hydrogens were placed in geometrically idealised positions (C–H = 1.00 Å) and constrained to Uiso(H) = 1.2Ueq(C). No attempt was made to locate water hydrogens.

A cif for this structure appears in Appendix I and an electronic version is available on the CD provided with this thesis.

5.8.3: The Crystal Packing. + Each Q6 has a water or H3O molecule located inside each portal with an … Owater Oportal distance of 3.0 Å. The cavities of each Q6 are otherwise vacant. The 2– SnCl6 dianions surround the sides of the Q6 and do not approach the portal openings.

The structure of [(Q6)(SnCl6)(H3O)2](H2O)x, shown in fig. 5.26, comprises of layers of Q6s in the yz plane in which the Q6s lie in zig-zag chains. Each layer is offset from its neighbour by half a unit cell along the y-axis that results in the formation of channels with approximately square cross-sections extending along the z-axis. The width of the square cross-section is 9.1 Å, when measured from the portal oxygens on opposite sides of the square cross-section. The cavities are filled only with solvent water despite being large enough to house the dianions. Computer modelling has shown that the cavity formed by four Q6s (as pictured in fig. 5.26(a)) is large enough to hold approximately 30 water molecules. Chapter 5: The Crystal Structures of the New Compounds. Page 214

90Þ x

y (a)

z (b)

Fig. 5.26: The packing viewed along the z-axis (a) and along the y-axis (b). The double-headed arrow in (a) indicates the width of the cavity (9.1 Å). Sn is shown in khaki and Cl in gold.

In fig. 5.27 the 2-fold and the 21 screw axes positions are shown and as can be seen the Sn atoms lie on the two-fold axes of rotation. The action of the c-glide planes normal to the b-axis on the Q6 molecules is illustrated in stereo in fig. 5.28. Chapter 5: The Crystal Structures of the New Compounds. Page 215

KEY 2-fold rotation axis =

21 axis =

Fig. 5.27: The positions of the 2-fold and 21 screw axes are highlighted in the figure above.

90º

z Fig. 5.28: A stereo view of the molecules related by the glide plane symmetry in the xz plane. The horizontal pink arrow indicates the direction of translation. Chapter 5: The Crystal Structures of the New Compounds. Page 216

There is little of the portal-to-side hydrogen bonding often seen in crystal structures containing Q6s. Only one C-H}O distance of 2.6 Å exists between the Q6s in the chains pictured in fig. 5.28 and another exists between the chains of neighbouring

} 2– layers. The lack of Q6 Q6 interactions is due to the six SnCl6 anions that surround each Q6. In previously reported structures (see § 5.6 and § 3.9), chlorine atoms can engage in interactions with the Q6s in which they lie over the five membered rings of the glycoluril monomers. Although in the structure reported here there is only one instance of a chlorine atom lying over the face of a ring, the distances are similar to previous structures: Cl}H = 2.6, 2.7, 2.8 Å; Cl}C = 3.5 Å; Cl}N = 3.4 Å. The anions are themselves separated by Cl}Cl distances of 3.6 Å, slightly shorter than those distances recorded in {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 (§ 5.6).

Fig. 5.29: A view of a Q6 surrounded by six anions. The Cl…Cl distances (3.6 Å) are represented by a solid magenta line and the Cl…Q distances listed in the text are represented by the black and white striped lines.

+ Apart from each Q6 having a water or H3O molecule located inside each portal, there is also a water molecule located above the portal with a distance of 2.7 Å between the water oxygen and the nearest portal oxygen. The Q6 is also surrounded by a further 10 water molecules with O…O distances of 2.8 Å and O…H distances of 2.4, 2.6 and 2.7 Å. It must be noted, however, that the PLATON SQUEEZE function was used to eliminate the contribution to the intensity data of approximately 10 waters per unit cell. The result is that although the waters present in the final structure are ordered and the Chapter 5: The Crystal Structures of the New Compounds. Page 217 water oxygen–Q6 distances listed are accurate, it is probable that there are additional waters missing from the final structure.

Fig. 5.30: Two different side views of the distribution of water molecules about Q6 are shown above. The blue and white stripes indicate hydrogen bonding between the portal oxygens and the two water molecules found inside and above the portals. Hydrogen bonding between the other water molecules and Q6 is not shown.

5.8.4: Comparison with literature structures. The structures analysed in § 3.4 all contain metal complexes uncoordinated to Qn and the structures presented in § 5.2–5.4, 5.6, 5.7 and this section, fall into this category. Due to electrostatic repulsions and the absence of water ligands capable of hydrogen bonding with the portal oxygens, there is no possibility of the anions in these structures approaching the Q6 portals. This differs from all but the final two examples presented 2– in § 3.4, XAVXUN and UCANOB, which contain anions of the type MCl4 . + 2+ However in these two examples the portals are capped by a ring of H3O7 or [H14O6] , preventing any portal-to-side interactions, and instead the Q6 molecules all lie parallel to one another. This effect is not seen in the structures of the compounds described here in chapter 5 despite their syntheses also being conducted in concentrated acid. In this respect they are unique in that they are free to engage, uninterrupted, in the portal-to- side motif.

However, although (Q6)(SnCl6)(H3O)2(H2O)x does feature these interactions they are not of a good quality – there is little overlap between Q6s and little C-H…O hydrogen 2– bonding as mentioned in § 5.8.3. This occurs because of the positioning of the SnCl6 Chapter 5: The Crystal Structures of the New Compounds. Page 218 about the equatorial plane of the Q6, disrupting the portal-to-side interaction (see fig. 5.29). It appears that another type of interference occurs when an electronegative group, such as Cl, is attracted to the electropositive regions of the Qn molecule and stops the portal oxygens of a neighbouring Qn from interacting with the methine hydrogens or C and N atoms. The affinity of chloride ligands for the Qn molecule’s glycoluril rings is also displayed in the structures {[cis-SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 (§ 5.6) and

[(Cl@Q5)@Q10](HCl)11(H2O)25.75 (§ 3.9). All three of these structures feature chlorides over their glycoluril rings and similar Cl…C, N, H and Cl distances.

5.8.5: Discussion.

Unlike Q7, Q6 does not have a cavity large enough to contain the cis-SnCl4(H2O)2 species and its portal may not be able to expand sufficiently to allow the passage of the

SnCl4 molecule. As a consequence, the Q6 in this structure remains empty and the 2– SnCl4 molecule coordinates to two free chloride anions to become SnCl6 . It then crystallises around the sides of the Q6 rather than near or over the portal due to the repulsions between the portal oxygens and the dianions.

Therefore, it is likely that the driving force for the inclusion of cis-SnCl4(H2O)2 in Q7 is the occupation of its cavity. It can be hypothesised from the results of this crystallisation that there is no force of attraction between cis-SnCl4(H2O)2 (or more likely SnCl4) and the portals of the cucurbiturils to draw these two groups close together in space, in a stable conformation, without the possibility of inclusion. The inclusion compound is the only stable end result for an interaction between the portals and the

SnCl4 molecule. As Q6 is not large enough to accommodate such a large molecule, this 2– experiment saw the formation of the SnCl6 anion and the Q6 cavity remain empty. Chapter 5: The Crystal Structures of the New Compounds. Page 219

5.9: The Compound (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26.

5.9.1: Introduction.

The crystals of (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26 form when the original

[(Cl@Q5)@Q10](HCl)11(H2O)25.75 (chapter 3, § 3.9) is dissolved in a 2:3 mixture of glacial acetic acid and water. The solubility of [(Cl@Q5)@Q10](HCl)11(H2O)25.75 in this solvent mixture was discovered while investigating the solubility of the different Qns in various solvents (chapter 4, § 4.2.1). Full details of the synthesis of

(Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26 appear in chapter 4, § 4.5.8.

5.9.2: Crystallographic Information.

The compound crystallises in the monoclinic space group P21/c. The cell dimensions are: a = 34.423 Å, b = 22.088 Å and c = 17.695 Å, E = 97.62q; V = 13454 Å3; Z = 4. R = 0.108 %. A colourless square plate of dimensions 0.46 x 0.42 x 0.12 mm was used for the collection and diffracted strongly. The collection was carried out at 150 K to reduce dynamic disorder, particularly of water molecules. The structure solution and refinement were carried out by Mr. Don Craig using SIR92 and RAELS. All Qn hydrogens were placed in geometrically idealised positions (C–H = 1.00 Å) and + constrained to Uiso(H) = Ueq(C). Many of the water/H3O oxygens are disordered – a total of 12 are assigned half occupancy while 22 are assigned full occupancy. No attempt was made to locate the water hydrogens.

A cif for this structure appears in Appendix I and an electronic version is available on the CD provided with this thesis.

5.9.3: The Crystal Packing. The Q5@Q10 species in this structure is identical to the one found in the previous Q5@Q10 structure both in its size, shape and in the orientation and position of the Q5 inside Q10. However, in this case, each Q5 contains a disordered water oxygen at its centre in place of a chloride ion (fig. 5.31(a) and (b)). In addition there is a water at each Q5 portal and, as in the structure of [(Cl@Q5)@Q10](HCl)11(H2O)25.75 (see § 3.9), the three are aligned as seen in fig. 5.31(c). This alignment between the two water Chapter 5: The Crystal Structures of the New Compounds. Page 220 oxygens at the portals and the central included atom is also seen in

(Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24 (§ 5.7).

(a)

Fig. 5.31: (a) A side view and (b)(c) two top (b) views of the Q5@Q10 complex in

(Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26. In (c) the alignment of the three water oxygens is evident. The Q10 is shaded grey and the water oxygens are coloured pink.

(c)

The distance between the water oxygens (Ow) at the portal of the Q5 and the oxygens lining the portal of the Q5 (OQ5) is between 2.8 – 3.0 Å. In addition, each water oxygen is positioned 3.0 Å from one of the oxygens lining the portal of the Q10 (OQ10). These distances are indicative of good hydrogen bonding. Typical angles between OQ5-Ow-

OQ5 are ~ 65q and ~125q. The packing of the Q5@Q10 molecules here differs from that in

[(Cl@Q5)@Q10](HCl)11(H2O)25.75 described in § 3.9: there are no pairs of Q5s arranged in offset face-to-face interactions. Instead, the packing of

(Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26 features layers of the Q5@Q10 complex in a herringbone array extending in the z and y directions (fig. 5.32), with adjacent layers eclipsing each other. Typical C}C distances are 3.7, 3.8 Å and above. Other distances are generally much shorter: C}O = 3.2 – 3.8 Å, O}O = 3.3 – 3.5 Å and O}H = 2.7 Chapter 5: The Crystal Structures of the New Compounds. Page 221

Å. These occur between the Q5@Q10 complexes of the same layer and also of adjacent layers.

Fig. 5.32: A stereo view of a single layer of (Q5@Q10)(CH 3COOH)(Cl)2(H3O)2(H2O)26 showing the Q5@Q10 complex arranged in a herringbone pattern. Solvent molecules, hydrogen atoms and free chlorides have been omitted for clarity.

Water molecules, chloride ions and molecules of acetic acid separate the layers. There are two types of inter-layer spaces: in between one pair of layers there are chloride ions, acetic acid and water molecules but the next gap contains only chloride ions and water molecules. This is illustrated below in fig. 5.33.

Fig. 5.33: The crystal packing of (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26 is shown with the individual layers (in the yz plane) clearly separated by the chloride ions (in gold) and the acetic acid + molecules (in magenta) which have been enlarged for clarity and by the water/H3O oxygens (in red). Hydrogens have been omitted for clarity. Chapter 5: The Crystal Structures of the New Compounds. Page 222

Each Q10 has two chloride anions lying over 5-membered glycoluril rings situated on opposite sides of the Q10 molecule. Typical distances between the chloride anions and the Q10 molecules are Cl…C, N, O = 3.5 – 3.7 Å and Cl…H = 2.9, 3.0 Å. Also, two … acetic acid molecules (AA) interact with each Q5@Q10 complex with OAA C, N, O = … … 3.3 – 3.5 Å; OAA H = 2.3 – 2.6 Å and CAA O = 3.5 Å.

The identical positioning of the Q5 inside the Q10 in both structures may indicate that there is a favoured orientation for the smaller macrocycle inside the larger. This appears to disagree with 13C NMR experimental work that concludes there is a low barrier to rotation and precession of the Q5 inside the Q10 [14]. The energy stabilisation due to the hydrogen bonding arising from the positioning of the

Cl or H2O at the centre of the Q5 portal, as seen in the crystal structures of

[(Cl@Q5)@Q10](HCl)11(H2O)25.75 and (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26, clearly gives rise to a favoured orientation of the Q5 inside the Q10 in the crystalline state. The NMR work, conducted in the solution phase where all molecules are free to move rapidly and are not forced to adopt a single orientation, will fail to detect a preference for one orientation. When crystallisation occurs the most stable structure forms, and the Q5@Q10 complex with three guest water molecules (or two waters and one Cl–) appears to be the most stable of all the possible orientations. However, before this can be conclusively determined more crystallisations of the Q5@Q10 complex need to be carried out.

5.10: Discussion of the Portal-to-Side Interaction.

The portal-to-side interaction was first discussed in chapter 3 where it was described as the motif in which the outer equatorial section of one Qn molecule lies over the portal of another Qn, thus enabling hydrogen bonding between the methine and methylene hydrogens and the portal oxygens. On numerous occasions in that chapter it is described as the motif that Qn molecules adopt when there are no interfering species in the crystal structure. The angle between the equatorial planes of the two Qn molecules involved in the interaction varies from 15º to 90º. Because of this there are a variety of ways that this Chapter 5: The Crystal Structures of the New Compounds. Page 223 motif can be organised into different packing patterns. The herringbone array is one such pattern but it does not occur that often, possibly because it extends in two dimensions and can only exist when there are no other species hydrogen bonding to both portals of the Qn molecules. There are no examples of the herringbone array in any of the structures presented in this chapter, with the exception of

(Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26. A more common pattern is the zig-zag chain as it can exist despite the presence of another species vying for hydrogen bonding interactions with the Qn portal. One such example is the zig-zag chain in XEMQEL in § 3.2.2 (fig. 3.11) which appears almost to be a disrupted herringbone array. Here the metal cluster only caps one portal of each Q6 leaving the other free to engage in portal-to-side interactions with its neighbouring Q6 molecules.

There is an unusually high incidence of structures crystallising into high symmetry space groups among the Qn compounds. Although the interaction between two Qn molecules is not usually highly symmetrical itself, it has been found to exist in high symmetry packing patterns such as in the spirals of Qn molecules formed about the 31 and 41 screw axes. Three of the eight structures presented here in chapter 5 crystallise in high symmetry space groups and these spiral chains are found in two of these:

(Q8)2(PtCl6)3(H3O)6(H2O)18 (§ 5.3.2) and (Q7)(Cr3O10)(H3O)2(H2O)x (§ 5.4.2) and also in the structures LIRTOV, YAVQIV, YAVQOB and YAVQUH (§ 3.1.1). In – another structure, (Q8)3(PtCl6)4(H3O)8(H2O)x (§ 5.2.2), the 3 symmetry element results in the formation of a ‘spoked wheel’. As Qns are neutral molecules they are able to come together in space with minimal repulsions and in fact are drawn to interact with one another in the portal-to-side interaction. A high symmetry space group with symmetry elements such as the roto- inversion axis will have the result of bringing Qns together in this favourable interaction. From this perspective, it is perhaps not quite so extraordinary that so many Qn structures crystallise in high symmetry space groups.

Despite the favourability of the portal-to-side interaction it is readily disrupted, particularly by the possibility of hydrogen bonding between the portal oxygens and Chapter 5: The Crystal Structures of the New Compounds. Page 224

+ other species with water ligands. It appears that even a ring of H3O7 hydrogen bonded to a portal can completely eliminate the portal-to-side interaction from the crystal packing (XAVXUN and UCANOB in § 3.4.2). Despite this there are many instances described in chapter 3 when the portal-to-side interaction is able to exist alongside hydrogen bonded portals, for example, some of the metal cluster structures described in § 3.2 feature zig-zag chains with the Qn molecules engaged in portal-to-side interactions.

In this chapter there is only one example, [(Q6)(Na3(H2O)7)(Na3(H2O)9)][CoCl4]4

[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17 containing 1D coordination chains, in which the portal-to-side interaction does not exist. In all the other structures here, the ions present in the structures cannot hydrogen bond with the portals or disrupt the portal-to- side interaction and so, in this group of eight structures, it is the dominant interaction between the molecules of Qn. Chapter 5: The Crystal Structures of the New Compounds. Page 225

REFERENCES

1. Bruker, SMART, SAINT and XPREP. Area detector control and data integration software. 1995, Bruker Analytical X-ray Instruments, Inc.: Madison, Wisconsin. 2. Sheldrick, G. M., Empirical absorption correction software. 1999, University of Göttingen, Germany. 3. Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Burla, M. C., Polidori, G., Camalli, M., and Spagna, R., SIR97, A Package for Crystal Structure Solution by Direct Methods and Refinement. 1997, University of Bari, Italy. 4. Sheldrick, G. M., SHELXL97. Program for Crystal Structure Refinement, University of Göttingen, Germany. 1997. 5. Farrugia, L. J., J. Appl. Crystallogr., 1999, 32, 837. 6. Altomare, A., Burla, M. C., Camalli, M., Cascarano, G., Giacovazzo, C., Guagliardi, A., and Polidori, G., J. Appl. Crystallogr., 1994, 27, 435. 7. Rae, A. D., RAELS92, a Comprehensive Constrained Least Squares Refinement Program. 1992, Australian National University: Canberra, Australia. 8. Spek, A. L., J. Appl. Cryst., 2003, 36, 7. 9. Molecular Simulations, Inc., www.accelrys.com. 10. Behr, W. J. and Fuchs, J., Z. Naturforsch., 1975, 30b, 299. 11. Zeltmann, A. H., Matwiyoff, N. A., and Morgan, L. O., J. Phys. Chem., 1968, 72(1), 121. 12. Pan, P. and Susak, N. J., Geochim. Cosmochim. Acta, 1989, 53, 327. 13. Day, A., Arnold, A. P., Blanch, R. J., and Snushall, B., J. Org. Chem., 2001, 66(24), 8094. 14. Day, A. I., Blanch, R. J., Arnold, A. P., Lorenzo, S., Lewis, G. R., and Dance, I., Angew. Chem. Int. Ed., 2002, 41(2), 275. Chapter 6: Computational Studies of Host-Guest Systems. Page 227

CHAPTER 6 COMPUTATIONAL STUDIES OF HOST-GUEST SYSTEMS.

6.1: Introduction.

The aim of this research project was to introduce various inorganic and organic guests into the cavity of different sized cucurbituril molecules. A range of molecules may be able to form guest@Qn complexes and computational methods are useful for testing size compatibility and the possibilities for complex formation in solution. Computational investigations were undertaken to help determine the fit of various molecules inside Qn and the feasibility of the passage of a molecule through the Qn portal. These results, which are presented in this chapter, may help to inform and guide the design of new experiments with different guest molecules. The investigation of a guest’s passage through the portal is of particular importance because of the electrostatic interactions between the portal oxygen atoms and the guest molecule.

Energy calculations, using molecular mechanics methods, were conducted on each guest@Qn system to help understand the mechanism for guest encapsulation and passage through the portals. This information was used to develop an idea of the geometry and energy of the transition states and to determine the lowest energy host- guest complex. The energies of the formed host-guest complex, the transition states and the far-separated host-guest pair give a trajectory for the association and dissociation of a host-guest complex. These trajectories can be used to derive the activation energies of association and dissociation.

The energy calculations involving Qn and guest molecules should ideally include solvent molecules in order to simulate experimental conditions. Attempts were made to include solvent in this study but difficulties were encountered (as described in § 6.2.2.4) and so the calculations were instead carried out without solvent. Although this is not ideal, previous research on this topic has neglected this effect yet produced modelled data that has had relevance to experimental systems[1]. Chapter 6: Computational Studies of Host-Guest Systems. Page 228

6.1.1: Studies on host-guest complexes in the literature. Little has been published on work involving the calculation of the energy of guest inclusion in Qns. This differs markedly from other macrocycle systems that have been studied extensively, namely cyclodextrins and calixarenes.

6.1.1.1: Studies involving cucurbituril molecules. Kellersberger et al.[2] conducted molecular mechanics, semi-empirical and Hartree-Fock calculations on the ability of the ammonium cation to bind to the portals of methylated

Q5 with various small molecules (N2, O2, CH3OH and CH3CN) trapped inside the Q5 cavity. They concluded that the guest molecules are large enough to interfere with the ability of the cation to bind to the portal oxygen atoms. Wagner et al.[3] used semi-empirical methods to study the lack of inclusion of 1- anilinonaphthalene-8-sulfonic acid (1, 8-ANS) in the cavity of Q7 and to calculate the binding energy of the complex (2, 6-ANS)@Q6. Márquez et al.[1] performed gas phase molecular mechanics studies. They calculated the activation energy for guest egress from the Q6 cavity in an energy minimised model of the host-guest complex being studied. The guest molecule (from a set of various sized cyclo- and bicyclo- compounds) was moved out in increments and at each step a geometry optimisation was conducted to provide the potential energy of the system. The highest of these energies was labelled as the activation energy for complexation (authors’ terminology) and invariably occurred at the point when the guest was lodged in the portal opening, also the point at which the greatest distortion of the Q6 molecule was seen. The authors found a rough agreement between the trends in the experimentally derived binding constants and the calculated values of complexation enthalpies (where the enthalpy was defined by the authors as the difference in energy between the ‘van der Waals complex’ – where host and guest are separated by ~5 Å– and the inclusion complex). Guo and co-workers used DFT and PM3 calculations to determine the stabilisation energy of the complexation of 2, 6-bis(4, 5-dihydro-1H-imidazol-2-yl)naphthalene with both Q7 and Q8[4, 5]. Their calculations provide reasonable structures and they conclude that PM3 is a feasible method for these host-guest calculations. This method gives the expected geometries of the 2:1 (guest:host) complex with Q8, including the syn orientation to facilitate a stronger SS stacking interaction. They also conducted some Chapter 6: Computational Studies of Host-Guest Systems. Page 229

calculations in solvated environments and found that this did not produce very different results but they concluded that their solvent model may not have been able to adequately describe the solvated system. DFT calculations were also carried out by Pichierri to investigate the molecular and electronic structures of Q6 and an analogue of Q6 with S atoms in place of O atoms[6]. Oh et al. used DFT and HF calculations to investigate the stabilities of the compounds in the Qn series, where n = 4-7 and of their [7] methylated forms (CH3)2nQn, where n = 4-6 . Other density functional calculations have been performed by Dance on the [cis-

SnCl4(H2O)2]@Q7 complex described in § 5.6. Using the VWN functional, the intermolecular energy of the complex was calculated and compared with the energy of an alternate orientation of the guest inside the host. A DFT study tracking the passage of SnCl4 into Q7 found that when the SnCl4 molecule is oriented so that two of its chlorines point down towards the portal it has a negative intermolecular energy, meaning that there is a favourable pathway to the entry of the Q7 portal for this guest molecule[8].

6.1.1.2: Studies involving cyclodextrins. The host-guest chemistry of cyclodextrins, on the other hand, has been studied in detail and a brief overview of just a few of these computational studies is outlined here. Jursic et al.[9] carried out calculations almost identical to those described by Márquez et al. (§ 6.1.1.1). A molecular mechanics calculation was performed on E-cyclodextrin complexes with tert-butyl benzene as the guest. The guest was brought closer to the host molecule in a stepwise fashion. At each step the system was optimised to find the optimised orientation for the guest and the lowest energy of the system at that host- guest separation. Jursic et al. conclude that because varying the value of the dielectric constant does not result in widely differing energies, it is the van der Waals forces that are the most stabilising. Solvent effects were neglected and this was recognised by the authors as a limitation of their study. The same methodology was employed by Jiang et al. who reached the same conclusion[10]. Similar studies appear in the literature[11, 12]. Liu et al. also used the same methodology as Jursic et al. but semi-empirical methods (PM3) were used instead[13]. Chapter 6: Computational Studies of Host-Guest Systems. Page 230

Studies by Faucci et al. calculated the minimised conformers of drug-cyclodextrin complexes using molecular dynamics methods[14]. The docking energy, the host-guest contact surface and the intermolecular interaction fields were measured and compared to experimentally derived equilibrium constants for these complexes. Semi-empirical methods have also been used to study cyclodextrins. Piel et al. tried to determine which part of a guest was included in the cavity of the cyclodextrins using this methodology[15].

6.1.1.3: Studies involving calixarenes. Host-guest calculations involving calixarenes have focused on cases where an alkali metal ion is the guest species but there are also a number of studies involving the encapsulation of small organic molecules. Kunsági-Máté et al. conducted ab initio studies to determine the interaction energies between calixarenes and a range of neutral trifluoromethyl-benzene molecules[16]. Stable geometries were found, optimised and their energies determined. These results were published along with studies of photoluminescence measurements to detect the formation of host-guest complexes between calixarenes and benzotrifluorides. The authors reported agreement between the computational calculations and the experimental measurements. There are a number of studies on calixarene host-guest complexes conducted using molecular mechanics methods. One force-field study performed by Domink et al. measured the host-guest interaction energies between different types of calix[4]arenes and small organic molecules such as toluene and chloroform. Their results agreed well with experimentally determined equilibrium constants[17]. Bell et al. tested the ability of the MM+ force field within HyperChem to predict the structures of various calixarenes about group 1 metals and solvent molecules[18]. The authors found that this method was reasonably good at producing geometries similar to those found in the crystal structures of the calixarene host-guest complexes. Many studies have utilised quantum mechanical methods to calculate the binding enthalpies, free energies and the strain energies of alkali metal-calixarene complexes[19].

As has just been described, there are numerous examples in the literature of successful attempts at mapping the potential energy changes of a host-guest complex as it forms Chapter 6: Computational Studies of Host-Guest Systems. Page 231

and at calculating the interaction energy between the host and guest molecules. When comparisons within studies of sets of compounds are made, these results can be useful in predicting whether a complex will form and so help direct future experimental work.

6.2: Methodology.

6.2.1: Hardware and software. The calculations were performed on the Discover®[20] simulation program, a module of the Insight II®[20] 4.0.0 program. This was run on a Silicon Graphics®[21] O2 work station. The Consistent Valence Forcefield (CVFF) was selected as one that had been tried and tested. The relevant sections of this file are reproduced in Appendix II. The Steepest Descent algorithm was used in all these calculations because it has been described as the most robust algorithm and ideal for starting structures far from their energy minima[22]. It is also the algorithm most likely to generate the conformer of lowest energy and it was mainly for this reason that it was used in this work. Furthermore, the Steepest Descent algorithm gives a slow and steady passage of the guest through the portal into the cavity, a likely scenario for the mechanism of host- guest formation. Many users begin their runs with Steepest Descent followed by further energy minimisation with a quicker algorithm such as Conjugate Gradients. However, in this work, the Conjugate Gradients algorithm produced a quick yet ‘bumpy’ ride for the guest that was deemed unrealistic. The main disadvantage of using Steepest Descent is the number of cycles required to reach an energy minimum compared to the Conjugate Gradients or Newton-Raphson methods. This difference is due to the way the Steepest Descent algorithm executes line searches. In this algorithm each line search is orthogonal to the previous one and hence there is a zig-zag path to the lowest energy point. As this point is neared, the minimisation slows down further as subsequent derivatives become smaller. In both the Conjugate Gradients and Newton-Raphson algorithms the change in successive derivatives is used to give a more accurate location of the minima and, as the line searches do not need to be orthogonal to each other, the algorithms are more efficient and quicker. Chapter 6: Computational Studies of Host-Guest Systems. Page 232

6.2.2: The energy calculations. 6.2.2.1: The guest molecule. The energy calculations required the development of intermolecular parameters for the inorganic guests as the Consistent Valence Forcefield (CVFF) is mainly used for organic molecules and did not have parameters for some atom types used in this project. Standard CVFF parameters were used for organic and rigid molecules. The guests chosen for analysis were a combination of those that had been published as known guests, those with which inclusion had been unsuccessful and those that had not been considered in experimental work. They also include species that had co- crystallised with Qns but only outside the Qn cavity (as outlined in chapter 5). They

2– 3– 2– – 2– 2– 2– include: PtCl6 , PO4 , SO4 , ClO4 , CrO4 ,Cr2O7 , Cr3O10 , SnCl4, benzene, + NH4 , diaminohexane. As many of these guests are metal complexes and flexible inorganic molecules, new parameters needed to be added to the CVFF file for these molecules. The new parameters, ra and ea, were developed in the following way. A search of the Cambridge Structural Database (CSD)[23-26] was performed for structures containing the desired guest molecules and measurements of the molecular dimensions (bond lengths and bond angles) of approximately ten examples were made. The averages were calculated and used as the ideal geometry of each guest molecule, and used as the input to the CVFF file. Literature searches were carried out to determine the most suitable force constants (K) for bond stretching and bond angle deformation. Performing minimisations on a guest in the ideal geometry validated these values of K: firstly one bond was extended by 0.1 Å and the guest allowed to minimise and return to its ideal geometry. An energy change of approximately 10 kcal mol–1 for this distortion was viewed as an indication that the force constant was valid. Similarly, one angle was distorted by 10q and an energy change of a few kcal mol–1 was taken as indication that the value of K was acceptable. Torsion angles were included as needed but set to small values. This was done to minimise the complexity of the model and did not result in unreasonable geometries or distortion energies. All guest molecule parameters used in this work appear in Appendix II. Chapter 6: Computational Studies of Host-Guest Systems. Page 233

6.2.2.2: The host molecule. The structures of the cucurbituril host molecules were taken either from crystal structures and minimised or built from larger sized cucurbiturils by removing the required number of glycoluril and methylene units and reconnecting the ends of the oligomer. Only minimised Qns were used in the starting structures of all the systems studied. In this work a structure was considered minimised when the root mean square (RMS) value of the derivative reached 0.001 kcal mol–1 Å–1. The potential types of each atom were taken from existing values in the CVFF file and are tabulated in Appendix II. All parameters were used as they appear in the CVFF with the exception of the force constant for the NCN angle that was set to 125 kcal mol–1 rads–2. This value enabled larger sized Qns (Q8 and Q9) to resist unrealistic distortion and retain their approximately circular geometry while undergoing energy minimisations. A value smaller than this resulted in the kinking of the Qn about the N-C(methylene)-N angle so that the normal curvature of the Qn was lost. This value of the force constant for the NCN angle allowed acceptable distortion of Q10, keeping in mind that Q10 is rarely observed with its cavity unoccupied, but not Q8 and Q9. This may be interpreted to mean that while Q8 and perhaps Q9 are able to exist without a large guest in their cavity, Q10 cannot. With the above exception, all bond lengths, bond angles, torsion angles, out-of-plane angles and van der Waals parameters for the Qn atoms were used, unchanged, as found in the CVFF file and are listed in Appendix II, table II.2. Some distortion of the Qn is possible when a guest enters into the portal opening. The carbonyl groups are able to splay outwards to allow the guest more room to enter the cavity but return promptly to their ideal geometry when the guest has passed far enough into the cavity.

6.2.2.3: Selection of intermolecular energy terms and other parameters. In chapter 7, § 7.2, a detailed description of the van der Waals and coulombic energy terms is given.

Values of atom parameters ra and ea in the van der Waals energy term were drawn from work done previously[27] and already included in the CVFF parameter set. For new atom types, values for existing similar atom types were substituted and not tested further, but in some cases modification and testing was required. The test used to Chapter 6: Computational Studies of Host-Guest Systems. Page 234

a a validate the values of r and e for the atom type cl in the molecule SnCl4 is described here.

The crystal structure of SnCl4 was retrieved from the CSD and 3 unit cells were built and analysed to measure typical Cl…Cl distances as well as intramolecular bond lengths and angles. An energy minimisation of this structure was conducted followed by the same analysis of inter and intramolecular parameters among the inner SnCl4 molecules. The values of ra and ea that did not cause much deviation of Cl…Cl distances or intramolecular bond lengths and angles from those in the crystal structure were selected for use in this computational work.

A permittivity constant of 1d (where d = interatomic distance in Å) was used in the coulombic energy term, as used in previous work[27]. This value gives permittivity constants in the range of 2-20 which is appropriate for a solvated system (even though solvent (water) molecules were not included; see § 6.2.2.4). The greater the interatomic separation, d, the more intervening solvent (and other) atoms there will be and therefore the greater the permittivity of the medium. Hence it is appropriate to set a distance dependent permittivity constant as this reflects the polarisability of the solvent molecules and also the polarity of the host and guest atoms. All atom partial charges were calculated using the Qeq 1.1[28] method implemented in Cerius2®[20]. The charge distributions and potential parameters are listed in Appendix II.

6.2.2.4: Limitations to this study: a gas phase versus a ‘soaked’ environment. The aim of this study was realised by tracing the total energy changes of host-guest systems as the distance between host and guest molecules changed. In reality, the inclusion of a guest molecule into a host cavity would occur in the solution phase and with water molecules, with any metal cations in solution, and with the pH of the solution playing a significant role in trapping guests. To mimic these conditions the minimisations should ideally be conducted in a ‘soaked’ environment with periodic boundary conditions. In Discover®, a soaked environment is one in which the molecules being studied (the system) are surrounded by solvent molecules. A sphere, layer or box of solvent can be Chapter 6: Computational Studies of Host-Guest Systems. Page 235

selected with dimensions determined by the user. The solvent atoms have standard force-field potential types and partial charges assigned and they engage in typical interactions (e.g. hydrogen bonding). Periodic boundary conditions (PBC) entail the placing of the system inside a cell followed by the soaking of that system with solvent so that solvent molecules only appear inside the one cell and not beyond. When PBC is applied the simulation proceeds as though the system was actually feeling the effect of many more cells of solvent than appear on the screen. It therefore takes into account the long-range forces found in bulk solution. The programmer may set cut-offs so that a limit is imposed on how far away a solvent molecule will be before it no longer engages in any interaction with the molecules being studied. Multiple attempts were made to incorporate the ‘soaked’ environment into this study as it was a closer approximation to the conditions in which host guest inclusion occurs. However several problems were encountered and this methodology was eventually abandoned. As the distance between host and guest was altered, the number of solvent (water) molecules varied as there was little control over the numbers of waters per cell. Therefore, the total energies recorded could not be compared between calculations of different host-guest distances because of the varying number of water molecules per calculation. These variations contributed significantly to the final energies. An attempt was made to circumvent this problem by removing water molecules so that regardless of the host-guest separation, there were an equal number of water molecules per cell. The results, however, showed that the final energy of such a calculation depended on which water molecules were removed. As this methodology did not provide the consistency required, it was foregone in favour of a solvent-free system, despite the limitations of that model.

6.2.3: Construction of trajectory profiles. The goal of this computational study was to find the lowest energy associated state (where the guest is included in the Qn) for each host-guest complex and to chart its trajectory of formation and dissociation. This required the identification of the transition state (with a specific guest orientation and host-guest separation) for each host-guest complex. Chapter 6: Computational Studies of Host-Guest Systems. Page 236

The lowest energy associated state for each host-guest complex was readily determined via an energy minimisation. After observing any changes in the orientation of the guest molecule during the minimisation, one particular orientation of the guest was selected and moved to a distance outside the Qn. The distance between the host and guest molecule centroids was displayed at all times during the calculations. The transition state was obtained by varying the host-guest separation and monitoring whether the guest moved towards the host and entered the portal or moved away rapidly. The transition state was identified as the conformer with the maximum host-guest separation that led to an association complex (a guest@Qn complex). Multiple guest orientations were trialed for each host-guest system and the conformer with the lowest energy was selected as the transition state and used for the construction of the trajectory plots.

The points in these trajectory plots were obtained in the following way. Starting with the selected transition state, a series of short minimisation runs were conducted whereby each run used the final structure of the previous run as its starting structure and this continued until the lowest energy associated state (guest@host complex) was reached. During each short minimisation the distance between the host and guest (usually) decreased and this was often accompanied by a change in guest orientation. The final energy of each run was recorded and plotted against the host-guest separation at that energy. The guest was then taken out to a distance where it could not be drawn into the host (slightly greater than the host-guest separation of the transition state) and a similar treatment of the system followed. These results were used to give the dissociation side of the trajectory plot. In addition, the energy of the dissociated state (a far-separated host-guest pair) was determined by increasing the host-guest separation to a distance where the host and guest were not drawn towards or away from each other and performing an energy minimisation. This methodology is similar to that used by Márquez et al. (§ 6.1.1.1) and Jursic et al. (§ 6.1.1.2). There is one important difference between the literature studies and this work however: in the literature studies an optimisation of a conformer at varying host- guest distances was conducted to obtain the potential energy of the system. That is, they were able to conduct the optimisation with a fixed host-guest separation. This was not possible in this work as any energy optimisation resulted in the guest molecule moving towards or away from the Qn. Chapter 6: Computational Studies of Host-Guest Systems. Page 237

The energies measured in the minimisations are the total potential energies of the host plus guest molecules and in order to calculate the intermolecular energies of the complexes, the potential energies of the minimised forms of the individual host and of the individual guest were subtracted. These values were recorded and used to construct the trajectory plots.

The trajectory plots are presented in the following section along with a pictorial representation of the passage of the various guests into the host molecule Qn.

6.3: Results and Discussion.

As mentioned in the introduction to this chapter, these energy calculations should ideally contain solvent and its exclusion from these calculations will necessarily produce different energy values. However, it is not the actual energy values so much as the shape of the trajectory plots, and the information that this provides, that is important. The calculations on the associated side of the transition states produce energy values that are more accurate as there are fewer solvent molecules between host and guest molecules here than on the dissociation side of the transition state, where there are greater host-guest separation values. Equations (1) and (2) explain how the energies of activation for the association and dissociation of the complex were calculated. For the purposes of calculating the activation energy for association, the energy of infinite separation (dissociated state) was used.

EA association = E transition state – E infinite separation (1)

EA dissociation = E transition state – E complex (2)

In the following sections the term Einter represents the intermolecular energy between host and guest molecules.

The intermolecular energy parameters for Qn are listed in Appendix II, table II.2. Table 6.1: Element colours used in schematics and figures presented in § 6.3. Chapter 6: Computational Studies of Host-Guest Systems. Page 238

ELEMENT COLOUR Platinum lilac Chlorine Light green Oxygen red Chromium orange Tin khaki Carbon green Nitrogen blue Hydrogen Light grey

In all the figures in this section the Qn molecule is shaded in grey for clarity.

2— 6.3.1: PtCl6 @Qn. 2— The intermolecular energy parameters for PtCl6 were set so that the anion did not distort appreciably during the minimisation and these appear in Appendix II, table II.3.

2— 6.3.1.1: PtCl6 @Q7. 2— The passage of PtCl6 through the portal of Q7 to form a complex is shown in fig. 6.1. As can be seen the transition state for this system involves the dianion positioned with three chlorides pointing up and three pointing down. As the guest passes through the host portal it rotates so that in its final orientation, in the formed host-guest complex, only two chlorines point upwards. Chapter 6: Computational Studies of Host-Guest Systems. Page 239

Transition state: Final State: host-guest centroid –1 Einter = 40.3 kcal mol separation = 1.85 Å

2– Fig. 6.1: Progress of PtCl6 into Q7. A top and a side view of each example are shown.

2– Table 6.2: Calculated intermolecular energies for PtCl6 @Q7.

–1 2– Energies (kcal mol ) PtCl6 @Q7 Transition state energy 42.8 Host-guest complex energy 40.3

EA of dissociation of complex 2.5

EA of association of complex 22.4 Dissociated state 20.4 (host-guest centroid separation = 6.15 Å)

In chart 6.1, the intermolecular energy versus the host-guest separation is plotted. The energy of the dissociated state is greater than zero meaning that there are still

2– interactions between the PtCl6 and Q7 molecules at this distance. This is to be expected, as the van der Waals and coulombic energies decrease gradually with distance, making the identification of the dissociated state arbitrary. –1 The EA of association is large (22.4 kcal mol ), as is the transition state energy (42.8 kcal mol–1), which suggests that the formation of the complex is unlikely. The small value of the EA of dissociation implies that the dissociation of the host-guest complex

2– PtCl6 @ Q7 will occur. Chapter 6: Computational Studies of Host-Guest Systems. Page 240 Chapter 6: Computational Studies of Host-Guest Systems. Page 241 Chapter 6: Computational Studies of Host-Guest Systems. Page 242

2– 6.3.1.2: PtCl6 @Q8 Unlike in the previous example the transition state of this host-guest complex involves the guest orientated so that two chlorine atoms point up, two point down and two out as shown in fig. 6.2. As it passes through the cavity it maintains this orientation with only a slight distortion. When it is close to the centre of the cavity the guest rotates into its final position with one chlorine atom pointing up, one pointing down and four pointing out into the central bulge of the Q8. This is shown schematically below.

Transition state: host- Final State: –1 guest centroid separation Einter = 30.2 kcal mol = 2.2 Å

2– Fig. 6.2: Progress of PtCl6 into Q8. A top and side view of each example are shown.

2– Table 6.3: Calculated intermolecular energies for PtCl6 @Q8.

–1 2– Energies (kcal mol ) PtCl6 @Q8 Transition state energy 31.5 Host-guest complex energy 30.2

EA of dissociation of complex 1.3

EA of association of complex 10.3 Dissociated state 21.2 (h-g centroid separation = 5.76 Å)

In chart 6.2, the intermolecular energy versus the host-guest separation is plotted.

2– 2– The trajectory for the passage of PtCl6 into Q8 is much like that for PtCl6 into Q7.

The energy values are also much the same with a large value for the EA of association Chapter 6: Computational Studies of Host-Guest Systems. Page 243

and a small one for the EA of dissociation. Therefore dissociation of the complex is likely.

2– These results were expected, as the PtCl6 guest carries a double negative charge and significant repulsion between the chlorine ligands and the portal oxygens would make the formation of such complexes unlikely. As can be seen in figs. 6.1 and 6.2, the

2– transition state involves the PtCl6 already well inside the cavity of the Qn and it was

2– only in this starting position that the PtCl6 would sink any further into the cavity.

6.3.2: Tetrahedral molecules @Qn. The parameters for the tetrahedral molecules were set so that no distortion of these relatively rigid ions was allowed. They are listed in Appendix II, tables 4-7. – 2– 3– 2– All the tetrahedral molecules (ClO4 , SO4 ,PO4 , CrO4 ) follow the same path of entry into the cavity of the Qns. The orientation with the lowest energy transition state in each case was found to be one that had two oxygens pointing up and two pointing down (fig. 6.3(a)). As the guest passes into the cavity, it slowly begins to rotate so that one X-O bond is horizontal (fig. 6.3(b)). It comes to rest with one oxygen pointing up and three pointing down, as pictured in fig. 6.3(c). The energies derived from the trajectory plots for each complex are listed in table 6.4. The trajectory plots appear in charts 6.3 – 6.10.

(a) (b) (c)

Fig. 6.3: Progress of a tetrahedral molecule into Qn, n = 5, 6. A top and side view of each example are shown. Chapter 6: Computational Studies of Host-Guest Systems. Page 244 Chapter 6: Computational Studies of Host-Guest Systems. Page 245 Chapter 6: Computational Studies of Host-Guest Systems. Page 246 Chapter 6: Computational Studies of Host-Guest Systems. Page 247 Chapter 6: Computational Studies of Host-Guest Systems. Page 248 Chapter 6: Computational Studies of Host-Guest Systems. Page 249 Chapter 6: Computational Studies of Host-Guest Systems. Page 250 Chapter 6: Computational Studies of Host-Guest Systems. Page 251 Chapter 6: Computational Studies of Host-Guest Systems. Page 252

Table 6.4: Calculated intermolecular energies for tetrahedral molecules@Qn, n = 5, 6. GUEST@Qn ) ) ) ) ) –1 –1 –1 –1 –1 (Å) (kcal mol (kcal mol (kcal mol (kcal mol (Å; kcal mol Transition state of association complex of dissociation complex Transition State Energy A A centroid separation;energy centroid separation;energy Dissociated state host-guest Dissociated state host-guest Host-Guest complex energy Host-Guest complex energy E E Host-guest centroid separation – ClO4 @Q5 2.49 84.5 45 39.5 61.7 5.11; 22.8 2– SO4 @Q5 2.41 119.9 87.7 32.2 74.7 5.13; 45.2 2– CrO4 @Q5 2.36 132.9 108.7 24.2 71.7 4.7; 61.2 3– PO4 @Q5 1.97 154.2 131.9 22.3 58.9 4.37; 95.3 – ClO4 @Q6 2.93 27.4 16.3 11.1 16.7 6.22; 10.7 2– SO4 @Q6 2.42 57.1 48.3 8.8 23.6 5.38; 33.5 2– CrO4 @Q6 2.31 63.4 52.8 10.6 24.0 5.17; 39.4 3– PO4 @Q6 2.09 89.4 82.9 6.5 38.1 5.48; 51.3

There are several trends identifiable in the energies listed in table 6.4, based on the charge on the tetrahedral molecule and the size of the Qn. As the charge on the guest molecule increases and there is greater repulsion between host and guest molecule, the intermolecular energies increase. Also as the charge

on the guest molecule increases, the value of the EA of dissociation decreases meaning that the host-guest complexes involving the guests of higher charge will more readily dissociate than those involving guests of lower charge. The host-guest centroid separation between the tetrahedral guest and Qn at the transition state decreases as the charge on the guest increases because of the increased repulsion between the two molecules. The guest needs to start further in the cavity of the Qn in order to be drawn in and form a complex. Chapter 6: Computational Studies of Host-Guest Systems. Page 253

The intermolecular energies for the complexes involving Q6 are lower than those

for Q5, and the EA of association are smaller (more attractive), due to the decrease in repulsions between host and guest molecules as the intermolecular distances increase.

2– As for the PtCl6 @ Qn complexes, the tetrahedral molecules@Qn complexes have a large EA of association and so they will not readily form due to electrostatic repulsions.

The tetrahedral molecules@Qn complexes have much larger EA of dissociation than the

2– PtCl6 @Qn complexes, meaning that the tetrahedral molecules form more stable

2– complexes with Qn than does the octahedral molecule, PtCl6 . Although strict comparisons between sets of guest molecules are difficult to make, this difference can be explained by the fact that a guest molecule with six ligands will encounter more repulsions within the cavity of a Qn than a guest molecule with just four ligands.

2– 6.3.3: Cr2O7 @Qn. 2– The intermolecular energy parameters for Cr2O7 are listed in Appendix II, table II.8. 2– 6.3.3.1: Cr2O7 @Q6. 2– The guest molecule Cr2O7 will only fit inside Q6 when placed in a vertical orientation. Any other orientation involves too much repulsion and no host-guest complex forms. This particular minimisation does not involve the guest completely leaving the host nor 2– sinking in a considerable way. This suggests that Cr2O7 is too large for the Q6 cavity yet there is enough attraction between the –CrO3 end of the anion and the Q6 to draw the guest into the final orientation and position depicted in fig. 6.4. In this final structure the host-guest centroid separation is only 2.96 Å. As can be seen in fig. 6.4, the dichromate anion distorts during the energy minimisation (from a staggered to an eclipsed conformer) but remains in a vertical position. It does so in order to minimise the repulsions between the anion’s oxygen atoms and the Q6 portal oxygen atoms. 2– The trajectory of the formation of Cr2O7 @Q6 is shown in chart 6.11. Chapter 6: Computational Studies of Host-Guest Systems. Page 254

Transition state: host-guest Final State: –1 centroid separation = 4.25 Å Einter = 100.5 kcal mol

2– Fig. 6.4: The progress of Cr2O7 into Q6. A top and side view are shown.

2– Table 6.5: Calculated intermolecular energies of Cr2O7 @Q6.

–1 2– Energies (kcal mol ) Cr2O7 @Q6 Transition state energy 103.8 Host-guest complex energy 100.5

EA of dissociation of complex 3.3

EA of association of complex 18.5 Dissociated state (host-guest centroid 85.3 separation = 6.01 Å)

The fact that the dichromate guest does not pass very far into the cavity of the Q6 molecule indicates that the formation of this complex is unlikely to occur. Its activation energy for association is large and the small activation energy for dissociation implies a complex that readily dissociates. Chapter 6: Computational Studies of Host-Guest Systems. Page 255 Chapter 6: Computational Studies of Host-Guest Systems. Page 256

2— 6.3.3.2: Cr2O7 @Q7. Unlike in the example presented in the previous section, the dichromate anion readily fits into the cavity of Q7, horizontally as well as vertically. There are a number of horizontal orientations that this anion can adopt inside the cavity of Q7 and each of these was trialed to find the one with the lowest energy transition state. The selected

2– orientation involves the Cr2O7 in a horizontal position as shown in fig. 6.5. During the minimisation the anion tilted so that in the formed complex it lies at an angle to the horizontal. When the energy minimisations for the dissociation side of the trajectory plot were conducted, the dichromate guest behaved unusually when compared to other guests

2– studied. Instead of moving smoothly out of the Q7, the Cr2O7 initially moved into the cavity (decreasing the host-guest centroid separation) before changing direction and moving out. This result made construction of the trajectory plot very difficult and hence a dissociation side to the trajectory plot for this host-guest pair was not included. The energy of the transition state can, therefore, only be approximate and any attempt to calculate an activation energy for association or dissociation can also only be approximate.

Transition State: host-guest centroid Final State: –1 separation = 1.7 Å Einter = 40.8 kcal mol 2– Fig. 6.5: The passage of Cr2O7 into Q7. Two side views and a top view of each example are shown. Chapter 6: Computational Studies of Host-Guest Systems. Page 257 Chapter 6: Computational Studies of Host-Guest Systems. Page 258

2– Chart 6.12 shows one half of the trajectory of formation of Cr2O7 @ Q7, between the (approximate) transition state and the host-guest complex.

2– Fig. 6.5 depicts the passage of Cr2O7 into Q7.

2– 6.3.3.3: Cr2O7 @ Q8.

2— As with the previous example of Cr2O7 @Q7, multiple orientations of the dichromate

2— guest in Q8 are possible. The orientation of Cr2O7 in Q8 with the lowest transition state energy also features the guest in a horizontal position. The final orientation of the dichromate inside the Q8 features the two –CrO3 groups in an eclipsed formation rather than in the original staggered formation, a result also observed in the formation of 2– 2– Cr2O7 @Q6. Figure 6.6 shows the progress of Cr2O7 into Q8.

Transition State: host-guest centroid Final State: –1 separation = 2.1 Å Einter = 33.9 kcal mol 2– Fig. 6.6: the Progress of Cr2O7 into Q8. Two side views and a top view of each example are shown.

2– Just as in the example of Cr2O7 @Q7, the behaviour of the dichromate anion at distances close to but greater than the transition state was unusual and unlike any other examples in this study. The anion would pass into the cavity, then tilt and pass out again which made constructing that half of the plot representing the dissociation of the Chapter 6: Computational Studies of Host-Guest Systems. Page 259

2– complex difficult. As for Cr2O7 @Q7, the energy of the transition state can only be approximately calculated and any attempt to calculate an activation energy for association or dissociation can also only be approximate.

2– Chart 6.13 shows one half of the trajectory of formation of Cr2O7 @ Q8, between the (approximate) transition state and the host-guest complex.

2– All the energy values calculated on the Cr2O7 @Qn host-guest complexes suggest that they are unlikely to form, although the Q7 complex is certainly the most stable of the three. This is likely to be a reflection of the good fit between the dichromate anion and the Q7 2– cavity, as evidenced by the vertical orientation of the dichromate anion in Cr2O7 @Q7 2– compared with its horizontal orientation in Cr2O7 @Q8. Chapter 6: Computational Studies of Host-Guest Systems. Page 260 Chapter 6: Computational Studies of Host-Guest Systems. Page 261

2– 6.3.4: The guest anion Cr3O10 . The trichromate dianion can adopt more than one type of geometry and the two used in this study are pictured below.

STRAIGHT CONFORMER BENT CONFORMER

(a) Front on view (c) Front on view

(b) Side on view (d) Side on view

2– Fig. 6.7: The two conformers of Cr3O10 .

Various orientations of both conformers of the guest failed to produce host-guest complexes with either Q7 or Q8. In the case of Q8, the guest only remained inside the cavity when placed at a host-guest centroid separation of zero, i.e. centred inside the 2– Q8. An increase in the separation of just 0.5 Å resulted in the Cr3O10 passing out of the Q8 completely. 2– Q9 did accommodate the straight conformer of Cr3O10 in a horizontal position but eventually the Q9 distorted. This distortion involved a deviation from the normal curvature of the Q9 with a kink developing about an N-C(methylene)-N angle. This occurred despite the altered parameter settings described in § 6.2.2.2. 2– These results suggest that the conformers of Cr3O10 are too large and incur too much repulsion from the portal oxygens to form host-guest complexes with the Qns. Chapter 6: Computational Studies of Host-Guest Systems. Page 262 Chapter 6: Computational Studies of Host-Guest Systems. Page 263 Chapter 6: Computational Studies of Host-Guest Systems. Page 264

6.3.5: Benzene@Qn. The formation of the host-guest complexes benzene@Q6 and benzene@Q7 is expected to be favourable as the literature contains many examples of benzyl groups encapsulated in the cavities of Qn[29-32]. Furthermore, as the hydrogen atoms carry a partial positive charge the benzene molecule will encounter electrostatic attractions from the Qn portal oxygen atoms. The intermolecular parameters for benzene are listed in Appendix II, table II.10.

6.3.5.1: Benzene@Q6. The construction of the trajectory plot of formation for this complex differed to those reported in the previous sections. In the previous examples, the energies on the association and dissociation side of the transition state were calculated and plotted. These calculations were also performed in this example of benzene@Q6 but with different results. When the energy minimisation on the dissociation side of the trajectory plot was calculated, the benzene molecule moved out to a distance of approximately 5.5 Å and then stopped instead of continuing on to infinity. In order to determine what happened beyond this system, another energy minimisation was conducted with a starting structure of host-guest centroid separation = 8 Å. During this minimisation the benzene molecule moved towards the host and stopped at 5.5 Å. Chart 6.14 shows the progress of the benzene into Q6 and the shape of the trajectory plot. There are two energy minima, with the host-guest complex corresponding to the lowest in energy. There are also changes in the orientation of the benzene involving a rotation about its C6 axis but no tilting about the C2 axis i.e. the benzene always remains vertical. All energy minimisations, regardless of the starting host-guest centroid separation, involve a rotation of the benzene molecule as pictured on chart 6.14. The presence of two energy minima indicates that there is more than one favourable association state for this system.

Table 6.6: Calculated intermolecular energies for benzene@Q6. Energies (kcal mol–1) benzene@Q6 Transition state energy 7.3 Host-guest complex energy –18.4 Chapter 6: Computational Studies of Host-Guest Systems. Page 265

EA of dissociation of complex 25.7

EA of association of complex 13.3 Dissociated state –2.3 (h-g centroid separation = 8 Å)

For this example the EA of association is taken as the energy of the transition state minus the energy of the second associated state (when the h-g centroid separation = 5.5 Å) as this is the energy barrier that has to be overcome for the host-guest complex to form. This gives a relatively large EA of association, larger than would be expected for this system. However, the process this value represents includes the dissociation of another favourable ‘complex’ and so 13.3 kcal mol–1 is not an unreasonably large value. The large, attractive intermolecular energy between the host and guest molecules of the formed complex suggests it is likely to form, despite a transition state that features the benzene molecule at a considerable distance from the centre of the Q6 cavity (see chart –1 6.14). An EA of dissociation of 25.7 kcal mol shows that the host-guest complex is very stable once formed. These results are in agreement with predictions drawn from published crystal structures.

6.3.5.2: Benzene@Q7. The trajectory plot for this complex is also different to the others reported so far as there is no transition state – rather the benzene molecule is attracted to the Q7 at even a host- guest centroid separation of 7 Å, which was taken as the starting structure. This starting structure, pictured in the chart 6.15, has the benzene in a vertical position with one hydrogen atom pointing up just as for the previous example, benzene@Q6. As the minimisation proceeds it tilts as it enters the cavity and finally ends in a horizontal position inside the cavity. Unlike in the example of benzene@Q6, there is no rotation of the benzene about the C6 axis, only about the C2 axis. The energy minimisation proceeds smoothly with no sudden drops in energy.

The energy of the formed complex = –20.4 kcal mol–1 The energy of the starting structure (h-g centroid separation = 7 Å) = –3.0 kcal mol–1 Chapter 6: Computational Studies of Host-Guest Systems. Page 266

These results are interpreted to mean that the formation of the complex benzene@Q7 is highly favourable and the formed complex stable and unlikely to dissociate. The trajectory plots for the formation of the complexes benzene@Q6 and benzene@Q7 show that benzene and Qn are strongly attracted to each other with the two neutral molecules drawn toward one another even at large separations. The differences in the trajectory plots at smaller separations are the result of greater repulsions between the guest molecule and the smaller portal of Q6. The differences in the types of complexes formed between Q6 and benzene and Q7 and benzene are a reflection of the size difference of the cavities. These results are as predicted, that is, they show that the formation of complexes between benzene and Q6 and Q7 are favourable and likely to occur, and that the formed complexes are stable and will not readily dissociate.

6.3.6: SnCl4@Qn. This guest molecule was of particular interest because the crystallisation of {[cis-

SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23 suggested the possibility that it was the neutral SnCl4 that passed into the cavity of Q7 followed by the binding of two water molecules.

The intermolecular parameters for SnCl4 are listed in Appendix II, table II.11.

6.3.6.1: SnCl4@Q6.

Chart 6.16 shows the trajectory of the passage of SnCl4 into Q6. It also details the dissociation side of the trajectory and shows that the lowest energy interaction between the SnCl4 and Q6 involves a host-guest centroid separation of 5 Å and only one chlorine partly inside the portal. The Q6 of the formed complex is quite distorted and this result is not so surprising.

Although the SnCl4 molecule is neutral, the chlorines carry a partial negative charge which will incur repulsions from the portal oxygens of the relatively small Q6. This also explains why the lowest energy structure is that with the fewest Cl…O short contacts. Chapter 6: Computational Studies of Host-Guest Systems. Page 267

Table 6.7: Calculated intermolecular energies for SnCl4@Q6. –1 Energies (kcal mol ) SnCl4@Q6 Transition state energy 39.9 Host-guest complex energy 24.9

EA of dissociation of complex 15.0

EA of association of complex 49.9 Dissociated state -1.7 (h-g centroid separation = 8 Å)

Both the transition state and host-guest complex energies are large positive values, reflecting the repulsion between the host and guest molecules. However, the EA of dissociation is also relatively large. Just as for the example of benzene@Q6, the EA of association is taken as the energy of the transition state minus the energy of the second associated state (when the h-g centroid separation = 5 Å and the energy = –10 kcal mol– 1). This represents the energy barrier that has to be overcome for the host-guest complex to form which, in this case, is very large because of the large positive energy of the transition state. From this result it is clear that a complex between Q6 and SnCl4 is unlikely to form.

6.3.6.2: SnCl4@Q7.

One main difference between the trajectory plot for the complex SnCl4@Q6 and the complex described here is that the energies for SnCl4@Q7 are all attractive, reflecting the smaller number of repulsions between the guest molecule and the oxygens lining the larger portal of the Q7. Another major difference is that the complex SnCl4@Q7 represents the lowest energy association state in this system. Again this is due to the

SnCl4 incurring fewer repulsions from the larger Q7 portal and cavity.

Chart 6.17 plots the trajectory of the formation of SnCl4@Q7. Unlike most other examples in this chapter, this trajectory plot does not have a smooth curvature. Instead it features a spike in the middle of the curve (possibly due to a calculation anomaly) and three energy minima. Fig. 6.8 shows the orientation of the SnCl4 molecule at various stages of the trajectory in greater detail. Chapter 6: Computational Studies of Host-Guest Systems. Page 268

Dissociated state: Associated state 1: host-guest centroid separation = 8.00 Å host-guest centroid separation = 4.52 Å –1 –1 Einter = –1.4 kcal mol Einter = – 8.6 kcal mol

Transition state: Associated state 2: host-guest centroid separation = 4.4 Å host-guest centroid separation = 3.79 Å –1 –1 Einter = –2.4 kcal mol Einter = – 7.3 kcal mol

Passage of SnCl4 into Q7.

Transition state: Host-guest complex: host-guest centroid host-guest centroid separation = 3.00 Å separation = 0.75 Å –1 –1 Einter = –6.3 kcal mol Einter = –15.1 kcal mol

Fig. 6.8: Passage of SnCl4 into Q7. The formation of the three association states is presented here. Chapter 6: Computational Studies of Host-Guest Systems. Page 269 Chapter 6: Computational Studies of Host-Guest Systems. Page 270 Chapter 6: Computational Studies of Host-Guest Systems. Page 271

As can be seen in chart 6.17, the three energy minima each correspond to a different guest orientation. The SnCl4 molecule rotates during the energy minimisation so that at different stages of the trajectory plot the energies of different host-guest conformers are plotted. Although guest molecule rotations occur during the formation of other complexes, as presented in previous sections, there are more changes in this system suggesting a ‘flexibility’ to the system. The energies remain attractive at all stages of the energy minimisation indicating that the SnCl4 molecule is able to approach the Q7 regardless of its position and orientation to form an association complex, all of which are much lower in energy than the dissociated state.

It can be concluded from these results that a complex between Q7 and SnCl4 is favourable and possible. These results are in agreement with experimental results, namely the formation of the inclusion complex {[cis-

SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23.

+ 6.3.7: NH4 @Qn. + NH4 readily forms a host-guest complex with both Q5 and Q6, as is expected for a small positively charged guest capable of hydrogen bonding with Qn portal oxygens.

As for the previous example of SnCl4@Q7, all stages of the formation of both + + complexes NH4 @Q5 and NH4 @Q6 are favourable i.e. they have large negative energies. + The intermolecular energy parameters for NH4 are listed in Appendix II, table II.12.

+ 6.3.7.1: NH4 @Q5. + In chart 6.18, the trajectory plot of the formation of NH4 @Q5 is shown. There are two energy minima, each representing an association state where there are a maximum number of hydrogen bonds between the host and guest in the range of 1.9 – 2.9 Å. The energy difference between these two states is 7.05 kcal mol–1. The second association state (or complex), lower in energy than the first, involves the ammonium cation encapsulated in the Q5 cavity. Both association states are pictured in chart 6.18. Chapter 6: Computational Studies of Host-Guest Systems. Page 272

(a) (b)

+ Fig. 6.9: The passage of NH4 into Q5 from two starting positions. A starting structure with host-guest centroid separation = 0 Å, (a), will lead to the energy minimum with host-guest centroid separation = 1.39 Å, (b). A second starting structure, (c), with a host-guest centroid separation of 3.2 Å will also lead to (b) via the intermediate pictured in (d).

Energy of first associated state (at a host-guest centroid separation = 3.59 Å) = –39.8 kcal mol–1 Energy of second complex (at a host-guest centroid separation = 1.39 Å) (pictured in fig. 6.9(b)) = –46.75 kcal mol–1

EA of association of second complex (at a host-guest centroid separation = 1.39 Å) = 0.1 kcal mol–1 –1 EA of dissociation of second complex = 7.05 kcal mol

As can be seen from chart 6.18, the energy curve between the first complex and the transition state (at a host-guest centroid separation = 3.19 Å) is very flat. Thus the energy barrier for the conversion of the first associated state to the second is only small. In comparison, the energy of dissociation is much larger meaning that although both complexes are favourable, the second (1.39 Å) is the more stable of the two.

+ The NH4 @Q5 association states formed in this computational study differ somewhat from the one seen in the literature. In the crystal structure of decamethylQ5(NH4Cl)2(H2O)4 (Refcode = LOZMOC) an ammonium cation lies over Chapter 6: Computational Studies of Host-Guest Systems. Page 273

each portal of the substituted Q5[33] in the same orientation as that displayed in the energy calculations. The ammonium cations are centered over the portals with O…H distances of 1.9 – 2.8 Å between the cation’s hydrogen atoms and the portal’s oxygen atoms, the same range of values found in the structures derived through these energy calculations. The distance between the ammonium nitrogen atom and the centre of the Q5 cavity in the crystal structure is 4.3 Å, a significantly larger value than those for the complexes derived in these energy minimisation results (1.39 Å and 3.59 Å). There are several points that may explain these differences. Firstly, and most importantly, two very different systems, one a gas phase calculation and the other a crystal structure, should be expected to give different results. Secondly, there are differences between the Q5 molecule used in the calculations and the one used to prepare the compound decamethylQ5(NH4Cl)2(H2O)4. The substituted Q5 has shorter distances between neighbouring portal oxygen atoms, i.e. the opening to the substituted Q5 is smaller than it is for the gas phase minimised Q5 used in these calculations. This shrinkage of the portal in the decamethylQ5 is a result of the repulsions between the substituent methyl groups, forcing the Q5 to compress to allow more room outside the + Q5. Finally, the interaction between the NH4 and the decamethylQ5 in the crystal structure is influenced by the solvent water molecules that also hydrogen bond to the portal oxygens. In addition to this, the effect of the chloride ions and interactions + between the decamethylQ5 molecules will affect the final association between NH4 and the decamethylQ5.

In summary, the gas phase energy calculations give reasonable and expected results for + the formation of associated states between NH4 and Q5 and, although these do not match the results published in the literature exactly, they do replicate the orientation of the guest molecule and the hydrogen bonding between host and guest. Chapter 6: Computational Studies of Host-Guest Systems. Page 274 Chapter 6: Computational Studies of Host-Guest Systems. Page 275 Chapter 6: Computational Studies of Host-Guest Systems. Page 276

+ 6.3.7.2: NH4 @Q6. + The formation of the complex NH4 @Q6 follows a more straightforward path than the + formation of NH4 @Q5 and its trajectory is plotted in chart 6.19. Only one complex forms, with a host-guest centroid separation of 2.08 Å and O…H distances ranging from 2.1 – 3.0 Å There is no transition state and instead the ammonium cation is drawn towards the Q6 from large distances just as in the case of benzene@Q7 (§ 6.3.5.2). In addition to this, a starting structure of host-guest centroid separation = 0 Å also reverts + to this NH4 @Q6 complex, as seen in chart 6.19.

The energy of the formed complex = –40.1 kcal mol–1 The energy of the starting structure (h-g centroid separation = 8 Å) = –7.2 kcal mol–1

This complex is clearly stable and unlikely to dissociate.

During the energy minimisation the ammonium cation rotates, as pictured on chart 6.19, and it also shifts to a position off-centre, that is, shifted closer to the oxygen atoms of one side of the portal so that the guest can engage in hydrogen bonding with the Q6

+ … portal oxygens. The NH4 @Q6 complex is 0.5 Å off-centre resulting in O H distances of 2.1 – 3.0 Å. This contrasts with the lack of hydrogen bonding between the ammonium cation and the Q6 when the host-guest centroid separation is 0 Å and the guest is centered.

+ + 6.3.8: NH3(CH2)6NH3 @Qn. + As in the example of NH4 @Qn, described in § 6.3.7, the formation of a complex between a Qn and a dication that is capable of engaging in hydrogen bonding is expected to be favourable. + + Three conformers of NH3(CH2)6NH3 were selected from the CSD and used to find the lowest energy transition states for each Qn. These are pictured in fig. 6.10. + + The spiral shaped NH3(CH2)6NH3 gave the lowest energy transition state for its complexes with Q6, Q7 and Q8. This is due to the better size match between the host + + and the spiral shaped NH3(CH2)6NH3 that is shorter than the other two, allowing for Chapter 6: Computational Studies of Host-Guest Systems. Page 277

+ + better hydrogen bonding. In addition, the spiral shaped NH3(CH2)6NH3 has its ammonium groups pointing outwards so that when it is encapsulated in the Qn cavity these groups will readily engage in hydrogen bonding with the portal oxygen atoms.

+ + STRAIGHT NH3(CH2)6NH3

90˚ 90º

+ + SQUARE NH3(CH2)6NH3

90˚ 90º

+ + SPIRAL NH3(CH2)6NH3

90˚ 90º

+ + Fig. 6.10: The three conformers of NH3(CH2)6NH3 . Three views of each conformer are shown.

+ + At all stages of the formation of the three complexes NH3(CH2)6NH3 @Q6, + + + + NH3(CH2)6NH3 @Q7 and NH3(CH2)6NH3 @Q8 the energies are favourable, i.e. large and negative. + + Intermolecular parameters for NH3(CH2)6NH3 are listed in Appendix II, table II.13.

+ + 6.3.8.1: NH3(CH2)6NH3 @Q6. + Just as for the examples of NH4 @Q6 and benzene@Q7 the trajectory plot of + + NH3(CH2)6NH3 @Q6 does not have a transition state (see chart 6.20). There is no Chapter 6: Computational Studies of Host-Guest Systems. Page 278

energy barrier to the formation of the complex, which has a host-guest centroid separation of 1.77 Å. As the guest moves towards the Q6 and enters the portal there is little guest distortion or re-orientation. Figure 6.11 shows the progress of the guest + + NH3(CH2)6NH3 into Q6. In chart 6.20 a second association state is seen with a host-guest centroid separation = 0 Å and a small barrier to its formation. The energy of this second association state = – 120.1 kcal mol–1. Therefore the complex with a host-guest centroid separation of 1.77 Å is more likely to form, as it has no barrier to formation, and unlikely to dissociate or convert to the second association state.

The energy of the formed complex = –122.5 kcal mol–1 The energy of the starting structure (h-g centroid separation = 6.49 Å) = – 81.9 kcal mol–1

(a) Host-guest centroid separation (b) Host-guest centroid separation = 0.65 Å = 1.77 Å H…O = 2.0, 2.2, 2.5 Å H…O = 2.0, 2.1, 2.3 Å

Host-guest centroid separation Host-guest centroid separation = 5.36 Å = 3.47 Å H…O = 2.2, 2.3 Å H…O > 3 Å + + Fig. 6.11: The passage of NH3(CH2)6NH3 into Q6 where (a), (c) and (d) all lead to the host-guest complex, (b). Chapter 6: Computational Studies of Host-Guest Systems. Page 279

The hydrogen bonding between the ammonium groups of the guest and the Q6 portal oxygens was measured at different stages of the minimisation. These measurements show that the host-guest complex (shown in fig. 6.11(b)) has a range of O…H distances of 2.03 – 2.93 Å involving both of the guest’s ammonium groups. The distance between the centre of the Q6 and the guest’s nitrogen atom located inside the cavity is + 1.93 Å. A comparison to the NH4 @Q6 system (see § 6.3.7.2) shows the hydrogen + bonding between Q6 and NH4 to be similar: it lies in the range 2.01 – 3.00 Å. The distance between the cavity’s centre and the ammonium nitrogen atom is 2.08 Å and + + just as the NH4 is off-centre in the complex NH4 @Q6, the N atom of the + + NH3(CH2)6NH3 guest is also off-centred, by 1.0 Å, forced into this position by the + + shape of the spiral NH3(CH2)6NH3 .

+ + 6.3.8.2: NH3(CH2)6NH3 @Q7. + + Just as for the example of NH3(CH2)6NH3 @Q6 the formation of this complex does not involve a transition state but rather a steady decrease in energy as the host and guest molecules approach one another to form a complex with a host-guest centroid separation = 0.07 Å. The trajectory plot is shown in chart 6.21.

The energy of the formed complex = –80.2 kcal mol–1 The energy of the starting structure (h-g centroid separation = 7.99 Å) = –23.8 kcal mol–1

+ + The NH3(CH2)6NH3 cation tilts as it passes into the Q7 but straightens as the final host-guest complex is formed. This is shown in fig. 6.12. The hydrogen bonding between the host and guest molecules lies in the range of 2.14 – 2.54 Å and the distances between the centre of the Q7 and the guest’s nitrogen atoms are 3.5 and 3.58 Å. Chapter 6: Computational Studies of Host-Guest Systems. Page 280

Host-guest centroid separation = 1.65 Å H … O = 2.26, 2.64, 2.66, 2.91 Å

Host-guest centroid separation = 6.13 Å H … O = 2.42 Å

Host-guest centroid separation = 0.07 Å H … O = 2.14, 2.25, 2.5 Å

+ + Fig. 6.12: The passage of NH3(CH2)6NH3 into Q7.

+ + 6.3.8.3: NH3(CH2)6NH3 @Q8. The trajectory plot for the formation of this complex is similar in shape to that of + + NH3(CH2)6NH3 @Q7, i.e. there is no transition state and the lowest energy state corresponds to the complex with a host-guest centroid separation = 0 Å. Chart 6.22 + + depicts the trajectory plot for the system NH3(CH2)6NH3 @Q8.

The energy of the formed complex = –86.8 kcal mol–1 The energy of the starting structure (h-g centroid separation = 7.98 Å) = –20.0 kcal mol–1

+ + + + Unlike the examples of NH3(CH2)6NH3 @Q6 and NH3(CH2)6NH3 @Q7 however, the host Q8 undergoes distortion in order to accommodate a horizontal cation in the + + final host-guest complex. Fig. 6.13 shows the progress of NH3(CH2)6NH3 into Q8. Chapter 6: Computational Studies of Host-Guest Systems. Page 281

Host-guest centroid separation = 2.47 Å H … O = 2.48

Host-guest centroid separation = 6.96 Å H … O >3 Å

Host-guest centroid separation Host-guest centroid separation = 0.0 Å = 0.63 Å H … O = 2.2, 2.73, 2.76, 2.83 H … O = 2.01, 2.15, 2.68, 2.72

+ + Fig. 6.13: The passage of NH3(CH2)6NH3 into Q8.

The final complex exhibits good hydrogen bonding with both the ammonium groups with an H…O range = 2.2 – 2.83 Å. This is achieved with the guest lying horizontally in the cavity, forcing the Q8 molecule to distort considerably while the + + NH3(CH2)6NH3 retains its original shape throughout the energy minimisation. A view of the final complex is shown in fig. 6.13 and in fig. 6.14, where a view of the complex is shown from above.

Fig. 6.14: The host-guest complex + + NH3(CH2)6NH3 @Q8 with host-guest centroid separation = 0 Å. The H…O distances < 2.9 Å are shown as red and white striped lines. This view of the complex shows the extent to which the Q8 distorts during the energy minimisation. Chapter 6: Computational Studies of Host-Guest Systems. Page 282 Chapter 6: Computational Studies of Host-Guest Systems. Page 283 Chapter 6: Computational Studies of Host-Guest Systems. Page 284 Chapter 6: Computational Studies of Host-Guest Systems. Page 285

The threading of Qn molecules by long chained diaminoalkanes to form pseudorotaxanes was described in chapter 2, and in chapter 3 the crystal structures of some of these complexes were described. There are no crystal structures of + + pseudorotaxanes containing a 6-carbon chain such as NH3(CH2)6NH3 , but there are three examples containing a 5-carbon chain. These crystal structures were analysed to determine the position of the Q6 on the pseudorotaxanes and specifically the distances between the amino nitrogen atoms and the Q6 portal oxygens. In the crystal structure of ADOFUU (see chapter 3, § 3.7.3.3 and fig. 3.43 for the details of this compound and its packing) the Q6 molecule is positioned so that one amino nitrogen atom is in the same plane as the Q6 portal oxygen atoms. The N…O distances are 2.9, 3.1, 3.1 Å while the N…O distances between the other nitrogen atom, which lies outside of the Q6, and the portal oxygen atoms are 2.8, 3.1 Å. The shape of the diaminopentane group in this structure most closely resembles the ‘straight’ + + NH3(CH2)6NH3 shown in fig. 6.10. The structure of PAPQUS (see chapter 3, § 3.7.3.3 and table 3.6 for the details of this compound and its packing) also sees the Q6 shifted closer to one amino group with N…O distances = 2.9, 2.9, 3.5 Å. The other amino group nitrogen atom has N…O distances = 2.8, 2.8, 3.1 Å. The shape of the diaminopentane group in this structure is + + also most similar to the ‘straight’ NH3(CH2)6NH3 shown in fig. 6.10. From these results it appears that an amino group located just out of the Q6 portal may be more favourable. While the Q6 is located at a similar position on the pseudorotaxanes of ADOFUU and PAPQUS, the arrangement in XIGXOA is different (see chapter 3, § 3.7.2 and fig. 3.37 for the details of this compound and its packing). This is because XIGXOA features a molecular necklace, formed when the ends of a pseudorotaxane are joined. The resultant close proximity of the three Q6 molecules on the one molecular necklace produces a slightly different interaction between the Q6 and amino groups and the three different Q6 molecules each interact slightly differently with the molecular necklace. One Q6 is positioned an equal distance from each amino nitrogen so that they both lie out of the portal and the N…O distances = 2.7 – 3.1 Å. The other two Q6 molecules each house an amino nitrogen just inside their portal while the other remains outside. The N…O distances range from 2.8 – 3.1 Å. The shape of the diaminopentane group in Chapter 6: Computational Studies of Host-Guest Systems. Page 286

+ + this structure is most similar to that of the ‘square’ NH3(CH2)6NH3 shown in fig. 6.10.

From these crystal structure analyses it appears that the Q6 molecule will position itself along a diaminoalkane chain so that one amino nitrogen atom is level with the Q6 portal oxygen atoms and the other amino nitrogen atom is just outside the portal. While the + + + + computational studies results for NH3(CH2)6NH3 @Q6 and NH3(CH2)6NH3 @Q8 do + + not match this, they do agree with NH3(CH2)6NH3 @Q7. This is probably due to a + + good size match between the cavity of the Q7 and the spiral shaped NH3(CH2)6NH3 .

There is a wealth of NMR data on pseudorotaxanes in the literature (see chapter 2, § 2.2) however only the general location of the Qn along the chain can be deduced from these measurements and not the intermolecular distances. Electrospray ionisation mass spectrometric experiments have been used to determine the composition of complexes between Qn (n = 5, 6) and diaminobutane (DAB)[34]. The 2+ results show that the main complex formed with Q5 was Q5•(DABH)2 where two singly protonated diaminobutane molecules are associated with Q5. Also, under acidic conditions, the main complex formed involved Q6 and two singly protonated diaminobutane molecules. The diaminobutanes lie outside of the cavity with their ammonium groups near the portal oxygen atoms but again the intermolecular distances cannot be deduced. This result shows that association states other than complete inclusion complexes are possible, particularly for Q6, and that these association states + + may involve the types of interactions seen in NH3(CH2)6NH3 @Q6, where one ammonium group is well outside of the Q6 portal.

6.4: Conclusion.

The aim of this computational study was to develop a methodology capable of determining the possibility of a guest molecule and a Qn molecule forming a complex together. Energy minimisations, using molecular mechanics methods, were conducted on various host-guest systems to construct trajectory plots of the formation and Chapter 6: Computational Studies of Host-Guest Systems. Page 287

dissociation of their host-guest complexes. These plots were used to derive a range of energies that were used to determine the likelihood of host-guest complex formation and the stability of the formed complex. The introduction to this chapter highlighted some of the limitations to the study of host- guest complex formation using energy calculations. The principal limitation was the absence of solvent water, omitted due to the inability to find a way of creating equivalent conditions for successive energy calculations. A major consequence of this omission is that the solvaphobic effect (chapter 1, § 1.2) is not considered and does not contribute to the results in this work. Despite this omission, the results of these computational studies are reasonable and + + agree with the literature. The results of the NH3(CH2)6NH3 @Qn series, § 6.3.8, are a good reflection of the crystal structures of the pseudorotaxanes, while the encapsulation of benzene by Q6 and SnCl4 by Q7 also agree with published results. The attraction between the ammonium cation and Qn is also reasonable, with stable complexes recorded. Just as importantly, the high EA of association for most of the anionic guests and the low EA of dissociation for their complexes with the Qn molecules indicate that these host-guest complexes are unlikely to form or to be stable.

These results show that the methodology developed in this study has proved to be a potentially useful tool. The combination of the EA of association and dissociation derived from the trajectory plots, along with the energies of the formed complexes, provide useful insight into the probability of a guest molecule forming a favourable complex with a Qn. Although it cannot be used as the sole predictor of what may occur in solution mixtures of host and guest compounds, and it cannot be used to give information on specific intermolecular interactions, it can be used as a guide to which complexes are likely to form. Chapter 6: Computational Studies of Host-Guest Systems. Page 288

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al., Editors., 2001, Kluwer Academic Publishers: Dordrecht, The Netherlands., vol. 20. Molecular Simulations, Inc., www.accelrys.com. 21. Silicon Graphics, Inc. 22. Forcefield-Based Simulations., April 1997, San Diego: Molecular Simulations, Inc. 23. Allen, F. H., Davies, J. E., Galloy, J. J., Johnson, O., Kennard, O., Macrae, C. F., and Watson, D. G., Chem. Inf. Comput. Sci., 1991, 31, 204. 24. Allen, F. H., Acta Cryst. Sect. B, 2002, 58, 380. 25. Allen, F. H. and Motherwell, W. D. S., Acta Cryst. Sect. B, 2002, 58, 407. 26. Orpen, A. G., Acta Cryst. Sect. B, 2002, 58, 398. 27. Ali, B. F.. 1998, University of New South Wales: Sydney. 28. Rappe, A. K. and Goddard, W. A., J. Phys. Chem., 1991, 95, 3358. 29. Ko, Y. H., Kim, K., Kang, J.-K., Chun, H., Lee, J. W., Sakamoto, S., Yamaguchi, K., Fettinger, J. C., and Kim, K., J. Am. Chem. Soc., 2004, 126, 1932. 30. Ong, W., Gomez-Kaifer, M., and Kaifer, A. E., Organic Letters, 2002, 4(10), 1791. 31. Sindelar, V., Moon, K., and Kaifer, A. E., Org. Lett., 2004, 6(16), 2665. 32. Freeman, W. A., Acta Cryst., Sect. B, 1984, 40(4), 382. 33. Miyahara, Y., Abe, K., and Inazu, T., Angew. Chem. Int. Ed., 2002, 41(16), 3020. 34. Zhang, H., Paulsen, E. S., Walker, K. A., Krakowiak, K. E., and Dearden, D. V., J. Am. Chem. Soc., 2003, 125(31), 9284. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 291

CHAPTER 7 THE INTERMOLECULAR INTERACTIONS OF THE – [B(C6F5)4] ANION.

ATOM COLOUR KEY FOR CHAPTER 7

C P Ge

F H Al Hg B O

7.1: Introduction.

The introductory section of Chapter 1 described the crystal as a supramolecular entity ‘par excellence’[1] and it follows that the examination of a crystal structure will provide information regarding the intermolecular interactions – the supramolecular chemistry – of the molecules in that structure. A high occurrence of a particular interaction among functional groups or molecules may indicate that the interaction is energetically favourable. The intermolecular interactions that occur between phenyl rings are one such example. A phenyl ring’s C–H bonds are polarised, with the carbon atoms carrying a partial negative charge and the hydrogen atoms a partial positive charge so that the hydrogen atoms of one phenyl ring will be attracted to the carbon atoms of another. As a result of these coulombic forces there are three main ways that two phenyl rings will come together in space to maximise the CG–…HG interactions. These are pictured in fig. 7.1. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 292

Offset face-to-face (off) Edge-to-face (ef) Vertex-to-face (vf)

Fig. 7.1: The three types of phenyl ring interactions.

It has been recognised for some time now that some phenylated compounds will orient themselves in crystals to engage in particular intermolecular interactions known as phenyl embraces. The phenyl rings of these compounds adopt a threefold rotor conformation in the manner shown in fig. 7.2. This conformation, in conjunction with the polarisation of the C–H bond and the underlying van der Waals forces, results in the phenyl embrace motifs.

(a) (b)

Fig. 7.2: Two views of a molecule of type Y-XPh3 in the rotor conformer. In (a) the space-filling view is along the Y-X vector while in (b) the side view is shown. Y and X are both represented in black. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 293

Dance and Scudder have studied the concerted embraces of phenylated systems in depth. In particular, they have looked at the compounds of the tetraphenylphosphonium + cation, Ph4P , and related compounds. Their studies have identified a number of recurring motifs in the crystal packing of such compounds that will be discussed in detail below[2][3][4]. When these interactions occur simultaneously between the phenyl groups of molecules + such as Ph4P , a phenyl embrace is formed. These interactions are driven by the van der Waals forces in conjunction with the coulombic forces arising from the polarity of the C–H bond. It is these coulombic forces that are responsible for the directionality of the phenyl ring interactions. This net attractive force occurs between neutral molecules. It was believed that attractive energies existed even between two cations: molecular + mechanics energy calculations on the phenyl embraces of Ph4P cations give values of –1 + [4] up to –9 kcal mol per Ph4P cation . However, recent DFT calculations now suggest that these interactions are not attractive. Instead, these calculations show that the energies between pairs of ions of the same charge engaged in phenyl embraces are positive and that these unfavourable interactions are stabilised in crystal structures by the proximity of the counter ions[5].

There are three main types of phenyl embraces and these are pictured and described in + figs. 7.3-7.5. The Ph4P cation is used to illustrate the phenyl interactions here. In these figures the direction of the arrows denotes the direction of the phenyl interactions (edge-to-face unless otherwise indicated).

P4PE (a) (b) ef

off

Fig. 7.3: (a) A view of the P4PE showing the pairs of parallel rings and (b) the ef and off interactions between the phenyl rings. Hydrogens omitted for clarity. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 294

The parallel fourfold phenyl embrace, or P4PE, is pictured in fig. 7.3. It involves two edge-to-face (ef) and an offset face-to-face (off) interaction with the facing C-P-C planes of each cation parallel to each other[3]. This results in two pairs of parallel (or near parallel) rings as illustrated in fig. 7.3(a). In fig. 7.3(b), the interactions between the rings are shown.

The orthogonal fourfold phenyl embrace, or O4PE, is pictured in fig. 7.4. In this motif the interacting C-P-C planes are at right angles to each other, as seen in fig. 7.4(a). This allows for four ef interactions in this motif, indicated by the arrows in fig. 7.4(b). As can be seen from the figures, the two molecules in an O4PE are related by translation.

O4PE

(a) (b) Fig. 7.4: (a) A view of the O4PE and (b) a detailed view of the interactions between the phenyl rings. Hydrogens omitted for clarity.

6PE

Fig. 7.5: The ef interactions between the phenyl rings in a 6PE. Hydrogens omitted for clarity. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 295

The sixfold phenyl embrace, 6PE, involves a set of six concerted ef interactions between six phenyl rings. These interactions are illustrated in fig. 7.5. Typically the P…P distances are less than 7.5 Å and the fourth P–Ph vectors on each molecule are close to or are parallel and collinear[6]. When these vectors are not collinear the embrace formed is an offset 6PE.

7.2: Fluorinated Phenyl rings.

In fluorinated phenyl rings, abbreviated to Pf, the polarity of the C-F bond is opposite to that of the C-H bond in phenyl rings. In the energy calculations conducted in this work the polarity and charge distribution of the fluorinated species is C+0.15—F–0.15. This compares with the C-H bond in phenyl rings that has a polarity and charge distribution of C–0.10—H+0.10. As a natural progression from phenylated systems, compounds containing Pf groups were investigated to see if any of the previously described established embraces occurred in this system.

Molecules with fluorinated peripheries are perceived to be unable to engage in strong – – – intermolecular interactions. For instance BF4 , PF6 and CF3SO3 (triflate) generally have soluble salts. The immisciblility of fluorous solvents with traditional organic solvents results in the formation of bilayers, useful for the separation of catalysts from products[7]. Fluorinated ligands have been used to construct coordination networks capable of enclathrating organic molecules[8]. The interactions between guest and network molecules override the weak interactions between the fluorinated compounds. Shimoni et al., in their study of the crystal structures of fluorinated organic compounds, concluded that despite the high electronegativity of the fluorine atom, the C-F group competes unfavourably with groups such as C-O– to form hydrogen bonds with O-H, N- H or C-H. Despite this, the influence of C-F…H-C interactions, although weak, is able to alter the packing seen in crystal structures[9]. This final result suggests the possibility that the intermolecular interactions occurring between Pf containing molecules differ from those seen in Ph containing molecules and that this may lead to different and new crystal packing patterns. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 296

The rest of this chapter details the analyses of the crystal packing patterns of some Pf containing molecules with emphasis on the recurring supramolecular motifs found in their structures.

A search of the Cambridge Structural Database (CSD)[10-13] showed that no structures of + the fluorinated version of the Ph4P cation existed so instead a search for the species E–

Pf4 was conducted, where E is any element. Close to 200 crystal structures featuring

– – the anion [B(C6F5)4] (abbreviated to Pf4B ) are currently listed in the CSD (Version 5.27, Nov. 2005). A number of these structures were analysed to determine what – intermolecular interactions existed between pairs of the Pf4B anions and how they + compared with those phenyl embraces of the Ph4P cation. The crystal structures of a representative sample of these compounds are described in § 7.2.2. Compounds of the type M–Pf3, where M is any group, also exist in the CSD and some of these are discussed in § 7.3. In order that comparisons may be made between these new studies on fluorinated phenyl compounds and published work on phenyl compounds, energy calculations in addition to crystal structure analyses need to be conducted. Molecular mechanics calculations using the Consistent Valence Forcefield (CVFF) were used to obtain the intermolecular energies of the fluorinated phenyl compounds. New intermolecular energy parameters had to be developed for these fluorinated systems. These parameters include the terms ra, ea, q and H from the energy equations used to calculate the van der Waals energy (1) and the coulombic energy (4) terms. The sum of these gives the total intermolecular energy. The Lennard-Jones potential was used to determine the van der Waals energies:

a a 12 a 6 EvdW = e ij [(dij dij ) 2(dij dij ) ] (1) – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 297

a where d ij is the distance between atoms i and j and d ij is the distance between the atoms a when the van der Waals energy is at a minimum, – e ij . When energies between two atom a a types i and j are calculated the values of r i and e i are determined using equations (2) a and (3). In equation (2) r i is that atomic radii of atom i which gives the van der Waals energy minimum.

a a a dij r i r j (2)

0.5 a a a (3) eij ei e j

The coulombic energy term is expressed in equation (4). Here q represents the atom partial charges while H is the permittivity constant.

qi q j Eelec (4) Hdij

A search of the literature for experimental association energies of simple fluorinated aromatics, from which the intermolecular energy parameters could be derived, found a lack of empirical data. Instead, Dance[14] performed density functional (DF) calculations on pairs of hexafluorobenzene molecules to determine their intermolecular energy potentials. These DF results were then used in this work to optimise the values of the parameters ra, ea and Hby performing molecular mechanics calculations on the same pairs of hexafluorobenzene molecules. A trial and error approach was adopted whereby the values of the parameters were altered until similar results to the DF calculations were reached. Four pairs of hexafluorobenzene molecules in four conformers (vf, ef, off and face-to-face, where the rings eclipse each other) were used in these calculations, with varying intermolecular distances between the molecules in each pair. These calculations were carried out with values of q between +/– 0.1 and +/– 0.15. The determined values of ra, ea and q for each atom type and Hare shown in table 7.1. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 298

– Table 7.1: The intermolecular energy parameters for Pf4B . Atom type ra ea q F 1.6 0.1 –0.15 B 1.98 0.06 +0.16 Cipso 1.8 0.06 –0.04 C 1.8 0.06 +0.10 H= 2d

The calculations were performed on the Discover®[15] simulation program, a module of the Insight II®[15] 4.0.0 program. This was run on a Silicon Graphics®[16] O2 work station.

– 7.2.1: The Pf4B anion.

+ – The principal difference between the geometries of Ph4P and Pf4B is the orientation – + of the rings: in general the rings of Pf4B do not form a rotor as they do in PPh4 (see fig. 7.2). Rather, they adopt a ‘flipper’ motif in which a pair of rings will orient – themselves to almost face one another as shown below in fig. 7.6. Most Pf4B molecules contain two flippers.

90Þ

– Fig. 7.6: Two views of the Pf4B anion in the flipper conformer. Each molecule contains two pairs of flippers, which are circled in the figures above.

– Although the Pf4B anion almost always adopts the flipper motif other compounds of the type [X(C6F5)4] can adopt other conformations. The compounds Sn(C6F5)4 (CSD – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 299

[17] [18] [17] Reference code = TFUPSN) , Si(C6F5)4 (PFPSIL) and Ge(C6F5)4 (PFPHGE10) each adopt the rotor conformer and although these are not perfect threefold rotors they are far from being flippers. Conversely, many non-fluorinated compounds of the type

M–PPh3 feature the flipper motif and in fact, the ideal threefold rotor is present in less [6] than half of all M–PPh3 structures . The analysis of crystal structures containing the – – Pf4B anion showed a wide variation in the quality of the flipper with some Pf4B anions exhibiting a very obvious flipper motif (such as in YIXWOR and ZEMTOA) while in a few structures (such as ZOJGEK and POPXOH) the ring arrangement is closer to that found in TFUPSN, PFPSIL and PFPHGE10, i.e. a threefold rotor.

When the search of the CSD for E–Pf4 was first performed only 17 structures – containing the Pf4B anion existed. In the analysis of these 17 crystal structures, familiar and new motifs were sought with particular attention directed at the involvement of fluorine in these interactions. When searching for anion to anion interactions, a cut off point of B…B < 10 Å was chosen although some interactions with slightly longer distances were still included because of their importance in describing the crystal structure. In determining whether or not rings were interacting, a brief examination of a collection of the embraces found that most rings had C…C distances between 3.5 Å to 4.5 Å and this was set as the range within which rings would be considered to be interacting. Embraces that had B…B distances less than 10 Å but C…C distances greater than 4.5 Å were also considered to be interacting. In table 7.2 the CSD reference codes (REFCODES) of the structures analysed are listed along with the chemical formulas of the compounds. A list of each structure’s phenyl embraces and their calculated energies are listed in table 7.3 at the end of § 7.2. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 300

– Table 7.2: Counter ions and REFCODES of the Pf4B structures. HAGCIB10[19] KIRYOZ[20] + + SiEt3 [Cp–Th(CH3)–Cp] solvent: toluene. solvent: benzene. NEJMAQ[21] NOLSEM[22]

Me + + H2 C N Zr WH CMe2 Br O

Br 2

PEHLOD[23] POBLIB[24]

Au 2+ SSS S P(CH ) + 3 3 CH3 S S S S MCp Ru Si S S (H3C)3P CH3 Au

POPXOH10[25] PUQTEA[26]

SiMe3 + MeMe +

N Me Me OH Cl NN Zr Zr NN N Cl Me Mcp Me OH 2 SiMe3 MeMe 2

solvent: CH2Cl2 solvent: C5H12 – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 301

RETMEI[27] RUTJUL[28] + OH MeNMeN NMe 2+ Co

N N MeO OMe Fe O N N Me Co Co NMe MeN Me NMe O N NMe Me N Me 2 solvent: CH2Cl2 solvent: toluene YIXWOR[29] SUHDAA[30] + H3C CH3 N N + S S Zr OO

F3C CF3 Ag t N Bu H2C Me S S Me Ph S solvent: C6H5Cl

solvent: CH2Cl2 YUBYOJ[31] ZEMTIU[32] NBut + ButN HNBut + [Me3Ge–O–GeMe3] Mn Mn

t t NBu HNBu NBut

YOXRAE[33] ZEMTOA[32] + + [Et3Sn–O–SnEt3] Ta(Me)2Mcp B NH(iPr)2 – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 302

ZOJGEK[34] 2+ NH N OHC-N Pd N-CHO NH HN

solvent: H2O

– In the following section the more common interactions between the Pf4B anions are described.

7.2.1.1: The parallel fourfold perfluorophenyl embrace (P4PFE). The flipper formation makes it impossible for a good quality 6PE to form so instead the P4PE is formed. In these fluorinated systems this embrace will be called the parallel fourfold perfluorophenyl embrace or the P4PFE. This embrace is ubiquitous in this series of crystal structures although the quality of the embraces varies widely. Two main types of P4PFEs form. The first involves a pair of flippers from each anion coming together so that the rings are involved in edge-to-face and offset face-to-face interactions. The molecules lie with their boron atoms and the four B–C bonds roughly in the same plane. Alternatively, the molecules can be displaced, or offset, so that the four B–C bonds are not in the same plane. An example of each of these embraces is given in fig. 7.7.

90º

Fig. 7.7(a): A P4PFE (non–offset). A side view (left) and a top view (right) are shown. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 303

90º

Fig. 7.7(b): An offset P4PFE. A side view (left) and a top view (right) are shown.

(a)

(b)

Fig. 7.8: The P4PFE involving a ring from each flipper of the one anion. A stereo view is shown in (a) and in (b) the arrows indicate the direction of the vertex-to-face interactions. In this specific example there is no offset face-to-face interaction.

The second type of P4PFE does not involve both rings of one flipper per anion, as the previously described P4PFEs do, but rather each anion contributes a ring from each of its two flippers for this embrace. In this embrace the specific interactions can include two ef and off interactions but there are examples of this embrace that feature two vertex-to-face (vf) interactions, where a fluorine atom of one ring will point towards the – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 304 ring of the other molecule. Figure 7.8 shows an example of one such interaction. Although there are two pairs of parallel rings in this embrace these rings are not oriented vertically (relative to the page) as they are in the standard P4PFE and offset P4PFE. In most P4PFE there are poor quality offset face-to-face (off) interactions between the central rings. While the off interactions are not impressive, the ef interactions are usually good quality with considerable overlap and with C…F distances in the range 3.0-5.0 Å. One exception to the poor off interaction occurs in the structure of PEHLOD. This interaction, with a B…B separation = 8.86 Å, involves only one ring from each anion in an almost perfect face-to-face motif. The C…C distances between the parallel rings are long at 5.6 Å but the amount of overlap between the rings is significant as they are almost eclipsed by one another, as is shown below in fig. 7.9.

90º

Fig. 7.9: This interaction found in PEHLOD displays a ring from each anion in an almost perfect face-to- face interaction.

7.2.1.2: The orthogonal fourfold perfluorophenyl embrace (O4PFE). – The Pf4B anion also engages in the orthogonal fourfold perfluorophenyl embrace, or O4PFE, although with less frequency than the P4PFE. In the O4PFEs, the angle between the two interacting flippers is roughly 90º, i.e. the Cipso–B–Cipso plane of one anion is – orthogonal to the Cipso–B–Cipso plane of the other Pf4B anion. An example of an O4PFE is pictured in fig. 7.10. There are four ef interactions per embrace, generally – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 305

with C…C distances <4 Å. Among this set of structures there are only three examples of O4PFEs, found in the structures of YUBYOJ, PEHLOD and ZOJGEK. These compare favourably with the O4PFEs engaged in by TFUPSN, PFPSIL and PFPHGE10, structures that contain the molecules SnPf4, SiPf4, GePf4 respectively, all of which adopt the threefold rotor conformer rather than the flipper conformer.

Fig. 7.10: The O4PFE.

7.2.1.3: Other types of embraces. The typical P4PE always has its central rings (those engaged in the off) parallel and – aligned but in these Pf4B structures there are examples where the central rings are – instead askew. This is due to one Pf4B anion being slightly tilted relative to the other so that their Cipso–B–Cipso planes are not parallel. Consequently, only three rings lie roughly in the same plane and this embrace is labelled a distorted P4PFE. Just as in the other P4PFE embraces there are two ef and, in this distorted P4PFE, the C…F distances are in the range of 3-5 Å. The parallel centre rings are normally engaged in a very good off with a lot of overlap of the rings and with C…F distances here in the range of 3-5 Å.

Fig. 7.11.: A stereo view of the distorted P4PFE featuring one ring out of the plane of the other three. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 306

Figure 7.12 shows one type of interaction that appears to lie between a P4PFE and a 6PFE. Four rings are involved in an offset P4PFE although, unlike the other embraces described here, the C…F distances between the four rings are generally greater than 4 Å. Furthermore, there does not appear to be the normal ef interactions but rather edge- to-edge interactions. In this motif a third ring from each molecule is interacting, almost like a 6PFE. There are three examples of this embrace, found in the structures NOLSEM, ZOJGEK and ZEMTOA.

90º

Fig. 7.12: A side (above) and a top (below) view of the embrace found in the structure NOLSEM. The double arrows indicate the edge-to-edge interactions.

In table 7.3 the calculated intermolecular energies of the various embraces found in the – – Pf4B structures are listed. In § 7.2.2 the crystal packing of the Pf4B structures is described.

– Table 7.3: The intermolecular energies of the Pf4B embraces.

Structure B…B Description of embrace Energy REFCODE distance (kcal mol–1) (Å) HAGCIB10 8.88 Distorted P4PFE -6.00 9.35 P4PFE (one ring from each flipper) -1.17 9.13 Distorted P4PFE -5.68 9.66 P4PFE (one ring from each flipper) -1.06 – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 307

9.91 P4PFE (one ring from each flipper) -2.07 KIRYOZ 9.58 P4PFE -4.31 10.68 Three rings involved -0.75 10.76 Two non-parallel rings -0.87 NEJMAQ 9.00 Offset P4PFE -3.31 9.61 P4PFE (one ring from each flipper) -2.60 11.65 Two non-parallel rings 0.23 NOLSEM 10.4 Three rings involved -1.31 9.35 Between an offset P4PFE and a 6PFE 0.03 9.63 P4PFE (one ring from each flipper) -1.15 9.68 P4PFE (one ring from each flipper) -0.71 9.40 Offset P4PFE -1.91 PEHLOD 8.69 O4PFE -3.51 8.86 P4PFE (one ring from each flipper) -1.85 9.65 P4PFE (one ring from each flipper) -1.08 9.85 P4PFE (one ring from each flipper) -0.88 POBLIB 9.91 P4PFE (one ring from each flipper) -0.65 10.93 P4PFE (one ring from each flipper) 0.63 10.97 Offset P4PFE -1.68 POPXOH10 8.84 P4PFE -5.45 9.69 P4PFE (one ring from each flipper) -1.17 9.75 P4PFE -1.22 PUQTEA 8.83 Distorted P4PFE -5.55 8.76 Distorted P4PFE -5.42 11.10 P4PFE (one ring from each flipper) 0.67 RETMEI 8.8 Offset P4PFE -4.34 RUTJUL 8.57 Distorted interaction with 5 rings. -3.08 9.27 Offset P4PFE -3.43 9.60 Offset P4PFE -4.35 9.91 P4PFE (one ring from each flipper) -0.68 10.81 Involves two non-parallel rings. 0.23 9.10 P4PFE -5.38 9.20 Offset P4PFE -3.97 SUHDAA 9.00 Offset P4PFE -4.39 9.43 Offset P4PFE -2.65 9.92 P4PFE (one ring from each flipper) -1.34 9.95 P4PFE (one ring from each flipper) 0.32 YIXWOR 8.71 Distorted interaction with four rings. -3.57 9.18 P4PFE (one ring from each flipper) -1.54 YOXRAE 8.99 Distorted P4PFE -5.27 10.00 P4PFE (one ring from each flipper) 0.06 YUBYOJ 8.81 O4PFE -4.02 9.39 Offset P4PFE -3.15 10.17 P4PFE -2.90 ZEMTIU 9.00 Offset P4PFE -2.88 9.13 Distorted P4PFE -4.83 9.64 Distorted interaction with four rings. -0.37 9.99 Offset P4PFE -2.55 – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 308

ZEMTOA 8.82 Offset P4PFE -4.58 9.92 Offset P4PFE -3.56 10.69 Interaction between two rings. 0.22 10.99 Offset P4PFE -1.45 ZOJGEK 8.00 O4PFE -5.58 8.41 P4PFE (one ring from each flipper) -3.76 9.19 Distorted interaction with four rings. -2.54 10.07 P4PFE (one ring from each flipper) -1.60 10.87 Between an offset P4PFE and a 6PFE 0.85

– 7.2.2: The crystal packing of the structures of the Pf4B anion. The analysis of the crystal structures of the compounds listed in table 7.2 revealed similarities between the crystal packing of some of these structures. In this section these crystal structures will be described.

7.2.2.1: Two dimensional networks of P4PFEs. Each layer of anions in this type of structure consists of a 2D network of P4PFEs with each anion engaged in four P4PFEs embraces with the surrounding anions. The + structures of ZEMTIU and ZEMTOA, which have the cations [Me3Ge–O–GeMe3] and + [Et3Sn–O–SnEt3] respectively, exhibit this packing style. Figure 7.13 shows one such layer of anions from the structure ZEMTIU where the four embraces have B…B = 9.13 Å, 9.13 Å(distorted P4PFE), 9.99Å (offset P4PFE) and 9.00Å(offset P4PFE).

The cations and anions are segregated in this structure with the cations nestled in between the layers of these anions resulting in some interactions between the cations – and the Pf4B anions. The structure RUTJUL, possessing a large dication, also exhibits this 2D network of interactions although the types of embraces in RUTJUL differ to those in ZEMTIU and ZEMTOA. SUHDAA and POPXOH10 both have a very similar style of packing to ZEMTIU although each anion engages in fewer embraces. Both these structures possess large cations whose structures are shown in table 7.2. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 309

Fig. 7.13: A layer of anions in ZEMTIU. Some of the anions’ P4PFE interactions are marked; red and white: B…B = 9.99 Å; light blue: B…B = 9.00 Å; pink: B…B = 9.13 Å.

Fig. 7.14: The structure of ZOJGEK. The chains of O4PFEs run into the page and the cations (omitted) fill the channels. One unit cell outline is shown. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 310

7.2.2.2: Linear chains of O4PFEs. The structures PEHLOD and ZOJGEK feature this packing style in which the anions and cations are segregated through the formation of linear chains of O4PFEs arranged in a hexagonal array. The large dications, listed in table 7.2, fill these channels. This packing is shown in fig. 7.14.

7.2.2.3: Chains of embracing anions. Each of the structures described in § 7.2.2.1 features discrete layers of anions, with the anions in a 2D network of fourfold phenyl embraces. Many of the other structures listed in table 7.2 also feature such layers of anions but without the array of interactions between the anions. This may be due to the solvent molecules, which are positioned within the anion layer, disrupting the embraces. The structures that fall into this category are briefly described below.

Fig. 7.15: A layer of anions from the structure PUQTEA. This layer is made of chains of distorted P4PFEs, indicated in the diagram by the striped bonds.

The layers of anions in YIXWOR are comprised of zig-zag chains of anions engaged in P4PFEs, where one ring of each flipper is involved, as well as distorted P4PFEs. These chains are interspersed by the chlorobenzene solvent molecules. YUBYOJ also contains zig-zag chains of fourfold perfluorophenyl embraces: P4PFEs alternate with O4PFEs in this structure. Despite an absence of solvent molecules in the – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 311 anionic layer there are no strict embraces between anions of different chains, although there is a pair of fluorophenyl rings involved in an offset face-to-face between the chains. The chains of anions in the structure of PUQTEA are comprised of distorted P4PFEs and there are no interactions between the anions of different chains. One layer of anions is shown in fig. 7.15.

7.2.2.4: Other structures. Both YOXRAE and HAGCIB feature chains of distorted P4PFEs running along one axis of the structure. These chains aggregate into zig-zag layers with the cavities occupied by the cation and solvent molecules. Figure 7.16 shows the chains of anions in the structure YOXRAE. This structure has a large, singly charged cation (pictured in + table 7.2) filling the gaps within layers while HAGCIB has the smaller cation SiEt3 and toluene solvent filling the gaps.

One chain of anions, running into the page

Cation and solvent molecules lie in the cavities.

Fig. 7.16: The packing of anions in YOXRAE. The cations are omitted for clarity.

In the following structures the anions and cations lie in the same layers. In the structure POBLIB the anions are organised into zig-zag chains of P4PFEs with one ring from each flipper. These chains do not lie directly in line with each other and so gaps are created which are filled by the singly charged cations. In a similar fashion – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 312

NOLSEM features linear chains of O4PFEs with the large singly charged cations (containing two cp groups coordinated to W) nestled in the gaps in the layers. In the structure KIRYOZ, the cations and anions also lie in the same layer, although the arrangement of anions differs from that seen in POBLIB and NOLSEM. The primary difference is that the interactions are of a poor quality, i.e. large distances and with no clear geometry. When a layer of anions is viewed end on, the chains are organised in an + offset zig-zag array. The [Cp–Th(CH3)–Cp] cations lie in the gaps created by this arrangement. NEJMAQ contains zig-zag chains of alternating embraces. These are an offset P4PFE of B…B = 9.0 Å and a P4PFE with a ring from each flipper of B…B = 9.6 Å. These chains, when viewed end on, are arranged in a herringbone array as shown in fig. 7.17. The large cations, comprised of Zr bound to two substituted naphthalene groups, lie in the channels formed by the herringbone pattern.

– Fig. 7.17: The herringbone pattern of Pf4B anions in the structure NEJMAQ. The cations have been omitted for clarity.

The structure of RETMEI is unique among this set of structures as it appears that the very large cations (two substituted porphyrin groups bound to the one Fe) form the principal motif in this structure whereby they stack on top of one another, overlapping each other. The anions form isolated P4PFEs with B…B = 8.80 Å and these lie between – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 313

the stacks of cations. The next shortest B…B distance is 13.5 Å, too far to be considered an embrace.

7.3: Other Fluorinated Phenyl Compounds.

A search of the CSD for compounds of the type M–Pf3, where M is any group, found structures where the fluorophenyl rings do not form the flipper motif (see fig. 7.6) but instead adopt the rotor conformer (see fig. 7.2). These molecules are able to engage in – F motifs not usually seen amongst the Pf4B structures. One such motif is the 6P E, or the fluorinated 6PE. The crystal structures of some of these M–Pf3 compounds are described in the following sections.

7.3.1: The six-fold perfluorophenyl embrace (6PFE). A search of the CSD for the 6PFE was conducted by drawing two figures of the fragment Y-X(C6F5)3 (where Y and X are atoms of any element other than hydrogen) and imposing three dimensional constraints on the fragments. These restraints included an X…X intermolecular distance in the range of 6-10 Å and a Y–X…X angle in the range 160-180º so that the two Y–X vectors are collinear. F All of these 6P Es occur between X–Pf3 groups that adopt the rotor conformer and not the flipper conformer. The 6PFEs in these structures have been identified as having the qualities characteristic of 6PEs, that is, three pairs of rings engaged in excellent ef interactions. In this respect 6PFEs are no different to 6PEs in hydrogenated systems. The structures described below are a representative sample of those retrieved from the CSD.

7.3.1.1: The hexagonal array of 6PFEs.

– [35] The structure of the compounds PH3BPf3 (JICWUN, space group = P3) and

– [36] Et3GeGePf3 (FUFVAD, space group = R3) each have threefold symmetry, with the 6PFEs lying along the threefold axes. This results in the formation of the hexagonal – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 314 array of 6PFEs, or the HA6PFE lattice, the fluorinated equivalent of the HA6PE lattice[37]. One such HA6PFE lattice is pictured in fig. 7.18. JICWUN features two types of linear chains of 6PFEs. One chain consists of 6PFEs of B…B distances = 6.19 Å while the other has B…B distances = 6.40 Å. Also, the direction of the rotors in the two different 6PFEs are opposite. Each chain of 6.19 Å 6PFEs is surrounded by six chains of 6.40 Å 6PFEs while each chain of 6.40 Å 6PFEs is surrounded by three chains of 6.19 Å and three chains of 6.40 Å 6PFEs.

90º

Fig. 7.18: The HA6PFE lattice is shown on the left viewed along the threefold axis. Fluorine atoms are omitted for clarity. On the right, one chain of 6PFEs is shown side on.

FUFVAD contains pairs of only one type of 6PFE with a Ge…Ge distances = 7.34 Å. In all other respects it has the same packing as JICWUN.

7.3.1.2: Other packing arrangements of the 6PFE. [38] – The structure JOHMAU contains the anion [Pf3Ge–(I)Hg–GePf3] and with a threefold rotor at both ends of the molecule it is able to engage in 6PFEs at both ends. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 315

Chains of alternating 6PFEs (Ge…Ge = 6.62 Å) and offset 6PFEs (Ge…Ge = 8.04 Å) form. These chains lie side by side to form layers that are connected by a P4PFE (Ge…Ge = 8.94 Å). These layers are separated by the [Ph–Cr–Ph]+ cations. [39] The structure GEZPEG contains a three armed anion of molecular formula [(Pf3Ge– – F S)3–Hg] and so has the potential to form a 2D network of 6P Es. However, only one arm per molecule engages in this embrace and it appears to do so at the cost of other good quality interactions in the crystal packing. Of the other interactions with a Ge…Ge distance less than 10 Å, only one has the geometry of a P4PFE and the parallel rings are distant. The packing of the structure GEZPEG involves the formation of – F layers made up of chains of [(Pf3Ge–S)3–Hg] linked together by a 6P E, with a Ge…Ge distance of 6.89 Å, and by a P4PFE of Ge…Ge = 9.9 Å. The toluene solvent molecules and [Cp–Co–Cp]+ cations separate the layers of anions.

[40] The structure of THF–AlPf3 (ZALPUX) is comprised solely of chains of alternating 6PFEs and pseudo 6PFEs. The pseudo 6PFE is formed between two pairs of Pf rings and a pair of THF rings. A short section of one such chain is pictured in fig. 7.19.

Fig. 7.19: The chains of molecules in ZALPUX consist of alternating 6PFEs (pink lines) and pseudo 6PFEs (blue and white striped lines). Fluorines are omitted for clarity.

7.3.2: E–Pf3 structures without the threefold rotor conformer. – There are some structures, other than those of the compounds of Pf4B , which do not adopt the threefold rotor ring conformer. One example is the structure of [(Pf3Ge)3– Hg]–[Cp-Co-Cp]+ (Refcode = VACXEC)[41], which also adopts the flipper conformer and as such does not engage in multiple 6PFEs. Instead, each anion engages in two – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 316

P4PFEs (one offset) with neighbouring anions. Fig. 7.20 shows the zig-zag chain of P4PFEs that results from these interactions.

Fig. 7.20: A chain of anions in the structure VACXEC. The blue and white striped lines represent the P4PFEs (Ge…Ge = 9.0 Å), while the red and white striped lines represent the offset P4PFEs (Ge…Ge = 8.78 Å). Fluorines are omitted for clarity.

– 2– As a stark contrast to the Pf4B anion, the planar [Pt(C6F5)4] anion in the compound + 2– [42] F [Cp2Co ]2[Pt(C6F5)4 ] (Refcode = EDOZIG) forms an ideal P4P E. In this F compound the Cipso–Pt– Cipso bond angle is close to 90º so the P4P Es have vertex to face (vf) interactions replacing edge-to-face (ef) interactions. The central rings have short C…C distances (3.45 Å) and have some ring overlap while the vfs have excellent overlap (the F of one ring points directly to the centre of the other) but with longer C…C distances.

7.4: Discussion.

Following on from the work of Dance and Scudder on the intermolecular interactions of phenylated molecules, this work turned to the fluorine analogues of these systems. In – particular the Pf4B anion and its crystal structures were compared to those of the M–

PPh3 species, where M is any group. The results show that molecules with fluorinated phenyl rings do engage in phenyl embraces but these differ considerably from those – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 317

noted between M–PPh3 molecules, both in their form and in their frequency of occurrence. Parallel 4PFEs, Offset Parallel 4PFEs and Orthogonal 4PFEs occur in a similar fashion to those seen in M–PPh3 systems. However the 6PE is not seen between – the Pf4B anions and there are new embraces in the fluorinated system: the distorted P4PFE and an alternative form of the P4PFE (one ring from each flipper) occur with high frequency. – A search of the CSD for the Pf4B anion and an examination of the results revealed that in the majority of its crystal structures the flipper motif is adopted. This contrasts with [6] M–PPh3 where the flipper is present in only a minority of structures . It appears that the fluorinated phenyl system has a preference for the flipper motif and this is the reason for the differences between the embraces seen in the fluorinated and hydrogenated systems. Although the presence of fluorinated phenyl rings means that there are greater distances between the interacting rings of the fluorinated embraces, the energies of these + embraces are comparable to those for the hydrogenated system involving PPh4 . In the structures examined in this work, the energies of the O4PFEs, the P4PFEs and the offset P4PFEs generally lie between –3 kcal mol–1 and –5.5 kcal mol–1. They are of the same order as those fourfold phenyl embraces studied elsewhere[4]. The energies of the distorted P4PFEs are even higher. Surprisingly, considering the frequency with which they occur, the P4PFEs featuring a ring from each flipper are quite low in energy with most below –2 kcal mol–1. The remaining interactions listed in table 7.3 are also generally low in energy. While there appears to be little difference in energy between the phenyl embraces of the + – PPh4 cation and the fluorinated phenyl embraces of the Pf4B anion, there is one – difference between these two systems. When the Pf4B anion adopts the flipper motif it loses the ability to engage in the 6PE, an embrace normally larger in attractive energy[43]. The sacrifice of this attractive embrace, in favour of the flipper conformer, – shows once again how this conformer is clearly favoured by the Pf4B anion. This is further highlighted by the presence of the flipper conformer in the three-armed anions of GEZPEG and VACXEC. GEZPEG does not display a high incidence of 6PFEs and instead favours the P4PFE, while in VACXEC the 6PFE is not seen at all as neither of its –GePf3 groups adopt the rotor conformer, preferring instead the flipper – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 318 conformer. The reason for this may lie in the large size of these anions. The formation of a 6PFE brings together three pairs of fluorophenyl rings and generally at a shorter central atom separation than seen in P4PFEs. This may bring about too many intermolecular as well as intramolecular repulsions between the interacting anions for these embraces to form. Nonetheless, there are other factors that point to the favourability of the fluorous embraces, such as the high incidence of cation and anion – segregation among the group of Pf4B structures. This indicates that those fluorophenyl embraces, despite occurring between two anions, possess enough stabilising energy to not require the attractive electrostatic forces of having a counter ion positioned nearby. It can be concluded that, in these structures, those fluorophenyl embraces are important to the crystal packing.

Ultimately, however, there are many other factors influencing molecular geometry in crystal structures. These include the effects of counter ions and solvent molecules as well as the crystallisation process. For this reason, the preference for the flipper motif – among Pf4B and other fluorinated phenyl compounds, and the precise role it plays in determining their crystal structures is difficult to determine. It is only through continued extensive examination of many crystal structures that general rules or trends can be identified. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 319

REFERENCES

1. Dunitz, J. D., Pure Appl. Chem., 1991, 63(2), 177. 2. Dance, I. G. and Scudder, M. L., Chem. Commun., 1995, 1039. 3. Dance, I. and Scudder, M., Chem. Eur. J., 1996, 2(5), 481. 4. Scudder, M. and Dance, I., Dalton Trans., 1998, 3155. 5. Dance, I., Mol. Cryst. Liq. Cryst., 2005, 440, 265. 6. Dance, I. G. and Scudder, M. L., Dalton Trans., 2000, 1579. 7. Horvath, I. T., Acc. Chem. Res., 1998, 31, 641. 8. Kasai, K., Aoyagi, M., and Fujita, M., J. Am. Chem. Soc., 2000, 122, 2140. 9. Shimoni, L. and Glusker, J. P., Struct. Chem., 1994, 5(6), 383. 10. Allen, F. H., Davies, J. E., Galloy, J. J., Johnson, O., Kennard, O., Macrae, C. F., and Watson, D. G., Chem. Inf. Comput. Sci., 1991, 31, 204. 11. Allen, F. H., Acta Cryst. Sect. B, 2002, 58, 380. 12. Allen, F. H. and Motherwell, W. D. S., Acta Cryst. Sect. B, 2002, 58, 407. 13. Orpen, A. G., Acta Cryst. Sect. B, 2002, 58, 398. 14. Lorenzo, S., Lewis, G. R., and Dance, I. G., New J. Chem., 2000, 24, 295. 15. Molecular Simulations, Inc.: www.accelrys.com. 16. Silicon Graphics, Inc. 17. Karipides, A., Forman, C., Thomas, R. H. P., and Reed, A. T., Inorg. Chem., 1974, 13, 811. 18. Karipides, A. and Foerst, B., Acta Cryst., Sect. B, 1978, 34, 3494. 19. Lambert, J. B., Zhang, S., Stern, C. L., and Huffman, J. C., Science, 1993, 260, 1917. 20. Yang, X., Stern, C. L., and Marks, T. J., Organometallics, 1991, 10, 840. 21. Bei, X., Swenson, D. C., and Jordan, R. F., Organometallics, 1997, 16, 3282. 22. Chernega, A., Cook, J., Green, M. L. H., Labella, L., Simpson, S. J., Souter, J., and Stephens, A. H. H., Dalton Trans., 1997, 3225. 23. Blake, A. J., Taylor, A., and Schröder, M., Chem. Commun., 1993, 1097. 24. Grumbine, S. K., Tilley, T. D., Arnold, F. P., and Rheingold, A. L., J. Am. Chem. Soc., 1994, 116, 5495. 25. Gomez, R., Green, M. L. H., and Haggitt, J. L., Dalton Trans., 1996, 939. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 320

26. Martin, A., Uhrhammer, R., Gardner, T. G., Jordan, R. F., and Rogers, R. D., Organometallics, 1998, 17, 382. 27. Evans, D. R., Mathur, R. S., Heerwegh, K., Reed, C. A., and Xie, Z., Angew. Chem. Int. Ed., 1997, 36, 1335. 28. Kohn, R. D., Haufe, M., Kociak-Kohn, G., and Filippou, A. C., Inorg. Chem., 1997, 36, 6064. 29. Tjaden, E. B., Swenson, D. C., Jordan, R. F., and Petersen, J. L., Organometallics, 1995, 14(371). 30. Blake, A. B., Collison, D., Gould, R. O., Reid, G., and Schröder, M., Dalton Trans., 1993, 521. 31. Danopoulos, A. A., Wilkinson, G., Sweet, T. K. N., and Hursthouse, M. B., Dalton Trans., 1995, 937. 32. Lambert, J. B., Ciro, S. M., and Stern, C. L., J. Organomet. Chem., 1995, 499, 49. 33. Bazan, G. C., Donnelly, S. J., and Rodriguez, G., J. Am. Chem. Soc., 1995, 117, 2671. 34. Blake, A. B., Fallis, I. A., Heppeler, A., Parsons, S., Ross, S. A., and Schröder, M., Dalton Trans., 1996, 31. 35. Bradley, D. C., Harding, I. S., Keefe, A. D., Motevalli, M., and Dao Hong, Z., Dalton Trans., 1996, 3931. 36. Bochkova, R. I., Drozdov, Y. N., Kuz'min, E. A., Bochkarev, L. N., and Bochkarev, M. N., Russ. J. Coord. Chem., 1987, 13, 1126. 37. Scudder, M. and Dance, I., Dalton Trans., 1998, 329. 38. Zakharov, L. N., Yanovsky, A. I., Struchkov, Y. T., Pankratov, L. V., and Bochkarev, M. N., Metalloorg.Khim.(Russ.)(Organomet.Chem.(USSR)), 1988, 1, 1231. 39. Zakharov, L. N., Bochkova, R. I., Struchkov, Y. T., Pankratov, L. V., and Bochkarev, M. N., Russ. J. Coord. Chem., 1987, 13, 1686. 40. Belgardt, T., Storre, J., Roesky, H. W., Noltemeyer, M., and Schmidt, H.-G., Inorg. Chem., 1995, 34, 3821. 41. Pankratov, L. V., Bochkarev, M. N., Razuvaev, G. A., Zakharov, L. N., Struchkov, Y. T., Grishin, Y. K., and Ustynyuk, Y. A., Russ. Chem. Bull., 1986, 2548. – Chapter 7: The Intermolecular Interactions of the [B(C6F5)4] Anion. Page 321

42. Bellamy, D., Connelly, N. G., Lewis, G. R., and Orpen, A. G., CrystEngComm, 2002, 4, 68. 43. Scudder, M. L. and Dance, I. G., Dalton Trans., 2000, 2909. Appendix I: Crystallographic Information Files. Page 323

APPENDIX I

CRYSTALLOGRAPHIC INFORMATION FILES.

I.1: (Q8)3(PtCl6)4(H3O)8(H2O)x. data_5.2

_audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ‘(C48 H48 N32 O16), 2(Pt Cl6 2-), 4(H3 O 1+), x(H2 O)’ _chemical_formula_sum 'C48 H60 Cl12 N32 O20 Pt2' _chemical_formula_weight 2220.80 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source 'C' 'C' 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'H' 'H' 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Pt' 'Pt' -1.7033 8.3905 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'O' 'O' 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Cl' 'Cl' 0.1484 0.1585 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'N' 'N' 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_symmetry_cell_setting ‘trigonal’ _symmetry_space_group_name_H-M ‘R-3’ loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-y, x-y, z' '-x+y, -x, z' 'x+2/3, y+1/3, z+1/3' '-y+2/3, x-y+1/3, z+1/3' '-x+y+2/3, -x+1/3, z+1/3' Appendix I: Crystallographic Information Files. Page 324

'x+1/3, y+2/3, z+2/3' '-y+1/3, x-y+2/3, z+2/3' '-x+y+1/3, -x+2/3, z+2/3' '-x, -y, -z' 'y, -x+y, -z' 'x-y, x, -z' '-x+2/3, -y+1/3, -z+1/3' 'y+2/3, -x+y+1/3, -z+1/3' 'x-y+2/3, x+1/3, -z+1/3' '-x+1/3, -y+2/3, -z+2/3' 'y+1/3, -x+y+2/3, -z+2/3' 'x-y+1/3, x+2/3, -z+2/3'

_cell_length_a 22.006(14) _cell_length_b 22.006(14) _cell_length_c 53.323(47) _cell_angle_alpha 90.00 _cell_angle_beta 90.00 _cell_angle_gamma 120.00 _cell_volume 25822 _cell_formula_units_Z 18 _cell_measurement_temperature 153(2) _cell_measurement_reflns_used ? _cell_measurement_theta_min ? _cell_measurement_theta_max ?

_exptl_crystal_description hexagonal plate _exptl_crystal_colour orange _exptl_crystal_size_max ? _exptl_crystal_size_mid ? _exptl_crystal_size_min ? _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.679 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 11466 _exptl_absorpt_coefficient_mu 3.006 _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min ? _exptl_absorpt_correction_T_max 1.000 _exptl_absorpt_process_details SADABS (Sheldrik, 1996)

_exptl_special_details ; ? ;

_diffrn_standards_number 122 _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% 1.6 _diffrn_reflns_number 22112 _diffrn_reflns_av_R_equivalents 0.0000 _diffrn_reflns_av_sigmaI/netI 0.0947 _diffrn_reflns_limit_h_min -29 _diffrn_reflns_limit_h_max 14 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 29 _diffrn_reflns_limit_l_min 0 _diffrn_reflns_limit_l_max 71 _diffrn_reflns_theta_min 1.13 _diffrn_reflns_theta_max 28.62 _reflns_number_total 12403 _reflns_number_gt 5144 _reflns_threshold_expression >2sigma(I)

_computing_data_collection ‘SMART (Bruker, 1995)’ _computing_cell_refinement ‘SAINT (Bruker, 1995)’ _computing_data_reduction ‘SAINT and XPREP (Bruker, 1995)’ _computing_structure_solution ‘SIR97 (Altomare et al., 1997)’ _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics ‘WinGX (Farrugia, 1995) _computing_publication_material ?

_refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ;

_refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 12403 _refine_ls_number_parameters 482 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.4594 _refine_ls_R_factor_gt 0.3598 Appendix I: Crystallographic Information Files. Page 326

_refine_ls_wR_factor_ref 0.7514 _refine_ls_wR_factor_gt 0.7138 _refine_ls_goodness_of_fit_ref 2.837 _refine_ls_restrained_S_all 2.837 _refine_ls_shift/su_max 11.569 _refine_ls_shift/su_mean 0.409 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.7485(12) 0.7642(10) 0.0722(4) 0.052(6) Uani 1 1 d . . . H1A H 0.7877 0.7570 0.0686 0.062 Uiso 1 1 calc R . . H1B H 0.7658 0.8060 0.0824 0.062 Uiso 1 1 calc R . . C2 C 0.6477(11) 0.7100(12) 0.1027(5) 0.058(6) Uani 1 1 d . . . H2 H 0.6729 0.7464 0.1154 0.069 Uiso 1 1 calc R . . C3 C 0.5267(14) 0.6588(15) 0.0948(5) 0.066(7) Uani 1 1 d . . . C4 C 0.6888(12) 0.6404(11) 0.0867(4) 0.048(5) Uani 1 1 d . . . C5 C 0.6145(12) 0.6398(11) 0.1142(5) 0.056(6) Uani 1 1 d . . . H5 H 0.6233 0.6435 0.1323 0.067 Uiso 1 1 calc R . . C6 C 0.6361(10) 0.5396(11) 0.1143(4) 0.040(5) Uani 1 1 d . . . H6A H 0.6377 0.5438 0.1324 0.048 Uiso 1 1 calc R . . H6B H 0.6760 0.5352 0.1090 0.048 Uiso 1 1 calc R . . C7 C 0.4795(15) 0.5502(13) 0.1216(5) 0.062(7) Uani 1 1 d . . . H7A H 0.4903 0.5520 0.1393 0.074 Uiso 1 1 calc R . . H7B H 0.4374 0.5535 0.1200 0.074 Uiso 1 1 calc R . . C8 C 0.5055(10) 0.4541(10) 0.1207(3) 0.039(4) Uani 1 1 d . . . H8 H 0.5133 0.4577 0.1389 0.047 Uiso 1 1 calc R . . C9 C 0.4085(11) 0.4443(12) 0.1012(4) 0.042(5) Uani 1 1 d . . . C10 C 0.5695(12) 0.4243(10) 0.0936(5) 0.051(6) Uani 1 1 d . . . C11 C 0.4577(11) 0.3773(9) 0.1121(4) 0.043(5) Uani 1 1 d . . . H11 H 0.4391 0.3451 0.1264 0.051 Uiso 1 1 calc R . . C12 C 0.3380(11) 0.3176(12) 0.0933(4) 0.053(5) Uani 1 1 d . . . H12A H 0.3278 0.2854 0.1072 0.063 Uiso 1 1 calc R . . H12B H 0.3005 0.3285 0.0923 0.063 Uiso 1 1 calc R . . C13 C 0.4890(10) 0.2954(10) 0.0881(4) 0.039(5) Uani 1 1 d . . . H13A H 0.5333 0.2996 0.0831 0.046 Uiso 1 1 calc R . . H13B H 0.4701 0.2616 0.1017 0.046 Uiso 1 1 calc R . . C14 C 0.5346(13) 0.7448(11) -0.0457(5) 0.060(7) Uani 1 1 d . . . C15 C 0.6314(10) 0.7640(11) -0.0711(4) 0.040(5) Uani 1 1 d . . . H15 H 0.6476 0.7955 -0.0857 0.048 Uiso 1 1 calc R . . C16 C 0.7020(9) 0.7275(10) -0.0512(4) 0.037(4) Uani 1 1 d . . . C17 C 0.6592(11) 0.8059(12) -0.0445(4) 0.040(5) Uani 1 1 d . . . H17 H 0.6854 0.8571 -0.0463 0.048 Uiso 1 1 calc R . . Appendix I: Crystallographic Information Files. Page 327

C18 C 0.5931(12) 0.8184(11) -0.0096(4) 0.045(5) Uani 1 1 d . . . H18A H 0.5447 0.8060 -0.0067 0.054 Uiso 1 1 calc R . . H18B H 0.6194 0.8682 -0.0134 0.054 Uiso 1 1 calc R . . C19 C 0.7567(11) 0.8137(12) -0.0173(3) 0.041(5) Uani 1 1 d . . . H19A H 0.7801 0.8637 -0.0205 0.049 Uiso 1 1 calc R . . H19B H 0.7911 0.7986 -0.0188 0.049 Uiso 1 1 calc R . . C20 C 0.6933(12) 0.8367(12) 0.0179(4) 0.049(5) Uani 1 1 d . . . H20 H 0.7182 0.8867 0.0135 0.059 Uiso 1 1 calc R . . C21 C 0.5786(14) 0.7774(13) 0.0339(4) 0.055(6) Uani 1 1 d . . . C22 C 0.7435(12) 0.7667(11) 0.0254(4) 0.047(5) Uani 1 1 d . . . C23 C 0.6940(11) 0.8226(12) 0.0476(4) 0.045(5) Uani 1 1 d . . . H23 H 0.7229 0.8655 0.0573 0.054 Uiso 1 1 calc R . . C24 C 0.5997(17) 0.7779(15) 0.0810(6) 0.081(10) Uani 1 1 d . . . H24A H 0.5538 0.7737 0.0822 0.097 Uiso 1 1 calc R . . H24B H 0.6321 0.8183 0.0909 0.097 Uiso 1 1 calc R . . Pt1 Pt 0.38207(14) 0.20261(14) 0.17328(5) 0.1012(11) Uiso 0.50 1 d P . . Pt2 Pt 0.0000 0.0000 0.0000 0.292(6) Uani 1.00 6 d SP . . O1 O 0.7258(8) 0.6225(8) 0.0741(3) 0.056(4) Uani 1 1 d . . . O2 O 0.4717(9) 0.6502(9) 0.0888(3) 0.059(4) Uani 1 1 d . . . O3 O 0.6164(8) 0.4265(7) 0.0825(3) 0.053(4) Uani 1 1 d . . . O4 O 0.3644(8) 0.4578(10) 0.0932(3) 0.070(5) Uani 1 1 d . . . O5 O 0.4779(8) 0.7243(9) -0.0393(3) 0.056(4) Uani 1 1 d . . . O6 O 0.7371(7) 0.6996(8) -0.0472(3) 0.058(4) Uani 1 1 d . . . O7 O 0.5170(10) 0.7560(11) 0.0344(3) 0.072(5) Uani 1 1 d . . . O8 O 0.7800(8) 0.7403(8) 0.0221(3) 0.052(4) Uani 1 1 d . . . O100 O 0.6667 0.3333 0.0703(7) 0.082(9) Uiso 1 3 d S . . O101 O 0.763(2) 0.914(2) 0.1101(7) 0.077(10) Uiso 0.50 1 d P . . O102 O 0.542(2) 0.735(2) 0.1498(8) 0.105(13) Uiso 0.50 1 d P . . N1 N 0.6964(9) 0.7055(9) 0.0857(3) 0.043(4) Uani 1 1 d . . . N2 N 0.5966(12) 0.7208(12) 0.0905(4) 0.066(6) Uani 1 1 d . . . N3 N 0.6423(8) 0.6040(8) 0.1032(3) 0.042(4) Uani 1 1 d . . . N4 N 0.5373(9) 0.6103(10) 0.1090(4) 0.055(5) Uani 1 1 d . . . N5 N 0.5692(10) 0.4739(9) 0.1068(3) 0.048(5) Uani 1 1 d . . . N6 N 0.4673(10) 0.4895(10) 0.1124(3) 0.050(5) Uani 1 1 d . . . N7 N 0.5022(9) 0.3645(9) 0.0975(3) 0.047(4) Uani 1 1 d . . . N8 N 0.4018(9) 0.3798(9) 0.0981(3) 0.050(5) Uani 1 1 d . . . N9 N 0.4425(11) 0.2698(10) 0.0678(4) 0.056(5) Uani 1 1 d . . . N10 N 0.6602(11) 0.7161(9) -0.0705(4) 0.058(5) Uani 1 1 d . . . N11 N 0.5955(8) 0.7805(9) -0.0309(3) 0.039(4) Uani 1 1 d . . . N12 N 0.7012(9) 0.7768(9) -0.0355(4) 0.048(5) Uani 1 1 d . . . N13 N 0.6223(9) 0.8049(10) 0.0143(3) 0.048(5) Uani 1 1 d . . . N14 N 0.7274(9) 0.7994(9) 0.0085(3) 0.043(4) Uani 1 1 d . . . N15 N 0.6236(12) 0.7902(11) 0.0536(4) 0.060(6) Uani 1 1 d . . . N16 N 0.7202(10) 0.7749(10) 0.0480(3) 0.052(5) Uani 1 1 d . . . Cl3 Cl 0.4880(12) 0.2725(12) 0.1554(4) 0.138(7) Uiso 0.50 1 d P . . Cl4 Cl 0.4172(19) 0.236(2) 0.2125(7) 0.195(12) Uiso 0.50 1 d P . . Cl1 Cl 0.3592(14) 0.2908(15) 0.1691(5) 0.169(8) Uiso 0.50 1 d P . . Cl2 Cl 0.3913(11) 0.1964(10) 0.1448(4) 0.106(5) Uiso 0.50 1 d P . . Cl5 Cl 0.3456(10) 0.1612(9) 0.1354(3) 0.110(5) Uiso 0.50 1 d P . . Cl7 Cl 0.3773(14) 0.0957(14) 0.1750(5) 0.148(8) Uiso 0.50 1 d P . . Cl6 Cl 0.0520(8) 0.1110(9) 0.0250(6) 0.293(12) Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 328

I.2: (Q8)2(PtCl6)3(H3O)6(H2O)18. data_5.3

_audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ‘(C48 H48 N32 O16), 2(Pt Cl6 2-), 4(H3 O 1+), 2(H2 O)’ _chemical_formula_sum 'C48 H64 Cl12 N32 O22 Pt2' _chemical_formula_weight 2256.83 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source 'C' 'C' 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'H' 'H' 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'O' 'O' 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'N' 'N' 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Cl' 'Cl' 0.1484 0.1585 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Pt' 'Pt' -1.7033 8.3905 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_symmetry_cell_setting ‘tetragonal’ _symmetry_space_group_name_H-M ‘I4(1)/a” loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, -y, z+1/2' '-y+3/4, x+1/4, z+1/4' 'y+3/4, -x+3/4, z+3/4' 'x+1/2, y+1/2, z+1/2' '-x+1, -y+1/2, z+1' '-y+5/4, x+3/4, z+3/4' 'y+5/4, -x+5/4, z+5/4' '-x, -y, -z' 'x-1/2, y, -z-1/2' 'y-3/4, -x-1/4, -z-1/4' '-y-3/4, x-3/4, -z-3/4' Appendix I: Crystallographic Information Files. Page 329

'-x+1/2, -y+1/2, -z+1/2' 'x, y+1/2, -z' 'y-1/4, -x+1/4, -z+1/4' '-y-1/4, x-1/4, -z-1/4'

_cell_length_a 28.3627(18) _cell_length_b 28.3627(18) _cell_length_c 21.856(2) _cell_angle_alpha 90.00 _cell_angle_beta 90.00 _cell_angle_gamma 90.00 _cell_volume 17582(2) _cell_formula_units_Z 16 _cell_measurement_temperature 150(2) _cell_measurement_reflns_used ? _cell_measurement_theta_min ? _cell_measurement_theta_max ?

_exptl_crystal_description prism _exptl_crystal_colour orange _exptl_crystal_size_max 0.61 _exptl_crystal_size_mid 0.42 _exptl_crystal_size_min 0.38 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.347 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 7120 _exptl_absorpt_coefficient_mu 1.858 _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min ? _exptl_absorpt_correction_T_max 1.000 _exptl_absorpt_process_details SADABS (Sheldrik, 1996)

_exptl_special_details ; ? ;

_diffrn_ambient_temperature 150(2) _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type ’Bruker SMART 1000 CCD’ _diffrn_measurement_method \w _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 11120 _diffrn_reflns_av_R_equivalents 0.0000 _diffrn_reflns_av_sigmaI/netI 0.0251 _diffrn_reflns_limit_h_min -26 Appendix I: Crystallographic Information Files. Page 330

_diffrn_reflns_limit_h_max 26 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 37 _diffrn_reflns_limit_l_min 0 _diffrn_reflns_limit_l_max 29 _diffrn_reflns_theta_min 1.02 _diffrn_reflns_theta_max 28.30 _reflns_number_total 10838 _reflns_number_gt 6278 _reflns_threshold_expression >2sigma(I)

_refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 10838 _refine_ls_number_parameters 519 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.2687 _refine_ls_R_factor_gt 0.2144 _refine_ls_wR_factor_ref 0.5850 _refine_ls_wR_factor_gt 0.5474 _refine_ls_goodness_of_fit_ref 2.403 _refine_ls_restrained_S_all 2.403 _refine_ls_shift/su_max 2.183 _refine_ls_shift/su_mean 0.191 loop_ Appendix I: Crystallographic Information Files. Page 331

_atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.9286(5) 0.9734(5) 0.7592(5) 0.040(3) Uani 1 1 d . . . C2 C 0.8900(4) 1.0455(4) 0.7466(5) 0.037(2) Uani 1 1 d . . . H2 H 0.8811 1.0569 0.7059 0.045 Uiso 1 1 calc R . . C3 C 0.8542(4) 1.0088(4) 0.7711(5) 0.037(2) Uani 1 1 d . . . H3 H 0.8271 1.0048 0.7438 0.045 Uiso 1 1 calc R . . C4 C 0.8591(4) 1.0719(4) 0.8389(6) 0.041(3) Uani 1 1 d . . . C5 C 0.9068(4) 1.1297(4) 0.7793(8) 0.047(3) Uani 1 1 d . . . H5A H 0.8900 1.1524 0.8044 0.057 Uiso 1 1 calc R . . H5B H 0.9010 1.1376 0.7368 0.057 Uiso 1 1 calc R . . C6 C 0.9747(4) 1.0361(5) 0.7109(6) 0.043(3) Uani 1 1 d . . . H6A H 0.9638 1.0511 0.6736 0.052 Uiso 1 1 calc R . . H6B H 0.9944 1.0096 0.6995 0.052 Uiso 1 1 calc R . . C7 C 0.8618(5) 0.9194(4) 0.7823(6) 0.043(3) Uani 1 1 d . . . H7A H 0.8840 0.8958 0.7680 0.052 Uiso 1 1 calc R . . H7B H 0.8341 0.9177 0.7564 0.052 Uiso 1 1 calc R . . C8 C 0.9754(5) 1.1603(5) 0.8361(8) 0.050(3) Uani 1 1 d . . . C9 C 0.9907(4) 1.1206(5) 0.7466(6) 0.044(3) Uani 1 1 d . . . H9 H 0.9820 1.1323 0.7060 0.053 Uiso 1 1 calc R . . C10 C 1.0369(4) 1.1421(5) 0.7690(6) 0.041(3) Uani 1 1 d . . . H10 H 1.0492 1.1652 0.7398 0.050 Uiso 1 1 calc R . . C11 C 1.0496(4) 1.0631(5) 0.7597(6) 0.044(3) Uani 1 1 d . . . C12 C 1.0517(5) 1.1979(5) 0.8596(9) 0.058(4) Uani 1 1 d . . . H12A H 1.0319 1.2159 0.8872 0.069 Uiso 1 1 calc R . . H12B H 1.0654 1.2197 0.8305 0.069 Uiso 1 1 calc R . . C13 C 1.1203(4) 1.1103(5) 0.7788(6) 0.044(3) Uani 1 1 d . . . H13A H 1.1358 1.0822 0.7636 0.053 Uiso 1 1 calc R . . H13B H 1.1284 1.1361 0.7517 0.053 Uiso 1 1 calc R . . C14 C 1.0906(6) 1.1797(5) 0.9573(7) 0.054(3) Uani 1 1 d . . . C15 C 1.1666(4) 1.0888(4) 0.8706(6) 0.037(2) Uani 1 1 d . . . C16 C 0.8679(6) 0.8718(5) 0.8750(6) 0.052(3) Uani 1 1 d . . . C17 C 0.7992(5) 0.8916(4) 0.9268(6) 0.042(3) Uani 1 1 d . . . H17 H 0.7703 0.8727 0.9249 0.050 Uiso 1 1 calc R . . C18 C 0.8040(4) 0.9225(4) 0.8717(6) 0.040(3) Uani 1 1 d . . . H18 H 0.7772 0.9195 0.8437 0.048 Uiso 1 1 calc R . . C19 C 1.1348(5) 1.1648(5) 0.8679(7) 0.046(3) Uani 1 1 d . . . H19 H 1.1461 1.1902 0.8413 0.055 Uiso 1 1 calc R . . C20 C 0.8339(5) 0.8407(4) 1.0750(6) 0.043(3) Uani 1 1 d . . . H20 H 0.8070 0.8190 1.0758 0.052 Uiso 1 1 calc R . . C21 C 0.7819(4) 0.9104(5) 1.0386(5) 0.040(3) Uani 1 1 d . . . H21A H 0.7694 0.9383 1.0586 0.048 Uiso 1 1 calc R . . H21B H 0.7563 0.8879 1.0346 0.048 Uiso 1 1 calc R . . Appendix I: Crystallographic Information Files. Page 332

C22 C 0.8010(4) 0.9692(5) 0.9599(6) 0.043(3) Uani 1 1 d . . . C23 C 0.7990(4) 1.0129(4) 0.8622(6) 0.042(3) Uani 1 1 d . . . H23A H 0.7742 1.0067 0.8328 0.051 Uiso 1 1 calc R . . H23B H 0.7883 1.0380 0.8890 0.051 Uiso 1 1 calc R . . C24 C 0.8483(7) 0.8198(5) 0.9632(7) 0.059(4) Uani 1 1 d . . . H24A H 0.8186 0.8032 0.9667 0.071 Uiso 1 1 calc R . . H24B H 0.8706 0.7990 0.9431 0.071 Uiso 1 1 calc R . . O1 O 0.8515(4) 1.0986(3) 0.8826(4) 0.048(2) Uani 1 1 d . . . O2 O 0.9584(3) 0.9423(3) 0.7569(4) 0.044(2) Uani 1 1 d . . . O3 O 0.9540(4) 1.1802(4) 0.8792(5) 0.060(3) Uani 1 1 d . . . O4 O 1.0692(3) 1.0233(3) 0.7576(4) 0.042(2) Uani 1 1 d . . . O5 O 1.1791(3) 1.0494(3) 0.8511(4) 0.043(2) Uani 1 1 d . . . O6 O 1.0564(5) 1.1921(4) 0.9870(6) 0.075(3) Uani 1 1 d . . . O7 O 0.9046(4) 0.8495(4) 0.8605(5) 0.062(3) Uani 1 1 d . . . O8 O 0.7981(4) 1.0034(3) 0.9932(4) 0.047(2) Uani 1 1 d . . . N1 N 0.8878(4) 1.0824(3) 0.7915(5) 0.039(2) Uani 1 1 d . . . N2 N 0.8410(3) 1.0284(4) 0.8299(5) 0.037(2) Uani 1 1 d . . . N3 N 0.9341(3) 1.0188(4) 0.7449(5) 0.040(2) Uani 1 1 d . . . N4 N 0.8830(4) 0.9656(4) 0.7759(5) 0.042(2) Uani 1 1 d . . . N5 N 1.0231(5) 1.1646(4) 0.8274(6) 0.054(3) Uani 1 1 d . . . N6 N 0.9570(4) 1.1337(4) 0.7916(6) 0.043(2) Uani 1 1 d . . . N7 N 1.0031(4) 1.0697(4) 0.7453(5) 0.039(2) Uani 1 1 d . . . N8 N 1.0693(4) 1.1031(4) 0.7772(5) 0.038(2) Uani 1 1 d . . . N9 N 1.0893(4) 1.1760(4) 0.8945(6) 0.045(2) Uani 1 1 d . . . N10 N 1.1380(4) 1.1206(4) 0.8389(5) 0.040(2) Uani 1 1 d . . . N11 N 0.8655(5) 0.8306(4) 1.0238(5) 0.049(3) Uani 1 1 d . . . N12 N 1.1815(4) 1.1099(3) 0.9233(5) 0.039(2) Uani 1 1 d . . . N13 N 0.8416(4) 0.8615(4) 0.9256(5) 0.047(3) Uani 1 1 d . . . N14 N 0.8485(4) 0.9081(4) 0.8437(5) 0.040(2) Uani 1 1 d . . . N15 N 0.8076(3) 0.9700(3) 0.8989(5) 0.035(2) Uani 1 1 d . . . N16 N 0.7986(4) 0.9231(3) 0.9781(5) 0.038(2) Uani 1 1 d . . . Cl1 Cl 0.9387(4) 0.8035(4) 0.3744(3) 0.154(4) Uani 1 1 d . . . Cl2 Cl 1.0000 0.7500 0.4805(3) 0.100(3) Uani 1 2 d S . . Cl3 Cl 0.5383(4) 0.0459(4) 0.0737(4) 0.135(3) Uani 1 1 d . . . Cl4 Cl 0.5302(4) -0.0677(4) 0.0439(4) 0.164(4) Uani 1 1 d . . . Cl5 Cl 0.4350(3) -0.0006(4) 0.0611(4) 0.138(3) Uani 1 1 d . . . Pt1 Pt 1.0000 0.7500 0.3750 0.0865(7) Uani 1 4 d S . . Pt2 Pt 0.5000 0.0000 0.0000 0.0947(6) Uani 1 2 d S . . O100 O 0.7624(5) 0.0652(5) 0.7133(7) 0.084(4) Uiso 1 1 d . . . O101 O 0.6727(8) 0.9070(8) 0.1219(10) 0.115(6) Uiso 1 1 d . . . O102 O 0.5273(6) 0.1155(7) 0.1550(9) 0.104(5) Uiso 1 1 d . . . O103 O 0.5294(10) 0.1384(10) 0.1952(13) 0.076(6) Uiso 0.50 1 d P . . O104 O 0.4613(7) -0.1116(7) 0.0809(9) 0.053(4) Uiso 0.50 1 d P . . O105 O 0.6427(12) 0.9987(12) 0.0570(16) 0.095(8) Uiso 0.50 1 d P . . O106 O 0.9832(18) 0.9335(18) 0.888(3) 0.140(15) Uiso 0.50 1 d P . . O107 O 0.9351(11) 0.0898(11) 0.9610(16) 0.091(8) Uiso 0.50 1 d P . . O108 O 0.4343(16) -0.0973(15) 0.129(2) 0.116(12) Uiso 0.50 1 d P . . Appendix I: Crystallographic Information Files. Page 333

I.3: (Q7)(Cr3O10)(H3O)2(H2O)x. data_5.4

_audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety (C42 H42 N28 O14), (CR3 O10 2-), 2(H3 O 1+), X(H2 O) _chemical_formula_sum 'C42 H48 Cr2 N28 O26' _chemical_formula_weight 1517.08 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source 'C' 'C' 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'N' 'N' 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'O' 'O' 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Cr' 'Cr' 0.3209 0.6236 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'H' 'H' 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_symmetry_cell_setting 'trigonal' _symmetry_space_group_name_H-M 'R-3' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-y, x-y, z' '-x+y, -x, z' 'x+2/3, y+1/3, z+1/3' '-y+2/3, x-y+1/3, z+1/3' '-x+y+2/3, -x+1/3, z+1/3' 'x+1/3, y+2/3, z+2/3' '-y+1/3, x-y+2/3, z+2/3' '-x+y+1/3, -x+2/3, z+2/3' '-x, -y, -z' 'y, -x+y, -z' 'x-y, x, -z' '-x+2/3, -y+1/3, -z+1/3' 'y+2/3, -x+y+1/3, -z+1/3' 'x-y+2/3, x+1/3, -z+1/3' Appendix I: Crystallographic Information Files. Page 334

'-x+1/3, -y+2/3, -z+2/3' 'y+1/3, -x+y+2/3, -z+2/3' 'x-y+1/3, x+2/3, -z+2/3'

_cell_length_a 57.678(3) _cell_length_b 57.678(3) _cell_length_c 13.7060(11) _cell_angle_alpha 90.00 _cell_angle_beta 90.00 _cell_angle_gamma 120.00 _cell_volume 45597(4) _cell_formula_units_Z 18 _cell_measurement_temperature 153(2) _cell_measurement_reflns_used 1018 _cell_measurement_theta_min 2.317 _cell_measurement_theta_max 18.154

_exptl_crystal_description long needle _exptl_crystal_colour orange _exptl_crystal_size_max 0.73 _exptl_crystal_size_mid 0.13 _exptl_crystal_size_min 0.12 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 0.696 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 8472 _exptl_absorpt_coefficient_mu 0.210 _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min 0.0015 _exptl_absorpt_correction_T_max 1.000 _exptl_absorpt_process_details SADABS (Sheldrik, 1996)

_exptl_special_details ; ? ;

_diffrn_ambient_temperature 153(2) _diffrn_radiation_wavelength 0.71069 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type ’Bruker SMART 1000 CCD’ _diffrn_measurement_method \w _diffrn_detector_area_resol_mean ? _diffrn_standards_number 0 _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% 0 _diffrn_reflns_number 136309 _diffrn_reflns_av_R_equivalents 0.178 _diffrn_reflns_av_sigmaI/netI 0.1208 _diffrn_reflns_limit_h_min -76 _diffrn_reflns_limit_h_max 37 Appendix I: Crystallographic Information Files. Page 335

_diffrn_reflns_limit_k_min 1 _diffrn_reflns_limit_k_max 76 _diffrn_reflns_limit_l_min 0 _diffrn_reflns_limit_l_max 18 _diffrn_reflns_theta_min 1.54 _diffrn_reflns_theta_max 28.29 _reflns_number_total 20992 _reflns_number_gt 7645 _reflns_threshold_expression >2sigma(I)

_computing_data_collection ‘SMART (Bruker, 1995)’ _computing_cell_refinement ‘SAINT (Bruker, 1995)’ _computing_data_reduction ‘SAINT and XPREP (Bruker, 1995)’ _computing_structure_solution ‘SIR97 (Altomare et al., 1997)’ _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'WinGX (Farrugia, 1995)' _computing_publication_material ?

_refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.1494P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 20992 _refine_ls_number_parameters 890 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.1794 _refine_ls_R_factor_gt 0.0762 _refine_ls_wR_factor_ref 0.2479 _refine_ls_wR_factor_gt 0.2117 _refine_ls_goodness_of_fit_ref 0.828 _refine_ls_restrained_S_all 0.828 _refine_ls_shift/su_max 0.003 _refine_ls_shift/su_mean 0.000 loop_ _atom_site_label Appendix I: Crystallographic Information Files. Page 336

_atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.46672(17) 0.07139(17) 0.4077(4) 0.0294(16) Uani 0.50 1 d P . . C2 C 0.53310(14) 0.11454(15) 0.5494(5) 0.0889(18) Uani 1 1 d . . . C3 C 0.50855(13) 0.07828(13) 0.4429(4) 0.0813(17) Uani 1 1 d . . . H3 H 0.5167 0.0701 0.4037 0.098 Uiso 1 1 calc R . . C4 C 0.51230(15) 0.10359(14) 0.3958(4) 0.098(2) Uani 1 1 d . . . H4 H 0.5224 0.1075 0.3347 0.118 Uiso 1 1 calc R . . C5 C 0.52823(10) 0.07150(11) 0.6020(4) 0.0710(14) Uani 1 1 d . . . H5A H 0.5331 0.0605 0.5634 0.085 Uiso 1 1 calc R . . H5B H 0.5435 0.0833 0.6418 0.085 Uiso 1 1 calc R . . C6 C 0.46675(11) 0.03375(13) 0.4729(3) 0.0772(16) Uani 1 1 d . . . H6A H 0.4766 0.0259 0.4444 0.093 Uiso 1 1 calc R . . H6B H 0.4490 0.0249 0.4439 0.093 Uiso 1 1 calc R . . C7 C 0.50901(10) 0.05670(11) 0.7646(3) 0.0576(12) Uani 1 1 d . . . C8 C 0.44104(12) 0.01851(12) 0.6286(4) 0.0742(15) Uani 1 1 d . . . C9 C 0.47150(9) 0.01542(10) 0.7318(3) 0.0635(13) Uani 1 1 d . . . H9 H 0.4704 -0.0019 0.7413 0.076 Uiso 1 1 calc R . . C10 C 0.48536(10) 0.02855(10) 0.6349(3) 0.0615(12) Uani 1 1 d . . . H10 H 0.4927 0.0184 0.6028 0.074 Uiso 1 1 calc R . . C11 C 0.48598(9) 0.02860(11) 0.9068(3) 0.0626(12) Uani 1 1 d . . . H11A H 0.5026 0.0412 0.9387 0.075 Uiso 1 1 calc R . . H11B H 0.4833 0.0108 0.9165 0.075 Uiso 1 1 calc R . . C12 C 0.42222(10) -0.00577(11) 0.7802(4) 0.0700(14) Uani 1 1 d . . . H12A H 0.4058 -0.0115 0.7442 0.084 Uiso 1 1 calc R . . H12B H 0.4237 -0.0215 0.7937 0.084 Uiso 1 1 calc R . . C13 C 0.46827(11) 0.05006(10) 1.0173(3) 0.0556(11) Uani 1 1 d . . . C14 C 0.39848(10) 0.00717(10) 0.8998(4) 0.0685(13) Uani 1 1 d . . . C15 C 0.43739(9) 0.00819(10) 0.9550(3) 0.0563(11) Uani 1 1 d . . . H15 H 0.4371 -0.0087 0.9682 0.068 Uiso 1 1 calc R . . C16 C 0.42431(9) 0.01584(9) 1.0402(3) 0.0547(11) Uani 1 1 d . . . H16 H 0.4203 0.0041 1.0969 0.066 Uiso 1 1 calc R . . C17 C 0.37902(10) 0.01270(9) 1.0520(4) 0.0640(12) Uani 1 1 d . . . H17A H 0.3777 0.0040 1.1141 0.077 Uiso 1 1 calc R . . H17B H 0.3622 0.0021 1.0178 0.077 Uiso 1 1 calc R . . C18 C 0.44351(10) 0.05691(10) 1.1469(3) 0.0591(12) Uani 1 1 d . . . H18A H 0.4616 0.0707 1.1636 0.071 Uiso 1 1 calc R . . H18B H 0.4365 0.0445 1.2012 0.071 Uiso 1 1 calc R . . C19 C 0.43845(11) 0.09660(11) 1.1204(3) 0.0577(12) Uani 1 1 d . . . C20 C 0.36894(10) 0.04901(10) 1.0202(4) 0.0603(12) Uani 1 1 d . . . C21 C 0.39290(10) 0.07993(10) 1.1439(3) 0.0617(12) Uani 1 1 d . . . H21 H 0.3849 0.0815 1.2047 0.074 Uiso 1 1 calc R . . C22 C 0.39877(10) 0.05638(9) 1.1481(3) 0.0580(12) Uani 1 1 d . . . H22 H 0.3937 0.0472 1.2114 0.070 Uiso 1 1 calc R . . Appendix I: Crystallographic Information Files. Page 337

C23 C 0.42526(11) 0.13036(10) 1.1449(3) 0.0644(13) Uani 1 1 d . . . H23A H 0.4134 0.1306 1.1946 0.077 Uiso 1 1 calc R . . H23B H 0.4434 0.1404 1.1698 0.077 Uiso 1 1 calc R . . C24 C 0.36319(10) 0.08837(10) 1.0290(4) 0.0666(13) Uani 1 1 d . . . H24A H 0.3567 0.0938 1.0847 0.080 Uiso 1 1 calc R . . H24B H 0.3480 0.0774 0.9874 0.080 Uiso 1 1 calc R . . C25 C 0.44452(13) 0.16405(11) 1.0133(4) 0.0680(13) Uani 1 1 d . . . C26 C 0.38166(10) 0.11328(10) 0.8759(4) 0.0594(12) Uani 1 1 d . . . C27 C 0.39784(10) 0.13858(10) 1.0169(3) 0.0607(12) Uani 1 1 d . . . H27 H 0.3875 0.1424 1.0642 0.073 Uiso 1 1 calc R . . C28 C 0.40646(10) 0.15772(9) 0.9305(3) 0.0606(12) Uani 1 1 d . . . H28 H 0.3984 0.1692 0.9336 0.073 Uiso 1 1 calc R . . C29 C 0.45246(11) 0.19693(11) 0.8846(4) 0.0737(14) Uani 1 1 d . . . H29A H 0.4698 0.2062 0.9166 0.088 Uiso 1 1 calc R . . H29B H 0.4450 0.2087 0.8858 0.088 Uiso 1 1 calc R . . C30 C 0.39258(11) 0.14875(11) 0.7534(4) 0.0727(14) Uani 1 1 d . . . H30A H 0.3783 0.1336 0.7192 0.087 Uiso 1 1 calc R . . H30B H 0.3868 0.1618 0.7634 0.087 Uiso 1 1 calc R . . C31 C 0.48047(13) 0.19782(12) 0.7463(5) 0.0828(16) Uani 1 1 d . . . C32 C 0.41616(13) 0.15092(13) 0.6031(4) 0.0712(14) Uani 1 1 d . . . C33 C 0.43726(11) 0.18778(11) 0.7049(4) 0.0711(14) Uani 1 1 d . . . H33 H 0.4302 0.2000 0.7120 0.085 Uiso 1 1 calc R . . C34 C 0.45378(12) 0.19352(13) 0.6100(4) 0.0812(16) Uani 1 1 d . . . H34 H 0.4562 0.2095 0.5758 0.097 Uiso 1 1 calc R . . C35 C 0.50321(13) 0.20707(14) 0.5870(5) 0.103(2) Uani 1 1 d . . . H35A H 0.5045 0.2211 0.5445 0.124 Uiso 1 1 calc R . . H35B H 0.5190 0.2146 0.6282 0.124 Uiso 1 1 calc R . . C36 C 0.44275(13) 0.16821(14) 0.4514(4) 0.0891(18) Uani 1 1 d . . . H36A H 0.4259 0.1558 0.4206 0.107 Uiso 1 1 calc R . . H36B H 0.4489 0.1858 0.4232 0.107 Uiso 1 1 calc R . . C37 C 0.51981(16) 0.17650(15) 0.5443(6) 0.101(2) Uani 1 1 d . . . C38 C 0.45538(17) 0.13581(16) 0.3889(4) 0.0840(19) Uani 1 1 d . . . C39 C 0.49021(16) 0.17842(15) 0.4313(4) 0.097(2) Uani 1 1 d . . . H39 H 0.4952 0.1944 0.3916 0.117 Uiso 1 1 calc R . . C40 C 0.50165(18) 0.16106(18) 0.3884(5) 0.106(2) Uani 1 1 d . . . H40 H 0.5115 0.1689 0.3279 0.128 Uiso 1 1 calc R . . C41 C 0.47931(17) 0.11462(16) 0.3168(4) 0.114(3) Uani 1 1 d . . . H41A H 0.4932 0.1225 0.2676 0.137 Uiso 1 1 calc R . . H41B H 0.4624 0.1042 0.2832 0.137 Uiso 1 1 calc R . . C42 C 0.53873(13) 0.15317(15) 0.4527(6) 0.107(2) Uani 1 1 d . . . H42A H 0.5461 0.1574 0.3872 0.128 Uiso 1 1 calc R . . H42B H 0.5534 0.1627 0.4984 0.128 Uiso 1 1 calc R . . N1 N 0.48427(13) 0.09621(14) 0.3786(3) 0.101(2) Uani 1 1 d . . . N2 N 0.52664(11) 0.12451(11) 0.4691(4) 0.0929(15) Uani 1 1 d . . . N3 N 0.47860(14) 0.13611(13) 0.3700(4) 0.0967(16) Uani 1 1 d . . . N4 N 0.51946(11) 0.16228(11) 0.4645(4) 0.0960(15) Uani 1 1 d . . . N5 N 0.46186(11) 0.16004(11) 0.4294(3) 0.0870(14) Uani 1 1 d . . . N6 N 0.50209(10) 0.18537(11) 0.5282(4) 0.0935(15) Uani 1 1 d . . . N7 N 0.43818(10) 0.16938(10) 0.5547(3) 0.0751(12) Uani 1 1 d . . . N8 N 0.47879(10) 0.19677(10) 0.6487(4) 0.0877(14) Uani 1 1 d . . . N9 N 0.45643(9) 0.19193(9) 0.7824(3) 0.0728(11) Uani 1 1 d . . . N10 N 0.41607(9) 0.16051(9) 0.6933(3) 0.0702(11) Uani 1 1 d . . . N11 N 0.39643(8) 0.13980(8) 0.8478(3) 0.0605(10) Uani 1 1 d . . . N12 N 0.43525(8) 0.17327(8) 0.9395(3) 0.0665(11) Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 338

N13 N 0.38197(8) 0.11208(8) 0.9752(3) 0.0593(10) Uani 1 1 d . . . N14 N 0.42313(8) 0.14344(8) 1.0582(3) 0.0608(10) Uani 1 1 d . . . N15 N 0.37448(8) 0.07265(8) 1.0627(3) 0.0654(10) Uani 1 1 d . . . N16 N 0.41859(8) 0.10284(8) 1.1276(3) 0.0569(9) Uani 1 1 d . . . N17 N 0.42688(7) 0.06941(8) 1.1331(3) 0.0545(9) Uani 1 1 d . . . N18 N 0.38270(7) 0.03899(7) 1.0702(3) 0.0595(10) Uani 1 1 d . . . N19 N 0.44444(7) 0.04276(7) 1.0615(2) 0.0516(9) Uani 1 1 d . . . N20 N 0.40024(7) 0.01288(8) 0.9956(3) 0.0581(9) Uani 1 1 d . . . N21 N 0.42070(8) 0.00585(8) 0.8714(3) 0.0641(10) Uani 1 1 d . . . N22 N 0.46384(8) 0.03015(8) 0.9519(3) 0.0591(10) Uani 1 1 d . . . N23 N 0.44474(8) 0.01253(8) 0.7196(3) 0.0617(10) Uani 1 1 d . . . N24 N 0.48817(8) 0.03443(9) 0.8030(3) 0.0602(10) Uani 1 1 d . . . N25 N 0.46406(8) 0.02831(8) 0.5778(3) 0.0647(11) Uani 1 1 d . . . N26 N 0.50625(8) 0.05462(8) 0.6643(3) 0.0594(10) Uani 1 1 d . . . N27 N 0.52196(9) 0.08742(10) 0.5371(3) 0.0766(12) Uani 1 1 d . . . N28 N 0.47983(10) 0.06127(11) 0.4479(3) 0.0777(13) Uani 1 1 d . . . O1 O 0.54671(9) 0.12732(9) 0.6201(3) 0.0971(12) Uani 1 1 d . . . O2 O 0.44370(10) 0.06306(9) 0.3940(3) 0.0999(14) Uani 1 1 d . . . O3 O 0.52670(6) 0.07500(7) 0.8101(2) 0.0707(9) Uani 1 1 d . . . O4 O 0.41973(7) 0.01534(8) 0.5945(3) 0.0863(11) Uani 1 1 d . . . O5 O 0.48948(7) 0.07033(7) 1.0324(2) 0.0667(9) Uani 1 1 d . . . O6 O 0.38009(7) 0.00375(8) 0.8440(3) 0.0822(11) Uani 1 1 d . . . O7 O 0.46219(7) 0.11221(7) 1.1074(2) 0.0660(9) Uani 1 1 d . . . O8 O 0.35369(7) 0.03816(7) 0.9510(3) 0.0729(9) Uani 1 1 d . . . O9 O 0.46830(7) 0.17323(7) 1.0357(3) 0.0769(10) Uani 1 1 d . . . O10 O 0.37032(7) 0.09457(7) 0.8208(3) 0.0713(9) Uani 1 1 d . . . O11 O 0.50054(9) 0.20340(9) 0.7944(3) 0.1031(13) Uani 1 1 d . . . O12 O 0.39848(9) 0.12969(9) 0.5701(3) 0.0864(11) Uani 1 1 d . . . O13 O 0.53366(9) 0.18104(10) 0.6187(4) 0.1134(15) Uani 1 1 d . . . O14 O 0.43289(12) 0.11788(11) 0.3707(3) 0.1036(15) Uani 1 1 d . . . O100 O 0.58362(12) 0.13406(12) 0.3965(4) 0.0620(16) Uiso 0.50 1 d P . . O101 O 0.33522(12) -0.05529(12) 0.1174(5) 0.0653(16) Uiso 0.50 1 d P . . O102 O 0.43074(12) -0.14967(12) 0.7732(5) 0.0650(16) Uiso 0.50 1 d P . . O103 O 0.47625(14) -0.12387(14) 0.8952(5) 0.0780(19) Uiso 0.50 1 d P . . O501 O 0.42957(6) -0.07996(6) 0.5694(2) 0.0665(8) Uani 1 1 d . . . O502 O 0.42046(7) -0.03995(8) 0.5919(2) 0.0801(10) Uani 1 1 d . . . O503 O 0.46917(6) -0.03090(7) 0.5614(2) 0.0732(9) Uani 1 1 d . . . O504 O 0.44674(6) -0.04974(7) 0.7411(2) 0.0632(8) Uani 1 1 d . . . O505 O 0.45758(7) -0.08832(7) 0.7918(3) 0.0887(11) Uani 1 1 d . . . O506 O 0.46679(6) -0.05068(8) 0.9148(2) 0.0833(11) Uani 1 1 d . . . O507 O 0.49924(6) -0.03975(7) 0.7564(2) 0.0735(9) Uani 1 1 d . . . O508 O 0.55411(6) -0.00936(6) 0.7472(2) 0.0637(8) Uani 1 1 d . . . O509 O 0.52987(7) 0.00211(7) 0.8842(2) 0.0808(10) Uani 1 1 d . . . O510 O 0.52724(7) 0.01465(7) 0.7009(3) 0.0811(10) Uani 1 1 d . . . Cr1 Cr 0.528822(13) -0.006286(15) 0.77338(5) 0.0538(2) Uani 1 1 d . . . Cr2 Cr 0.468022(14) -0.057257(16) 0.80517(5) 0.0596(2) Uani 1 1 d . . . Cr3 Cr 0.441197(15) -0.050415(16) 0.61044(5) 0.0602(2) Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 339

I.4: [(Q6)(Na3(H2O)8)]2[CoCl4]4[Co(H2O)6]2[CoCl(H2O)5]2(Cl)4(H2O)17. data_5.5

_audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety 2(C36 H52 N24 O20 Na 3 3+), 4(Co Cl4 2-), 2(Co O6 H12 2+), 2(Co Cl O5 H10 1+), 4(Cl 1-) 17(H2 O) _chemical_formula_sum 'C72 H182 Cl422 Co8 N24 Na6 O96' _chemical_formula_weight 4373.94 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source 'C' 'C' 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'H' 'H' 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Cl' 'Cl' 0.1484 0.1585 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Co' 'Co' 0.3494 0.9721 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'N' 'N' 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Na' 'Na' 0.0362 0.0249 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'O' 'O' 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_symmetry_cell_setting 'monoclinic' _symmetry_space_group_name_H-M 'P2(1)/c' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2'

_cell_length_a 25.764(4) _cell_length_b 21.850(3) _cell_length_c 29.420(4) Appendix I: Crystallographic Information Files. Page 340

_cell_angle_alpha 90.00 _cell_angle_beta 91.357(2) _cell_angle_gamma 90.00 _cell_volume 16558(6) _cell_formula_units_Z 4 _cell_measurement_temperature 150(2) _cell_measurement_reflns_used 1021 _cell_measurement_theta_min 2.549 _cell_measurement_theta_max 28.020

_exptl_crystal_description block _exptl_crystal_colour dark blue _exptl_crystal_size_max 0.69 _exptl_crystal_size_mid 0.31 _exptl_crystal_size_min 0.22 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.469 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 7464 _exptl_absorpt_coefficient_mu 0.590 _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min 0.0015 _exptl_absorpt_correction_T_max 1.000 _exptl_absorpt_process_details SADABS (Sheldrik, 1996)

_exptl_special_details ; ? ;

_diffrn_ambient_temperature 150(2) _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type ’Bruker SMART 1000 CCD’ _diffrn_measurement_method \w _diffrn_detector_area_resol_mean ? _diffrn_standards_number 1259 _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% 0 _diffrn_reflns_number 152805 _diffrn_reflns_av_R_equivalents 0.0314 _diffrn_reflns_av_sigmaI/netI 0.0281 _diffrn_reflns_limit_h_min -34 _diffrn_reflns_limit_h_max 34 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 28 _diffrn_reflns_limit_l_min 0 _diffrn_reflns_limit_l_max 38 _diffrn_reflns_theta_min 0.79 _diffrn_reflns_theta_max 28.27 _reflns_number_total 39472 Appendix I: Crystallographic Information Files. Page 341

_reflns_number_gt 30799 _reflns_threshold_expression >2sigma(I)

_computing_data_collection ‘SMART (Bruker, 1995)’ _computing_cell_refinement ‘SAINT (Bruker, 1995)’ _computing_data_reduction ‘SAINT and XPREP (Bruker, 1995)’ _computing_structure_solution ‘SIR97 (Altomare et al., 1997)’ _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'WinGX (Farrugia, 1995)' _computing_publication_material ?

_refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type fullcycle _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0625P)^2^+34.2178P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 39472 _refine_ls_number_parameters 2107 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0629 _refine_ls_R_factor_gt 0.0442 _refine_ls_wR_factor_ref 0.1356 _refine_ls_wR_factor_gt 0.1220 _refine_ls_goodness_of_fit_ref 1.050 _refine_ls_restrained_S_all 1.050 _refine_ls_shift/su_max 1.495 _refine_ls_shift/su_mean 0.002 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy Appendix I: Crystallographic Information Files. Page 342

_atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.12684(10) 0.15605(12) -0.17904(9) 0.015 Uani 1 1 d . . . C2 C 0.14951(10) 0.24400(12) -0.13814(9) 0.014 Uani 1 1 d . . . H2 H 0.1717 0.2479 -0.1108 0.017 Uiso 1 1 calc R . . C3 C 0.18195(10) 0.24105(12) -0.18215(9) 0.014 Uani 1 1 d . . . H3 H 0.2191 0.2363 -0.1753 0.017 Uiso 1 1 calc R . . C4 C 0.13269(10) 0.33139(12) -0.18254(9) 0.015 Uani 1 1 d . . . C5 C 0.08867(10) 0.16608(12) -0.10256(9) 0.016 Uani 1 1 d . . . H5A H 0.0856 0.1219 -0.1040 0.019 Uiso 1 1 calc R . . H5B H 0.1051 0.1765 -0.0736 0.019 Uiso 1 1 calc R . . C6 C 0.08950(10) 0.32795(12) -0.10877(9) 0.015 Uani 1 1 d . . . H6A H 0.1093 0.3224 -0.0806 0.018 Uiso 1 1 calc R . . H6B H 0.0876 0.3715 -0.1148 0.018 Uiso 1 1 calc R . . C7 C 0.02512(10) 0.24845(12) -0.07973(9) 0.014 Uani 1 1 d . . . H7 H 0.0399 0.2475 -0.0487 0.017 Uiso 1 1 calc R . . C8 C -0.03547(10) 0.24875(12) -0.07977(9) 0.014 Uani 1 1 d . . . H8 H -0.0487 0.2523 -0.0489 0.017 Uiso 1 1 calc R . . C9 C -0.00577(11) 0.33685(12) -0.11654(9) 0.017 Uani 1 1 d . . . C10 C -0.00630(11) 0.15723(12) -0.11251(9) 0.016 Uani 1 1 d . . . C11 C -0.10160(10) 0.16924(12) -0.10746(9) 0.015 Uani 1 1 d . . . H11A H -0.1216 0.1800 -0.0811 0.018 Uiso 1 1 calc R . . H11B H -0.1013 0.1250 -0.1097 0.018 Uiso 1 1 calc R . . C12 C -0.10086(10) 0.32796(12) -0.10856(9) 0.016 Uani 1 1 d . . . H12A H -0.1178 0.3178 -0.0805 0.019 Uiso 1 1 calc R . . H12B H -0.0983 0.3722 -0.1103 0.019 Uiso 1 1 calc R . . C13 C -0.16063(11) 0.24843(12) -0.14729(9) 0.015 Uani 1 1 d . . . H13 H -0.1862 0.2462 -0.1232 0.017 Uiso 1 1 calc R . . C14 C -0.18695(10) 0.24801(12) -0.19551(9) 0.015 Uani 1 1 d . . . H14 H -0.2249 0.2478 -0.1939 0.018 Uiso 1 1 calc R . . C15 C -0.13709(10) 0.33716(12) -0.18701(9) 0.016 Uani 1 1 d . . . C16 C -0.13164(10) 0.16277(12) -0.18820(9) 0.014 Uani 1 1 d . . . C17 C -0.18926(11) 0.33028(13) -0.25784(9) 0.016 Uani 1 1 d . . . H17A H -0.1855 0.3744 -0.2563 0.019 Uiso 1 1 calc R . . H17B H -0.2261 0.3212 -0.2598 0.019 Uiso 1 1 calc R . . C18 C -0.18557(11) 0.16907(12) -0.25916(9) 0.016 Uani 1 1 d . . . H18A H -0.2226 0.1768 -0.2624 0.020 Uiso 1 1 calc R . . H18B H -0.1804 0.1251 -0.2598 0.020 Uiso 1 1 calc R . . C19 C -0.17838(10) 0.25105(12) -0.32116(9) 0.015 Uani 1 1 d . . . H19 H -0.2156 0.2485 -0.3284 0.018 Uiso 1 1 calc R . . C20 C -0.14533(10) 0.25238(12) -0.36506(9) 0.014 Uani 1 1 d . . . H20 H -0.1671 0.2563 -0.3926 0.017 Uiso 1 1 calc R . . C21 C -0.12755(10) 0.34014(12) -0.32151(9) 0.015 Uani 1 1 d . . . C22 C -0.12696(10) 0.16278(12) -0.32408(9) 0.014 Uani 1 1 d . . . C23 C -0.08326(10) 0.33285(12) -0.39487(9) 0.015 Uani 1 1 d . . . H23A H -0.1028 0.3271 -0.4232 0.018 Uiso 1 1 calc R . . H23B H -0.0800 0.3765 -0.3896 0.018 Uiso 1 1 calc R . . C24 C -0.08663(10) 0.17052(12) -0.39939(9) 0.015 Uani 1 1 d . . . H24A H -0.0847 0.1263 -0.3967 0.018 Uiso 1 1 calc R . . H24B H -0.1033 0.1800 -0.4285 0.018 Uiso 1 1 calc R . . C25 C 0.01223(11) 0.33717(12) -0.38583(9) 0.016 Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 343

C26 C 0.00828(11) 0.15891(13) -0.39045(9) 0.017 Uani 1 1 d . . . C27 C -0.02113(10) 0.25062(12) -0.42357(9) 0.014 Uani 1 1 d . . . H27 H -0.0366 0.2507 -0.4543 0.017 Uiso 1 1 calc R . . C28 C 0.03915(10) 0.24896(12) -0.42425(9) 0.014 Uani 1 1 d . . . H28 H 0.0521 0.2522 -0.4552 0.016 Uiso 1 1 calc R . . C29 C 0.10735(10) 0.32455(12) -0.39414(9) 0.016 Uani 1 1 d . . . H29A H 0.1244 0.3144 -0.4222 0.019 Uiso 1 1 calc R . . H29B H 0.1065 0.3688 -0.3916 0.019 Uiso 1 1 calc R . . C30 C 0.10364(10) 0.16595(12) -0.39739(9) 0.014 Uani 1 1 d . . . H30A H 0.1239 0.1767 -0.4236 0.017 Uiso 1 1 calc R . . H30B H 0.1018 0.1216 -0.3960 0.017 Uiso 1 1 calc R . . C31 C 0.16436(10) 0.24170(12) -0.35620(9) 0.014 Uani 1 1 d . . . H31 H 0.1902 0.2396 -0.3800 0.017 Uiso 1 1 calc R . . C32 C 0.19012(10) 0.23932(12) -0.30763(9) 0.014 Uani 1 1 d . . . H32 H 0.2280 0.2369 -0.3088 0.016 Uiso 1 1 calc R . . C33 C 0.14322(10) 0.33072(12) -0.31584(9) 0.015 Uani 1 1 d . . . C34 C 0.13480(10) 0.15487(12) -0.31711(9) 0.015 Uani 1 1 d . . . C35 C 0.18511(11) 0.15979(12) -0.24471(9) 0.015 Uani 1 1 d . . . H35A H 0.2224 0.1653 -0.2415 0.018 Uiso 1 1 calc R . . H35B H 0.1781 0.1162 -0.2444 0.018 Uiso 1 1 calc R . . C36 C 0.19548(11) 0.31996(13) -0.24496(9) 0.016 Uani 1 1 d . . . H36A H 0.1936 0.3643 -0.2461 0.019 Uiso 1 1 calc R . . H36B H 0.2319 0.3087 -0.2431 0.019 Uiso 1 1 calc R . . C37 C 0.50293(12) 0.40796(13) 0.36606(10) 0.021 Uani 1 1 d . . . C38 C 0.47526(11) 0.49663(12) 0.32732(9) 0.016 Uani 1 1 d . . . H38 H 0.4636 0.4949 0.2954 0.020 Uiso 1 1 calc R . . C39 C 0.53532(11) 0.49663(12) 0.33190(9) 0.015 Uani 1 1 d . . . H39 H 0.5518 0.4960 0.3022 0.018 Uiso 1 1 calc R . . C40 C 0.50274(11) 0.58688(13) 0.36377(10) 0.019 Uani 1 1 d . . . C41 C 0.59848(11) 0.57731(13) 0.36131(10) 0.019 Uani 1 1 d . . . H41A H 0.5965 0.6214 0.3645 0.023 Uiso 1 1 calc R . . H41B H 0.6171 0.5685 0.3338 0.023 Uiso 1 1 calc R . . C42 C 0.59844(11) 0.41590(13) 0.36182(10) 0.020 Uani 1 1 d . . . H42A H 0.6166 0.4245 0.3340 0.024 Uiso 1 1 calc R . . H42B H 0.5957 0.3718 0.3648 0.024 Uiso 1 1 calc R . . C43 C 0.63559(11) 0.40860(13) 0.44015(9) 0.018 Uani 1 1 d . . . C44 C 0.63502(11) 0.58491(13) 0.43928(10) 0.020 Uani 1 1 d . . . C45 C 0.65819(11) 0.49665(13) 0.39906(9) 0.018 Uani 1 1 d . . . H45 H 0.6827 0.4970 0.3741 0.021 Uiso 1 1 calc R . . C46 C 0.68667(11) 0.49708(14) 0.44643(10) 0.020 Uani 1 1 d . . . H46 H 0.7245 0.4959 0.4435 0.023 Uiso 1 1 calc R . . C47 C 0.69001(12) 0.41803(16) 0.51005(9) 0.026 Uani 1 1 d . . . H47A H 0.7270 0.4261 0.5105 0.031 Uiso 1 1 calc R . . H47B H 0.6853 0.3740 0.5102 0.031 Uiso 1 1 calc R . . C48 C 0.69192(13) 0.57860(17) 0.50841(10) 0.029 Uani 1 1 d . . . H48A H 0.6883 0.6228 0.5078 0.035 Uiso 1 1 calc R . . H48B H 0.7287 0.5693 0.5098 0.035 Uiso 1 1 calc R . . C49 C 0.68489(12) 0.49994(16) 0.57258(10) 0.026 Uani 1 1 d . . . H49 H 0.7224 0.5000 0.5791 0.031 Uiso 1 1 calc R . . C50 C 0.65290(12) 0.50121(15) 0.61714(10) 0.023 Uani 1 1 d . . . H50 H 0.6754 0.5007 0.6445 0.027 Uiso 1 1 calc R . . C51 C 0.63164(11) 0.41269(15) 0.57553(10) 0.024 Uani 1 1 d . . . C52 C 0.63364(12) 0.58886(16) 0.57372(10) 0.027 Uani 1 1 d . . . C53 C 0.59180(11) 0.58296(14) 0.64851(10) 0.021 Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 344

H53A H 0.6084 0.5746 0.6778 0.025 Uiso 1 1 calc R . . H53B H 0.5899 0.6270 0.6449 0.025 Uiso 1 1 calc R . . C54 C 0.59149(11) 0.42265(14) 0.65057(10) 0.021 Uani 1 1 d . . . H54A H 0.5901 0.3784 0.6481 0.025 Uiso 1 1 calc R . . H54B H 0.6093 0.4326 0.6791 0.025 Uiso 1 1 calc R . . C55 C 0.39453(11) 0.07430(13) 0.63726(10) 0.018 Uani 1 1 d . . . H55A H 0.3944 0.1185 0.6344 0.022 Uiso 1 1 calc R . . H55B H 0.3736 0.0637 0.6631 0.022 Uiso 1 1 calc R . . C56 C 0.40192(11) -0.08665(13) 0.63547(10) 0.020 Uani 1 1 d . . . H56A H 0.4065 -0.1305 0.6325 0.024 Uiso 1 1 calc R . . H56B H 0.3816 -0.0794 0.6623 0.024 Uiso 1 1 calc R . . C57 C 0.34176(11) -0.00924(13) 0.59641(10) 0.017 Uani 1 1 d . . . H57 H 0.3165 -0.0102 0.6207 0.021 Uiso 1 1 calc R . . C58 C 0.31488(11) -0.00982(14) 0.54867(10) 0.019 Uani 1 1 d . . . H58 H 0.2770 -0.0125 0.5507 0.023 Uiso 1 1 calc R . . C59 C 0.36865(11) -0.09564(13) 0.55592(9) 0.017 Uani 1 1 d . . . C60 C 0.36219(11) 0.08087(13) 0.55744(10) 0.020 Uani 1 1 d . . . C61 C 0.30924(13) 0.07091(16) 0.48632(10) 0.027 Uani 1 1 d . . . H61A H 0.3129 0.1151 0.4860 0.032 Uiso 1 1 calc R . . H61B H 0.2724 0.0616 0.4847 0.032 Uiso 1 1 calc R . . C62 C 0.31314(12) -0.09012(15) 0.48591(10) 0.024 Uani 1 1 d . . . H62A H 0.3187 -0.1340 0.4865 0.029 Uiso 1 1 calc R . . H62B H 0.2760 -0.0830 0.4859 0.029 Uiso 1 1 calc R . . C63 C 0.31675(11) -0.00932(15) 0.42266(10) 0.023 Uani 1 1 d . . . H63 H 0.2793 -0.0092 0.4162 0.027 Uiso 1 1 calc R . . C64 C 0.37199(11) -0.09445(14) 0.42084(9) 0.020 Uani 1 1 d . . . C65 C 0.36770(12) 0.08022(15) 0.42149(10) 0.024 Uani 1 1 d . . . C66 C 0.34872(11) -0.00761(14) 0.37799(10) 0.020 Uani 1 1 d . . . H66 H 0.3262 -0.0100 0.3507 0.024 Uiso 1 1 calc R . . C67 C 0.41497(11) -0.08382(13) 0.34707(10) 0.018 Uani 1 1 d . . . H67A H 0.4178 -0.1279 0.3496 0.022 Uiso 1 1 calc R . . H67B H 0.3989 -0.0746 0.3177 0.022 Uiso 1 1 calc R . . C68 C 0.40847(11) 0.07567(14) 0.34628(10) 0.019 Uani 1 1 d . . . H68A H 0.3940 0.0650 0.3166 0.023 Uiso 1 1 calc R . . H68B H 0.4084 0.1199 0.3487 0.023 Uiso 1 1 calc R . . C69 C 0.47870(11) -0.00052(12) 0.32634(9) 0.016 Uani 1 1 d . . . H69 H 0.4669 -0.0011 0.2944 0.020 Uiso 1 1 calc R . . C70 C 0.53896(11) 0.00295(12) 0.33091(9) 0.016 Uani 1 1 d . . . H70 H 0.5551 0.0059 0.3012 0.020 Uiso 1 1 calc R . . C71 C 0.50997(11) -0.08985(14) 0.36122(10) 0.022 Uani 1 1 d . . . C72 C 0.50193(12) 0.08971(14) 0.36455(10) 0.022 Uani 1 1 d . . . Cl1 Cl 0.26676(3) 0.58953(3) 0.18405(2) 0.022 Uani 1 1 d . . . Cl2 Cl 0.35699(3) 0.49736(3) 0.25081(2) 0.022 Uani 1 1 d . . . Cl3 Cl 0.26143(3) 0.41822(3) 0.17625(3) 0.026 Uani 1 1 d . . . Cl4 Cl 0.21510(3) 0.50081(3) 0.28066(3) 0.024 Uani 1 1 d . . . Cl5 Cl 0.24229(3) 0.34466(3) 0.06125(3) 0.024 Uani 1 1 d . . . Cl6 Cl 0.27289(3) 0.25215(4) -0.04785(3) 0.030 Uani 1 1 d . . . Cl7 Cl 0.25041(3) 0.17946(4) 0.06493(3) 0.028 Uani 1 1 d . . . Cl8 Cl 0.14382(3) 0.25938(3) -0.00433(2) 0.022 Uani 1 1 d . . . Cl9 Cl 0.24816(3) 0.82537(4) 0.56968(3) 0.029 Uani 1 1 d . . . Cl10 Cl 0.27721(3) 0.74720(3) 0.46055(3) 0.025 Uani 1 1 d . . . Cl11 Cl 0.23908(3) 0.65676(3) 0.56862(2) 0.023 Uani 1 1 d . . . Cl12 Cl 0.14466(3) 0.74094(3) 0.49975(2) 0.022 Uani 1 1 d . . . Cl13 Cl 0.24079(3) 0.04382(4) 0.30356(3) 0.035 Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 345

Cl14 Cl 0.35101(3) -0.01765(4) 0.24417(3) 0.026 Uani 1 1 d . . . Cl15 Cl 0.21695(3) -0.03564(4) 0.19196(3) 0.030 Uani 1 1 d . . . Cl16 Cl 0.27798(3) 0.10948(3) 0.18612(2) 0.021 Uani 1 1 d . . . Cl17 Cl 0.68128(3) -0.19733(5) 0.20074(3) 0.038 Uani 1 1 d . . . Cl18 Cl 0.32285(3) -0.29572(4) 0.29442(3) 0.035 Uani 1 1 d . . . Cl19 Cl 0.02490(3) 0.62987(3) 0.00389(2) 0.023 Uani 1 1 d . . . Cl20 Cl 0.02382(3) 0.13183(3) 0.00053(2) 0.021 Uani 1 1 d . . . Cl21 Cl 0.52767(3) -0.37945(3) 0.25348(3) 0.026 Uani 1 1 d . . . Cl22 Cl 0.47556(3) -0.11988(3) 0.24511(2) 0.022 Uani 1 1 d . . . Co1 Co 0.272805(15) 0.499233(17) 0.223243(13) 0.017 Uani 1 1 d . . . Co2 Co 0.229333(15) 0.259070(19) 0.018892(14) 0.020 Uani 1 1 d . . . Co3 Co 0.229798(15) 0.743753(18) 0.525196(13) 0.018 Uani 1 1 d . . . Co4 Co -0.116867(15) 0.013187(18) 0.002799(13) 0.017 Uani 1 1 d . . . Co5 Co 0.272490(15) 0.026090(19) 0.232677(14) 0.021 Uani 1 1 d . . . Co6 Co 0.618532(16) -0.228818(19) 0.256378(14) 0.021 Uani 1 1 d . . . Co7 Co 0.385638(15) -0.268683(18) 0.237141(14) 0.019 Uani 1 1 d . . . Co8 Co 0.118364(16) 0.485148(18) -0.004404(13) 0.020 Uani 1 1 d . . . N1 N 0.12154(9) 0.18674(10) -0.13909(8) 0.015 Uani 1 1 d . . . N2 N 0.16029(9) 0.18790(10) -0.20573(8) 0.015 Uani 1 1 d . . . N3 N 0.11695(9) 0.29829(10) -0.14566(7) 0.014 Uani 1 1 d . . . N4 N 0.17036(9) 0.29900(10) -0.20398(8) 0.016 Uani 1 1 d . . . N5 N 0.03722(9) 0.19275(10) -0.10480(8) 0.016 Uani 1 1 d . . . N6 N 0.03771(9) 0.30479(10) -0.10284(8) 0.016 Uani 1 1 d . . . N7 N -0.04888(9) 0.19046(10) -0.10022(8) 0.016 Uani 1 1 d . . . N8 N -0.04876(9) 0.30217(10) -0.10733(8) 0.016 Uani 1 1 d . . . N9 N -0.12741(9) 0.19415(10) -0.14792(8) 0.015 Uani 1 1 d . . . N10 N -0.13268(9) 0.30627(10) -0.14647(8) 0.017 Uani 1 1 d . . . N11 N -0.16786(9) 0.30381(10) -0.21637(8) 0.016 Uani 1 1 d . . . N12 N -0.16751(9) 0.19211(10) -0.21563(8) 0.016 Uani 1 1 d . . . N13 N -0.15945(9) 0.19632(10) -0.29775(8) 0.016 Uani 1 1 d . . . N14 N -0.16491(9) 0.30828(10) -0.29901(8) 0.015 Uani 1 1 d . . . N15 N -0.11832(9) 0.19434(10) -0.36327(8) 0.015 Uani 1 1 d . . . N16 N -0.11215(9) 0.30574(10) -0.35789(8) 0.016 Uani 1 1 d . . . N17 N -0.03437(9) 0.19528(10) -0.39863(8) 0.016 Uani 1 1 d . . . N18 N -0.03197(9) 0.30693(10) -0.39949(8) 0.016 Uani 1 1 d . . . N19 N 0.05430(9) 0.30145(10) -0.39644(8) 0.016 Uani 1 1 d . . . N20 N 0.05151(9) 0.18998(10) -0.40387(8) 0.016 Uani 1 1 d . . . N21 N 0.13048(9) 0.18805(10) -0.35667(8) 0.016 Uani 1 1 d . . . N22 N 0.13745(9) 0.29999(10) -0.35637(8) 0.016 Uani 1 1 d . . . N23 N 0.17312(9) 0.29556(10) -0.28664(8) 0.016 Uani 1 1 d . . . N24 N 0.16793(9) 0.18450(10) -0.28800(8) 0.016 Uani 1 1 d . . . N25 N 0.46067(9) 0.55393(11) 0.34834(8) 0.019 Uani 1 1 d . . . N26 N 0.46056(9) 0.44173(11) 0.35175(8) 0.019 Uani 1 1 d . . . N27 N 0.54673(9) 0.44175(11) 0.35826(8) 0.019 Uani 1 1 d . . . N28 N 0.54639(9) 0.55286(11) 0.35678(8) 0.018 Uani 1 1 d . . . N29 N 0.62741(10) 0.55230(12) 0.40006(9) 0.022 Uani 1 1 d . . . N30 N 0.62873(10) 0.43975(11) 0.40020(8) 0.020 Uani 1 1 d . . . N31 N 0.66736(10) 0.44249(11) 0.46847(8) 0.020 Uani 1 1 d . . . N32 N 0.66969(11) 0.55369(12) 0.46662(8) 0.023 Uani 1 1 d . . . N33 N 0.66810(11) 0.55514(13) 0.54928(9) 0.027 Uani 1 1 d . . . N34 N 0.66794(10) 0.44342(13) 0.55095(9) 0.026 Uani 1 1 d . . . N35 N 0.62134(10) 0.44660(13) 0.61339(9) 0.027 Uani 1 1 d . . . N36 N 0.62376(10) 0.55782(13) 0.61298(9) 0.025 Uani 1 1 d . . . N37 N 0.37096(9) 0.04787(11) 0.59644(8) 0.020 Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 346

N38 N 0.37337(10) -0.06422(11) 0.59599(8) 0.020 Uani 1 1 d . . . N39 N 0.33633(10) -0.06365(11) 0.52694(8) 0.019 Uani 1 1 d . . . N40 N 0.33083(10) 0.04749(12) 0.52886(8) 0.022 Uani 1 1 d . . . N41 N 0.33364(10) 0.04597(13) 0.44630(9) 0.025 Uani 1 1 d . . . N42 N 0.33369(10) -0.06578(13) 0.44428(8) 0.023 Uani 1 1 d . . . N43 N 0.37549(10) 0.05046(12) 0.38112(8) 0.022 Uani 1 1 d . . . N44 N 0.38193(9) -0.06117(12) 0.38269(8) 0.020 Uani 1 1 d . . . N45 N 0.46652(9) -0.05717(11) 0.34928(8) 0.019 Uani 1 1 d . . . N46 N 0.46151(9) 0.05418(11) 0.34946(8) 0.019 Uani 1 1 d . . . N47 N 0.54748(10) 0.05832(11) 0.35791(9) 0.021 Uani 1 1 d . . . N48 N 0.55260(9) -0.05390(11) 0.35393(9) 0.020 Uani 1 1 d . . . Na1 Na 0.05590(4) 0.57317(5) -0.24478(4) 0.019 Uani 1 1 d . . . Na2 Na -0.04272(4) 0.44298(5) -0.19233(4) 0.020 Uani 1 1 d . . . Na3 Na 0.05144(4) 0.44032(5) -0.30879(4) 0.018 Uani 1 1 d . . . Na4 Na 0.45199(8) 0.18852(10) 0.43826(7) 0.017 Uiso 0.50 1 d P . . Na5 Na 0.44066(9) 0.31958(11) 0.50186(8) 0.022 Uiso 0.50 1 d P . . Na6 Na 0.53780(9) 0.30925(11) 0.56231(8) 0.024 Uiso 0.50 1 d P . . Na7 Na 0.52988(9) 0.19380(11) 0.56423(8) 0.023 Uiso 0.50 1 d P . . Na8 Na 0.43976(10) 0.17640(12) 0.50080(9) 0.031 Uiso 0.50 1 d P . . Na9 Na 0.45181(10) 0.30764(11) 0.43922(8) 0.025 Uiso 0.50 1 d P . . O1 O 0.10537(8) 0.10712(9) -0.18933(7) 0.020 Uani 1 1 d . . . O2 O 0.11569(8) 0.38190(9) -0.19409(7) 0.020 Uani 1 1 d . . . O3 O -0.00665(8) 0.10455(9) -0.12686(7) 0.022 Uani 1 1 d . . . O4 O -0.00593(8) 0.38818(9) -0.13353(8) 0.024 Uani 1 1 d . . . O5 O -0.10819(8) 0.11549(9) -0.19747(7) 0.018 Uani 1 1 d . . . O6 O -0.11763(8) 0.38705(9) -0.19534(7) 0.021 Uani 1 1 d . . . O7 O -0.10875(8) 0.11220(9) -0.31418(7) 0.018 Uani 1 1 d . . . O8 O -0.11066(8) 0.39114(9) -0.31118(7) 0.020 Uani 1 1 d . . . O9 O 0.00832(9) 0.10730(10) -0.37430(8) 0.028 Uani 1 1 d . . . O10 O 0.01389(8) 0.38756(9) -0.36764(7) 0.022 Uani 1 1 d . . . O11 O 0.11203(8) 0.10640(9) -0.30909(7) 0.020 Uani 1 1 d . . . O12 O 0.12589(8) 0.38152(9) -0.30730(7) 0.020 Uani 1 1 d . . . O13 O 0.50173(9) 0.35656(11) 0.38228(8) 0.033 Uani 1 1 d . . . O14 O 0.50137(9) 0.63801(10) 0.38056(8) 0.028 Uani 1 1 d . . . O15 O 0.61671(9) 0.35836(10) 0.44886(7) 0.027 Uani 1 1 d . . . O16 O 0.61485(9) 0.63423(10) 0.44806(8) 0.029 Uani 1 1 d . . . O17 O 0.61237(9) 0.36275(11) 0.56569(8) 0.030 Uani 1 1 d . . . O18 O 0.61535(10) 0.63895(11) 0.56259(8) 0.034 Uani 1 1 d . . . O19 O 0.37942(9) 0.13233(10) 0.55003(8) 0.028 Uani 1 1 d . . . O20 O 0.39002(9) -0.14456(10) 0.54716(7) 0.024 Uani 1 1 d . . . O21 O 0.39343(9) -0.14275(10) 0.43208(7) 0.026 Uani 1 1 d . . . O22 O 0.38654(10) 0.12942(11) 0.43304(8) 0.031 Uani 1 1 d . . . O23 O 0.49862(9) 0.14090(11) 0.38103(9) 0.034 Uani 1 1 d . . . O24 O 0.01027(15) 0.38622(13) -0.24676(11) 0.063 Uani 1 1 d . . . O25 O -0.09460(9) 0.50219(9) -0.13627(7) 0.023 Uani 1 1 d . . . O26 O 0.02176(9) 0.51611(10) -0.18199(8) 0.026 Uani 1 1 d . . . O27 O -0.08777(8) 0.49579(10) -0.25164(8) 0.025 Uani 1 1 d . . . O28 O 0.11327(8) 0.48904(9) -0.25095(7) 0.022 Uani 1 1 d . . . O29 O 0.00008(8) 0.52660(10) -0.29968(7) 0.021 Uani 1 1 d . . . O30 O 0.09866(9) 0.50611(10) -0.36146(7) 0.024 Uani 1 1 d . . . O31 O -0.01910(10) 0.64381(11) -0.23930(9) 0.036 Uani 1 1 d . . . O32 O 0.5156(2) 0.3916(3) 0.51465(19) 0.041 Uiso 0.50 1 d P . . O33 O 0.4856(2) 0.3658(2) 0.50524(17) 0.036 Uiso 0.50 1 d P . . O34 O 0.58614(11) 0.25108(11) 0.62114(8) 0.036 Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 347

O35 O 0.40188(9) 0.24570(10) 0.38340(8) 0.028 Uani 1 1 d . . . O36 O 0.58686(10) 0.25415(12) 0.50872(9) 0.038 Uani 1 1 d . . . O37 O 0.46542(13) 0.2522(2) 0.56999(11) 0.080 Uani 1 1 d . . . O38 O 0.50249(17) 0.2752(2) 0.45277(15) 0.024 Uiso 0.50 1 d P . . O39 O 0.3873(2) 0.2617(3) 0.49453(18) 0.034 Uiso 0.50 1 d P . . O40 O 0.39061(18) 0.2315(2) 0.49188(16) 0.026 Uiso 0.50 1 d P . . O41 O 0.50203(18) 0.2226(2) 0.45213(16) 0.031 Uiso 0.50 1 d P . . O42 O 0.48895(9) 0.14234(11) 0.62434(10) 0.040 Uani 1 1 d . . . O43 O 0.5152(2) 0.1066(3) 0.5123(2) 0.051 Uiso 0.50 1 d P . . O44 O 0.5031(3) 0.1354(4) 0.4968(2) 0.060 Uiso 0.50 1 d P . . O45 O -0.09355(9) 0.10439(10) -0.00071(8) 0.027 Uani 1 1 d . . . O46 O -0.06464(9) -0.00741(10) -0.04864(7) 0.025 Uani 1 1 d . . . O47 O -0.05545(9) -0.00572(10) 0.05028(8) 0.025 Uani 1 1 d . . . O48 O -0.13937(8) -0.07913(10) 0.00149(8) 0.026 Uani 1 1 d . . . O49 O -0.16691(9) 0.02854(10) 0.05727(7) 0.025 Uani 1 1 d . . . O50 O -0.17821(9) 0.03261(10) -0.04343(8) 0.028 Uani 1 1 d . . . O51 O 0.59122(9) -0.13969(10) 0.26385(8) 0.028 Uani 1 1 d . . . O52 O 0.56210(9) -0.25024(11) 0.20578(8) 0.030 Uani 1 1 d . . . O53 O 0.56224(9) -0.25430(12) 0.30620(8) 0.033 Uani 1 1 d . . . O54 O 0.67293(9) -0.21191(11) 0.30981(8) 0.028 Uani 1 1 d . . . O55 O 0.63909(9) -0.32193(11) 0.25397(8) 0.031 Uani 1 1 d . . . O56 O 0.36225(9) -0.17642(10) 0.23382(8) 0.026 Uani 1 1 d . . . O57 O 0.33209(9) -0.28582(10) 0.18321(8) 0.027 Uani 1 1 d . . . O58 O 0.44324(9) -0.24781(11) 0.18819(8) 0.030 Uani 1 1 d . . . O59 O 0.44104(9) -0.24435(10) 0.28737(8) 0.027 Uani 1 1 d . . . O60 O 0.41182(9) -0.35897(10) 0.23560(8) 0.027 Uani 1 1 d . . . O61 O 0.14060(9) 0.57762(10) -0.00069(8) 0.028 Uani 1 1 d . . . O62 O 0.17795(10) 0.46380(11) 0.04200(8) 0.034 Uani 1 1 d . . . O63 O 0.09261(9) 0.39476(10) -0.00518(8) 0.030 Uani 1 1 d . . . O64 O 0.05827(10) 0.50959(12) -0.05251(8) 0.034 Uani 1 1 d . . . O65 O 0.06410(9) 0.50492(10) 0.04646(8) 0.027 Uani 1 1 d . . . O66 O 0.16848(9) 0.47090(11) -0.05899(7) 0.029 Uani 1 1 d . . . O101 O 0.31164(12) -0.15511(17) 0.31929(12) 0.066 Uani 1 1 d . . . O102 O 0.20187(9) -0.13007(11) 0.43668(8) 0.031 Uani 1 1 d . . . O103 O 0.23065(11) -0.09022(13) 0.35257(9) 0.044 Uani 1 1 d . . . O104 O 0.12568(11) 0.00192(11) 0.35770(8) 0.035 Uani 1 1 d . . . O105 O 0.21786(11) 0.13056(13) 0.40731(10) 0.046 Uani 1 1 d . . . O106 O 0.2967(2) 0.1623(2) 0.3439(2) 0.036 Uiso 0.50 1 d P . . O108 O 0.35572(11) 0.26034(12) 0.10340(9) 0.038 Uani 1 1 d . . . O109 O 0.20384(9) 0.37299(11) 0.43550(8) 0.031 Uani 1 1 d . . . O110 O 0.25240(11) 0.40274(12) 0.35521(9) 0.040 Uani 1 1 d . . . O111 O 0.19740(9) 0.44229(11) 0.60413(8) 0.030 Uani 1 1 d . . . O112 O 0.5216(4) 0.4830(5) 0.4717(3) 0.098 Uiso 0.50 1 d P . . O113 O 0.10771(10) 0.50035(10) 0.36540(8) 0.027 Uani 1 1 d . . . O114 O 0.18978(9) 0.55430(11) 0.10358(8) 0.029 Uani 1 1 d . . . O115 O 0.26808(11) 0.59798(12) 0.34744(9) 0.039 Uani 1 1 d . . . O116 O 0.20877(9) 0.63574(11) 0.41737(8) 0.032 Uani 1 1 d . . . O117 O 0.28899(10) 0.64825(12) 0.67087(9) 0.041 Uani 1 1 d . . . O118 O 0.38339(11) 0.74897(11) 0.10466(8) 0.034 Uani 1 1 d . . . O119 O 0.0152(2) 0.7307(3) 0.2811(2) 0.050 Uiso 0.50 1 d P . . O120 O 0.3064(4) 0.1814(4) 0.3433(3) 0.075 Uiso 0.50 1 d P . . Appendix I: Crystallographic Information Files. Page 348

cis I.5: {[ -SnCl4(H2O)2]@Q7}2(SnCl6)3(H3O)6(H2O)23. data_5.6

_audit_creation_method 'RAELSPUB and manual entry'

_computing_structure_solution 'SIR92 (Altomare et al, 1994)' _computing_structure_refinement 'RAELS, (Rae, 1989)' _computing_molecular_graphics 'ORTEP-II, (Johnson, 1976)' _computing_publication_material 'Local programs'

# CHEMICAL DATA

_chemical_name_systematic ? _chemical_formula_moiety '2(C42 H42 N28 O14),1.25(Cl4 Sn),4(H2 O),3(Cl6 Sn 2-),6(H3 O 1+),23(H2 O)' _chemical_formula_sum 'C84 H156 Cl23 N56 O61 Sn4.25' _chemical_formula_iupac ? _chemical_formula_weight 4246.4

# CRYSTAL DATA

_symmetry_cell_setting orthorhombic _symmetry_space_group_name_H-M 'F d d 2' loop_ _symmetry_equiv_pos_site_id _symmetry_equiv_pos_as_xyz 1 x,y,z 2 -x,-y,z 3 1/4-x,1/4+y,1/4+z 4 1/4+x,1/4-y,1/4+z 5 x,1/2+y,1/2+z 6 -x,1/2-y,1/2+z 7 1/4-x,3/4+y,3/4+z 8 1/4+x,3/4-y,3/4+z 9 1/2+x,y,1/2+z 10 1/2-x,-y,1/2+z 11 3/4-x,1/4+y,3/4+z 12 3/4+x,1/4-y,3/4+z 13 1/2+x,1/2+y,z 14 1/2-x,1/2-y,z 15 3/4-x,3/4+y,1/4+z 16 3/4+x,3/4-y,1/4+z

_cell_length_a 47.180(4) _cell_length_b 71.699(5) _cell_length_c 18.939(1) _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 64066(8) _cell_formula_units_Z 16 _cell_measurement_reflns_used 971 Appendix I: Crystallographic Information Files. Page 349

_cell_measurement_theta_min 2.428 _cell_measurement_theta_max 20.215 _cell_measurement_temperature 153 _exptl_crystal_description prism _exptl_crystal_colour colourless _exptl_crystal_size_max 0.74 _exptl_crystal_size_mid 0.09 _exptl_crystal_size_min 0.09 _exptl_crystal_size_rad ? _exptl_crystal_density_diffrn 1.76 _exptl_crystal_density_meas ? _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 34296.0 _exptl_absorpt_coefficient_mu 1.143 _exptl_absorpt_correction_type empirical _exptl_absorpt_process_details SADABS (Sheldrik, 1996) _exptl_absorpt_correction_T_min 0.0015 _exptl_absorpt_correction_T_max 1.000

# EXPERIMENTAL DATA

_diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_measurement_device_type ’Bruker SMART 1000 CCD’ _diffrn_measurement_method \w _diffrn_reflns_number 141095 _diffrn_reflns_av_R_equivalents 0.1035 _diffrn_reflns_theta_max 28 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 60 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 92 _diffrn_reflns_limit_l_min 0 _diffrn_reflns_limit_l_max 25 _diffrn_standards_number 398 _diffrn_standards_interval_time 30min _diffrn_standards_decay_% 0

# REFINEMENT DATA

_refine_special_details ? _reflns_number_total 38569 _reflns_number_gt 18193 _reflns_threshold_expression >2sigma(I) _refine_ls_structure_factor_coef F _refine_ls_R_factor_gt 0.061 _refine_ls_wR_factor_ref 0.079 _refine_ls_hydrogen_treatment noref _refine_ls_number_reflns 18193 _refine_ls_number_parameters 1097 _refine_ls_goodness_of_fit_ref 1.34 _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'w = 1/[\s^2^(F) + 0.0016F^2^]' _refine_ls_shift/su_max 0.031 Appendix I: Crystallographic Information Files. Page 350

_refine_diff_density_max 1.26 _refine_diff_density_min -0.96 _refine_ls_extinction_method none _refine_ls_extinction_coef ? _atom_type_scat_source 'International Tables for X-ray Crystallography, Vol. IV'

# ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_type_symbol _atom_site_occupancy O11A 0.7653(2) 0.1465(1) 0.0802(4) 0.0415(8) Uani O ? O21A 0.8678(2) 0.1973(1) 0.0808(4) 0.0368(6) Uani O ? N11A 0.7775(2) 0.1773(1) 0.0732(5) 0.0396(8) Uani N ? N21A 0.7997(2) 0.1599(1) 0.1516(5) 0.0411(9) Uani N ? N31A 0.8386(2) 0.1811(1) 0.1578(5) 0.0393(8) Uani N ? N41A 0.8195(2) 0.1964(1) 0.0679(5) 0.0376(7) Uani N ? C11A 0.7955(2) 0.1899(2) 0.1086(6) 0.0393(8) Uani C ? C21A 0.8094(2) 0.1781(2) 0.1675(6) 0.0405(9) Uani C ? C31A 0.7794(2) 0.1599(2) 0.0992(6) 0.0406(8) Uani C ? C41A 0.8447(2) 0.1923(2) 0.0977(6) 0.0376(7) Uani C ? C51A 0.8003(2) 0.1450(2) 0.2043(6) 0.043(1) Uani C ? C61A 0.8602(2) 0.1743(2) 0.2039(6) 0.0402(9) Uani C ? O12A 0.8079(2) 0.1068(1) 0.1550(4) 0.0435(9) Uani O ? O22A 0.9097(2) 0.1589(1) 0.1356(4) 0.0380(7) Uani O ? N12A 0.8268(2) 0.1340(1) 0.1992(5) 0.0425(9) Uani N ? N22A 0.8540(2) 0.1093(1) 0.1906(5) 0.0426(9) Uani N ? N32A 0.8937(2) 0.1296(1) 0.1737(5) 0.0401(8) Uani N ? N42A 0.8677(2) 0.1549(1) 0.1956(5) 0.0404(8) Uani N ? C12A 0.8534(3) 0.1403(2) 0.2327(6) 0.042(1) Uani C ? C22A 0.8732(3) 0.1234(2) 0.2203(6) 0.0423(9) Uani C ? C32A 0.8276(2) 0.1160(2) 0.1779(7) 0.0428(9) Uani C ? C42A 0.8918(2) 0.1487(2) 0.1652(6) 0.0392(8) Uani C ? C52A 0.8624(2) 0.0898(2) 0.1766(6) 0.0431(9) Uani C ? C62A 0.9216(2) 0.1205(2) 0.1620(6) 0.0397(8) Uani C ? O13A 0.8420(2) 0.0760(1) 0.0435(4) 0.0409(7) Uani O ? O23A 0.9419(2) 0.1261(1) 0.0195(4) 0.0355(5) Uani O ? N13A 0.8781(2) 0.0875(1) 0.1096(5) 0.0407(8) Uani N ? N23A 0.8878(2) 0.0760(1) 0.0050(5) 0.0382(6) Uani N ? N33A 0.9303(2) 0.0954(1) -0.0016(5) 0.0361(5) Uani N ? N43A 0.9204(2) 0.1074(1) 0.1035(5) 0.0385(7) Uani N ? C13A 0.9082(3) 0.0886(2) 0.1075(6) 0.0397(7) Uani C ? C23A 0.9157(2) 0.0804(2) 0.0333(6) 0.0379(6) Uani C ? C33A 0.8662(2) 0.0798(2) 0.0517(6) 0.0399(7) Uani C ? C43A 0.9319(2) 0.1114(2) 0.0396(6) 0.0365(6) Uani C ? C53A 0.8844(2) 0.0620(2) -0.0539(6) 0.0377(6) Uani C ? C63A 0.9437(2) 0.0942(1) -0.0704(6) 0.0344(5) Uani C ? Appendix I: Crystallographic Information Files. Page 351

O14A 0.8371(2) 0.0684(1) -0.1464(4) 0.0374(5) Uani O ? O24A 0.9331(1) 0.1229(1) -0.1710(4) 0.0322(4) Uani O ? N14A 0.8854(2) 0.0704(1) -0.1225(5) 0.0358(5) Uani N ? N24A 0.8712(2) 0.0791(1) -0.2270(5) 0.0342(4) Uani N ? N34A 0.9103(2) 0.1008(1) -0.2378(5) 0.0321(4) Uani N ? N44A 0.9233(2) 0.0935(1) -0.1288(5) 0.0337(4) Uani N ? C14A 0.9108(2) 0.0759(2) -0.1579(6) 0.0341(4) Uani C ? C24A 0.9009(2) 0.0815(2) -0.2320(6) 0.0330(4) Uani C ? C34A 0.8630(2) 0.0729(2) -0.1636(6) 0.0357(5) Uani C ? C44A 0.9236(2) 0.1073(2) -0.1777(6) 0.0325(4) Uani C ? C54A 0.8529(2) 0.0797(2) -0.2886(6) 0.0341(4) Uani C ? C64A 0.9125(2) 0.1104(2) -0.3040(6) 0.0312(4) Uani C ? O15A 0.8000(1) 0.0998(1) -0.2760(4) 0.0359(5) Uani O ? O25A 0.90144(13) 0.14959(9) -0.32124(37) 0.0311(4) Uani O ? N15A 0.8461(2) 0.0985(1) -0.3124(5) 0.0335(4) Uani N ? N25A 0.8187(2) 0.1209(1) -0.3561(5) 0.0338(4) Uani N ? N35A 0.8597(2) 0.1411(1) -0.3739(5) 0.0319(4) Uani N ? N45A 0.8868(2) 0.1193(1) -0.3274(5) 0.0315(4) Uani N ? C15A 0.8639(2) 0.1086(2) -0.3619(6) 0.0322(4) Uani C ? C25A 0.8447(2) 0.1235(2) -0.3921(6) 0.0325(4) Uani C ? C35A 0.8191(2) 0.1059(2) -0.3125(6) 0.0344(4) Uani C ? C45A 0.8850(2) 0.1377(1) -0.3385(6) 0.0313(4) Uani C ? C55A 0.7927(2) 0.1313(2) -0.3699(6) 0.0347(4) Uani C ? C65A 0.8523(2) 0.1592(2) -0.4037(6) 0.0321(4) Uani C ? O16A 0.7573(1) 0.1406(1) -0.2522(4) 0.0370(5) Uani O ? O26A 0.86221(14) 0.18976(9) -0.30879(36) 0.0322(4) Uani O ? N16A 0.7922(2) 0.1486(1) -0.3330(5) 0.0345(5) Uani N ? N26A 0.7707(2) 0.1710(1) -0.2724(5) 0.0355(5) Uani N ? N36A 0.8146(2) 0.1887(1) -0.2824(5) 0.0336(5) Uani N ? N46A 0.8323(2) 0.1694(1) -0.3642(5) 0.0327(4) Uani N ? C16A 0.8021(2) 0.1663(2) -0.3667(6) 0.0339(4) Uani C ? C26A 0.7890(2) 0.1817(1) -0.3176(6) 0.0344(5) Uani C ? C36A 0.7720(2) 0.1523(2) -0.2817(6) 0.0357(5) Uani C ? C46A 0.8389(2) 0.1830(1) -0.3172(6) 0.0327(4) Uani C ? C56A 0.7486(2) 0.1800(2) -0.2280(6) 0.0368(6) Uani C ? C66A 0.8138(2) 0.2057(2) -0.2398(6) 0.0339(5) Uani C ? O17A 0.7356(1) 0.1635(1) -0.0952(4) 0.0392(7) Uani O ? O27A 0.8483(1) 0.2035(1) -0.1124(4) 0.0340(5) Uani O ? N17A 0.7588(2) 0.1853(1) -0.1598(5) 0.0367(6) Uani N ? N27A 0.7610(2) 0.1872(1) -0.0421(5) 0.0380(7) Uani N ? N37A 0.8061(2) 0.2043(1) -0.0512(5) 0.0359(6) Uani N ? N47A 0.8042(2) 0.2020(1) -0.1682(5) 0.0347(5) Uani N ? C17A 0.7754(2) 0.2028(2) -0.1474(6) 0.0359(6) Uani C ? C27A 0.7757(2) 0.2045(2) -0.0666(6) 0.0368(6) Uani C ? C37A 0.7506(2) 0.1773(2) -0.0984(6) 0.0379(7) Uani C ? C47A 0.8217(2) 0.2033(2) -0.1098(6) 0.0347(5) Uani C ? C57A 0.7534(2) 0.1837(2) 0.0284(6) 0.0396(8) Uani C ? C67A 0.8172(2) 0.2112(2) 0.0154(6) 0.0366(6) Uani C ? O11B 0.83421(14) 0.01678(9) 0.30772(35) 0.0296(4) Uani O ? O21B 0.8785(1) 0.0441(1) 0.5893(4) 0.0341(6) Uani O ? N11B 0.8655(2) 0.0380(1) 0.3532(4) 0.0285(4) Uani N ? N21B 0.8659(2) 0.0096(1) 0.3974(4) 0.0308(4) Uani N ? N31B 0.8856(2) 0.0202(1) 0.5088(5) 0.0327(6) Uani N ? N41B 0.8814(2) 0.0492(1) 0.4687(4) 0.0303(4) Uani N ? Appendix I: Crystallographic Information Files. Page 352

C11B 0.8876(2) 0.0384(1) 0.4040(5) 0.0294(4) Uani C ? C21B 0.8892(2) 0.0183(1) 0.4320(6) 0.0312(5) Uani C ? C31B 0.8537(2) 0.0208(1) 0.3488(5) 0.0294(4) Uani C ? C41B 0.8816(2) 0.0385(2) 0.5278(5) 0.0322(5) Uani C ? C51B 0.8641(2) -0.0110(1) 0.3880(6) 0.0328(5) Uani C ? C61B 0.8917(2) 0.0053(2) 0.5587(6) 0.0356(7) Uani C ? O12B 0.81180(14) -0.03046(9) 0.39528(37) 0.0341(5) Uani O ? O22B 0.8551(2) -0.0019(1) 0.6733(4) 0.0382(8) Uani O ? N12B 0.8524(2) -0.0201(1) 0.4492(5) 0.0341(5) Uani N ? N22B 0.8274(2) -0.0423(1) 0.5027(5) 0.0368(6) Uani N ? N32B 0.8415(2) -0.0290(1) 0.6155(5) 0.0380(8) Uani N ? N42B 0.8704(2) -0.0091(1) 0.5632(5) 0.0359(7) Uani N ? C12B 0.8693(2) -0.0247(2) 0.5126(6) 0.0365(7) Uani C ? C22B 0.8497(2) -0.0390(2) 0.5509(6) 0.0382(8) Uani C ? C32B 0.8285(2) -0.0307(2) 0.4456(6) 0.0347(5) Uani C ? C42B 0.8551(2) -0.0127(2) 0.6231(6) 0.0373(8) Uani C ? C52B 0.8063(2) -0.0565(2) 0.5113(6) 0.0382(6) Uani C ? C62B 0.8274(2) -0.0378(2) 0.6721(7) 0.0400(9) Uani C ? O13B 0.7496(2) -0.0503(1) 0.4631(4) 0.0359(5) Uani O ? O23B 0.7893(2) -0.0119(1) 0.7326(4) 0.0381(8) Uani O ? N13B 0.7814(2) -0.0510(1) 0.5535(5) 0.0370(6) Uani N ? N23B 0.7363(2) -0.0461(1) 0.5800(5) 0.0358(6) Uani N ? N33B 0.7523(2) -0.0289(1) 0.6822(5) 0.0364(7) Uani N ? N43B 0.7964(2) -0.0380(1) 0.6678(5) 0.0382(8) Uani N ? C13B 0.7804(2) -0.0522(2) 0.6306(6) 0.0383(7) Uani C ? C23B 0.7496(2) -0.0466(2) 0.6472(6) 0.0370(7) Uani C ? C33B 0.7551(2) -0.0487(2) 0.5256(6) 0.0359(5) Uani C ? C43B 0.7797(2) -0.0250(2) 0.6973(6) 0.0373(7) Uani C ? C53B 0.7054(2) -0.0460(2) 0.5702(6) 0.0356(5) Uani C ? C63B 0.7295(2) -0.0208(2) 0.7237(6) 0.0367(6) Uani C ? O14B 0.6801(2) -0.0233(1) 0.4608(4) 0.0348(5) Uani O ? O24B 0.7181(2) 0.0185(1) 0.7293(4) 0.0368(6) Uani O ? N14B 0.6921(2) -0.0284(1) 0.5780(5) 0.0346(5) Uani N ? N24B 0.6677(2) -0.0032(1) 0.5483(5) 0.0346(5) Uani N ? N34B 0.6782(2) 0.0122(1) 0.6617(5) 0.0357(6) Uani N ? N44B 0.7094(2) -0.0106(1) 0.6802(5) 0.0352(6) Uani N ? C14B 0.6859(2) -0.0200(2) 0.6457(6) 0.0351(6) Uani C ? C24B 0.6651(2) -0.0030(2) 0.6267(6) 0.0352(6) Uani C ? C34B 0.6802(2) -0.0181(2) 0.5243(6) 0.0343(5) Uani C ? C44B 0.7033(2) 0.0075(2) 0.6927(6) 0.0356(6) Uani C ? C54B 0.6509(2) 0.0093(2) 0.5073(6) 0.0356(6) Uani C ? C64B 0.6653(2) 0.0304(2) 0.6690(6) 0.0374(6) Uani C ? O15B 0.6854(1) 0.0234(1) 0.3921(4) 0.0345(6) Uani O ? O25B 0.70369(14) 0.06108(9) 0.67181(40) 0.0385(6) Uani O ? N15B 0.6632(2) 0.0275(1) 0.5000(5) 0.0356(6) Uani N ? N25B 0.6819(2) 0.0520(1) 0.4456(5) 0.0358(6) Uani N ? N35B 0.6875(2) 0.0681(1) 0.5589(5) 0.0377(6) Uani N ? N45B 0.6713(2) 0.0427(1) 0.6144(5) 0.0370(6) Uani N ? C15B 0.6557(2) 0.0433(2) 0.5456(6) 0.0373(6) Uani C ? C25B 0.6685(2) 0.0602(2) 0.5106(6) 0.0377(7) Uani C ? C35B 0.6774(2) 0.0333(2) 0.4415(6) 0.0350(6) Uani C ? C45B 0.6894(2) 0.0576(2) 0.6198(6) 0.0376(6) Uani C ? C55B 0.6885(2) 0.0637(2) 0.3842(6) 0.0364(7) Uani C ? C65B 0.6983(2) 0.0867(2) 0.5540(6) 0.0393(6) Uani C ? Appendix I: Crystallographic Information Files. Page 353

O16B 0.7389(1) 0.0592(1) 0.2980(4) 0.0329(5) Uani O ? O26B 0.7579(2) 0.0931(1) 0.5848(4) 0.0375(5) Uani O ? N16B 0.7157(2) 0.0735(1) 0.3918(5) 0.0351(6) Uani N ? N26B 0.7544(2) 0.0871(1) 0.3462(5) 0.0335(5) Uani N ? N36B 0.7644(2) 0.0973(1) 0.4666(5) 0.0349(5) Uani N ? N46B 0.7217(2) 0.0892(1) 0.5049(5) 0.0372(6) Uani N ? C16B 0.7180(2) 0.0911(2) 0.4298(6) 0.0369(6) Uani C ? C26B 0.7467(2) 0.0992(1) 0.4036(6) 0.0355(6) Uani C ? C36B 0.7368(2) 0.0721(2) 0.3407(6) 0.0335(6) Uani C ? C46B 0.7488(2) 0.0929(2) 0.5237(6) 0.0364(5) Uani C ? C56B 0.7763(2) 0.0906(2) 0.2973(6) 0.0323(5) Uani C ? C66B 0.7921(2) 0.1048(2) 0.4721(6) 0.0345(5) Uani C ? O17B 0.80685(14) 0.05961(9) 0.24131(35) 0.0294(4) Uani O ? O27B 0.8305(2) 0.0818(1) 0.5464(4) 0.0332(4) Uani O ? N17B 0.8040(2) 0.0847(1) 0.3171(5) 0.0302(4) Uani N ? N27B 0.8435(2) 0.0675(1) 0.3176(4) 0.0280(4) Uani N ? N37B 0.8531(2) 0.0766(1) 0.4403(4) 0.0298(4) Uani N ? N47B 0.8137(2) 0.0933(1) 0.4405(4) 0.0318(4) Uani N ? C17B 0.8221(2) 0.0943(1) 0.3690(6) 0.0304(4) Uani C ? C27B 0.8506(2) 0.0826(1) 0.3659(5) 0.0287(4) Uani C ? C37B 0.8164(2) 0.0691(1) 0.2881(5) 0.0289(4) Uani C ? C47B 0.8323(2) 0.0839(1) 0.4807(6) 0.0314(4) Uani C ? C57B 0.8626(2) 0.0523(1) 0.2992(5) 0.0277(4) Uani C ? C67B 0.8799(2) 0.0691(1) 0.4690(5) 0.0303(4) Uani C ? Sn1A 0.85968(3) 0.14673(2) -0.08173 0.0336(3) Uani Sn 0.5 Cl1A 0.8591(2) 0.1379(1) 0.0366(3) 0.071(2) Uani Cl 0.5 Cl2A 0.85407(13) 0.11571(8) -0.12126(41) 0.057(2) Uani Cl 0.5 Cl3A 0.81087(12) 0.15486(9) -0.08221(41) 0.058(2) Uani Cl 0.5 Cl4A 0.86676(13) 0.15803(9) -0.19476(30) 0.047(2) Uani Cl 0.5 O1A 0.8736(3) 0.1753(2) -0.0459(7) 0.120(4) Uani O ? O2A 0.9028(2) 0.1437(2) -0.0759(6) 0.104(4) Uani O ? Sn2B 0.76914(2) 0.01983(1) 0.46249(6) 0.0302(2) Uani Sn 0.75 Cl1B 0.74167(9) -0.00681(6) 0.47355(27) 0.058(1) Uani Cl 0.75 Cl2B 0.80370(9) 0.00927(7) 0.54416(23) 0.060(1) Uani Cl 0.75 Cl3B 0.74180(9) 0.03713(6) 0.54330(22) 0.051(1) Uani Cl 0.75 Cl4B 0.79534(7) 0.04587(5) 0.42490(22) 0.0414(9) Uani Cl 0.75 O1B 0.7419(2) 0.0264(1) 0.3780(5) 0.058(2) Uani O ? O2B 0.7886(2) 0.0049(1) 0.3802(5) 0.053(2) Uani O ? Sn3 0.92588(1) 0.02334(1) 0.15858(5) 0.0304(1) Uani Sn ? Cl13 0.88361(5) 0.03848(4) 0.11509(15) 0.0346(6) Uani Cl ? Cl23 0.93482(7) 0.04952(4) 0.23682(20) 0.0569(8) Uani Cl ? Cl33 0.95350(6) 0.03755(4) 0.06539(20) 0.0585(8) Uani Cl ? Cl43 0.96839(6) 0.00808(5) 0.20151(21) 0.0631(9) Uani Cl ? Cl53 0.91896(7) -0.00289(4) 0.07874(17) 0.0476(7) Uani Cl ? Cl63 0.89926(6) 0.00683(4) 0.24720(16) 0.0463(7) Uani Cl ? Sn4 0.00616(2) 0.08110(1) 0.66959(5) 0.0437(2) Uani Sn ? Cl14 0.05359(6) 0.09445(5) 0.67698(24) 0.0706(9) Uani Cl ? Cl24 0.02174(15) 0.05679(7) 0.74933(27) 0.129(2) Uani Cl ? Cl34 0.02072(8) 0.06037(5) 0.57512(19) 0.0689(9) Uani Cl ? Cl44 -0.04073(8) 0.06793(6) 0.66237(30) 0.109(1) Uani Cl ? Cl54 -0.00566(9) 0.10454(5) 0.58268(22) 0.078(1) Uani Cl ? Cl64 -0.00823(8) 0.10068(6) 0.76617(21) 0.082(1) Uani Cl ? Sn5 0.17273(2) 0.11978(1) 0.67404(4) 0.0357(2) Uani Sn ? Cl15 0.17724(6) 0.14792(4) 0.59897(15) 0.0410(7) Uani Cl ? Appendix I: Crystallographic Information Files. Page 354

Cl25 0.12092(5) 0.12187(4) 0.66477(17) 0.0422(7) Uani Cl ? Cl35 0.17348(7) 0.10158(4) 0.56632(16) 0.0520(8) Uani Cl ? Cl45 0.16681(8) 0.09087(5) 0.74082(19) 0.073(1) Uani Cl ? Cl55 0.22298(7) 0.11686(6) 0.68390(20) 0.073(1) Uani Cl ? Cl65 0.17094(7) 0.13957(5) 0.77425(17) 0.0618(9) Uani Cl ? OW1 -0.0258(2) 0.0793(1) 0.4468(4) 0.068(3) Uani O ? OW2 0.1115(2) 0.0739(1) 0.6434(7) 0.132(4) Uani O ? OW3 -0.0298(2) 0.0459(1) 0.8643(5) 0.084(2) Uani O ? OW4 0.8977(2) 0.0379(1) 0.7254(4) 0.060(2) Uani O ? OW5 0.9553(2) 0.0454(2) 0.4600(6) 0.108(3) Uani O ? OW6 1.0000 0.0000 0.0439(7) 0.094(4) Uani O ? OW7 0.9877(2) 0.1474(1) -0.0104(6) 0.088(3) Uani O ? OW8 0.7724(2) 0.0219(1) 0.7546(6) 0.106(4) Uani O ? OW9 0.7627(2) 0.0664(1) 0.6765(6) 0.119(4) Uani O ? OW10 0.7134(2) -0.0383(1) 0.3677(6) 0.110(4) Uani O ? OW11 0.7792(2) -0.0527(1) 0.3121(4) 0.080(3) Uani O ? OW12 0.7702(4) 0.0906(2) 0.0664(7) 0.199(5) Uani O ? OW13 0.7367(3) 0.1193(2) 0.0183(6) 0.126(5) Uani O ? OW14 0.8734(2) 0.0256(2) -0.1610(6) 0.112(4) Uani O ? OW15 0.80582(9) 0.23027(6) 0.20052(24) 0.127(1) Uani O ? OW16 0.7560(3) 0.2265(2) -0.3263(7) 0.178(6) Uani O ? OW17 0.7406(2) 0.1289(1) -0.1023(5) 0.131(5) Uani O 0.5 OW17' 0.7395(2) 0.1284(2) -0.1087(5) 0.131(5) Uani O 0.5 OW18 0.9577(3) 0.1645(2) 0.0765(6) 0.112(5) Uani O 0.5 OW18' 0.9687(3) 0.1627(2) 0.0982(5) 0.112(5) Uani O 0.5 OW19 0.8047(3) 0.0535(2) 0.6200(6) 0.154(4) Uani O ? OW20 0.8354(3) 0.0046(2) -0.1894(6) 0.251(4) Uani O ? OW21 0.9172(3) 0.0156(2) -0.0768(7) 0.166(5) Uani O ? OW22 0.7869(3) 0.1164(2) -0.1403(7) 0.198(6) Uani O ? OW23 0.8075(3) 0.2357(2) -0.3984(7) 0.183(6) Uani O ? OW24 0.0596(6) 0.0253(4) 0.6313(16) 0.161(9) Uani O 0.5 OW25 0.7983(3) 0.0863(2) -0.0603(10) 0.221(6) Uani O ? OW26 0.9520(3) 0.0260(3) 0.7346(9) 0.188(6) Uani O ? OW27 0.9704(5) 0.0227(3) 0.5735(13) 0.125(7) Uani O 0.5 OW27' 0.9516(5) 0.0321(2) 0.5807(5) 0.125(7) Uani O 0.5 OW28 0.9774(6) 0.0240(2) 0.3720(11) 0.285(9) Uani O ? OW29 0.8299(5) 0.0314(3) 0.6979(12) 0.231(9) Uani O 0.5 OW29' 0.8281(4) 0.0384(2) 0.7860(11) 0.231(9) Uani O 0.5 OW30 0.1106(5) 0.0336(2) 0.8284(10) 0.269(8) Uani O ? HC11A 0.7845 0.2005 0.1289 0.040 Uani H ? HC21A 0.8031 0.1822 0.2154 0.042 Uani H ? H1C51A 0.7838 0.1365 0.1963 0.044 Uani H ? H2C51A 0.7989 0.1506 0.2525 0.045 Uani H ? H1C61A 0.8536 0.1761 0.2536 0.042 Uani H ? H2C61A 0.8777 0.1819 0.1957 0.040 Uani H ? HC12A 0.8509 0.1432 0.2840 0.044 Uani H ? HC22A 0.8818 0.1190 0.2655 0.044 Uani H ? H1C52A 0.8449 0.0820 0.1745 0.044 Uani H ? H2C52A 0.8747 0.0854 0.2162 0.044 Uani H ? H1C62A 0.9271 0.1136 0.2059 0.041 Uani H ? H2C62A 0.9361 0.1302 0.1514 0.039 Uani H ? HC13A 0.9170 0.0811 0.1463 0.041 Uani H ? HC23A 0.9279 0.0690 0.0373 0.038 Uani H ? H1C53A 0.8657 0.0556 -0.0482 0.039 Uani H ? Appendix I: Crystallographic Information Files. Page 355

H2C53A 0.9000 0.0526 -0.0504 0.038 Uani H ? H1C63A 0.9555 0.0827 -0.0719 0.035 Uani H ? H2C63A 0.9561 0.1054 -0.0768 0.034 Uani H ? HC14A 0.9250 0.0655 -0.1594 0.034 Uani H ? HC24A 0.9095 0.0734 -0.2694 0.033 Uani H ? H1C54A 0.8348 0.0732 -0.2767 0.035 Uani H ? H2C54A 0.8626 0.0730 -0.3281 0.034 Uani H ? H1C64A 0.9183 0.1012 -0.3408 0.031 Uani H ? H2C64A 0.9275 0.1202 -0.2993 0.031 Uani H ? HC15A 0.8735 0.1035 -0.4049 0.032 Uani H ? HC25A 0.8423 0.1220 -0.4443 0.033 Uani H ? H1C55A 0.7761 0.1236 -0.3545 0.036 Uani H ? H2C55A 0.7913 0.1338 -0.4217 0.035 Uani H ? H1C65A 0.8443 0.1571 -0.4520 0.032 Uani H ? H2C65A 0.8700 0.1668 -0.4073 0.032 Uani H ? HC16A 0.7948 0.1675 -0.4160 0.034 Uani H ? HC26A 0.7787 0.1916 -0.3445 0.035 Uani H ? H1C56A 0.7326 0.1710 -0.2217 0.038 Uani H ? H2C56A 0.7416 0.1914 -0.2530 0.037 Uani H ? H1C66A 0.8006 0.2148 -0.2625 0.034 Uani H ? H2C66A 0.8333 0.2111 -0.2379 0.034 Uani H ? HC17A 0.7657 0.2138 -0.1692 0.036 Uani H ? HC27A 0.7662 0.2161 -0.0494 0.037 Uani H ? H1C57A 0.7384 0.1738 0.0289 0.041 Uani H ? H2C57A 0.7457 0.1955 0.0491 0.040 Uani H ? H1C67A 0.8041 0.2211 0.0338 0.037 Uani H ? H2C67A 0.8364 0.2167 0.0072 0.036 Uani H ? HC11B 0.9059 0.0423 0.3823 0.029 Uani H ? HC21B 0.9076 0.0122 0.4197 0.032 Uani H ? H1C51B 0.8835 -0.0160 0.3792 0.034 Uani H ? H2C51B 0.8517 -0.0137 0.3464 0.033 Uani H ? H1C61B 0.8939 0.0109 0.6066 0.037 Uani H ? H2C61B 0.9100 -0.0007 0.5443 0.037 Uani H ? HC12B 0.8884 -0.0299 0.5011 0.038 Uani H ? HC22B 0.8601 -0.0507 0.5623 0.041 Uani H ? H1C52B 0.8154 -0.0675 0.5348 0.041 Uani H ? H2C52B 0.7995 -0.0602 0.4633 0.038 Uani H ? H1C62B 0.8329 -0.0312 0.7165 0.041 Uani H ? H2C62B 0.8341 -0.0510 0.6743 0.042 Uani H ? HC13B 0.7849 -0.0650 0.6480 0.041 Uani H ? HC23B 0.7404 -0.0560 0.6787 0.038 Uani H ? H1C53B 0.6969 -0.0547 0.6058 0.037 Uani H ? H2C53B 0.7012 -0.0507 0.5216 0.036 Uani H ? H1C63B 0.7379 -0.0120 0.7590 0.038 Uani H ? H2C63B 0.7193 -0.0310 0.7490 0.038 Uani H ? HC14B 0.6765 -0.0291 0.6783 0.036 Uani H ? HC24B 0.6453 -0.0052 0.6430 0.036 Uani H ? H1C54B 0.6320 0.0106 0.5304 0.037 Uani H ? H2C54B 0.6485 0.0038 0.4591 0.036 Uani H ? H1C64B 0.6722 0.0360 0.7141 0.039 Uani H ? H2C64B 0.6443 0.0286 0.6713 0.038 Uani H ? HC15B 0.6347 0.0445 0.5522 0.039 Uani H ? HC25B 0.6534 0.0694 0.4975 0.040 Uani H ? H1C55B 0.6731 0.0731 0.3783 0.039 Uani H ? Appendix I: Crystallographic Information Files. Page 356

H2C55B 0.6894 0.0556 0.3413 0.036 Uani H ? H1C65B 0.7049 0.0905 0.6020 0.040 Uani H ? H2C65B 0.6824 0.0950 0.5386 0.041 Uani H ? HC16B 0.7019 0.0997 0.4183 0.039 Uani H ? HC26B 0.7449 0.1125 0.3882 0.037 Uani H ? H1C56B 0.7770 0.1044 0.2890 0.034 Uani H ? H2C56B 0.7713 0.0841 0.2523 0.032 Uani H ? H1C66B 0.7967 0.1064 0.5233 0.036 Uani H ? H2C66B 0.7923 0.1173 0.4482 0.036 Uani H ? HC17B 0.8256 0.1075 0.3546 0.031 Uani H ? HC27B 0.8672 0.0901 0.3497 0.028 Uani H ? H1C57B 0.8818 0.0578 0.2900 0.027 Uani H ? H2C57B 0.8553 0.0463 0.2552 0.028 Uani H ? H1C67B 0.8820 0.0735 0.5189 0.032 Uani H ? H2C67B 0.8959 0.0740 0.4400 0.030 Uani H ? H1O1A 0.8735 0.1807 0.0027 0.120 Uani H ? H2O1A 0.8646 0.1843 -0.0796 0.120 Uani H ? H1O2A 0.9137 0.1394 -0.0337 0.104 Uani H ? H2O2A 0.9105 0.1375 -0.1192 0.104 Uani H ? H1O1B 0.7214 0.0238 0.3870 0.058 Uani H ? H2O1B 0.7436 0.0381 0.3493 0.058 Uani H ? H1O2B 0.8040 0.0112 0.3528 0.053 Uani H ? H2O2B 0.7942 -0.0083 0.3897 0.053 Uani H ?

I.6: (Cl@Q5)4Q6(SnCl6)8(H3O)20(H2O)24. data_5.7 _audit_creation_method 'RAELSPUB and manual entry'

# SUBMISSION DETAILS

_publ_contact_author_name ? _publ_contact_author_address ? _publ_contact_author_email ? _publ_contact_letter ? _publ_requested_journal ? _publ_requested_category ?

# TITLE AND AUTHOR LIST

_publ_section_title ? _publ_section_title_footnote ? loop_ _publ_author_name _publ_author_footnote _publ_author_address ? ? ?

# TEXT

_publ_section_abstract ? Appendix I: Crystallographic Information Files. Page 357

_publ_section_comment ? _publ_section_acknowledgements ? _publ_section_references ; Altomare, A., Burla, M.C., Camalli, M., Cascarano, G., Giacovazzo, C., Guagliardi, A., Polidori, G., J. Appl. Cryst., 1994, 27, 435.

Ibers, J.A. and Hamilton, W.C., (Eds) International Tables for X-Ray Crystallography Vol. 4 , Kynoch Press, Birmingham, 1974.

Johnson, C.K.,'ORTEP-II', Oak Ridge National Laboratory, Tennessee, U.S.A., 1976.

Rae, A.D., RAELS. A comprehensive Constrained Least Squares Refinement Program, University of New South Wales, 1989. ;

_publ_section_figure_captions ? _publ_section_exptl_prep ? _publ_section_exptl_refinement ? _computing_data_collection ‘SMART (Bruker, 1995)’ _computing_cell_refinement ‘SAINT (Bruker, 1995)’ _computing_data_reduction ‘SAINT and XPREP (Bruker, 1995)’ _computing_structure_solution 'SIR92 (Altomare et al, 1994)' _computing_structure_refinement 'RAELS, (Rae, 1989)' _computing_molecular_graphics 'ORTEP-II, (Johnson, 1976)' _computing_publication_material 'Local programs'

# CHEMICAL DATA

_chemical_name_systematic ? _chemical_formula_moiety ; '2(C30 H30 N20 O10),0.5(C36 H36 N24 O12),4(Cl6 Sn 2-),2(Cl 1-),10(H3 O 1+), 12(H2 O)' ; _chemical_formula_sum 'C78 H132 Cl26 N52 O48 Sn4' _chemical_formula_iupac ? _chemical_formula_weight 3962.8

# CRYSTAL DATA

_symmetry_cell_setting monoclinic _symmetry_space_group_name_H-M 'P 21/n' loop_ _symmetry_equiv_pos_site_id _symmetry_equiv_pos_as_xyz 1 x,y,z 2 1/2-x,1/2+y,1/2-z 3 -x,-y,-z 4 1/2+x,1/2-y,1/2+z

_cell_length_a 21.339(2) _cell_length_b 32.811(4) _cell_length_c 21.579(2) Appendix I: Crystallographic Information Files. Page 358

_cell_angle_alpha 90 _cell_angle_beta 95.766(2) _cell_angle_gamma 90 _cell_volume 15109(5) _cell_formula_units_Z 4 _cell_measurement_reflns_used 974 _cell_measurement_theta_min 2.54 _cell_measurement_theta_max 20.68 _cell_measurement_temperature 150 _exptl_crystal_description hexagonal plate _exptl_crystal_colour colourless _exptl_crystal_size_max 0.29 _exptl_crystal_size_mid 0.23 _exptl_crystal_size_min 0.07 _exptl_crystal_size_rad ? loop_ _exptl_crystal_face_index_h _exptl_crystal_face_index_k _exptl_crystal_face_index_l _exptl_crystal_face_perp_dist ? ? ? ? _exptl_crystal_density_diffrn 1.75 _exptl_crystal_density_meas ? _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 7960.0 _exptl_absorpt_coefficient_mu 1.220 _exptl_absorpt_correction_type empirical _exptl_absorpt_process_details SADABS (Sheldrik, 1996) _exptl_absorpt_correction_T_min 0.0015 _exptl_absorpt_correction_T_max 1.000

# EXPERIMENTAL DATA

_diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_measurement_device_type 'Bruker SMART 1000 CCD' _diffrn_measurement_method '\w' _diffrn_ambient_temperature 150(2) _diffrn_reflns_number 133662 _diffrn_reflns_av_R_equivalents 0.064 _diffrn_reflns_theta_max 28.3 _diffrn_reflns_limit_h_min -27 _diffrn_reflns_limit_h_max 27 _diffrn_reflns_limit_k_min -42 _diffrn_reflns_limit_k_max 41 _diffrn_reflns_limit_l_min -28 _diffrn_reflns_limit_l_max 28 _diffrn_standards_number 265 _diffrn_standards_interval_time 30min _diffrn_standards_decay_% 0.07

# REFINEMENT DATA

_refine_special_details ? Appendix I: Crystallographic Information Files. Page 359

_reflns_number_total 34999 _reflns_number_gt 17188 _reflns_threshold_expression >2sigma(I) _refine_ls_structure_factor_coef F _refine_ls_R_factor_gt 0.088 _refine_ls_wR_factor_ref 0.113 _refine_ls_abs_structure_Flack ? _refine_ls_hydrogen_treatment noref _refine_ls_number_reflns 17188 _refine_ls_number_parameters 859 _refine_ls_goodness_of_fit_ref 1.63 _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'w = 1/[\s^2^(F) + 0.0004F^2^]' _refine_ls_shift/su_max 0.012 _refine_diff_density_max 3.55 _refine_diff_density_min -3.44 _refine_ls_extinction_method none _refine_ls_extinction_coef ? _atom_type_scat_source 'International Tables for X-ray Crystallography, Vol. IV'

C52A 0.2316(8) 0.4435(5) 0.1008(8) 0.040(3) Uani C 1.0 C62A 0.3330(9) 0.3999(6) 0.0049(8) 0.040(3) Uani C 1.0 O13A 0.2695(5) 0.4428(3) 0.2325(5) 0.037(3) Uani O 1.0 O23A 0.4459(5) 0.3645(4) 0.0634(5) 0.039(3) Uani O 1.0 N13A 0.2966(7) 0.4435(4) 0.1332(6) 0.034(3) Uani N 1.0 N23A 0.3724(7) 0.4434(4) 0.2100(6) 0.033(2) Uani N 1.0 N33A 0.4434(6) 0.4138(4) 0.1392(6) 0.033(2) Uani N 1.0 N43A 0.3686(7) 0.4138(4) 0.0626(6) 0.034(3) Uani N 1.0 C13A 0.3516(8) 0.4489(5) 0.1004(8) 0.033(3) Uani C 1.0 C23A 0.4057(8) 0.4476(5) 0.1540(7) 0.032(3) Uani C 1.0 C33A 0.3076(8) 0.4424(5) 0.1953(8) 0.034(3) Uani C 1.0 C43A 0.4215(8) 0.3944(5) 0.0852(8) 0.034(3) Uani C 1.0 C53A 0.4012(8) 0.4444(5) 0.2735(8) 0.037(3) Uani C 1.0 C63A 0.4993(8) 0.3997(5) 0.1772(8) 0.037(3) Uani C 1.0 O14A 0.3328(6) 0.3914(4) 0.3478(5) 0.040(2) Uani O 1.0 O24A 0.5021(5) 0.3122(4) 0.1719(6) 0.044(3) Uani O 1.0 N14A 0.4184(7) 0.4043(4) 0.2972(6) 0.038(2) Uani N 1.0 N24A 0.4120(7) 0.3449(5) 0.3452(6) 0.041(2) Uani N 1.0 N34A 0.4847(7) 0.3141(5) 0.2774(7) 0.044(2) Uani N 1.0 N44A 0.4887(6) 0.3721(5) 0.2274(7) 0.038(2) Uani N 1.0 C14A 0.4801(8) 0.3840(6) 0.2914(8) 0.041(2) Uani C 1.0 C24A 0.4747(8) 0.3438(6) 0.3234(9) 0.045(2) Uani C 1.0 C34A 0.3830(9) 0.3814(6) 0.3319(8) 0.039(2) Uani C 1.0 C44A 0.4918(8) 0.3307(6) 0.2210(9) 0.041(2) Uani C 1.0 C54A 0.3877(9) 0.3169(6) 0.3891(8) 0.045(2) Uani C 1.0 C64A 0.4820(8) 0.2702(6) 0.2865(9) 0.048(2) Uani C 1.0 O15A 0.2573(5) 0.3085(3) 0.3581(5) 0.035(1) Uani O 1.0 O25A 0.4223(5) 0.2293(4) 0.1808(6) 0.043(2) Uani O 1.0 N15A 0.3563(7) 0.2817(5) 0.3585(6) 0.039(2) Uani N 1.0 N25A 0.2756(6) 0.2479(4) 0.3080(6) 0.029(1) Uani N 1.0 N35A 0.3418(6) 0.2135(4) 0.2407(7) 0.034(1) Uani N 1.0 N45A 0.4205(6) 0.2542(5) 0.2804(7) 0.041(2) Uani N 1.0 C15A 0.3844(8) 0.2461(6) 0.3347(8) 0.040(2) Uani C 1.0 C25A 0.3273(8) 0.2219(5) 0.3035(8) 0.034(1) Uani C 1.0 C35A 0.2930(8) 0.2814(5) 0.3427(7) 0.033(1) Uani C 1.0 C45A 0.3975(8) 0.2323(5) 0.2298(9) 0.038(2) Uani C 1.0 C55A 0.2098(7) 0.2371(5) 0.2863(7) 0.026(1) Uani C 1.0 C65A 0.3046(7) 0.1892(5) 0.1963(8) 0.033(1) Uani C 1.0 O11B 0.1955(5) 0.2487(3) 0.5365(5) 0.028(1) Uani O 1.0 O21B 0.3704(5) 0.1397(3) 0.6989(5) 0.0302(8) Uani O 1.0 N11B 0.1968(6) 0.1864(4) 0.5841(6) 0.029(1) Uani N 1.0 N21B 0.2755(6) 0.2026(4) 0.5317(6) 0.032(1) Uani N 1.0 N31B 0.3455(6) 0.1560(4) 0.5970(6) 0.033(1) Uani N 1.0 N41B 0.2694(6) 0.1480(4) 0.6566(6) 0.0282(8) Uani N 1.0 C11B 0.2348(8) 0.1518(5) 0.5944(7) 0.030(1) Uani C 1.0 C21B 0.2901(8) 0.1610(5) 0.5523(7) 0.034(1) Uani C 1.0 C31B 0.2212(8) 0.2154(5) 0.5510(7) 0.029(1) Uani C 1.0 C41B 0.3306(8) 0.1474(5) 0.6530(7) 0.0302(8) Uani C 1.0 C51B 0.3102(8) 0.2229(6) 0.4866(7) 0.036(2) Uani C 1.0 C61B 0.4104(8) 0.1613(6) 0.5792(8) 0.038(1) Uani C 1.0 O12B 0.3080(5) 0.3079(3) 0.5149(5) 0.032(2) Uani O 1.0 O22B 0.4808(5) 0.1996(4) 0.6836(5) 0.036(1) Uani O 1.0 N12B 0.3612(6) 0.2481(5) 0.5141(6) 0.036(2) Uani N 1.0 N22B 0.4116(6) 0.3026(5) 0.5561(6) 0.037(2) Uani N 1.0 Appendix I: Crystallographic Information Files. Page 361

N32B 0.4814(6) 0.2582(5) 0.6226(6) 0.039(2) Uani N 1.0 N42B 0.4311(7) 0.2038(5) 0.5828(6) 0.037(1) Uani N 1.0 C12B 0.4265(8) 0.2328(6) 0.5328(8) 0.040(2) Uani C 1.0 C22B 0.4606(8) 0.2703(6) 0.5599(8) 0.040(2) Uani C 1.0 C32B 0.3570(8) 0.2875(6) 0.5267(8) 0.034(2) Uani C 1.0 C42B 0.4656(5) 0.2187(4) 0.6343(5) 0.037(1) Uani C 1.0 C52B 0.4219(8) 0.3449(6) 0.5703(8) 0.038(3) Uani C 1.0 C62B 0.5176(8) 0.2838(6) 0.6715(8) 0.041(2) Uani C 1.0 O13B 0.3038(5) 0.3717(3) 0.6196(5) 0.032(2) Uani O 1.0 O23B 0.4740(5) 0.2660(3) 0.7908(5) 0.035(1) Uani O 1.0 N13B 0.4101(6) 0.3546(4) 0.6355(7) 0.036(2) Uani N 1.0 N23B 0.3573(6) 0.3715(4) 0.7160(6) 0.034(2) Uani N 1.0 N33B 0.4273(6) 0.3298(4) 0.7894(6) 0.036(2) Uani N 1.0 N43B 0.4766(6) 0.3083(4) 0.7053(7) 0.038(2) Uani N 1.0 C13B 0.4582(8) 0.3511(6) 0.6905(8) 0.039(2) Uani C 1.0 C23B 0.4217(8) 0.3645(5) 0.7455(8) 0.038(2) Uani C 1.0 C33B 0.3520(8) 0.3663(5) 0.6538(8) 0.034(2) Uani C 1.0 C43B 0.4612(8) 0.2983(6) 0.7651(8) 0.036(1) Uani C 1.0 C53B 0.3060(8) 0.3863(5) 0.7504(8) 0.034(2) Uani C 1.0 C63B 0.4073(8) 0.3288(5) 0.8517(8) 0.036(2) Uani C 1.0 O14B 0.1927(5) 0.3490(3) 0.7013(5) 0.029(1) Uani O 1.0 O24B 0.3688(5) 0.2480(3) 0.8848(5) 0.029(1) Uani O 1.0 N14B 0.2732(6) 0.3547(4) 0.7807(6) 0.032(1) Uani N 1.0 N24B 0.1979(6) 0.3107(4) 0.7913(6) 0.028(1) Uani N 1.0 N34B 0.2659(6) 0.2721(4) 0.8680(6) 0.028(1) Uani N 1.0 N44B 0.3448(7) 0.3150(4) 0.8529(6) 0.032(1) Uani N 1.0 C14B 0.2890(8) 0.3410(5) 0.8430(7) 0.033(1) Uani C 1.0 C24B 0.2349(8) 0.3101(5) 0.8523(7) 0.030(1) Uani C 1.0 C34B 0.2194(8) 0.3391(5) 0.7527(7) 0.029(1) Uani C 1.0 C44B 0.3308(8) 0.2763(5) 0.8702(7) 0.030(1) Uani C 1.0 C54B 0.1354(8) 0.2920(5) 0.7811(7) 0.028(1) Uani C 1.0 C64B 0.2342(7) 0.2334(5) 0.8740(7) 0.027(1) Uani C 1.0 O15B 0.1201(5) 0.2752(3) 0.6490(5) 0.026(1) Uani O 1.0 O25B 0.3004(5) 0.1705(3) 0.8190(5) 0.025(1) Uani O 1.0 N15B 0.1352(6) 0.2527(4) 0.7512(6) 0.026(1) Uani N 1.0 N25B 0.1452(6) 0.2089(4) 0.6756(6) 0.025(1) Uani N 1.0 N35B 0.2138(6) 0.1652(4) 0.7460(6) 0.025(1) Uani N 1.0 N45B 0.2151(6) 0.2138(4) 0.8157(6) 0.025(1) Uani N 1.0 C15B 0.1502(7) 0.2156(5) 0.7846(7) 0.025(1) Uani C 1.0 C25B 0.1536(7) 0.1837(5) 0.7320(7) 0.025(1) Uani C 1.0 C35B 0.1330(7) 0.2479(5) 0.6879(7) 0.025(1) Uani C 1.0 C45B 0.2477(7) 0.1818(5) 0.7962(7) 0.024(1) Uani C 1.0 C55B 0.1376(7) 0.1919(5) 0.6125(7) 0.0275(9) Uani C 1.0 C65B 0.2395(7) 0.1325(5) 0.7107(7) 0.0268(9) Uani C 1.0 O11C 0.4786(6) -0.0459(4) 0.1831(6) 0.047(2) Uani O 1.0 O21C 0.7158(5) -0.0013(4) 0.0612(6) 0.041(3) Uani O 1.0 N11C 0.5784(7) -0.0716(4) 0.1640(7) 0.041(2) Uani N 1.0 N21C 0.5705(6) -0.0083(4) 0.1993(6) 0.035(2) Uani N 1.0 N31C 0.6654(6) 0.0094(4) 0.1494(6) 0.032(2) Uani N 1.0 N41C 0.6734(7) -0.0532(4) 0.1172(7) 0.038(3) Uani N 1.0 C11C 0.6441(8) -0.0571(5) 0.1733(8) 0.037(2) Uani C 1.0 C21C 0.6392(8) -0.0139(5) 0.1983(8) 0.034(2) Uani C 1.0 C31C 0.5373(6) -0.0428(4) 0.1822(5) 0.040(2) Uani C 1.0 C41C 0.6866(8) -0.0140(5) 0.1058(8) 0.035(2) Uani C 1.0 Appendix I: Crystallographic Information Files. Page 362

C51C 0.5457(8) 0.0259(6) 0.2327(8) 0.039(2) Uani C 1.0 C61C 0.6773(8) 0.0540(5) 0.1568(8) 0.035(2) Uani C 1.0 O12C 0.4260(6) 0.0525(4) 0.1780(5) 0.042(2) Uani O 1.0 O22C 0.6482(5) 0.0968(3) 0.0408(5) 0.037(1) Uani O 1.0 N12C 0.5328(7) 0.0621(4) 0.1953(6) 0.036(2) Uani N 1.0 N22C 0.4774(7) 0.1080(4) 0.1385(6) 0.034(1) Uani N 1.0 N32C 0.5693(6) 0.1286(4) 0.0870(6) 0.033(1) Uani N 1.0 N42C 0.6216(6) 0.0787(4) 0.1393(6) 0.032(1) Uani N 1.0 C12C 0.5793(8) 0.0919(5) 0.1821(8) 0.035(2) Uani C 1.0 C22C 0.5392(8) 0.1254(5) 0.1474(8) 0.035(1) Uani C 1.0 C32C 0.4740(8) 0.0722(6) 0.1714(8) 0.036(2) Uani C 1.0 C42C 0.6162(8) 0.1015(5) 0.0844(8) 0.033(1) Uani C 1.0 C52C 0.4209(8) 0.1308(5) 0.1172(8) 0.036(2) Uani C 1.0 C62C 0.5497(8) 0.1575(5) 0.0397(8) 0.034(1) Uani C 1.0 O13C 0.3322(5) 0.0764(4) 0.0525(6) 0.039(2) Uani O 1.0 O23C 0.5552(5) 0.1224(4) -0.0795(5) 0.038(1) Uani O 1.0 N13C 0.4054(6) 0.1278(4) 0.0509(6) 0.030(1) Uani N 1.0 N23C 0.3586(6) 0.1053(4) -0.0386(6) 0.031(1) Uani N 1.0 N33C 0.4473(6) 0.1274(4) -0.0934(6) 0.031(1) Uani N 1.0 N43C 0.4973(6) 0.1438(4) -0.0032(6) 0.030(1) Uani N 1.0 C13C 0.4338(8) 0.1527(5) 0.0065(7) 0.029(1) Uani C 1.0 C23C 0.3956(7) 0.1392(5) -0.0582(7) 0.029(1) Uani C 1.0 C33C 0.3626(8) 0.1003(5) 0.0238(8) 0.032(1) Uani C 1.0 C43C 0.5058(8) 0.1304(5) -0.0589(8) 0.032(1) Uani C 1.0 C53C 0.3063(8) 0.0874(5) -0.0796(8) 0.038(2) Uani C 1.0 C63C 0.4386(9) 0.1136(6) -0.1569(8) 0.039(2) Uani C 1.0 Sn1A 0.50878(5) 0.13293(3) 0.38993(5) 0.0187(6) Uani Sn 1.0 Cl1A 0.4805(2) 0.0640(1) 0.3614(2) 0.038(1) Uani Cl 1.0 Cl2A 0.4833(2) 0.1558(1) 0.2843(2) 0.031(1) Uani Cl 1.0 Cl3A 0.6165(2) 0.1195(1) 0.3687(2) 0.030(1) Uani Cl 1.0 Cl4A 0.5392(2) 0.2024(1) 0.4219(2) 0.0261(4) Uani Cl 1.0 Cl5A 0.5327(2) 0.1121(1) 0.4980(2) 0.031(1) Uani Cl 1.0 Cl6A 0.4007(2) 0.1465(1) 0.4103(2) 0.0279(8) Uani Cl 1.0 Sn1B 0.20516(5) 0.00456(3) 0.64331(5) 0.0274(8) Uani Sn 1.0 Cl1B 0.1331(2) 0.0612(1) 0.6264(2) 0.040(1) Uani Cl 1.0 Cl2B 0.2969(2) 0.0485(1) 0.6512(2) 0.0439(7) Uani Cl 1.0 Cl3B 0.2152(3) 0.0024(2) 0.5331(2) 0.076(2) Uani Cl 1.0 Cl4B 0.2740(2) -0.0537(1) 0.6569(3) 0.062(2) Uani Cl 1.0 Cl5B 0.1143(2) -0.0414(1) 0.6314(3) 0.056(1) Uani Cl 1.0 Cl6B 0.2000(3) 0.0088(2) 0.7538(2) 0.052(1) Uani Cl 1.0 Sn1C 0.12241(5) 0.13244(3) 0.97605(5) 0.0211(6) Uani Sn 1.0 Cl1C 0.0826(2) 0.2012(1) 0.9535(2) 0.032(1) Uani Cl 1.0 Cl2C 0.0150(2) 0.1069(1) 0.9589(2) 0.038(1) Uani Cl 1.0 Cl3C 0.1052(2) 0.1422(1) 1.0862(2) 0.0319(7) Uani Cl 1.0 Cl4C 0.1597(2) 0.0643(1) 0.9999(2) 0.034(1) Uani Cl 1.0 Cl5C 0.2272(2) 0.1597(1) 0.9978(2) 0.0274(5) Uani Cl 1.0 Cl6C 0.1371(2) 0.1227(1) 0.8667(2) 0.0298(8) Uani Cl 1.0 Sn1D 0.13548(9) 0.11906(6) 0.36491(9) 0.028(1) Uani Sn 1.0 Cl1D 0.1314(2) 0.1265(1) 0.2530(1) 0.060(2) Uani Cl 1.0 Cl2D 0.0291(2) 0.0924(1) 0.3540(2) 0.073(3) Uani Cl 1.0 Cl3D 0.0945(2) 0.1875(1) 0.3728(2) 0.064(1) Uani Cl 1.0 Cl4D 0.1396(2) 0.1116(1) 0.4769(1) 0.059(2) Uani Cl 1.0 Cl5D 0.2418(2) 0.1457(1) 0.3758(2) 0.062(2) Uani Cl 1.0 Cl6D 0.1765(2) 0.0507(1) 0.3570(2) 0.078(2) Uani Cl 1.0 Appendix I: Crystallographic Information Files. Page 363

Sn1D' 0.1477(3) 0.1180(2) 0.3601(3) 0.029(1) Uani Sn 1.0 Cl1D' 0.1065(6) 0.1469(4) 0.2611(4) 0.054(2) Uani Cl 1.0 Cl2D' 0.0414(4) 0.1090(4) 0.3878(6) 0.061(2) Uani Cl 1.0 Cl3D' 0.1510(7) 0.1853(3) 0.4064(5) 0.0607(9) Uani Cl 1.0 Cl4D' 0.1888(6) 0.0891(4) 0.4592(4) 0.062(3) Uani Cl 1.0 Cl5D' 0.2540(4) 0.1271(4) 0.3325(6) 0.073(3) Uani Cl 1.0 Cl6D' 0.1443(7) 0.0507(3) 0.3139(6) 0.087(2) Uani Cl 1.0 Cl1 0.8062(2) 0.2365(2) 0.1785(2) 0.048(1) Uani Cl 1.0 Cl2 0.8272(3) 0.1725(2) 0.6768(3) 0.081(2) Uani Cl 1.0 OW1 0.2462(7) 0.3622(5) 0.2548(7) 0.070(4) Uani O 1.0 OW2 0.4219(6) 0.2805(4) 0.0842(6) 0.051(4) Uani O 1.0 OW3 0.2092(5) 0.3193(4) 0.5938(5) 0.039(3) Uani O 1.0 OW4 0.3833(7) 0.2140(4) 0.7602(6) 0.058(4) Uani O 1.0 OW5 0.1586(8) 0.2959(5) 0.4319(8) 0.093(6) Uani O 1.0 OW6 0.2509(9) 0.3827(6) 0.4748(11) 0.128(8) Uani O 1.0 OW7 0.4783(6) 0.2436(4) 0.9534(6) 0.057(4) Uani O 1.0 OW8 0.5186(7) 0.3161(5) -0.0067(6) 0.072(5) Uani O 1.0 OW9 0.6226(8) 0.0297(5) 0.4460(9) 0.100(7) Uani O 1.0 OW10 0.2462(7) 0.1014(5) 0.1377(6) 0.073(5) Uani O 1.0 OW11 0.5802(9) 0.0204(5) 0.5671(8) 0.097(6) Uani O 1.0 OW12 0.5473(10) 0.2179(5) 0.8783(8) 0.102(6) Uani O 1.0 OW13 0.5081(14) 0.1059(9) 0.6967(14) 0.094(8) Uani O 1.0 OW13' 0.4580(14) 0.0745(9) 0.6878(14) 0.094(8) Uani O 1.0 OW14 0.0431(9) 0.0082(6) 0.7553(10) 0.133(9) Uani O 1.0 OW15 0.0704(10) 0.0206(6) 0.8828(12) 0.144(9) Uani O 1.0 OW16 0.8049(15) 0.0507(9) 0.0178(14) 0.100(8) Uani O 1.0 OW16' 0.8351(14) 0.0327(9) 0.0874(14) 0.100(8) Uani O 1.0 OW17 0.4687(11) 0.0384(5) 0.5972(10) 0.123(8) Uani O 1.0 OW18 0.5976(11) 0.0389(8) -0.0637(13) 0.169(9) Uani O 1.0 OW19 -0.0319(16) -0.0505(7) 0.7853(16) 0.245(9) Uani O 1.0 OW20 0.6068(15) 0.0375(10) 0.7236(15) 0.108(9) Uani O 1.0 OW20' 0.6571(15) -0.0223(10) 0.7340(15) 0.108(9) Uani O 1.0 OW21 0.3070(20) -0.0019(8) 0.0837(17) 0.277(9) Uani O 1.0 OW22 0.3391(15) 0.0532(10) 0.4143(15) 0.109(9) Uani O 1.0 OW22' 0.2963(15) 0.0715(10) 0.4803(15) 0.109(9) Uani O 1.0 HC11A 0.1699 0.1946 0.1740 0.026 Uani H 1.0 HC21A 0.1338 0.2321 0.0866 0.034 Uani H 1.0 H1C51A 0.0870 0.3306 0.1357 0.039 Uani H 1.0 H2C51A 0.0880 0.3059 0.0701 0.042 Uani H 1.0 H1C61A 0.1722 0.2660 -0.0006 0.045 Uani H 1.0 H2C61A 0.2467 0.2561 -0.0042 0.046 Uani H 1.0 HC12A 0.1438 0.3432 -0.0052 0.049 Uani H 1.0 HC22A 0.1994 0.4017 -0.0126 0.049 Uani H 1.0 H1C52A 0.2030 0.4556 0.1299 0.043 Uani H 1.0 H2C52A 0.2317 0.4611 0.0630 0.044 Uani H 1.0 H1C62A 0.3157 0.4243 -0.0188 0.044 Uani H 1.0 H2C62A 0.3622 0.3849 -0.0205 0.044 Uani H 1.0 HC13A 0.3506 0.4751 0.0767 0.036 Uani H 1.0 HC23A 0.4307 0.4734 0.1555 0.033 Uani H 1.0 H1C53A 0.3706 0.4567 0.3004 0.041 Uani H 1.0 H2C53A 0.4399 0.4616 0.2754 0.039 Uani H 1.0 H1C63A 0.5218 0.4242 0.1958 0.038 Uani H 1.0 H2C63A 0.5267 0.3854 0.1491 0.041 Uani H 1.0 HC14A 0.5163 0.4005 0.3108 0.047 Uani H 1.0 Appendix I: Crystallographic Information Files. Page 364

HC24A 0.5077 0.3414 0.3595 0.053 Uani H 1.0 H1C54A 0.3568 0.3318 0.4128 0.047 Uani H 1.0 H2C54A 0.4236 0.3070 0.4187 0.053 Uani H 1.0 H1C64A 0.5020 0.2637 0.3293 0.055 Uani H 1.0 H2C64A 0.5063 0.2567 0.2549 0.052 Uani H 1.0 HC15A 0.4093 0.2301 0.3680 0.048 Uani H 1.0 HC25A 0.3217 0.1959 0.3265 0.036 Uani H 1.0 H1C55A 0.1812 0.2518 0.3128 0.027 Uani H 1.0 H2C55A 0.2044 0.2070 0.2911 0.026 Uani H 1.0 H1C65A 0.2819 0.1683 0.2194 0.032 Uani H 1.0 H2C65A 0.3334 0.1752 0.1693 0.039 Uani H 1.0 HC11B 0.2117 0.1262 0.5815 0.032 Uani H 1.0 HC21B 0.2901 0.1415 0.5166 0.038 Uani H 1.0 H1C51B 0.2804 0.2405 0.4599 0.035 Uani H 1.0 H2C51B 0.3283 0.2017 0.4602 0.040 Uani H 1.0 H1C61B 0.4116 0.1515 0.5355 0.042 Uani H 1.0 H2C61B 0.4398 0.1447 0.6080 0.039 Uani H 1.0 HC12B 0.4465 0.2222 0.4961 0.044 Uani H 1.0 HC22B 0.4968 0.2779 0.5361 0.045 Uani H 1.0 H1C52B 0.3929 0.3616 0.5413 0.038 Uani H 1.0 H2C52B 0.4666 0.3519 0.5645 0.043 Uani H 1.0 H1C62B 0.5466 0.3022 0.6508 0.045 Uani H 1.0 H2C62B 0.5429 0.2655 0.7014 0.042 Uani H 1.0 HC13B 0.4956 0.3688 0.6862 0.044 Uani H 1.0 HC23B 0.4400 0.3899 0.7655 0.042 Uani H 1.0 H1C53B 0.2749 0.4008 0.7205 0.034 Uani H 1.0 H2C53B 0.3242 0.4058 0.7830 0.038 Uani H 1.0 H1C63B 0.4105 0.3570 0.8694 0.040 Uani H 1.0 H2C63B 0.4359 0.3101 0.8780 0.037 Uani H 1.0 HC14B 0.2903 0.3639 0.8737 0.037 Uani H 1.0 HC24B 0.2091 0.3192 0.8859 0.033 Uani H 1.0 H1C54B 0.1072 0.3107 0.7544 0.029 Uani H 1.0 H2C54B 0.1186 0.2886 0.8225 0.030 Uani H 1.0 H1C64B 0.1959 0.2383 0.8960 0.028 Uani H 1.0 H2C64B 0.2635 0.2147 0.8994 0.027 Uani H 1.0 HC15B 0.1180 0.2083 0.8133 0.027 Uani H 1.0 HC25B 0.1191 0.1631 0.7324 0.027 Uani H 1.0 H1C55B 0.1100 0.2107 0.5854 0.028 Uani H 1.0 H2C55B 0.1166 0.1647 0.6143 0.029 Uani H 1.0 H1C65B 0.2046 0.1135 0.6955 0.028 Uani H 1.0 H2C65B 0.2717 0.1173 0.7386 0.027 Uani H 1.0 HC11C 0.6699 -0.0746 0.2039 0.040 Uani H 1.0 HC21C 0.6632 -0.0101 0.2401 0.037 Uani H 1.0 H1C51C 0.5773 0.0331 0.2684 0.043 Uani H 1.0 H2C51C 0.5056 0.0170 0.2489 0.045 Uani H 1.0 H1C61C 0.7108 0.0619 0.1299 0.039 Uani H 1.0 H2C61C 0.6922 0.0596 0.2013 0.039 Uani H 1.0 HC12C 0.6026 0.1026 0.2212 0.042 Uani H 1.0 HC22C 0.5403 0.1517 0.1708 0.042 Uani H 1.0 H1C52C 0.4278 0.1601 0.1285 0.040 Uani H 1.0 H2C52C 0.3849 0.1199 0.1385 0.041 Uani H 1.0 H1C62C 0.5862 0.1634 0.0154 0.039 Uani H 1.0 H2C62C 0.5369 0.1831 0.0602 0.038 Uani H 1.0 HC13C 0.4280 0.1823 0.0149 0.032 Uani H 1.0 Appendix I: Crystallographic Information Files. Page 365

HC23C 0.3691 0.1616 -0.0785 0.030 Uani H 1.0 H1C53C 0.2876 0.1090 -0.1084 0.038 Uani H 1.0 H2C53C 0.2737 0.0772 -0.0532 0.042 Uani H 1.0 H1C63C 0.4790 0.1179 -0.1759 0.045 Uani H 1.0 H2C63C 0.4046 0.1303 -0.1797 0.040 Uani H 1.0

I.7: (Q6)(SnCl6)(H3O)2(H2O)x. data_5.8

_audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety (C36 H36 N24 O12), (Sn Cl6 2-), 2(H3 O 1+), x(H2 O) _chemical_formula_sum 'C36 H42 Cl6 N24 O14 Sn' _chemical_formula_weight 2363.22 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source 'C' 'C' 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'H' 'H' 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'N' 'N' 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'O' 'O' 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Cl' 'Cl' 0.1484 0.1585 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Sn' 'Sn' -0.6537 1.4246 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_symmetry_cell_setting 'monoclinic' _symmetry_space_group_name_H-M 'C2/c' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y, -z+1/2' 'x+1/2, y+1/2, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' Appendix I: Crystallographic Information Files. Page 366

'x, -y, z-1/2' '-x+1/2, -y+1/2, -z' 'x+1/2, -y+1/2, z-1/2'

_cell_length_a 26.966(8) _cell_length_b 20.624(6) _cell_length_c 13.457(4) _cell_angle_alpha 90.00 _cell_angle_beta 115.445(5) _cell_angle_gamma 90.00 _cell_volume 7484(4) _cell_formula_units_Z 8 _cell_measurement_temperature 150(2) _cell_measurement_reflns_used 944 _cell_measurement_theta_min 2.696 _cell_measurement_theta_max 27.638

_exptl_crystal_description block _exptl_crystal_colour colourless _exptl_crystal_size_max 26.966 _exptl_crystal_size_mid 20.624 _exptl_crystal_size_min 13.457 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.236 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 2536 _exptl_absorpt_coefficient_mu 0.599 _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min 0.0015 _exptl_absorpt_correction_T_max 1.000 _exptl_absorpt_process_details SADABS (Sheldrik, 1996)

_exptl_special_details ; ? ;

_diffrn_ambient_temperature 150(2) _diffrn_radiation_wavelength 0.71069 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'Bruker SMART 1000 CCD' _diffrn_measurement_method \w _diffrn_detector_area_resol_mean ? _diffrn_standards_number 265 _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% 0.24 _diffrn_reflns_number 33100 _diffrn_reflns_av_R_equivalents 0.0368 _diffrn_reflns_av_sigmaI/netI 0.0348 _diffrn_reflns_limit_h_min -35 _diffrn_reflns_limit_h_max 35 Appendix I: Crystallographic Information Files. Page 367

_diffrn_reflns_limit_k_min -27 _diffrn_reflns_limit_k_max 26 _diffrn_reflns_limit_l_min -17 _diffrn_reflns_limit_l_max 17 _diffrn_reflns_theta_min 1.67 _diffrn_reflns_theta_max 28.29 _reflns_number_total 8065 _reflns_number_gt 6305 _reflns_threshold_expression >2sigma(I)

_computing_data_collection ‘SMART (Bruker, 1995)’ _computing_cell_refinement ‘SAINT (Bruker, 1995)’ _computing_data_reduction ‘SAINT and XPREP (Bruker, 1995)’ _computing_structure_solution ‘SIR97 (Altomare et al., 1997)’ _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'WinGX (Farrugia, 1995)' _computing_publication_material ?

_refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.1130P)^2^+48.9823P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method SHELXL _refine_ls_extinction_coef 0.00000(13) _refine_ls_extinction_expression 'Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^' _refine_ls_number_reflns 8065 _refine_ls_number_parameters 417 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0774 _refine_ls_R_factor_gt 0.0590 _refine_ls_wR_factor_ref 0.2063 _refine_ls_wR_factor_gt 0.1867 _refine_ls_goodness_of_fit_ref 1.090 _refine_ls_restrained_S_all 1.090 _refine_ls_shift/su_max 1.970 _refine_ls_shift/su_mean 0.012 Appendix I: Crystallographic Information Files. Page 368

loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.56858(17) 0.8017(2) -0.6653(4) 0.0263(9) Uani 1 1 d . . . C2 C 0.58483(19) 0.9129(2) -0.6738(4) 0.0270(9) Uani 1 1 d . . . H2 H 0.5580 0.9482 -0.6913 0.032 Uiso 1 1 calc R . . C3 C 0.6670(2) 0.9313(2) -0.6892(4) 0.0282(10) Uani 1 1 d . . . C4 C 0.57210(18) 0.8665(3) -0.5089(4) 0.0290(10) Uani 1 1 d . . . H4A H 0.5542 0.9069 -0.5066 0.035 Uiso 1 1 calc R . . H4B H 0.5504 0.8314 -0.5001 0.035 Uiso 1 1 calc R . . C5 C 0.6596(2) 0.9821(2) -0.5302(4) 0.0308(10) Uani 1 1 d . . . H5A H 0.6854 1.0120 -0.5382 0.037 Uiso 1 1 calc R . . H5B H 0.6284 1.0072 -0.5340 0.037 Uiso 1 1 calc R . . C6 C 0.64648(18) 0.8111(2) -0.3532(4) 0.0249(9) Uani 1 1 d . . . C7 C 0.65617(19) 0.9234(2) -0.3663(4) 0.0256(9) Uani 1 1 d . . . H7 H 0.6329 0.9552 -0.3525 0.031 Uiso 1 1 calc R . . C8 C 0.7414(2) 0.9461(2) -0.3656(4) 0.0271(9) Uani 1 1 d . . . C9 C 0.70254(18) 0.8978(2) -0.2575(4) 0.0236(9) Uani 1 1 d . . . H9 H 0.7010 0.9179 -0.1928 0.028 Uiso 1 1 calc R . . C10 C 0.71590(18) 0.7876(2) -0.1650(4) 0.0245(9) Uani 1 1 d . . . H10A H 0.7207 0.8130 -0.1008 0.029 Uiso 1 1 calc R . . H10B H 0.6901 0.7531 -0.1724 0.029 Uiso 1 1 calc R . . C11 C 0.80628(19) 0.9077(2) -0.1816(4) 0.0292(10) Uani 1 1 d . . . H11A H 0.8062 0.9201 -0.1121 0.035 Uiso 1 1 calc R . . H11B H 0.8313 0.9364 -0.1948 0.035 Uiso 1 1 calc R . . C12 C 0.77420(19) 0.6958(2) -0.1672(4) 0.0261(9) Uani 1 1 d . . . C13 C 0.81967(18) 0.7936(2) -0.0998(4) 0.0250(9) Uani 1 1 d . . . H13 H 0.8269 0.8122 -0.0279 0.030 Uiso 1 1 calc R . . C14 C 0.86785(19) 0.8258(2) -0.2005(4) 0.0295(10) Uani 1 1 d . . . C15 C 0.86209(18) 0.7407(2) -0.0906(4) 0.0256(9) Uani 1 1 d . . . H15 H 0.8885 0.7333 -0.0141 0.031 Uiso 1 1 calc R . . C16 C 0.8505(2) 0.6198(2) -0.1323(4) 0.0295(10) Uani 1 1 d . . . H16A H 0.8233 0.5887 -0.1337 0.035 Uiso 1 1 calc R . . H16B H 0.8825 0.6151 -0.0624 0.035 Uiso 1 1 calc R . . C17 C 0.93680(18) 0.7389(3) -0.1592(4) 0.0308(10) Uani 1 1 d . . . H17A H 0.9599 0.7214 -0.0870 0.037 Uiso 1 1 calc R . . H17B H 0.9573 0.7730 -0.1746 0.037 Uiso 1 1 calc R . . C18 C 0.91842(19) 0.6210(2) -0.2200(4) 0.0280(10) Uani 1 1 d . . . H18 H 0.9494 0.6048 -0.1540 0.034 Uiso 1 1 calc R . . N1 N 0.57235(16) 0.8605(2) -0.6164(3) 0.0291(8) Uani 1 1 d . . . N2 N 0.64085(17) 0.9371(2) -0.6212(3) 0.0290(8) Uani 1 1 d . . . N3 N 0.62603(16) 0.8653(2) -0.4171(3) 0.0263(8) Uani 1 1 d . . . N4 N 0.68556(17) 0.9520(2) -0.4230(3) 0.0286(8) Uani 1 1 d . . . Appendix I: Crystallographic Information Files. Page 369

N5 N 0.69244(15) 0.82888(18) -0.2615(3) 0.0236(7) Uani 1 1 d . . . N6 N 0.75180(16) 0.91616(19) -0.2682(3) 0.0262(8) Uani 1 1 d . . . N7 N 0.76813(15) 0.75891(19) -0.1467(3) 0.0263(8) Uani 1 1 d . . . N8 N 0.82625(16) 0.8416(2) -0.1729(3) 0.0290(8) Uani 1 1 d . . . N9 N 0.82855(16) 0.6842(2) -0.1382(3) 0.0288(8) Uani 1 1 d . . . N10 N 0.88817(17) 0.7667(2) -0.1564(3) 0.0302(9) Uani 1 1 d . . . N11 N 0.86622(17) 0.6041(2) -0.2201(3) 0.0292(8) Uani 1 1 d . . . N12 N 0.92527(16) 0.6884(2) -0.2398(3) 0.0290(8) Uani 1 1 d . . . O1 O 0.55982(14) 0.75031(18) -0.6324(3) 0.0335(8) Uani 1 1 d . . . O2 O 0.71068(16) 0.95543(17) -0.6739(3) 0.0352(8) Uani 1 1 d . . . O3 O 0.62683(14) 0.75664(17) -0.3735(3) 0.0322(7) Uani 1 1 d . . . O4 O 0.77567(16) 0.96618(18) -0.3950(3) 0.0368(8) Uani 1 1 d . . . O5 O 0.73719(15) 0.65545(17) -0.2045(3) 0.0350(8) Uani 1 1 d . . . O6 O 0.88433(17) 0.8590(2) -0.2554(3) 0.0436(9) Uani 1 1 d . . . Cl1 Cl 0.59962(5) 0.87976(6) -0.16929(10) 0.0316(3) Uani 1 1 d . . . Cl2 Cl 0.50094(5) 0.79544(6) -0.12536(9) 0.0276(3) Uani 1 1 d . . . Cl3 Cl 0.50176(6) 0.96289(6) -0.11866(10) 0.0343(3) Uani 1 1 d . . . O101 O 0.7708(2) 0.9074(2) 0.0251(4) 0.0512(11) Uani 1 1 d . . . O102 O 0.9419(2) 0.8760(3) 0.0483(4) 0.0684(16) Uani 1 1 d . . . O103 O 0.6637(3) 0.6786(3) -0.5103(6) 0.0297(14) Uiso 0.50 1 d P . . O104 O 0.5399(3) 0.6582(3) -0.4817(6) 0.0307(14) Uiso 0.50 1 d P . . O105 O 0.9048(4) 0.7986(5) 0.1685(8) 0.047(2) Uiso 0.50 1 d P . . O106 O 0.8181(2) 0.9322(3) -0.5893(6) 0.094(2) Uani 1 1 d . . . O107 O 0.6230(5) 0.5985(6) -0.2880(9) 0.068(3) Uiso 0.50 1 d P . . Sn1 Sn 0.5000 0.880304(19) -0.2500 0.01916(15) Uani 1 2 d S . . O108 O 0.8801(7) 0.9961(8) -0.4099(14) 0.105(5) Uiso 0.50 1 d P . . O109 O 0.6036(7) 0.4959(8) -0.2045(14) 0.108(5) Uiso 0.50 1 d P . . O110 O 0.8939(6) 0.8103(7) 0.1941(12) 0.082(4) Uiso 0.50 1 d P . . O111 O 0.9302(7) 0.9797(8) 0.0553(14) 0.113(5) Uiso 0.50 1 d P . .

I.8: (Q5@Q10)(CH3COOH)(Cl)2(H3O)2(H2O)26. data_5.9 _audit_creation_method 'RAELSPUB and manual entry'

# SUBMISSION DETAILS

_publ_contact_author_name ? _publ_contact_author_address ? _publ_contact_author_email ? _publ_contact_letter ? _publ_requested_journal ? _publ_requested_category ?

# TITLE AND AUTHOR LIST

_publ_section_title ? _publ_section_title_footnote ? loop_ _publ_author_name _publ_author_footnote Appendix I: Crystallographic Information Files. Page 370

_publ_author_address ? ? ?

# TEXT

_publ_section_abstract ? _publ_section_comment ? _publ_section_acknowledgements ? _publ_section_references ; Altomare, A., Burla, M.C., Camalli, M., Cascarano, G., Giacovazzo, C., Guagliardi, A., Polidori, G., J. Appl. Cryst., 1994, 27, 435.

Ibers, J.A. and Hamilton, W.C., (Eds) International Tables for X-Ray Crystallography Vol. 4 , Kynoch Press, Birmingham, 1974.

Johnson, C.K.,'ORTEP-II', Oak Ridge National Laboratory, Tennessee, U.S.A., 1976.

Rae, A.D., RAELS. A comprehensive Constrained Least Squares Refinement Program, University of New South Wales, 1989. ;

# CHEMICAL DATA

_chemical_name_systematic ? _chemical_formula_moiety ; '(C60 H60 N40 O20), (C30 H30 N20 O10),2(Cl -1), (C2 H4 O2),2(H3 O 1+),26(H2 O)' ; _chemical_formula_sum 'C92 H152 Cl2 N60 O60' _chemical_formula_iupac ? _chemical_formula_weight 3129.6

# CRYSTAL DATA

_symmetry_cell_setting monoclinic _symmetry_space_group_name_H-M 'P 21/c' loop_ _symmetry_equiv_pos_site_id _symmetry_equiv_pos_as_xyz 1 x,y,z 2 -x,1/2+y,1/2-z 3 -x,-y,-z Appendix I: Crystallographic Information Files. Page 371

4 x,1/2-y,1/2+z

_cell_length_a 34.423(4) _cell_length_b 22.088(3) _cell_length_c 17.695(2) _cell_angle_alpha 90 _cell_angle_beta 97.615(2) _cell_angle_gamma 90 _cell_volume 13454(5) _cell_formula_units_Z 4 _cell_measurement_reflns_used 946 _cell_measurement_theta_min 2.56 _cell_measurement_theta_max 24.19 _cell_measurement_temperature 150 _exptl_crystal_description square plate _exptl_crystal_colour colourless _exptl_crystal_size_max 34.4226 _exptl_crystal_size_mid 22.088 _exptl_crystal_size_min 17.6953 _exptl_crystal_size_rad ? _exptl_crystal_density_diffrn 1.57 _exptl_crystal_density_meas ? _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 6584.0 _exptl_absorpt_coefficient_mu 0.185 _exptl_absorpt_correction_type empirical _exptl_absorpt_process_details SADABS (Sheldrik, 1996) _exptl_absorpt_correction_T_min 0.0015 _exptl_absorpt_correction_T_max 1.000

# EXPERIMENTAL DATA

_diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_measurement_device_type 'Bruker SMART 1000 CCD' _diffrn_measurement_method '\w' _diffrn_ambient_temperature 150(2) _diffrn_reflns_number 79638 _diffrn_reflns_av_R_equivalents 0.037 _diffrn_reflns_theta_max 28.3 _diffrn_reflns_limit_h_min -45 _diffrn_reflns_limit_h_max 44 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 29 _diffrn_reflns_limit_l_min 0 _diffrn_reflns_limit_l_max 23 _diffrn_standards_number 0 _diffrn_standards_interval_time ? _diffrn_standards_decay_% 0

# REFINEMENT DATA

_refine_special_details ? _reflns_number_total 31298 Appendix I: Crystallographic Information Files. Page 372

_reflns_number_gt 14088 _reflns_threshold_expression >2sigma(I) _refine_ls_structure_factor_coef F _refine_ls_R_factor_gt 0.108 _refine_ls_wR_factor_ref 0.159 _refine_ls_abs_structure_Flack ? _refine_ls_hydrogen_treatment noref _refine_ls_number_reflns 14088 _refine_ls_number_parameters 861 _refine_ls_goodness_of_fit_ref 1.89 _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'w = 1/[\s^2^(F) + 0.0004F^2^]' _refine_ls_shift/su_max 0.003 _refine_diff_density_max 1.72 _refine_diff_density_min -2.67 _refine_ls_extinction_method none _refine_ls_extinction_coef ? _atom_type_scat_source 'International Tables for X-ray Crystallography, Vol. IV'

# ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_type_symbol _atom_site_occupancy O11A 0.1888(2) 0.5467(2) 0.0969(3) 0.0210(3) Uani O 1.0 O21A 0.1122(2) 0.3186(2) 0.2050(3) 0.0216(3) Uani O 1.0 N11A 0.1803(2) 0.4453(3) 0.0709(4) 0.0210(3) Uani N 1.0 N21A 0.1297(2) 0.4989(3) 0.0974(4) 0.0205(3) Uani N 1.0 N31A 0.0991(2) 0.4082(3) 0.1399(4) 0.0209(3) Uani N 1.0 N41A 0.1517(2) 0.3564(3) 0.1198(4) 0.0213(4) Uani N 1.0 C11A 0.1485(2) 0.4025(4) 0.0615(5) 0.0213(3) Uani C 1.0 C21A 0.1125(2) 0.4397(4) 0.0772(4) 0.0209(3) Uani C 1.0 C31A 0.1684(2) 0.5016(4) 0.0885(4) 0.0207(3) Uani C 1.0 C41A 0.1199(2) 0.3574(4) 0.1600(5) 0.0212(3) Uani C 1.0 C51A 0.1059(2) 0.5532(4) 0.0991(4) 0.0206(3) Uani C 1.0 C61A 0.0597(2) 0.4168(4) 0.1612(5) 0.0214(3) Uani C 1.0 O12A 0.1158(2) 0.6553(2) 0.1997(3) 0.0213(3) Uani O 1.0 O22A 0.0468(2) 0.4174(2) 0.3196(3) 0.0216(3) Uani O 1.0 N12A 0.0892(2) 0.5603(3) 0.1697(4) 0.0205(3) Uani N 1.0 N22A 0.0655(2) 0.6149(3) 0.2577(4) 0.0213(3) Uani N 1.0 N32A 0.0405(2) 0.5214(3) 0.3088(4) 0.0214(3) Uani N 1.0 N42A 0.0575(2) 0.4686(3) 0.2101(4) 0.0209(3) Uani N 1.0 C12A 0.0524(2) 0.5296(4) 0.1799(4) 0.0209(3) Uani C 1.0 C22A 0.0382(2) 0.5656(4) 0.2453(4) 0.0214(3) Uani C 1.0 C32A 0.0925(2) 0.6149(4) 0.2079(4) 0.0209(3) Uani C 1.0 C42A 0.0476(2) 0.4645(4) 0.2831(5) 0.0212(3) Uani C 1.0 C52A 0.0564(2) 0.6698(4) 0.2978(5) 0.0224(3) Uani C 1.0 Appendix I: Crystallographic Information Files. Page 373

C62A 0.0191(2) 0.5302(4) 0.3736(5) 0.0224(3) Uani C 1.0 O13A 0.1153(2) 0.7297(2) 0.4027(3) 0.0238(3) Uani O 1.0 O23A 0.0500(2) 0.5011(3) 0.5292(3) 0.0229(3) Uani O 1.0 N13A 0.0630(2) 0.6638(3) 0.3800(4) 0.0227(3) Uani N 1.0 N23A 0.0805(2) 0.6979(3) 0.4964(4) 0.0244(3) Uani N 1.0 N33A 0.0573(2) 0.6042(3) 0.5491(4) 0.0238(3) Uani N 1.0 N43A 0.0379(2) 0.5712(3) 0.4309(4) 0.0226(3) Uani N 1.0 C13A 0.0350(3) 0.6369(4) 0.4236(5) 0.0233(3) Uani C 1.0 C23A 0.0473(3) 0.6599(4) 0.5044(5) 0.0244(3) Uani C 1.0 C33A 0.0888(3) 0.6997(4) 0.4238(5) 0.0235(3) Uani C 1.0 C43A 0.0484(3) 0.5545(4) 0.5041(5) 0.0229(3) Uani C 1.0 C53A 0.0944(3) 0.7433(4) 0.5524(5) 0.0262(3) Uani C 1.0 C63A 0.0569(3) 0.6030(4) 0.6310(5) 0.0251(3) Uani C 1.0 O14A 0.1755(2) 0.7614(3) 0.6020(3) 0.0272(4) Uani O 1.0 O24A 0.1073(2) 0.5454(3) 0.7550(3) 0.0252(4) Uani O 1.0 N14A 0.1172(2) 0.7189(3) 0.6199(4) 0.0263(3) Uani N 1.0 N24A 0.1634(2) 0.7246(3) 0.7186(4) 0.0279(4) Uani N 1.0 N34A 0.1354(2) 0.6388(3) 0.7800(4) 0.0269(4) Uani N 1.0 N44A 0.0923(2) 0.6286(3) 0.6762(4) 0.0254(3) Uani N 1.0 C14A 0.0981(3) 0.6943(4) 0.6808(5) 0.0269(3) Uani C 1.0 C24A 0.1294(3) 0.7011(4) 0.7508(5) 0.0280(4) Uani C 1.0 C34A 0.1537(3) 0.7372(4) 0.6433(5) 0.0270(3) Uani C 1.0 C44A 0.1116(3) 0.5983(4) 0.7387(5) 0.0256(3) Uani C 1.0 C54A 0.1928(3) 0.7602(4) 0.7652(5) 0.0301(4) Uani C 1.0 C64A 0.1539(3) 0.6275(4) 0.8579(5) 0.0280(4) Uani C 1.0 O15A 0.2759(2) 0.7569(3) 0.7580(3) 0.0309(5) Uani O 1.0 O25A 0.2094(2) 0.5355(3) 0.9089(3) 0.0267(4) Uani O 1.0 N15A 0.2225(2) 0.7227(3) 0.8105(4) 0.0298(4) Uani N 1.0 N25A 0.2817(2) 0.6979(3) 0.8672(4) 0.0308(5) Uani N 1.0 N35A 0.2552(2) 0.6126(3) 0.9291(4) 0.0290(4) Uani N 1.0 N45A 0.1956(2) 0.6340(3) 0.8691(4) 0.0281(4) Uani N 1.0 C15A 0.2153(3) 0.6933(4) 0.8795(5) 0.0302(4) Uani C 1.0 C25A 0.2561(3) 0.6777(4) 0.9202(5) 0.0308(5) Uani C 1.0 C35A 0.2610(3) 0.7290(4) 0.8054(5) 0.0304(5) Uani C 1.0 C45A 0.2190(3) 0.5879(4) 0.9037(5) 0.0277(4) Uani C 1.0 C55A 0.3230(3) 0.7108(4) 0.8892(5) 0.0326(5) Uani C 1.0 C65A 0.2849(3) 0.5789(4) 0.9771(5) 0.0294(5) Uani C 1.0 O16A 0.3782(2) 0.6871(3) 0.7825(3) 0.0317(6) Uani O 1.0 O26A 0.3125(2) 0.4657(3) 0.9307(3) 0.0263(4) Uani O 1.0 N16A 0.3477(2) 0.6580(3) 0.8865(4) 0.0313(5) Uani N 1.0 N26A 0.3962(2) 0.6021(3) 0.8538(4) 0.0305(5) Uani N 1.0 N36A 0.3707(2) 0.5133(3) 0.9128(4) 0.0282(4) Uani N 1.0 N46A 0.3201(2) 0.5687(3) 0.9404(4) 0.0288(4) Uani N 1.0 C16A 0.3529(3) 0.6114(4) 0.9445(5) 0.0309(5) Uani C 1.0 C26A 0.3869(3) 0.5735(4) 0.9236(5) 0.0305(5) Uani C 1.0 C36A 0.3754(3) 0.6520(4) 0.8354(5) 0.0311(5) Uani C 1.0 C46A 0.3321(3) 0.5103(4) 0.9296(5) 0.0275(4) Uani C 1.0 C56A 0.4337(3) 0.5942(4) 0.8262(5) 0.0316(6) Uani C 1.0 C66A 0.3935(3) 0.4584(4) 0.9104(5) 0.0277(5) Uani C 1.0 O17A 0.4480(2) 0.5847(3) 0.6697(3) 0.0305(6) Uani O 1.0 O27A 0.3772(2) 0.3568(3) 0.8096(3) 0.0248(4) Uani O 1.0 N17A 0.4357(2) 0.5379(3) 0.7816(4) 0.0295(5) Uani N 1.0 N27A 0.4556(2) 0.4805(3) 0.6912(4) 0.0286(5) Uani N 1.0 N37A 0.4267(2) 0.3927(3) 0.7441(4) 0.0262(4) Uani N 1.0 Appendix I: Crystallographic Information Files. Page 374

N47A 0.4074(2) 0.4492(3) 0.8367(4) 0.0271(4) Uani N 1.0 C17A 0.4422(3) 0.4795(4) 0.8181(5) 0.0289(5) Uani C 1.0 C27A 0.4560(3) 0.4396(4) 0.7554(5) 0.0283(5) Uani C 1.0 C37A 0.4468(3) 0.5390(4) 0.7099(5) 0.0295(5) Uani C 1.0 C47A 0.4011(3) 0.3957(4) 0.7979(5) 0.0257(4) Uani C 1.0 C57A 0.4791(3) 0.4681(4) 0.6295(5) 0.0294(6) Uani C 1.0 C67A 0.4345(3) 0.3356(4) 0.7090(5) 0.0259(4) Uani C 1.0 O18A 0.4534(2) 0.4904(3) 0.4689(3) 0.0283(5) Uani O 1.0 O28A 0.3778(2) 0.2740(3) 0.6019(3) 0.0236(3) Uani O 1.0 N18A 0.4609(2) 0.4252(3) 0.5727(4) 0.0276(5) Uani N 1.0 N28A 0.4452(2) 0.3862(3) 0.4574(4) 0.0267(4) Uani N 1.0 N38A 0.4177(2) 0.2981(3) 0.5122(4) 0.0250(4) Uani N 1.0 N48A 0.4310(2) 0.3392(3) 0.6267(4) 0.0255(4) Uani N 1.0 C18A 0.4623(3) 0.3616(4) 0.5875(5) 0.0271(5) Uani C 1.0 C28A 0.4524(3) 0.3344(4) 0.5055(5) 0.0267(4) Uani C 1.0 C38A 0.4534(3) 0.4386(4) 0.4968(5) 0.0275(5) Uani C 1.0 C48A 0.4059(3) 0.3009(4) 0.5821(5) 0.0245(4) Uani C 1.0 C58A 0.4469(3) 0.3832(4) 0.3750(5) 0.0272(5) Uani C 1.0 C68A 0.4030(3) 0.2513(4) 0.4572(5) 0.0249(4) Uani C 1.0 O19A 0.3969(2) 0.4472(3) 0.2554(3) 0.0259(4) Uani O 1.0 O29A 0.3217(2) 0.2380(2) 0.4083(3) 0.0228(3) Uani O 1.0 N19A 0.4102(2) 0.3622(3) 0.3312(4) 0.0256(4) Uani N 1.0 N29A 0.3648(2) 0.3572(3) 0.2298(4) 0.0245(3) Uani N 1.0 N39A 0.3338(2) 0.2749(3) 0.2917(4) 0.0234(3) Uani N 1.0 N49A 0.3812(2) 0.2766(3) 0.3889(4) 0.0243(3) Uani N 1.0 C19A 0.4001(3) 0.2986(4) 0.3263(5) 0.0254(3) Uani C 1.0 C29A 0.3680(3) 0.2953(4) 0.2576(5) 0.0247(3) Uani C 1.0 C39A 0.3914(3) 0.3951(4) 0.2707(5) 0.0252(3) Uani C 1.0 C49A 0.3432(3) 0.2611(4) 0.3663(5) 0.0233(3) Uani C 1.0 C59A 0.3472(3) 0.3703(4) 0.1529(5) 0.0246(3) Uani C 1.0 C69A 0.3021(3) 0.2433(4) 0.2455(5) 0.0235(3) Uani C 1.0 O110A 0.2936(2) 0.4699(3) 0.1118(3) 0.0230(3) Uani O 1.0 O210A 0.2189(2) 0.2493(2) 0.2486(3) 0.0222(3) Uani O 1.0 N110A 0.3049(2) 0.3690(3) 0.1418(4) 0.0232(3) Uani N 1.0 N210A 0.2451(2) 0.3985(3) 0.0921(4) 0.0221(3) Uani N 1.0 N310A 0.2155(2) 0.3080(3) 0.1402(4) 0.0221(3) Uani N 1.0 N410A 0.2743(2) 0.2844(3) 0.2010(4) 0.0227(3) Uani N 1.0 C110A 0.2830(3) 0.3122(4) 0.1311(5) 0.0233(3) Uani C 1.0 C210A 0.2423(2) 0.3317(4) 0.0905(5) 0.0227(3) Uani C 1.0 C310A 0.2822(2) 0.4177(4) 0.1139(5) 0.0227(3) Uani C 1.0 C410A 0.2347(3) 0.2779(4) 0.2024(5) 0.0221(3) Uani C 1.0 C510A 0.2174(2) 0.4349(4) 0.0419(5) 0.0219(3) Uani C 1.0 C610A 0.1742(3) 0.3002(4) 0.1167(5) 0.0222(3) Uani C 1.0 O11B 0.3481(2) 0.4292(3) 0.4445(3) 0.0349(6) Uani O 1.0 O21B 0.2632(2) 0.6726(3) 0.4306(4) 0.0393(7) Uani O 1.0 N11B 0.3556(2) 0.5302(4) 0.4767(4) 0.0354(6) Uani N 1.0 N21B 0.3252(2) 0.5054(3) 0.3625(4) 0.0301(5) Uani N 1.0 N31B 0.2919(2) 0.6038(3) 0.3551(4) 0.0312(6) Uani N 1.0 N41B 0.3234(2) 0.6290(4) 0.4690(4) 0.0377(6) Uani N 1.0 C11B 0.3499(3) 0.5879(5) 0.4383(5) 0.0372(7) Uani C 1.0 C21B 0.3281(3) 0.5707(4) 0.3592(5) 0.0325(6) Uani C 1.0 C31B 0.3434(3) 0.4834(5) 0.4296(5) 0.0325(6) Uani C 1.0 C41B 0.2894(3) 0.6380(4) 0.4198(5) 0.0351(6) Uani C 1.0 C51B 0.3095(3) 0.4667(4) 0.3017(5) 0.0299(5) Uani C 1.0 Appendix I: Crystallographic Information Files. Page 375

C61B 0.2611(3) 0.6025(4) 0.2911(5) 0.0304(7) Uani C 1.0 O12B 0.2729(2) 0.3651(3) 0.3626(3) 0.0313(6) Uani O 1.0 O22B 0.1877(2) 0.6049(3) 0.3511(4) 0.0339(7) Uani O 1.0 N12B 0.2679(2) 0.4557(3) 0.2947(4) 0.0269(5) Uani N 1.0 N22B 0.2129(2) 0.4086(3) 0.3153(4) 0.0282(6) Uani N 1.0 N32B 0.1792(2) 0.5052(3) 0.3135(4) 0.0289(5) Uani N 1.0 N42B 0.2342(2) 0.5536(3) 0.2935(4) 0.0272(5) Uani N 1.0 C12B 0.2372(3) 0.4948(4) 0.2571(5) 0.0267(5) Uani C 1.0 C22B 0.1988(3) 0.4610(4) 0.2725(5) 0.0282(5) Uani C 1.0 C32B 0.2536(3) 0.4060(4) 0.3283(5) 0.0278(6) Uani C 1.0 C42B 0.1993(3) 0.5588(4) 0.3229(5) 0.0290(5) Uani C 1.0 C52B 0.1890(3) 0.3605(4) 0.3423(5) 0.0324(6) Uani C 1.0 C62B 0.1398(3) 0.4971(5) 0.3343(5) 0.0341(6) Uani C 1.0 O13B 0.2201(2) 0.3143(3) 0.4900(3) 0.0323(6) Uani O 1.0 O23B 0.1366(2) 0.5593(3) 0.4755(4) 0.0377(7) Uani O 1.0 N13B 0.1762(2) 0.3758(3) 0.4148(4) 0.0301(6) Uani N 1.0 N23B 0.1706(2) 0.3653(3) 0.5375(4) 0.0300(5) Uani N 1.0 N33B 0.1416(2) 0.4652(4) 0.5343(4) 0.0319(5) Uani N 1.0 N43B 0.1390(2) 0.4702(4) 0.4081(4) 0.0326(6) Uani N 1.0 C13B 0.1391(3) 0.4060(4) 0.4222(5) 0.0332(5) Uani C 1.0 C23B 0.1378(3) 0.4025(4) 0.5100(5) 0.0327(6) Uani C 1.0 C33B 0.1921(3) 0.3489(4) 0.4816(5) 0.0298(6) Uani C 1.0 C43B 0.1392(3) 0.5035(5) 0.4732(5) 0.0333(6) Uani C 1.0 C53B 0.1828(3) 0.3511(4) 0.6166(5) 0.0301(6) Uani C 1.0 C63B 0.1361(2) 0.4872(3) 0.6087(3) 0.0350(6) Uani C 1.0 O14B 0.2650(2) 0.3552(3) 0.6418(3) 0.0294(6) Uani O 1.0 O24B 0.1823(2) 0.5938(3) 0.6375(4) 0.0387(5) Uani O 1.0 N14B 0.2059(2) 0.3971(3) 0.6572(4) 0.0270(5) Uani N 1.0 N24B 0.2600(2) 0.4379(3) 0.7187(4) 0.0281(5) Uani N 1.0 N34B 0.2263(2) 0.5352(3) 0.7153(4) 0.0323(4) Uani N 1.0 N44B 0.1720(2) 0.4927(3) 0.6600(4) 0.0312(5) Uani N 1.0 C14B 0.1913(3) 0.4446(4) 0.7031(5) 0.0290(5) Uani C 1.0 C24B 0.2289(3) 0.4743(4) 0.7453(5) 0.0297(5) Uani C 1.0 C34B 0.2463(3) 0.3934(4) 0.6694(5) 0.0269(5) Uani C 1.0 C44B 0.1925(3) 0.5449(4) 0.6677(5) 0.0332(4) Uani C 1.0 C54B 0.3012(3) 0.4465(4) 0.7421(5) 0.0323(6) Uani C 1.0 C64B 0.2532(3) 0.5835(4) 0.7377(5) 0.0382(4) Uani C 1.0 O15B 0.3456(2) 0.4204(3) 0.6206(4) 0.0357(7) Uani O 1.0 O25B 0.2589(2) 0.6605(3) 0.6096(4) 0.0430(5) Uani O 1.0 N15B 0.3189(2) 0.4902(4) 0.6958(4) 0.0334(5) Uani N 1.0 N25B 0.3568(2) 0.5237(4) 0.6130(4) 0.0381(6) Uani N 1.0 N35B 0.3205(3) 0.6177(4) 0.6039(4) 0.0401(4) Uani N 1.0 N45B 0.2861(3) 0.5875(4) 0.6945(4) 0.0374(4) Uani N 1.0 C15B 0.3215(3) 0.5539(5) 0.7117(5) 0.0383(5) Uani C 1.0 C25B 0.3467(3) 0.5787(5) 0.6513(5) 0.0415(5) Uani C 1.0 C35B 0.3404(3) 0.4721(5) 0.6404(5) 0.0345(6) Uani C 1.0 C45B 0.2849(3) 0.6253(4) 0.6324(5) 0.0393(4) Uani C 1.0 C55B 0.3788(3) 0.5204(5) 0.5489(5) 0.0411(8) Uani C 1.0 C65B 0.3309(3) 0.6559(5) 0.5439(5) 0.0443(6) Uani C 1.0 Cl1 0.00717(8) 0.65251(13) 0.08089(17) 0.0538(8) Uani Cl 1.0 Cl2 0.4845(1) 0.3431(3) 0.9088(3) 0.157(3) Uani Cl 1.0 OW1 0.2525(8) 0.4785(11) 0.5056(16) 0.112(6) Uani O 0.5 OW1' 0.2434(8) 0.5112(11) 0.5061(16) 0.112(6) Uani O 0.5 OW2 0.3056(2) 0.3395(3) 0.5121(4) 0.050(2) Uani O 1.0 Appendix I: Crystallographic Information Files. Page 376

OW3 0.1902(2) 0.6570(3) 0.4998(4) 0.058(2) Uani O 1.0 OW4 0.0380(2) 0.3843(3) 0.4748(3) 0.031(2) Uani O 1.0 OW5 0.2746(2) 0.1423(3) 0.4401(5) 0.057(2) Uani O 1.0 OW6 -0.0304(2) 0.5223(4) 0.0410(5) 0.074(3) Uani O 1.0 OW7 -0.0107(2) 0.7790(4) 0.1555(5) 0.069(3) Uani O 1.0 OW8 0.0626(2) 0.2867(3) 0.5633(5) 0.061(2) Uani O 1.0 OW9 0.0938(3) 0.2825(4) 0.3472(5) 0.069(3) Uani O 1.0 OW10 -0.0808(2) 0.6830(4) 0.0071(4) 0.059(2) Uani O 1.0 OW11 0.0078(3) 0.7213(3) -0.0786(5) 0.067(2) Uani O 1.0 OW12 0.0297(2) 0.8297(4) 0.2908(4) 0.065(2) Uani O 1.0 OW13 0.0338(2) 0.5380(4) 0.8171(6) 0.081(3) Uani O 1.0 OW14 0.2053(3) 0.1543(4) 0.3450(5) 0.081(3) Uani O 1.0 OW15 0.3640(4) 0.5346(6) 0.0986(7) 0.140(6) Uani O 1.0 OW16 0.1509(5) 0.2139(5) 0.4243(6) 0.139(5) Uani O 1.0 OW17 0.2951(4) 0.7942(5) 0.6121(6) 0.126(5) Uani O 1.0 OW18 0.2287(4) 0.6508(4) 0.0853(10) 0.156(7) Uani O 1.0 OW19 0.4598(3) 0.6160(5) 0.4968(11) 0.170(8) Uani O 1.0 OW20 0.5822(4) 0.0525(6) 0.1649(9) 0.164(7) Uani O 1.0 OW21 0.1405(5) 0.4798(8) 0.9088(11) 0.196(8) Uani O 1.0 OW22 0.4617(7) 0.1827(10) 0.6937(13) 0.103(5) Uani O 0.5 OW22' 0.4456(6) 0.1284(10) 0.5946(13) 0.103(5) Uani O 0.5 OW23 0.5241(5) 0.4582(9) 0.9741(12) 0.224(9) Uani O 1.0 OW24 0.5110(5) 0.2267(10) 0.8188(11) 0.222(9) Uani O 1.0 OW25 0.5988(7) 0.1680(11) 0.1923(15) 0.155(8) Uani O 0.5 OW25' 0.5486(8) 0.1391(11) 0.2308(17) 0.155(8) Uani O 0.5 OW26 0.4711(10) 0.0414(15) 0.6827(19) 0.165(8) Uani O 0.5 OW26' 0.4437(10) -0.0363(14) 0.7020(19) 0.165(8) Uani O 0.5 OW27 0.5523(9) 0.1910(13) 0.5390(18) 0.151(8) Uani O 0.5 OW27' 0.5761(10) 0.1893(15) 0.4848(20) 0.151(8) Uani O 0.5 OW28 0.5858(10) 0.2190(15) 0.8599(20) 0.179(9) Uani O 0.5 OW28' 0.5933(11) 0.2869(16) 0.9467(22) 0.179(9) Uani O 0.5 O1AA 0.0995(3) 0.1654(4) 0.1924(6) 0.083(3) Uani O 1.0 O2AA 0.0401(3) 0.1479(8) 0.2156(7) 0.144(6) Uani O 1.0 C1AA 0.0931(5) 0.1068(7) 0.3023(7) 0.080(4) Uani C 1.0 C2AA 0.0752(5) 0.1408(7) 0.2339(7) 0.068(4) Uani C 1.0 HC11A 0.1448 0.3845 0.0092 0.022 Uani H 1.0 HC21A 0.0920 0.4418 0.0316 0.021 Uani H 1.0 H1C51A 0.0840 0.5512 0.0560 0.021 Uani H 1.0 H2C51A 0.1227 0.5892 0.0924 0.021 Uani H 1.0 H1C61A 0.0523 0.3798 0.1885 0.022 Uani H 1.0 H2C61A 0.0408 0.4226 0.1137 0.022 Uani H 1.0 HC12A 0.0331 0.5311 0.1325 0.021 Uani H 1.0 HC22A 0.0108 0.5805 0.2310 0.022 Uani H 1.0 H1C52A 0.0282 0.6801 0.2822 0.023 Uani H 1.0 H2C52A 0.0732 0.7035 0.2827 0.023 Uani H 1.0 H1C62A 0.0161 0.4899 0.3982 0.023 Uani H 1.0 H2C62A -0.0074 0.5467 0.3543 0.023 Uani H 1.0 HC13A 0.0076 0.6498 0.4040 0.024 Uani H 1.0 HC23A 0.0258 0.6831 0.5241 0.026 Uani H 1.0 H1C53A 0.0712 0.7649 0.5680 0.027 Uani H 1.0 H2C53A 0.1111 0.7727 0.5282 0.027 Uani H 1.0 H1C63A 0.0542 0.5600 0.6469 0.025 Uani H 1.0 H2C63A 0.0337 0.6268 0.6427 0.026 Uani H 1.0 HC14A 0.0734 0.7164 0.6871 0.028 Uani H 1.0 Appendix I: Crystallographic Information Files. Page 377

HC24A 0.1208 0.7291 0.7897 0.030 Uani H 1.0 H1C54A 0.1795 0.7857 0.8007 0.032 Uani H 1.0 H2C54A 0.2062 0.7870 0.7310 0.031 Uani H 1.0 H1C64A 0.1474 0.5852 0.8720 0.027 Uani H 1.0 H2C64A 0.1427 0.6567 0.8924 0.030 Uani H 1.0 HC15A 0.2034 0.7070 0.9251 0.032 Uani H 1.0 HC25A 0.2617 0.6988 0.9704 0.033 Uani H 1.0 H1C55A 0.3266 0.7270 0.9425 0.034 Uani H 1.0 H2C55A 0.3313 0.7421 0.8538 0.033 Uani H 1.0 H1C65A 0.2737 0.5388 0.9892 0.029 Uani H 1.0 H2C65A 0.2924 0.6021 1.0254 0.031 Uani H 1.0 HC16A 0.3591 0.6291 0.9967 0.033 Uani H 1.0 HC26A 0.4098 0.5745 0.9648 0.032 Uani H 1.0 H1C56A 0.4548 0.5930 0.8709 0.033 Uani H 1.0 H2C56A 0.4383 0.6295 0.7929 0.032 Uani H 1.0 H1C66A 0.3768 0.4231 0.9208 0.027 Uani H 1.0 H2C66A 0.4167 0.4607 0.9508 0.029 Uani H 1.0 HC17A 0.4627 0.4820 0.8637 0.030 Uani H 1.0 HC27A 0.4828 0.4226 0.7715 0.030 Uani H 1.0 H1C57A 0.5049 0.4511 0.6525 0.031 Uani H 1.0 H2C57A 0.4834 0.5071 0.6032 0.030 Uani H 1.0 H1C67A 0.4155 0.3048 0.7232 0.025 Uani H 1.0 H2C67A 0.4618 0.3226 0.7289 0.027 Uani H 1.0 HC18A 0.4887 0.3484 0.6127 0.029 Uani H 1.0 HC28A 0.4743 0.3092 0.4910 0.028 Uani H 1.0 H1C58A 0.4684 0.3548 0.3658 0.029 Uani H 1.0 H2C58A 0.4529 0.4246 0.3567 0.028 Uani H 1.0 H1C68A 0.3855 0.2235 0.4817 0.024 Uani H 1.0 H2C68A 0.4258 0.2279 0.4428 0.026 Uani H 1.0 HC19A 0.4232 0.2731 0.3184 0.027 Uani H 1.0 HC29A 0.3749 0.2666 0.2178 0.026 Uani H 1.0 H1C59A 0.3568 0.3396 0.1181 0.026 Uani H 1.0 H2C59A 0.3559 0.4116 0.1390 0.025 Uani H 1.0 H1C69A 0.2875 0.2187 0.2799 0.023 Uani H 1.0 H2C69A 0.3137 0.2159 0.2094 0.025 Uani H 1.0 HC110A 0.2960 0.2830 0.0994 0.024 Uani H 1.0 HC210A 0.2368 0.3154 0.0375 0.023 Uani H 1.0 H1C510A 0.2119 0.4137 -0.0083 0.023 Uani H 1.0 H2C510A 0.2297 0.4751 0.0345 0.022 Uani H 1.0 H1C610A 0.1640 0.2697 0.1509 0.023 Uani H 1.0 H2C610A 0.1703 0.2849 0.0630 0.023 Uani H 1.0 HC11B 0.3755 0.6079 0.4336 0.044 Uani H 1.0 HC21B 0.3434 0.5834 0.3177 0.036 Uani H 1.0 H1C51B 0.3231 0.4268 0.3091 0.034 Uani H 1.0 H2C51B 0.3153 0.4854 0.2529 0.032 Uani H 1.0 H1C61B 0.2734 0.5989 0.2432 0.031 Uani H 1.0 H2C61B 0.2461 0.6413 0.2904 0.034 Uani H 1.0 HC12B 0.2388 0.4989 0.2014 0.029 Uani H 1.0 HC22B 0.1824 0.4494 0.2237 0.032 Uani H 1.0 H1C52B 0.2048 0.3224 0.3485 0.036 Uani H 1.0 H2C52B 0.1654 0.3538 0.3038 0.037 Uani H 1.0 H1C62B 0.1247 0.4705 0.2953 0.038 Uani H 1.0 H2C62B 0.1269 0.5377 0.3340 0.038 Uani H 1.0 HC13B 0.1163 0.3851 0.3923 0.039 Uani H 1.0 Appendix I: Crystallographic Information Files. Page 378

HC23B 0.1126 0.3843 0.5217 0.038 Uani H 1.0 H1C53B 0.1986 0.3129 0.6192 0.032 Uani H 1.0 H2C53B 0.1589 0.3445 0.6419 0.033 Uani H 1.0 H1C63B 0.1184 0.4584 0.6315 0.038 Uani H 1.0 H2C63B 0.1234 0.5279 0.6028 0.040 Uani H 1.0 HC14B 0.1746 0.4275 0.7399 0.032 Uani H 1.0 HC24B 0.2297 0.4731 0.8020 0.032 Uani H 1.0 H1C54B 0.3147 0.4067 0.7387 0.034 Uani H 1.0 H2C54B 0.3050 0.4608 0.7962 0.036 Uani H 1.0 H1C64B 0.2638 0.5776 0.7926 0.041 Uani H 1.0 H2C64B 0.2385 0.6226 0.7315 0.044 Uani H 1.0 HC15B 0.3343 0.5619 0.7648 0.044 Uani H 1.0 HC25B 0.3705 0.6008 0.6756 0.049 Uani H 1.0 H1C55B 0.3910 0.4793 0.5485 0.044 Uani H 1.0 H2C55B 0.3999 0.5518 0.5558 0.048 Uani H 1.0 H1C65B 0.3595 0.6654 0.5548 0.051 Uani H 1.0 H2C65B 0.3154 0.6943 0.5437 0.049 Uani H 1.0 Appendix II: Intermolecular Energy Parameters used in Computational Studies. Page 379

APPENDIX II

INTERMOLECULAR ENERGY PARAMETERS USED IN COMPUTATIONAL STUDIES.

The values listed in the following tables are either a modification of the standard CVFF or are taken directly from the CVFF. Although all bond angles are listed in degrees radians are used in the energy calculations hence the force constants for angles have the units kcal mol–1 rads –2.

Table II.1: Definitions of potential types, as they appear in the CVFF. Atom Type Definition h Hydrogen bonded to C. hn Hydrogen bonded to N hc Hydrogen bonded to carbon c sp3 aliphatic carbon c’ sp2 carbon in carbonyl (C=O) group cp sp2 aromatic carbon (partial double bonds) bonded to fluorine cx sp2 aromatic carbon (partial double bonds) c2 sp3 carbon bonded to 2 H's, 2 heavy atoms npc sp2 nitrogen in 5- or 6- membered ring bonded to a heavy atom n4 sp3 nitrogen with four substituents o’ Oxygen in carbonyl (C=O) group o sp3 oxygen in ether or ester groups o– Oxygen in charged carboxylate group Pt Platinum Cr Chromium Sn Tin B Boron p General phosphorus atom sf Sulfur in sulfate cl Chlorine bonded to a carbon Appendix II: Intermolecular Energy Parameters used in Computational Studies. Page 380

f Fluorine bonded to a carbon

Table II.2: Intermolecular energy parameters for Qn. Atom Potential Type Partial charge ra ea oxygen o’ –0.25 1.8 0.08 carbon c 0.05 2.03 0.05 carbon in c’ 0.1 2.03 0.15 carbonyl group nitrogen npc –0.2 2.08 0.06 hydrogen h 0.15 1.68 0.02

–1 –2 O-Ccarbonyl bond length = 1.23 Å; k = 615.322 kcal mol Å . –1 –2 N-Ccarbonyl bond length = 1.32 Å; k = 388.0 kcal mol Å . N-C bond length = 1.475 Å; k = 336.8 kcal mol–1 Å–2. C-C bond length = 1.526 Å; k = 322.7158 kcal mol–1 Å–2. H-C bond length = 1.105 Å; k = 340.6175 kcal mol–1 Å–2. –1 –2 O- Ccarbonyl -N bond angle = 120.0º; k = 68 kcal mol rads . –1 –2 Ccarbonyl -N-C bond angle = 118.0 º; k = 111.0 kcal mol rads . N-C-N bond angle = 113.0º; k = 125 kcal mol–1 rads –2. N-C-C bond angle = 109.5º; k = 80.0 kcal mol–1 rads –2. N-C-H bond angle = 109.5º; k = 80.0 kcal mol–1 rads –2. H-C-H bond angle = 106.4º; k = 39.5 kcal mol–1 rads –2. C-C-H bond angle = 110.0º; k = 44.4 kcal mol–1 rads –2.

2– Table II.3: Intermolecular energy parameters for PtCl6 . Atom Type Potential Type Partial charge ra ea Platinum Pt 0.46 2.2 0.24 Chlorine cl –0.41 2.0 0.26

Pt-Cl bond length = 2.28 Å; k = 600 kcal mol–1 Å–2. Cl-Pt-Cl angle = 90º, 180º; k = 150 kcal mol–1 rads –2. Appendix II: Intermolecular Energy Parameters used in Computational Studies. Page 381

– Table II.4: Intermolecular energy parameters for ClO4 . Atom Type Potential Type Partial charge ra ea Chlorine cl –0.2 2.0 0.26 Oxygen o– –0.2 1.83 0.15

Cl-O bond length = 1.41 Å; k = 1000 kcal mol–1 Å–2. O-Cl-O angle = 109.5º; k = 100 kcal mol–1 rads –2.

2– Table II.5: Intermolecular energy parameters for SO4 . Atom Type Potential Type Partial charge ra ea Sulfur sf –0.2 2.13 0.30 Oxygen o– –0.45 1.83 0.15

S-O bond length = 1.47 Å; k = 1000 kcal mol–1 Å–2. O-S-O angle = 109.5º; k = 100 kcal mol–1 rads –2.

2– Table II.6: Intermolecular energy parameters for CrO4 . Atom Type Potential Type Partial charge ra ea Chromium Cr 0.3 1.95 0.20 Oxygen o– –0.575 1.83 0.15

Cr-O bond length = 1.64 Å; k = 1000 kcal mol–1 Å–2. O-Cr-O angle = 109.5º; k = 100 kcal mol–1 rads –2.

3– Table II.7: Intermolecular energy parameters for PO4 . Atom Type Potential Type Partial charge ra ea Phosphorus p –0.28 2.1 0.20 Oxygen o– –0.68 1.83 0.15

P-O bond length = 1.53 Å; k = 1000 kcal mol–1 Å–2. O-P-O angle = 109.5º; k = 100 kcal mol–1 rads –2. Appendix II: Intermolecular Energy Parameters used in Computational Studies. Page 382

2– Table II.8: Intermolecular energy parameters for Cr2O7 . Atom Type Potential Type Partial charge ra ea Chromium Cr 0.3 1.95 0.20 Oxygen o –0.2 1.8 0.08

Oxygenterminal o– –0.4 1.83 0.15

Cr-O bond length = 1.77 Å; k = 1000 kcal mol–1 Å–2. –1 –2 Cr-Oterminal bond length = 1.60 Å; k = 1000 kcal mol Å . –1 –2 O-Cr-Oterminal angle = 109.0º; k = 80 kcal mol rads . –1 –2 Oterminal-Cr-Oterminal angle = 110.3º; k = 100 kcal mol rads . Cr-O-Cr angle = 129.6º; k = 150 kcal mol–1 rads –2.

2– Table II.9: Intermolecular energy parameters for Cr3O10 . Atom Type Potential Type Partial charge ra ea Chromium Cr 0.4 1.95 0.20 Oxygen o –0.2 1.8 0.08

Oxygenterminal o– –0.35 1.83 0.15

Cr-O bond length = 1.76 Å; k = 1000 kcal mol–1 Å–2. –1 –2 Cr-Oterminal bond length = 1.62 Å; k = 1000 kcal mol Å . –1 –2 O-Cr-Oterminal angle = 109º; k = 80 kcal mol rads . –1 –2 Oterminal-Cr-Oterminal angle = 110.7º; k = 100 kcal mol rads . Cr-O-Cr angle = 125.7º (bent conformer),135º (straight conformer); k = 100 kcal mol–1 rads –2. O-Cr-O angle = 109.0º; k = 100 kcal mol–1 rads –2.

Table II.10: Intermolecular energy parameters for benzene. Atom Type Potential Type Partial charge ra ea Carbon cx –0.1 1.98 0.09 Hydrogen h 0.1 1.68 0.02 Appendix II: Intermolecular Energy Parameters used in Computational Studies. Page 383

C-C bond length = 1.34 Å; k = 480 kcal mol–1 Å–2. C-H bond length = 1.08 Å; k = 363.4164 kcal mol–1 Å–2. C-C-C bond angle = 120º; k = 90 kcal mol–1 rads –2. C-C-H bond angle = 120º; k = 37 kcal mol–1 rads –2.

Table II.11: Intermolecular energy parameters for SnCl4. Atom Type Potential Type Partial charge ra ea Tin Sn 0.6 2.17 0.24 Chlorine cl –0.15 2.0 0.26

Sn-Cl bond length = 2.28 Å; k = 600 kcal mol–1 Å–2. Cl-Sn-Cl bond angle = 109.5º; k = 80 kcal mol–1 rads –2.

+ Table II.12: Intermolecular energy parameters for NH4 . Atom Type Potential Type Partial charge ra ea Nitrogen n4 –0.2 2.08 0.06 Hydrogen hn 0.3 0.0 0.0

N-H bond length = 1.01 Å; k = 1000 kcal mol–1 Å–2. H-N-H bond angle = 109.5º; k = 80 kcal mol–1 rads –2.

+ + Table II.13: Intermolecular energy parameters for NH3(CH2)6NH3 . Atom Type Potential Type Partial charge ra ea Nitrogen n4 –0.69 2.08 0.06

Carbon c2 C1 = –0.22 2.03 0.05

C2 = –0.27

C3 = –0.3 Hydrogen hn 0.32 0.0 0.0 bonded to N Hydrogen hc H1 = –0.22 1.68 0.02 bonded to C H2 = –0.27

H3 = –0.3 Appendix II: Intermolecular Energy Parameters used in Computational Studies. Page 384

NC1 C2 C3 C3 C2 C1 N

H1 H2 H3 H3 H2 H1

N-H bond length = 1.01 Å; k = 1000 kcal mol–1 Å–2. C-H bond length = 1.1 Å; k = 700 kcal mol–1 Å–2. N-C bond length = 1.47 Å; k = 1000 kcal mol–1 Å–2. C-C bond length = 1.54 Å; k = 750 kcal mol–1 Å–2. –1 –2 HN-N-HN bond angle = 109.5º; k = 80 kcal mol rads . –1 –2 HN-N-C bond angle = 109.5º; k = 35 kcal mol rads . –1 –2 HC-C-N bond angle = 109.5º; k = 50 kcal mol rads . –1 –2 HC-C-HC bond angle = 109.5º; k = 80 kcal mol rads . –1 –2 C-C-HC bond angle = 109.5º; k = 44.4 kcal mol rads . C-C-N bond angle = 109.5º; k = 25 kcal mol–1 rads –2. C-C-C bond angle = 109.5º; k = 35 kcal mol–1 rads–2.

— Table II.14: Intermolecular energy parameters for [B(C6F5)] . Atom Type Potential Type Partial charge ra ea Boron B +0.16 1.98 0.06 Carbon cp 0.1 1.8 0.06

Cipso cp –0.04 1.8 0.06 Fluorine f –0.15 1.6 0.1

— As the parameters for [B(C6F5)] were only used in energy calculations and not energy minimisations the bond lengths and angles do not appear in the CVFF.