Fundamental Chlorophosphazene Chemistry

FUNDAMENTAL CHLOROPHOSPHAZENE CHEMISTRY

A Dissertation

Presented to

The Graduate Faculty of The University of Akron

In Partial Fulfillment

of the Requirements for the Degree

Doctor of Philosophy

Zin-Min Tun

December, 2011

FUNDAMENTAL CHLOROPHOSPHAZENE CHEMISTRY

Zin-Min Tun

Dissertation

Approved: Accepted:

Advisor Department Chair Dr. Claire A. Tessier Dr. Kim C. Calvo

Co-Advisor Dean of the College Dr. Wiley J. Youngs Dr. Chand Midha

Committee Member Dean of the Graduate School Dr. Peter L. Rinaldi Dr. George R. Newkome

Committee Member Date Dr. Chrys Wesdemiotis

Committee Member Dr. Edward Evans

ABSTRACT

Even though chlorophosphazene chemistry has been around since the

1800s, it was not until the 1950s when Allcock successfully synthesized the soluble chlorophosphazene polymer that the door to functionalized polyphosphazenes was opened. At present, polyphosphazenes constitute the largest group of inorganic backbone polymers, with their potential applications ranging from elastomers to biomaterials. Most functionalized polyphosphazenes are derived from polychlorophosphazenes. The problems surrounding the synthesis and storage of polychlorophosphazenes hinder the commercial development of functionalized polyphosphazenes. In the quest for a cost- effective synthetic route and for storage solutions, our group focuses on the fundamental chlorophosphazene chemistry.

This dissertation discusses our endeavors to understand fundamental

chlorophosphazene chemistry, the majority of the work being on the chemistry of

[PCl2N]3. The dissertation is divided into six chapters; Introduction, Mechanistic

Studies of the Fluxional Behavior of Group 13 Lewis Acid Adducts of [PCl2N]3,

Group 13 Super Acid Adducts of [PCl2N]3, Crown ether complexes of HPCl6,

Reactions of Group 15 Superacids with Chlorophosphazenes and Conclusion.

Chapter I, the introduction, provides the overview of the previous studies of the

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acid-base chemistry of chlorophosphazenes. Chapter II describes a mechanistic study of the fluxional behavior of the Group 13 Lewis acid adducts of [PCl2N]3 and evaluates the likelihood that these adducts are directly involved as intermediates in the ROP process. The synthesis and characterization of Group

13 superacid adducts of [PCl2N]3 are discussed in Chapter III. The fragile acid

HPCl6, which can potentially play an important role in chlorophosphazene chemistry, was isolated as complexes of crown ethers. Chapter IV describes the synthesis and characterization of these complexes. The reactivity of Group 15 acids, HPCl6 and HSbCl6 towards cyclic [PCl2N]n (n = 3, 4, 5, and 6) and polymeric [PCl2N]n follows in Chapter V. This chapter also qualitatively compares the acid strengths of the relatively unknown HPCl6 and HSbCl6 acids to the strengths of more commonly known superacids, such as HAlCl4, HAlBr4, HGaCl4 and superacids with carborane anions.

DEDICATION

To my wonderful husband

And to all the kind souls who have contributed big or small along the way

ACKNOWLEDGEMENTS

First and foremost, I would like to thank my research advisor, Dr. Claire A.

Tessier. I can not thank you enough for all that you have done for me and for your guidance both inside and outside of the research lab. You are an advisor, a mentor, a friend, and an inspiration, and I am very fortunate to have you as my chemistry mom. I have grown a lot under your mentorship not just as a chemist but also as a person. I do not think I will ever meet another boss who is more supportive of their employees. I will miss our passionate discussions about anything and everything under the sun. I would also like to thank my co-advisor,

Dr. Wiley J. Youngs for his many brilliant ideas and suggestions for my research.

I really appreciate the fun and relaxed, yet challenging learning atmosphere that you and Dr. Tessier have created in our group. Thank you very much for letting me and Brian be a part of the fun ‘bible study’ sessions. This is not a goodbye yet though because I will make sure that you two are a part of my life after grad school.

A lot of collaborators have contributed greatly to the success of my research project. Dr. Matthew J. Panzner has my deepest gratitude. If it were not for your patience, perseverance and your keen crystallographic skills, I would not have been able to characterize half of my air-sensitive products

crystallographically. With your thirst for knowledge and your willingness to help others, you are one of the best people to work with. I also would like to thank Dr.

Doug Medvetz and Brian Wright for their help with x-ray crystallography. I would like to thank Dr. Peter L. Rinaldi for patiently teaching me about dynamic NMR. I would also like to thank Dr. Venkat Dudipala and Linlin Li for all their gracious help with the NMR over the years. I would like to thank Dr. Chrys Wesdemiotis and Vincenco Scionti for their help with the Mass Spec. Thank you very much, V for willing to go the extra mile and even learn to prepare the air-sensitive samples in the glove-box yourself. I also would like to thank Dr. Amy J. Heston who started this research project in our group. I would like to thank Dr. Chris Allen

(The University of Vermont), Dr. Supat Moolsin, Dr. Sujeewani Ekanayake and

David J. Bowers for providing me with some of my starting materials.

I also would like to thank many chemistry professors that I have met through my graduate and undergraduate years who have been exceptionally inspiring and who cares deeply for the students; thank you very much, Dr. Kim

Calvo, Dr. Henry Stevens, Dr. Virginia Pat and Dr. Mark Snider. I also would like to thank the professors on my defense committee who had been kind enough to thoroughly read my dissertation and gave me many useful suggestions and insight.

I would like to thank the Tessier-Youngs group members, past and present for all their support and friendship over the years; thank you Dr. Matthew

J. Panzner, Dr. Doug Medvetz, Dr. Khadijah Hindi, Dr. Tammy Siciliano, Dr.

Amanda Knapp, Dr. Joanna Beres, Nikki Robishaw, Brian Wright, Mike Deblock,

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Pat Wagers, David J. Bowers and Nick Johnson. Thank you, Nick for always

being a patient and understanding friend-in-need. I will miss all the fun trips to

the Lockview, as well as the ones to the ACS meetings. I also would like to

thank Natalie for her friendship that made the Chem seminars almost as fun as

the many trips to the lizard.

I would like to thank my parents and my two sisters for all their love and

support. Even though you have not been by my side physically this past decade because we inhabit four different continents, I have always been able to draw strength from the fact that, where ever we are, we are all resiliently following our

own dreams in our own ways. I am grateful to have met my host-parents, Jim

and Janelle Collier. I can not thank you enough for all that you have done for me

and for all that you have been to me.

Last but not least, I would like to thank my wonderful husband, Brian

Darby. Thank you, baby for all your love, support and patience that saw me

through this long process. Thank you especially for loving the very frustrated,

and most probably very frustrating at times :-), me while I was writing this

dissertation. I am very grateful to have you as my life partner and I can just hope

that I am to you what you are to me.

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TABLE OF CONTENTS

Page

LIST OF TABLES ...... xv

LIST OF FIGURES ...... xvi

LIST OF CHARTS ...... xxii

LIST OF SCHEMES ...... xxiii

LIST OF EQUATIONS ...... xxiv

CHAPTER

I. INTRODUCTION ...... 1

1.1. Functionalized polyphosphazenes ...... 1

1.2. [PCl2N]n ...... 3

1.2.1. Synthesis of [PCl2N]n ...... 3

1.2.2. Mechanism of the ROP of [PCl2N]3 ...... 5

1.2.3. Synthesis of [PCl2N]n ...... 3

1.3. Acid-Base Chemistry of [PCl2N]3 ...... 14

1.3.1. Previously Reported Interactions of Lewis Acids with [PCl2N]3...... 14

1.3.2. Previously Reported Interactions of Brønsted-Lowry Acids with [PCl2N]3 and [PR2N]3-5...... 17

1.4. Superacids...... 19

1.5. Lewis acid/Brønsted acid dichotomy and the protonic impurities affecting the chlorophosphazene chemistry...... 22

1.6. Topics in this dissertation...... 23

1.7. References...... 25

II. MECHANISTIC STUDIES OF THE FLUXIONAL BEHAVIOR OF GROUP 13 LEWIS ACID ADDUCTS OF [PCl2N]3 ...... 29

2.1. Introduction ...... 29

2.2. Experimental ...... 31

2.2.1. General Experimental Methods ...... 31

2.2.2. Materials ...... 32

2.2.3. NMR Spectroscopy ...... 32

2.2.4. X-ray Crystallography ...... 33

2.2.5. Mass Spectrometry ...... 34

. 2.2.6. Preparations of [PCl2N]3 MX3 ...... 34

2.3. Results and Discussion ...... 35

2.3.1. X-ray Crystal Structures ...... 38

2.3.2. NMR Studies ...... 45

2.4. Conclusions ...... 59

2.5. References ...... 60

III. GROUP 13 SUPER ACID ADDUCTS OF [PCl2N]3 ...... 63

3.1. Introduction ...... 63

3.2. Experimental ...... 65

3.2.1. General Experimental Methods ...... 65

3.2.2. Materials ...... 66

3.2.3. NMR Spectroscopy ...... 67

3.2.4. X-ray Crystallography ...... 68

3.2.5. Mass Spectrometry ...... 68

3.2.6. Syntheses ...... 69

. 3.2.6.1. Synthesis of [PCl2N]3 [HAlCl4] ...... 70

. 3.2.6.2. Synthesis of [PCl2N]3 [HAlBr4] ...... 71

. 3.2.6.3. Synthesis of [PCl2N]3 [HGaCl4] ...... 73

. 3.2.6.4. Attempted Synthesis of [PCl2N]3 [HBCl4]...... 74

. 3.2.6.5. Attempted ROP of [PCl2N]3 catalyzed by [PCl2N]3 [HAlCl4] ...... 74

3.3. Results and Discussion ...... 75

3.3.1. X-ray Crystal Structures ...... 76

3.3.2. NMR Studies ...... 80

3.3.3. Mass Spectrometry ...... 89

3.4. Conclusions ...... 93

3.5. References ...... 95

IV. CROWN ETHER COMPLEXES OF HPCl6 ...... 97

4.1. Introduction ...... 97

4.2. Experimental ...... 99

4.2.1. General Experimental Methods ...... 99

4.2.2. Materials ...... 100

4.2.3. NMR Spectroscopy ...... 101

4.2.4. X-ray Crystallography ...... 101

4.2.5. Mass Spectrometry ...... 102

4.2.6. Syntheses ...... 103

4.2.6.1. Synthesis of [H(12-crown-4)][PCl6] ...... 103

4.2.6.2. Synthesis of [H(18-crown-6)2][PCl6] ...... 103

4.3. Results and Discussion ...... 104

4.4. Conclusion ...... 113

4.5. References ...... 114

V. REACTIONS OF GROUP 15 SUPERACIDS WITH CHLOROPHOSPHAZENES...... 116

5.1. Introduction ...... 116

5.2. Experimental ...... 120

5.2.1. General Experimental Methods ...... 120

5.2.2. Materials ...... 121

5.2.3. NMR Spectroscopy ...... 122

5.2.4. X-ray Crystallography ...... 122

5.2.5. Mass Spectrometry ...... 123

5.2.6. Syntheses ...... 124

. 5.2.6.1. Synthesis of [PCl2N]3 [HSbCl6] ...... 124

. 5.2.6.2. Synthesis of [PCl2N]4 [HSbCl6] ...... 126

. 5.2.6.3. Synthesis of a mixture of [PCl2N]5 [HSbCl6] and . [PCl2N]6 [HSbCl6]...... 127

5.2.6.4. The reaction of polymeric [PCl2N]n with HSbCl6 ...... 128

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5.2.6.5. The reaction of a mixture of cyclic [PCl2N]m with HPCl6, where m = 3, 4, 5, or 6 ...... 129

5.2.6.6. The reaction of polymeric [PCl2N]n with HPCl6 ...... 129

5.2.6.7. Synthesis of tri-n-octylammonium tetrachloroaluminate...... 130

5.2.6.8. Synthesis of tri-n-octylammonium tetrachlorogallate...... 130

5.2.6.9. Synthesis of tri-n-octylammonium tetrabromoaluminate...... 131

5.2.6.10. Synthesis of tri-n-octylammonium hexachloroantimonate...... 131

5.2.6.11. Synthesis of tri-n-octylammonium phosphorushexachloride...... 132

5.3. Results and Discussion ...... 132

. 5.3.1. [PCl2N]3 HSbCl6 ...... 132

. 5.3.2. [PCl2N]4 HSbCl6 ...... 140

. . 5.3.3. [PCl2N]5 HSbCl6 and [PCl2N]6 HSbCl6 ...... 144

5.3.4. Reaction of HSbCl6 with [PCl2N]n ...... 150

5.3.5. Reactions of PCl5 and HCl with cyclic [PCl2N]m (m = 3, 4, 5, 6) and polymeric [PCl2N]n ...... 152

5.3.6. Qualitative comparison of the acidities of superacids of interest ...... 153

5.4. Conclusion ...... 156

5.5. References ...... 157

IV. CONCLUSION ...... 160

APPENDICES ...... 163

APPENDEX A ...... 164

APPENDIX B ...... 169

APPENDIX C ...... 174

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APPENDIX D ...... 181

APPENDIX E ...... 186

APPENDIX F ...... 204

APPENDIX G ...... 209

APPENDIX H ...... 214

APPENDIX I ...... 221

APPENDIX J ...... 228

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LIST OF TABLES

Table Page

1.1. Conjugate bases of certain acids and corresponding ν(NH) in CCl4 ...... 21

. 2.1. Selected distances (Ǻ) and angles in [PCl2N]3, [PCl2N]3 AlBr3, . . [PCl2N]3 AlCl3 and [PCl2N]3 GaCl3...... 44

. 2.2. Rate constants of the exchange of [PCl2N]3 AlBr3 in CDCl3 derived from simulation of 31P NMR spectra at various temperatures ...... 53

. 2.3. Rate constants of the exchange of [PCl2N]3 AlCl3 in CDCl3 derived from simulation of 31P NMR spectra at various temperatures ...... 53

. 2.4. Rate constants of the exchange of [PCl2N]3 GaCl3 in CDCl3 derived from simulation of 31P NMR spectra at various temperatures ...... 53

. 2.5. Calculated activation parameters of the [PCl2N]3 MX3 exchange systems in CDCl3 ...... 57

. 3.1. Selected distances (Å) and angles(°) in [PCl2N]3, [PCl2N]3 HAlCl4, . . [PCl2N]3 HGaCl4 and [PCl2N]3 HAlBr4...... 80

. 5.1. Selected distances (Ǻ) and angles in [PCl2N]3 and [PCl2N]3 HSbCl6 ..... 137

. 5.2. Selected distances (Ǻ) and angles in [PCl2N]4 and [PCl2N]4 HSbCl6 ..... 142

. 5.3. Selected distances (Ǻ) and angles in [PCl2N]5 and [PCl2N]5 HSbCl6 ..... 147

LIST OF FIGURES

Figure Page

1.1. The Backbone of the phosphazene polymer. R and R’ can be organic, organometallic, or inorganic groups ...... 1

1.2. Allcock’s mechanism of the ROP of [PCl2N]3 to give [PCl2N]n ...... 7

1.3. Examples of the Lewis acid catalyzed ROP of [PCl2N]3 at lower ROP temperatures ...... 8

1.4. Emsley’s mechanism of the ROP of [PCl2N]3 to give [PCl2N]n ...... 10

1.5. Species Proposed as Intermediates in the ROP of [PCl2N]3, both catalyzed and non-catalyzed ...... 12

1.6. (a) phosphazenium cation, (b) phosphonium cation ...... 13

6+ 1.7. The hexacation [P3N3(DMAP)6] ...... 13

1.8. Crystallographically characterized adducts of [PCl2N]3 with structure 3 (Figure 1.5) [R = methyl, ethyl; Rf = C(CF3)3]...... 16

1.9. Crystallographically characterized protonated adducts of [PCl2N]3 with structure 4 (Figure 1.5)...... 18

1.10. Examples of [H(PR2N)3][X] ...... 19

1.11. Tri-n-octylammonium salt contact ion pair used in Reed’s qualitative acidity scale...... 21

. 2.1. (a) Thermal ellipsoid plot for the crystal structure of [PCl2N]3 AlBr3, (b) . Chair-like structure of [PCl2N]3 AlBr3...... 41

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. 2.2. (a) Thermal ellipsoid plot for the crystal structure of [PCl2N]3 AlCl3, (b) . Chair-like structure of [PCl2N]3 AlCl3...... 42

. 2.3. (a) Thermal ellipsoid plot for the crystal structure of [PCl2N]3 GaCl3, (b) . Chair-like structure of [PCl2N]3 GaCl3...... 43

31 15 15 . 2.4. P NMR spectra at 25 ºC in C6D6 (a) [PCl2 N]3, (b) [PCl2 N]3 GaCl3, 15 . 15 . (c) [PCl2 N]3 AlCl3, (d) [PCl2 N]3 AlBr3 ...... 45

31 . 2.5. P VT NMR spectra of [PCl2N]3 AlBr3 in CDCl3 taken between . -40 and 25 °C. The singlet is [PCl2N]3 HAlBr4 (Chapter III)...... 47

31 . 2.6. P VT NMR spectra of [PCl2N]3 AlCl3 in CDCl3 taken between . -40 and 25 °C. The singlet is [PCl2N]3 HAlCl4 (Chapter III)...... 48

31 . 2.7. P VT NMR spectra of [PCl2N]3 GaCl3 in CDCl3 taken between . -55 and 35 °C. The singlet is [PCl2N]3 HGaCl4 (Chapter III)...... 48

. 2.8. Possible scenarios for the fluxionality of [PCl2N]3 MX3 ...... 49

31 . 2.9. Simulation of P NMR spectrum of [PCl2N]3 AlBr3 at -40 °C in CDCl3 by WinDNMR Software. For clarity, the simulated spectrum is offset by about 2 ppm. The simulated spectrum was obtained with a rate constant of 6...... 51

31 . 2.10. Simulation of P NMR spectrum of [PCl2N]3 AlCl3 at -40 °C in CDCl3 by WinDNMR Software. For clarity, the simulated spectrum is offset by about 2 ppm. The simulated spectrum was obtained with a rate constant of 15...... 51

31 . 2.11. Simulation of P NMR spectrum of [PCl2N]3 GaCl3 at -40 °C in CDCl3 by WinDNMR Software. For clarity, the simulated spectrum is offset by about 2 ppm. The simulated spectrum was obtained with a rate constant of 50...... 52

. 2.12. (a) Plot of ln[k] vs. 1/T of [PCl2N]3 AlBr3 and (b) plot of . ln(k/T) vs. 1/T of [PCl2N]3 AlBr3. The data are in Table 2.2...... 54

. 2.13. (a) Plot of ln[k] vs. 1/T of [PCl2N]3 AlCl3 and (b) plot of . ln(k/T) vs. 1/T of [PCl2N]3 AlCl3. The data are in Table 2.3...... 55

. 2.14. (a) Plot of ln[k] vs. 1/T of [PCl2N]3 GaCl3 and (b) plot of . ln(k/T) vs. 1/T of [PCl2N]3 GaCl3. The data are in Table 2.4...... 56

xvii

2.15. Proposed intermediate for the bound MX3 scenario in the . fluxionality of [PCl2N]3 MX3...... 58

. 3.1. Ball and stick structure of [PCl2N]3 HAlBr4 ...... 78

. 3.2. Thermal ellipsoid plot for the crystal structure of [PCl2N]3 HAlCl4. N atoms are drawn in blue, C atoms in orange and Cl atoms in green. ... 79

. 3.3. Thermal ellipsoid plot for the crystal structure of [PCl2N]3 HGaCl4. N atoms are drawn in blue, C atoms in orange and Cl atoms in green...... 79

31 . 3.4. P VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40°C...... 82

31 . 3.5. P VT NMR spectra of [PCl2N]3 HGaCl4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C...... 82

31 . 3.6. P VT NMR spectra of [PCl2N]3 HAlBr4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C...... 83

1 . 3.7. H VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C...... 83

1 . 3.8. H VT NMR spectra of [PCl2N]3 HGaCl4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C...... 84

1 . 3.9. H VT NMR spectra of [PCl2N]3 HAlBr4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C...... 84

27 . 3.10. Al VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C. The spectra were offset by ~ 4 ppm for clarity...... 85

27 . 3.11. Al VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken at 30 °C to investigate the effect of excess AlCl3 concentration in the sample. . (a) sample of [PCl2N]3 HAlCl4 with no excess AlCl3, (b) the same . sample of [PCl2N]3 HAlCl4 with excess AlCl3...... 87

1 . 3.12. H VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken at 30 °C to investigate the effect of excess AlCl3 concentration in the sample. . (a) sample of [PCl2N]3 HAlCl4 with no excess AlCl3, (b) the same . sample of [PCl2N]3 HAlCl4 with excess AlCl3...... 87

xviii

31 . 3.13. P VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken at 30 °C to investigate the effect of excess AlCl3 concentration in the sample. . (a) sample of [PCl2N]3 HAlCl4 with no excess AlCl3, (b) the same . sample of [PCl2N]3 HAlCl4 with excess AlCl3...... 88

1 . 3.14. H VT NMR spectra of [PCl2N]3 HGaCl4 in CDCl3 taken at 30 °C to investigate the effect of excess GaCl3 concentration in the sample. . (a) sample of [PCl2N]3 HGaCl4 with no excess GaCl3, (b) the same . sample of [PCl2N]3 HGaCl4 with excess GaCl3...... 88

31 . 3.15. P VT NMR spectra of [PCl2N]3 HGaCl4 in CDCl3 taken at 30 °C to investigate the effect of excess GaCl3 concentration in the sample. . (a) sample of [PCl2N]3 HGaCl4 with no excess GaCl3, (b) the same . sample of [PCl2N]3 HGaCl4 with excess GaCl3...... 89

. 3.16. ESI Mass spectrum of [PCl2N]3 HAlCl4 in positive mode. (a) theoretical + distribution for (H[PCl2N]3) , (b) experimental isotope distribution...... 91

. 3.17. ESI Mass spectrum of [PCl2N]3 HGaCl4 in positive mode. (a) theoretical + distribution for (H[PCl2N]3) , (b) experimental isotope distribution...... 91

. 3.18. ESI Mass spectrum of [PCl2N]3 HAlBr4 in positive mode. (a) theoretical + distribution for (H[PCl2N]3) , (b) experimental isotope distribution...... 92

. 3.19. ESI Mass spectrum of [PCl2N]3 HAlCl4 in negative mode. (a) theoretical - distribution for AlCl4 , (b) experimental isotope distribution...... 92

. 3.20. ESI Mass spectrum of [PCl2N]3 HGaCl4 in negative mode. (a) theoretical - distribution for GaCl4 , (b) experimental isotope distribution...... 93

4.1. ESI MS in positive mode of (a) [H(12-Crown-4)][PCl6], (b) [H(18-Crown-6)2][PCl6] freshly made, and (c) [H(18-Crown-6)2][PCl6] degraded...... 105

4.2. Thermal ellipsoid plot of the cation of 1 with ellipsoids at 50% and showing the position of the acidic hydrogen in the O-H-O hydrogen bond (o—O = 2.446 Å).O atoms are drawn in red and C atoms in grey. Other hydrogen atoms are omitted for clarity...... 107

4.3. Thermal ellipsoid plot of the cation of 2 with ellipsoids at 50% and showing the position of the acidic hydrogen in the O-H-O hydrogen bond (o—O = 2.423 Å).O atoms are drawn in red and C atoms in grey. Other hydrogen atoms are omitted for clarity...... 107

1 4.4. H NMR spectrum of [H(12-crown-4)][PCl6] in CDCl3 at 30 °C...... 109

xix

1 4.5. H NMR spectrum of [H(18-crown-6)2][PCl6] in CDCl3 at 30 °C...... 109

13 4.6. C NMR spectrum of [H(12-crown-4)][PCl6] in CDCl3 at 30 °C...... 110

13 4.7. C NMR spectrum of [H(18-crown-6)2][PCl6] in CDCl3 at 30 °C...... 110

31 4.8. P NMR spectrum of [H(12-crown-4)][PCl6] in CDCl3 at 30 °C...... 111

31 4.9. P NMR spectrum of [H(18-crown-6)2][PCl6] in CDCl3 at 30 °C...... 111

31 4.10. P NMR spectra of [H(18-crown-6)2][PCl6] in CD2Cl2 at (a) -20 °C, (b) 30 °C...... 111

5.1. Allcock’s mechanism of the ROP of [PCl2N]3 to give [PCl2N]n ...... 117

. 5.2. [P3N3Cl5] SbCl6 proposed by Kravcheko as the product of the interaction between SbCl5 and [PCl2N]3 ...... 118

5.3. Prevalent usage of PCl5 in the syntheses of chlorophosphazenes ...... 119

. 5.4. Glassware used for the attempted synthesis of [PCl2N]3 SbCl5. The . reaction yielded [PCl2N]3 HSbCl6 instead ...... 125

. 5.5. Thermal ellipsoid plot fro the crystal structure of [PCl2N]3 HSbCl6. N atoms are drawn in blue, P atoms in orange and chlorine atoms in green ...... 135

. 5.6. Degradation product in solid of [PCl2N]3 HSbCl6 showing the co- crystallization of [PCl2N]3 with SbCl3. N atoms are drawn in blue, P atoms in orange and chlorine atoms in green ...... 136

. 5.7. High resolution ESI mass spectrum of [PCl2N]3 HSbCl6 in the + positive mode. (a) Theoretical isotope distribution for H[PCl2N]3 , (b) experimental isotope distribution ...... 138

. 5.8. High resolution ESI Mass spectrum of [PCl2N]3 HSbCl6 in the - negative mode, (a) theoretical isotope distribution for SbCl6 , (b) experimental isotope distribution ...... 138

31 . 5.9. P VT NMR spectra of [PCl2N]3 HSbCl6 in CD2Cl2 taken between -80 and 30 °C. (a) 30 °C, (b) 0 °C, (c) -20 °C, (d) -40 °C, (e) -60 °C, and (f) -80 °C ...... 139

1 . 5.10. H VT NMR spectra of [PCl2N]3 HSbCl6 in CD2Cl2 taken between -60 and 30 °C. (a) 30 °C, (b) 0 °C, (c) -20 °C, (d) -40 °C, and (e) -60 °C ...... 139

. 5.11. Thermal ellipsoid plot for the crystal structure of [PCl2N]4 HSbCl6 ...... 141

31 . 5.12. P VT NMR spectra of [PCl2N]4 HSbCl6 in CDCl3 taken (a) at 30 °C, and (b) at -40 °C...... 143

1 . 5.13. H NMR spectrum of [PCl2N]5-7 HSbCl6 in CDCl3 taken at 30 °C ...... 146

31 . 5.14. P NMR spectrum of [PCl2N]5-7 HSbCl6 in CDCl3 taken at 30 °C ...... 146

. 5.15. Thermal ellipsoid plot for the crystal structure of [PCl2N]5 HSbCl6 ...... 147

. 5.16. The ball and stick plot of the structure of [PCl2N]6 HSbCl6 ...... 149

1 5.17. H NMR spectrum of [H(PCl2N)][SbCl6][PCl2N]10 in CDCl3 taken at 30 °C ...... 151

31 5.18. P NMR spectrum of [H(PCl2N)][SbCl6][PCl2N]10 in CDCl3 taken at 30 °C ...... 151

1 5.19. H NMR spectrum of [H(PCl2N)][PCl6][PCl2N]10 in CD2Cl2 taken at 30 °C ...... 153

5.20. The ν(NH) frequencies of tri-n-octylammonium salts of certain acids of interest. The table on the right lists value reported by Reed ...... 155

xxi

LIST OF CHARTS

Chart Page

2.1. Proposed Intermediates in the ROP of [PCl2N]3 ...... 30

xxii

LIST OF SCHEMES

Scheme Page

1.1. Synthesis of functionalized polyphosphazenes by replacing the chlorides of premade polymeric [PCl2N]n ...... 2

1.2. Major Synthetic Routes of [PCl2N]n ...... 4

. 3.1. A Series of experiments to investigate how [PCl2N]3 HMX4 species were formed...... 75

5.1. Reactions involving [PCl2N]3 with SbCl5 or HSbCl6 ...... 133

5.2. The reactions of PCl5 and HCl with the cyclic [PCl2N]n (n = 3–6) and polymeric [PCl2N]n ...... 152

xxiii

LIST OF EQUATIONS

Equation Page

1.1...... 22

2.1...... 36

2.2...... 50

2.3...... 50

2.4...... 50

4.1 ...... 98

4.2 ...... 104

4.3 ...... 104

5.1 ...... 140

5.2 ...... 144

5.3 ...... 150

xxiv CHAPTER I

INTRODUCTION

1.1. Functionalized polyphosphazenes

Polyphosphazenes constitute the largest group of inorganic backbone polymers, surpassing polysiloxanes.1 The backbones of polyphosphazenes are

made of alternating phosphorous and nitrogen atoms, with each phosphorus

atom bearing two substituent groups (Figure 1.1). The substituents can be

organic, organometallic, or inorganic, and the nature of the substituents dictates

the properties of the resulting polymer.1 By tailoring the properties of the

substituents, the polymer can be fine-tuned to give the desired functionality.

Potential applications of polyphosphazenes range from solvent-resistant

elastomers, fire-retardants, membranes, to biomaterials for controlled drug-

release.2

R R R R P N N P N P N P R R R R Figure 1.1. The Backbone of the phosphazene polymer. R can be organic, organometallic, or inorganic groups.

The majority of polyphosphazenes are synthesized by the reactions

described in Scheme 1.1, in which the chlorides on the highly reactive polychlorophosphazenes, [PCl2N]n, are replaced by the desired functional

groups.1 This ability of polyphosphazenes to achieve novel structural and

functional attributes through substitution of an already premade [PCl2N]n polymer

sets them apart from classical organic and other inorganic polymers.3 In the

case of organic polymers, a new monomer with the desired traits needs to be

synthesized and then be polymerized in order to give a novel polymeric material.3

Facile substitution of the chlorides from [PCl2N]n with the desired functional group

has made it possible for polyphosphazene field to diversify rapidly in the last 40

years.

OR P N MOR OR n -MCl Cl M = Na, K P N Cl n HNR2 -HCl NR2 P N NR 2 n Scheme 1.1. Synthesis of functionalized polyphosphazenes by replacing the chlorides of premade polymeric [PCl2N]n.

1.2. [PCl2N]n

Despite their versatility, polyphosphazenes are not widely used in industry

because 1) synthesis of the starting polymer, [PCl2N]n, is inefficient,

1 irreproducible, or expensive, and 2) [PCl2N]n can degrade upon storage. In

order for the industry to tap into the full potential of polyphosphazenes, cost-

effective solutions to the problems surrounding the synthesis and storage of

[PCl2N]n need to be developed.

1.2.1. Synthesis of [PCl2N]n

Major synthetic routes to [PCl2N]n are shown in Scheme 1.2. The bottom

part of Scheme 1.2 shows the general condensation route to [PCl2N]n. There are

three different condensation routes: a) condensation of OCl2PN=PCl3, b)

2,3 condensation of Me3SiN=PCl3, and c) condensation of phosphorus azides.

[PCl2N]n synthesis through the condensation of OCl2PN=PCl3 is the most cost-

effective condensation route because OCl2PN=PCl3 can be made from the

reactions of NH4Cl with POCl3, NH4Cl with PCl5 in the presence of HSO3(NH2),

3 or (NH4)2SO4 with PCl5. The downsides to these condensation routes are the

lower molecular weight and the larger polydispersity values of the [PCl2N]n

3 polymer produced. The polydispersity of [PCl2N]n synthesized through

condensation of Me3SiN=PCl3 is smaller than that of [PCl2N]n made through

condensation of OCl2PN=PCl3, however the molecular weight of the polymer is

3 also lower. However, the main reason why the Me3SiN=PCl3 condensation

3 route is not commercially viable is the expense involved in making Me3SiN=PCl3 starting material. The drawback of the azide condensation route, on the other hand, is the fact that phosphorus azides are explosion hazards.3

[PCl2N]3 + [PCl2N]4 melt ROP 250 oC

[PCl2N]n Cl Condensation X P N Z - X Z

Cl Scheme 1.2. Major Synthetic Routes of [PCl2N]n.

The top part of Scheme 1.2 represents the classical route to [PCl2N]n which is the ring-opening polymerization (ROP) of [PCl2N]3, or [PCl2N]4, in a sealed-tube around 250 °C in a solvent-free process called melt-polymerization.

[PCl2N]3 acts as the reaction solvent at this temperature and the reaction needs to be stopped when ~50% of [PCl2N]3 is polymerized. If the reaction is carried out for a longer time or at a higher temperature, an insoluble polymer will start to form. Therefore, 100% conversion of [PCl2N]3 into soluble [PCl2N]n can not be achieved in the melt ROP. The insoluble, presumably cross-linked polymer was termed “inorganic rubber” by Stokes in 1897.4

The ROP route has great advantages over other synthetic routes because

1) the starting materials for the ROP process, [PCl2N]3 and [PCl2N]4, are made easily from cheap, commercially available PCl5 and NH4Cl, and 2) this route

affords the highest molecular weight [PCl2N]n compared to those of [PCl2N]n

obtained through other routes. The flaws of the ROP route include high reaction

temperature, inefficiency, irreproducibility, and the difficulty to avoid making

insoluble byproducts in high-conversion reactions.

Although there are several options for [PCl2N]n synthesis, the classical

ROP route remains the most used route. If the problems surrounding the ROP synthesis and the [PCl2N]n storage were solved, the commercial development of

polyphosphazenes would become attainable. We believe that the best approach

to tackling these problems is through the study of fundamental

chlorophosphazene chemistry.

1.2.2. Mechanism of the ROP of [PCl2N]3

4 Although the ROP reaction of [PCl2N]3 has been known since 1897, the

mechanism of the process is still a topic of debate to this day. Allcock and

Emsley have proposed two different mechanisms.4,5 Allcock’s mechanism which

is depicted in Figure 1.2 is the more generally accepted mechanism. In this mechanism, a chloride anion is removed from [PCl2N]3 at the ROP temperature

+ forming [P3Cl5N3] , which is a phosphazenium cation. The observation that the

ROP temperature increases in the order [PBr2N]3 < [PCl2N]3 < [PF2N]3 suggested

that cleavage of the phosphorus halide bond is involved in the rate determining step. A lone pair of electrons on a nitrogen of a nearby [PCl2N]3 attacks the

phosphazenium cation. This breaks a phosphorous-nitrogen bond in the second

[PCl2N]3 ring and ROP process is initiated. A phosphazenium cation forms at the

broken P-N bond site and the polymerization continues.

Allcock’s mechanism has been used to explain the fact that the use of

certain Lewis acids as catalysts or initiators improves some aspects of the ROP.

For instance, the ROP temperature is lower in some Lewis acid catalyzed ROP

(Figure 1.3).6,7 A Lewis acid can help remove the chloride anion in the initial step

of the ROP and it can stabilize the removed chloride anion by forming a more weakly-coordinating anion. Lewis acids such as BCl3 and AlCl3 have been

reported to catalyze the ROP around 210 °C. The BCl3 catalyzed reaction in

particular has been successful in making [PCl2N]n in higher yield, at a lower

temperature and with greater reproducibility than the traditional melt ROP, and

this catalysis route has been used by the Firestone company in Akron, Ohio

during the 1970-1980’s.8 However, it also requires the use of toxic

trichlorobenzene solvent, and the [PCl2N]n polymer has a lower molecular weight

than that produced by the melt ROP. The AlCl3 catalyzed reaction, on the other

hand, yields only oligomeric and not polymeric products.9 Not all Lewis acids

have positive effects on the ROP. For example, the Lewis acid PCl5 inhibits the

ROP process.10

In 2008, after this work was begun, Manners and Reed reported the ROP

of [PCl2N]3 at room temperature catalyzed or initiated by tri-alkyl silyl salts of

7 carboranes, [R3Si(CHB11X11)] where R is Me or Et. Although this synthetic route

is not industry friendly due to the inaccessibility of the required carboranes, it is

the first example showing that [PCl2N]3 can undergo the ROP at room

11 temperature. The Si R3Cl separated out of the ROP reaction. This observation

+ supports the idea that the Lewis acid “Si R3 ” might help extract the chloride

anion.

Cl Cl Cl N Cl Cl N P P Cl heat Cl P P Cl N N P (>250 C) N N P Cl Cl Cl Cl Cl Cl Cl N P P Cl N N P Cl Cl Cl Cl Cl N N P P P Cl P N N Cl P N N Cl P Cl Cl

4 Figure 1.2. Allcock’s Mechanism of the ROP of [PCl2N]3 to give [PCl2N]n.

Figure 1.3. Examples of the Lewis acid catalyzed ROP of [PCl2N]3 at lower ROP temperatures.6,7

One of the aspects of the ROP that is not explained well by Allcock’s mechanism is the fact that a trace of water is required for the ROP to take place.

If one attempts to conduct the ROP using water- or HCl-free quartz tubes,

12 10 14 [PCl2N]3 does not polymerize. Allcock and Magill also reported that the presence of trace amount of water reduces the reaction time of the ROP. These

13 observations support Emsley’s mechanism for the ROP in which [PCl2N]3 is protonated in the first step (Figure 1.4). The protonation weakens, and eventually breaks, a P-N bond between the protonated nitrogen and an adjacent phosphorus atom, resulting in a phosphazenium cation. After the phosphazenium cation formation, the propagation of the polymerization in

Emsley’s mechanism is similar to that in Allcock’s. A lone pair of electrons on a

nitrogen of a neighboring [PCl2N]3 attacks the cation, causing the second

[PCl2N]3 ring to break open, and a new phosphazenium cation to form.

There are several reports of Brønsted-Lowry acids catalyzed or promoted

ROP reactions that support the Emsley’s mechanism. Magill et al. reported that

sulfamic acid, toluenesulfonic acid and sulfobenzoic acid in the presence of the

. promoter CaSO4 2H2O yielded high molecular weight polymer with narrow polydispersity in a fast ROP reaction.14 Gray and co-workers tested the catalytic

activity of several organic compounds on the ROP reaction at 210 °C and

concluded that the compounds that attack the nitrides at the reaction

temperature, such as carboxylic acids, are catalytically active.15 On the other hand, the compounds that do not react with the nitrides even at the reaction temperature, such as saturated hydrocarbons and alkyl halides, are catalytically inert.15 Not all Brønsted-Lowry acids catalyze or promote the ROP process. For example, HCl which is a Brønsted-Lowry acid is a mild inhibitor of ROP.10

H H Cl Cl Cl N Cl Cl Cl Cl Cl N N P P Cl P P Cl + H Cl P P Cl N N N N P N N P P Cl Cl Cl Cl Cl Cl

Cl Cl Cl N P P Cl N N P Cl Cl Cl N Cl Cl N P P P Cl P N N Cl P N N Cl P Cl Cl

5 Figure 1.4. Emsley’s Mechanism of the ROP of [PCl2N]3 to give [PCl2N]n

Figure 1.5 sums up the different species that have been proposed as

reaction intermediates for both catalyzed and non-catalyzed ROP processes.

Species 1 is the phosphazenium cation intermediate that was proposed by

Allcock for the non-catalyzed ROP.10 Species 2 is one of the two different types

of intermediates proposed for the Lewis acid catalyzed ROP.6 Species 2 is in

fact a variant of 1 in which the removed chloride forms a more weakly- coordinating anion with the Lewis acid. The second type of intermediate

proposed for the Lewis acid catalyzed ROP is 3.6 In 3, the interaction between

the lone pair of electrons on the ring nitrogen and the Lewis acid results in adduct

formation. The proposed intermediates for the Brønsted-Lowry acid catalyzed

ROP process are the species 4.5

The tricoordinate phosphazenium16 cations 1 and 2 are extremely

electrophilic. These reactive species might interact with any nearby electron

donor resulting in a base-stabilized, tetracoordinate phosphonium16 cation

(Figure 1.6). Allcock and Emsley mentioned only phosphazenium cations and

not phosphonium cations as intermediates of the ROP. No crystal structure has

been reported of a phosphazenium cation that is derived from a phosphazene.

One example of a phosphonium hexacation derived from a phosphazene was

reported in 2007. The reaction of [PCl2N]3 and 4-(dimethylamino)pyridine

6+ (DMAP) under microwave irradiation at 100 °C gave the [P3N3(DMAP)6] hexacation (Figure 1.7).17

Cl N Cl Cl Cl P P P Cl Cl N N H N N Cl P P P Cl N Cl Cl + H Cl Cl 1 4 [PCl2N]3 LA LA LA Cl Cl N N Cl P P Cl P P Cl Cl Cl N N LA(Cl) N N P P Cl Cl Cl Cl 3 2

Figure 1.5. Species Proposed as Intermediates in the ROP of [PCl2N]3, both catalyzed and non-catalyzed.

Base Cl Cl N Cl N P P Base Cl P P Cl Cl Cl N N N N P P Cl Cl Cl Cl (b) (a)

Figure 1.6. (a) phosphazenium cation, (b) phosphonium cation.16

N N

N N N P P N N N N N N P N N

N N

6+ 17 Figure 1.7. The hexacation [P3N3(DMAP)6] .

1.3. Acid-Base Chemistry of [PCl2N]3

Given the ambiguity surrounding the mechanism of the ROP process, our

group decided to study the acid-base chemistry related to the ROP of [PCl2N]3.

These studies are described in Chapters II and III. Better understanding of the

acid-base chemistry of [PCl2N]3 can help identify the reaction intermediates, shed

light on the mechanism of the ROP process, and consequently, lead to an

improved synthesis of [PCl2N]n. Although the acid-base chemistry of [PCl2N]3

has been studied for decades, discrepancies exist in the proposed products of

those interactions. This might be due to the fact that most of the studies were

done before the full development of modern analytical techniques such as

multinuclear NMR, mass spectrometry and X-ray crystallography.

1.3.1. Previously Reported Interactions of Lewis Acids with [PCl2N]3

The interactions of [PCl2N]3 with several Lewis acids including those

containing Group 6, 10, 11, 13, 14, 15 and 16 elements has been reported. Most

of the structural claims prior to our group’s work were based solely on elemental

analysis or IR. Species 2 and 3 (Figure 1.5) and their variants were proposed as

. the structures of the reaction products. In 1942, Bode proposed (PCl2N)3 2AlCl3

[Variant of 2 (Figure 1.5)] as a reaction intermediate in the Friedel-Crafts

18 phenylation of [PCl2N]3 in the presence of AlCl3. Others proposed

. 4 [PCl2N]3 AlCl3 [2 (Figure 1.5)] as the intermediate instead. In 1954, Goehring

. reported [PCl2N]3 (SO3)3 [Variant of 3 (Figure 1.5)] as the product of the reaction

19 between SO3 and [PCl2N]3. Na2PtCl6 was reported to react with [PCl2N]3 to

20 give P3N3Cl2(PtCl4)2 [Variant of 2 (Figure 1.5)] in 1965. Coxon proposed the

. 21 [PCl2N]3 AlBr3 adduct [3 (Figure 1.5)] from the reaction of [PCl2N]3 and AlBr3.

He also reported in 1968 that there was no reaction between [PCl2N]3 and BBr3,

21 MeI, SnCl4, TiCl4 or SbCl5. However, Kravcheko claimed the formation of

. . 22 [PCl2N]3 SbCl5 [2 (Figure 1.5)] and [PCl2N]3 TaCl5 [2 (Figure 1.5)] in 1977.

. 23 [PCl2N]3 VOCl3 [3 (Figure 1.5)] was reported in 2003. Manners reported in

24 2004 that no reaction occurred between [PCl2N]3 and GaCl3. However our

. group was able to synthesize [PCl2N]3 GaCl3 [3 (Figure 1.5)] in hexane. In 2005,

our group communicated the synthesis and crystallographic characterization of

. . 25 [PCl2N]3 GaCl3 and [PCl2N]3 AlCl3 [3 (Figure 1.5)] based on the work of Heston.

That was the first time the claim for the adduct formation between [PCl2N]3 and

Lewis acids was backed by crystallographic evidence. In 2006, Reed reported

. . [PCl2N]3 CH3(CHB11Me5Br6) and [PCl2N]3 SiR3(CHB11Me5Br6) where R is methyl

26 . or ethyl as species 3 (Figure 1.5). [Ag(PCl2N)3] [Al(ORf)4] and

. [Ag{(PCl2N)3}2] [Al(ORf)4] (where Rf = C(CF3)3) were synthesized by Krossing in

2006 [3 (Figure 1.5)].27 They were unable to generate 2 (Figure 1.5) by using

Ag[Al(ORf)4] to remove chloride from [PCl2N]3. All the x-ray crystallographically characterized products have the structure of species 3 (Figure 1.5) and some of these products are shown in Figure 1.8.

Cl Cl Cl Cl P P N N N N Cl P P Cl Cl P P Cl N N Cl Cl Cl Cl AlCl3 GaCl3

Cl Cl Cl Cl P P N N N N Cl P P Cl Cl P P Cl N N Cl Cl Cl Cl CH3[CHB11Me5Br6] SiR3[CHB11Me5Br6]

Cl Cl P N N Cl Cl Cl P P Cl N P Cl Cl N N Ag Cl P P Cl Cl Cl N N Cl Cl Cl P P Cl Ag[Al(ORf)4] N N P Cl Cl

Figure 1.8. Crystallographically characterized adducts of [PCl2N]3 with structure 3 25,26,27 (Figure 1.5) [R = methyl, ethyl; Rf = C(CF3)3].

1.3.2. Previously Reported Interactions of Brønsted-Lowry Acids with [PCl2N]3

and [PR2N]3-5

There have been only a few examples of the species 4 (Figure 1.5) in the

literature. In 1948, Bode reported a protonated adduct of [PCl2N]3 that was

formed from the reaction of [PCl2N]3 with the super Brønsted-Lowry acid,

28 HClO4. In 2002, there was a claim of the protonation of [PCl2N]3 by HCl that

was backed only by IR spectroscopy.29 This claim contradicts the generally

30 accepted fact that the nitrogen atoms on [PCl2N]3 are very poor bases and that

7 it would require an acid that is at least as strong as H2SO4 to protonate them. In

31 fact, the basicity of [PCl2N]3 has been reported to be too weak to measure. The

4,7 pKa of [PCl2N]3 in nitrobenzene is less than -6. The basicity of the nitrogen

atoms in the phosphazene ring is governed by the electron withdrawing or

donating ability of the substituents on the ring phosphorus. The low basicity of

[PCl2N]3 can be attributed to the electron withdrawing chloride groups on

[PCl2N]3.

In 2004 based on the work of Heston, our group communicated the

. formation of [PCl2N]3 [HAlBr4] which was the first crystallographically-

32 characterized, protonated adduct of [PCl2N]3. Reed reported the protonation of

26 [PCl2N]3 by carborane superacids in 2006. It has been suggested that the

protonation of the poor base, [PCl2N]3 was achieved only with the aid of the

extremely weakly coordinating carborane counter-ions.7 As shown in Figure 1.9,

. . both [PCl2N]3 [HAlBr4] and [H(PCl2N)3] [HCB11H5Br6] have the general structure 4

(Figure 1.5).

Cl Cl Cl Cl P P N N N N Cl P P Cl Cl P P Cl N N Cl Cl Cl Cl H H AlBr CHB11R5X6 4

Figure 1.9. Crystallographically characterized protonated adducts of [PCl2N]3 with structure 4 (Figure 1.5).26,32

As mentioned above, the basicity of the nitrogen atoms in the phosphazene ring depends on the substituents on the phosphorus atoms on the ring. [PR2N]3 with electron donating substituents (R = amino or alkyl groups) are

much stronger bases than their halogen analogs, and several examples of

33 protonated [PR2N]3 can be found in literature. Three examples of [H(PR2N)3][X]

(where R = NMe2, X = Mo6O19; R = NMe2, X = CoCl4; R = N(i-Pr)H, X = Cl) are

shown in Figure 1.10. Protonated [PR2N]4 and [PR2N]5 have also been

33 . reported. Similar to our observation with [PCl2N]3 [HAlBr4], protonation

lengthens the P-N bond that flank the protonated nitrogen atom in [H(PR2N)n][X]

(n = 3, 4, or 5).33

NMe2 NMe2 NMe2 NMe2 P P N N N N NMe 2- 2- 2 [Mo6O19] NMe2 [CoCl4] NMe2 P P NMe P P N 2 NMe2 N NMe2 NMe2 NMe2 H H 2 2

N(i-Pr)H N(i-Pr)H P N N N(i-Pr)H - N(i-Pr)H P P [Cl] N N(i-Pr)H N(i-Pr)H H

33 Figure 1.10. Examples of [H(PR2N)3][X].

1.4. Superacids

It was mentioned in the previous section that protonation of the very weak

base [PCl2N]3 is believed to take place only with the use of superacids such as

26,32 HAlBr4 and carboranes. Superacids are arbitrarily defined as any acid that is stronger than 100% H2SO4 for Brønsted acids, and any acid that is stronger than

34 anhydrous AlCl3 for Lewis acids. The term superacid was coined by Conant

and Hall in 1927 to describe the perchloric acid system that protonated carbonyl

compounds in acetic acid.34 However it was during the 1950s that superacid

systems billion times stronger than mineral acids were discovered.34 The initial

driving force behind the superacid chemistry research was the discovery of the

ability of superacidic media to stabilize carbocations.34

There are four types of superacids namely Brønsted superacids (eg.

CF3SO3H), Lewis superacids (eg. SbF5), conjugate Brønsted-Lewis superacids

34 (eg. HAlBr4), and solid superacids (eg. carboranes). Most related to this

dissertation are the conjugate Brønsted-Lewis superacids such as HAlBr4. A conjugate Brønsted-Lewis superacid forms when a Lewis acid (MXm) reacts with a Brønsted acid (HX). It can also be formed when a water sensitive metal halide

Lewis acid (MXm) reacts with water. Water can hydrolyze the metal-halogen

bond in the Lewis acid MXm and give the Brønsted acid HX, which in turn can

react with a second molecule of the Lewis acid MXm and give HMXm+1. HMXm+1

- is a stronger Brønsted-Lowry acid than the parent HX because MXm+1 anion is

- more weakly coordinating than X . Super acids HMXm+1 are also described as

HX/MXm because these acid systems are complex and different cations and

anions can be present based on the concentration of MXm in the solution. For

+ + - - - example, the cations H3F2 and H2F and the anions SbF6 , Sb2F11 and Sb3F16

35 have been detected in the HF/SbF6 system.

Superacidity can not be measured using the pH scale due to solvent

leveling of superacids in water. The Hammett acidity scale36 is usually used for

measuring the acidity of liquid superacids. To measure the acidity of both liquid

and solid superacids, Reed has devised a qualitative scale that is based on the

νN-H frequencies of tri-n-octylammonium salts of the conjugate base of the

superacids of interest.37 Figure 1.11 shows the tri-n-octylamonium salt contact ion pair.

- N H A

3 Figure 1.11. Tri-n-octylammonium salt contact ion pair used in Reed’s qualitative acidity scale.37

The idea behind this acidity scale is that a stronger acid with its more weakly-coordinated conjugate base will lead to a stronger N-H bond with a higher

νN-H frequency.37 Table 1.1 lists the relative acidities of some of the superacids reported by Reed.37 In chapter V, we will apply Reed’s scale and derive the acidities of known superacids HAlCl4 and HAlBr4 as well as those of lesser known superacids HSbCl6 and HPCl6.

37 Table 1.1 Conjugate bases of certain acids and corresponding ν(NH) in CCl4.

-1 Anion ν(NH) in CCl4 (cm ) - [CHB11Cl11] 3163

- [CHB11Me11] 3156

- [CHB11H11] 3129

- [GaCl4] 3126

2- [HSO4]2 3021, 2660

- [CF3SO3] 3031

- [NO3] 2451

Cl- 2330

1.5. Lewis acid/Brønsted acid dichotomy and the protonic impurities affecting the

chlorophosphazene chemistry

Brønsted-Lowry chemistry plays an important role in both synthesis and

storage of chlorophosphazenes. Formation of protonic impurities are

unavoidable in the synthesis of [PCl2N]3 from PCl5 and NH4Cl, described in

equation 1.1. The identity of the acidic impurities is not obvious. Because the

HCl produced should be removed by the vigorous refluxing at 140º, and the

unreacted NH4Cl by the filtration from the cooled reaction mixture, these two

Brønsted-Lowry acids can not be the impurities. The presence of the protonic

impurities in the ROP process can promote the cross-linking of the product

polymer. Therefore, [PCl2N]3 and [PCl2N]4 are diligently purified prior to use for

ROP,1 usually via sublimation and recrystalization followed by a second

sublimation. Stannett et al. even “dried” [PCl2N]3 with BaO before using it in a

38 BCl3 catalyzed ROP.

145 oC PCl5 + NH4Cl [PCl2N]3 + [PCl2N]4 + higher oligomers and linears - HCl

Equation 1.1

In addition, protonic impurities can react with [PCl2N]n upon storage and

cause the linear polymer to cross-link or degrade. Andrianov have reported that

[PCl2N]n can be stored for up to 4 years in diglyme in air without any cross-

linking.39 It has not yet been determined which attribute of diglyme is responsible

for this stabilizing ability. One plausible explanation is the ability of diglyme to

39 solvate water molecules and deter them from hydrolyzing [PCl2N]n. Another

possibility is that diglyme, being a poly(ethylene oxide), coordinates the charged

impurities and inhibits them from protonating the nitrogen atoms on the [PCl2N]n

backbone.39

As pointed out in section 1.4, a Lewis acid can react with water and

become a strong Brønsted-Lowry acid. Previous work in our group32 shows that

the Lewis acid chemistry of chlorophosphazenes can become the Brønsted-

Lowry acid chemistry with the presence of adventitious water. This is an important point not only for the chlorophosphazene chemistry but also for any type of chemistry where water sensitive metal halide Lewis acids, such as AlCl3,

are used. Because Lewis acids have been widely used in organic syntheses

including in Friedel-Crafts chemistry and carbocationic polymerization,40 the

Lewis acid/Brønsted acid dichotomy can have a broader impact beyond the

chlorophosphazene chemistry.

1.6. Topics in this dissertation

This dissertation discusses the acid-base chemistry of cyclic [PCl2N]n (n =

3, 4, 5, and 6) and polymeric [PCl2N]n. The interactions of Group 13 Lewis acids and Group 13 superacids with [PCl2N]3 are studied in Chapter II and III,

respectively. Some of these interactions had been mentioned in the dissertation

of Dr. Amy J. Heston41 (a former member in our group) and in the author’s

Master’s thesis42. This dissertation describes a more thorough characterization

of these compounds that is needed in order to understand their roles in the ring-

23 opening polymerization of [PCl2N]3. Isolation of the fragile acid, HPCl6 in Chapter

IV is followed by the interactions of Group 15 acids with cyclic and polymeric

[PCl2N]n in Chapter V.

1.7. References

(1) Allcock, H. R. Chemistry and Applications of Polyphosphazenes, Wiley- Interscience: New York, 2003.

(2) Gleria, M.; De Jaeger, R., eds. Phosphazenes a Worldwide Insight, Nova Science: New York, 2004.

(3) Mark, J. E.; Allcock, H. R.; West, R. “Polyphosphazenes” in Inorganic Polymers; 2nd ed., Prentice Hall: Englewood Cliffs, NJ, 2005; Chapter 3.

(4) Allcock, H. R. Phosphorus-Nitrogen Compounds, Academic: New York, 1972.

(5) Emsley, J.; Udy, P. B. Polymer, 1972, 13, 593-594.

(6) (a) Sennett, M. S.; Hagnauer, G. L.; Singler, R. E.; Davies, G. “Kinetics and Mechanism of the Boron Trichloride Catalyzed Thermal Ring-Opening Polymerization of Hexachlorocyclotriphosphazene in 1,2,4-Trichlorobenzene Solution,” Macromolecules 1986, 19, 959-964. (b) Kayser Potts, M.; Hagnauer, G. L.; Sennett, M. S.; Davies, G “Monomer Concentration Effects on the Kinetics and Mechanism of the Boron Trichloride Catalyzed Solution Polymerization of Hexachlorocyclotriphosphazene”, Macromolecules 1989, 22, 4235-4239. (c) Singler, R. E.; Sennett, M. S.; Willingham, R. A. “Phosphazene Polymers: Synthesis, Structure, and Properties” in Inoganic and Organometallic Polymers, Zeldin, M.; Wynne, K. J.; Allcock, H. R., eds; American Chemical Society Symposium Series, 360; American Chemical Society: Washington, DC, 1988; Chapter 20. (d) Sennett, M. S.; Hagnauer, G. L.; Singler, R. E. “Boron trichloride catalyzed polymerization of hexachlorocyclotriphosphazene,” Polym. Mater. Sci. and Eng. 1983, 49, 297-300. (e) Fieldhouse, J. W.; Graves, D. F. “Polymerization of hexachlorocyclotriphosphazene,” in Phosphorus Chemistry, ACS Symposium Series, 171; American Chemical Society: Washington, DC, 1981, 315-20. (f) Singler, R. E.; Hagnauer, G. L.; Sicka, R. W. “Phosphazene elastomers, synthesis, properties and applications,” in Polymers for Fibers and Elastomers, Authur, J. C. Jr., ed.; American Chemical Society Symposium Series, 260; American Chemical Society: Washington, DC, 1984; Chapter 9.

(7) Zhang, Y.; Huynh, K.; Manners, I.; Reed, C. “Ambient temperature ring- opening polymerization (ROP) of cyclic chlorophosphazene trimer [N3P3Cl6] catalyzed by silylium ions” Chem. Commun. 2008, 494-496. (8) The Firestone Tire & Rubber Co; DE 2816227 1979.

(9) Sohn, Y. S.; Cho,Y. H.; Baek, H.; Jung, O.-S.” Synthesis and Properties of Low Molecular Weight Polyphosphazenes” Macromolecules 1995, 28, 7566- 7568.

(10) Allcock, H. R.; Gardner, J. E.; Smeltz, K. M. “Polymerization of Hexachlorocyclotriphosphazene. The role of Phosphorus Pentachloride, Water, and Hydrogen Chloride” Macromolecules 1975, 8, 36-42.

(11) Blackstone, V.; Soto, A.; Manners, I. “Polymeric materials based on main group elements: the recent development of ambient temperature and controlled routes to polyphosphazenes” Dalton Trans. 2008, 4363-4371.

(12) Sulkowski, W. W. “Some aspects of synthesis and investigation of poly(diorgnanoxyphosphazene)s,” in Phosphazenes: A Worldwide Insight, Gleria, M. De Jaeger, R., eds.; Nova Science: New York, 2004, Chapter 4.

(13) Emsley, J.; Udy, P. B. “Polymerization of hexachlorotriphonitrile, (NPCl2)3” Polymer, 1972, 13, 593-594.

(14) Mujumdar, A. N.; Young, S,. G.; Merker,R. L.; Magill, J. H. “A Study of Solution Polymerization of Polyphosphazenes” Macromolecules 1990, 23,14-21.

(15) Konecny, J. O.; Douglas, C. M.; Gray, M. Y. “Polymerization of dichlorophosphinic nitrides” J. Polym. Sci. 1960, 42, 383-90.

(16) Cristau, H.-J.; Fruchier, A.; Plenat, F.; Taillefer, M.; Vicente, V. “Cyclophosphazenes with P-C bond(s) I - syntheses and reactivity” in reference 1(b), Chapter 38, pp 931-981.

(17) Boomishankar, R.; Ledger, J.; Jean-Baptiste Guilbaud,J.-B. Campbell, N. L.; Bacsa, J.; Bonar-Law, R.; Khimyak, Y. Z.; Steiner, A. “The N-donor stabilised 6+ cyclotriphosphazene hexacation [P3N3(DMAP)6] ” Chem. Commun., 2007, 5152–5154.

(18) (a) Bode, H.; Bütow, K.; Lienau, G. “Phosphonitrile compounds. IV. The structure and the amides of the trimer” Chem. Ber. 1948, 81, 547-552. (b) Refference 6.

(19) Goehring, M.; Hohenschutz, H.; Appel, R. “Compounds of sulfur trioxide,” Z. Naturforsch. B 1954, 9b, 678-681.

(20) Derbisher, G. V.; Babaeva, A. V. “Reaction of hexachlorotriphosphazene and its derivatives with platinum complexes” Russ. J. Inorg. Chem. 1965, 10, 1194-1195.

(21) Coxon, G. E.; Sowerby, D. B. “Cyclic inorganic compounds. VIII. Aluminum tribromide addition compounds of hexabromo- and hexachloro- triphosphonitriles” J. Chem. Soc. A 1969, 3012-3014.

(22) Kravchenko, E. A.; Levin, B. V.; Bananyarly, S. I.; Toktomatov, T. A. “NQR study of compounds of phosphonitrile chlorides with antimony pentachloride and tantalum pentachloride” Koord. Khim. 1977, 3, 374-379.

(23) Kandermirli, F. “Synthesis and theoretical study of vanadium oxytrichloride complex of hexachlorophosphazene and ab initio investigations of some simple cyclic triphosphazenes” Phos. Sulf. Silicon 2003, 178, 2331-2342.

(24) Rivard, E.; Lough, A. J.; Manners, I. “A New, Convenient Synthesis of the Linear Phosphazene Salt [Cl3P:N:PCl3]Cl: Preparation of Higher Linear Homologues [Cl3P=N-(PCl2=N)x=PCl3]Cl (x = 1-3) and the 16-Membered Macrocycle [NCCl(NPCl2)3]2” Inorg. Chem. 2004, 43, 2765-2767.

(25) Heston, A. J.; Panzner, M.; Youngs W. J.; Tessier, C. A. “Lewis acid adducts of [PCl2N]3” Inorg. Chem. 2005, 44, 6518-6520.

(26) Zhang, Y.; Tham, F. S.; Reed, C. A. “Phosphazene Cations” Inorg. Chem. 2006, 45, 10446-10448.

(27) Gonsior, M.; Antonijevic, S.; Krossing, I. “Silver Complexes of Cyclic Hexachlorotriphosphazene” Chem. Eur. J. 2006, 12, 1997-2008.

(28) Reference 20 (a).

(29) Paddock, N. L.; Searle, H. T. “Phosphonitrilic halides and their derivatives” Adv. Inorg. Chem. Radiochem. 1959, 1, 347-83.

(30) (a) Allcock, H. R. “Complex and adduct formation,” Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapter 11. (b) Allcock, H. R. “Friedel- Crafts substitutions” Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapter 10. (c) Allcock, H. R. “Phosphazenes as Brönsted-Lowry Bases” Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapter 12. (d) Chadrasekhar, V.; Krishnan, V. “Coordination chemistry of phosphazenes” in Phosphazenes: A Worldwide Insight, Gleria, M. De Jaeger, R., eds.; Nova Science: New York, 2004, Chapter 7, pp 159-184.

(31) Feakins, D.; Last, W. A.; Neemuchwala, N.; Shaw, R. A. “Basicities and structural effects in phosphazene derivatives” Chemistry & Industry 1963, 164- 165.

(32) Heston, A. J.; Panzner, M.; Youngs W. J.; Tessier, C. A. “Acid-base chemistry of [PCl2N]3” Phosphorus, Sulfur Silicon Rel. Elem. 2004, 179, 831-837.

(33) Gleria, M.; De Jaeger, R., eds. Phosphazenes a Worldwide Insight, Nova Science: New York, 2004; Chapter 34, 828-832.

(34) Olah, G. A. Sommer, J Superacids; Wiley: New York, 1985.

(35) Molnar, A.; Olah, G. A.; Surya Prakash, G. K.; Sommer, J. “General Aspects” and “Superacid Systems” Superacids, 2nd ed.; Wiley: New York, 2009; Chapters 1-2.

(36) Hammett, L. P.; Deyrup, A. J. Am. Chem. Soc. 1932, 54, 2721-2739

(37) (a) Stoyanov, E. S.; Kim, K.-C., Reed, C. A. “An infrared υNH for weakly basic anions. Implications for single-molecule acidity and superacidity,” J. Am. Chem. Soc. 2006, 128, 8500-8508. (b) Juhasz, M.; Hoffmann, S.; Stoyanov, E.; Kim, K.; Reed, C. A. “The Strongest Isolable Acid” Angew. Chem. Int. Ed. 2004, 43, 5352-5355.

(38) Liu, H. Q.; Stannett, V. T. “Radiation polymerization of hexachlorotriphosphazene” Macromolecules 1990, 23, 140-144.

(39) (a) Andrianov, A. K.; Chen, J.; LeGolvan, M. P. “Poly(dichlorophosphazene) as a precursor for biologically active polyphosphazenes: synthesis, characterization and stabilization” Macromolecules 2004, 37, 414-420. (b) Allcock, H. R.; Kugel, R. L.; Valan, K. J. “Phosphonitrillic compounds. VI. High- molecular-weight poly(alkoxy- and aryloxyphosphazenes)” Inorg. Chem. 1966, 5, 1709-15. (c) Hagnauer, G. L.; Koulouris, T. N. “Polyphosphazene polymerization studies using high performance GPC” in Liquid Chromatography of Polymers and Related Materails III, Cazes, J., ed.; Marcel Dekker: New York, 1985; pp 99-114. d) Liu, H. Q.; Stannett, V. T. “Radiation ploymerization of hexachlorocyclotriphosphazene” Macromolecules 1990, 23, 140-144. e) Hagnauer, G. L. “Polydichlorophosphazene polymerization studies,” J. Macromol. Sci.-Chem. 1981, A16, 385-408.

(40) (a) Yamamoto, H.; Ishihara, K. eds.; Acid Catalysis in Modern Organic Synthesis, Vol. 1 and 2, Wiley-VCH: New York, 2008. (b) Olah, G. A. Friedel- Crafts Chemistry, Wiley & Sons: New York, 1973.

(41) Heston, A. J. Lewis and Brønsted Acid Adducts of Hexachlorotriphosphazene and Carboxylate Derivatives of Disilanes. PhD Dissertation, University of Akron, Akron, OH, 2005.

(42) Tun, Z. Interactions of Group 13 Lewis Acids with Hexachlorocyclotriphosphazene. MS Thesis, University of Akron, Akron, OH, 2008.

CHAPTER II

MECHANISTIC STUDIES OF THE FLUXIONAL BEHAVIOR OF GROUP 13

LEWIS ACID ADDUCTS OF [PCl2N]3

Reproduced in part with permission from [Tun, Z; Heston, A.; Panzner, M;

Medvetz, D; Wright, B.; Savant, D.; Dudipala, V.; Banerjee, D.; Rinaldi, P.;

Youngs, W.; Tessier, C. Inorg. Chem. 2011, 50, 8937–8945]. Copyright [2011]

American Chemical Society.

2.1. Introduction

An important route to phosphazene polymers involves the ring-opening

polymerization (ROP) of [PCl2N]3 to produce the parent polymer [PCl2N]n, which

is then functionalized.1 The mechanism of the ROP, which can take place both

with or without a catalyst or initiator, is still the subject of some controversy.1,2,3

We have embarked on a project to better understand the species that have been

proposed as intermediates in the ROP of [PCl2N]3. Chart 2.1 shows four such

species. Phosphazenium ion 1 has been proposed as intermediate in the most commonly accepted mechanism of the uncatalyzed ROP.1 Though species 1

never has been isolated, a base-stabilized hexacation, in which all six chlorides

4 of [PCl2N]3 were ionized, has recently been reported. The phosphazenium ion 2 29 and the isomeric adduct 3 have been proposed as intermediates in the Lewis- acid (LA) initiated ROP.5 In fact, compounds of structure 3, in which the LA is a silyl cation are catalysts or initiators for the ROP and allow it to proceed at room temperature.6 Ion 2 can be viewed as a stabilized analog of 1 in which the Cl- anion is replaced by a more weakly coordinating anion (LA(Cl)-). Interestingly, 2 also has been proposed as an intermediate in the AlCl3-catalyzed Friedel-Crafts

7 substitution of [PCl2N]3. Cation 4 has been proposed in an alternative mechanism of the ROP to explain that small quantities of water are required in the ROP.2,3 Structure 4 is simply a variant of 3, in which the Lewis acid is H+.

Cl LA(Cl) Cl N Cl N P P P P Cl Cl Cl Cl N N N N P P Cl Cl Cl Cl 1 2 LA = Lewis acid LA H Cl Cl N Cl Cl N P P P P Cl Cl Cl Cl N N N N P P Cl Cl Cl Cl 3 4

Chart 2.1. Proposed Intermediates in the ROP of [PCl2N]3.

It has been known for a long time that the nitrogen atoms of [PCl2N]3 are

weak Lewis and Brönsted bases.8 Though a number of reactions between

9,10 [PCl2N]3 and Lewis acids had been reported, it was only recently that such

compounds have been characterized well enough to know whether their

structures are 2-4 or other possibilities. Within the last seven years, we

communicated our studies, including crystal structures, of the adducts formed

+ 11 from the reactions of [PCl2N]3 and the Lewis acids AlCl3, GaCl3 and H . Since

+ + + + then, crystal structures of adducts of Ag , SiMe3 , Me and H have been

reported.6,12 All these recent studies are consistent with the structure 3 or its

variant 4. Herein we describe complete characterization of the adducts

. [PCl2N]3 MX3, including variable temperature NMR, dynamic NMR, and X-ray

crystallographic studies.

2.2. Experimantal

This section describes the general experimental methods, materials used,

characterization techniques and syntheses.

2.2.1. General Experimental Methods

All manipulations were carried out under vacuum or under dry and

oxygen-free argon or nitrogen atmosphere, applying standard anaerobic

techniques such as Schlenk, vacuum line and glove-box techniques.13,14 The

vacuum line had the ultimate capacity of 2x10-4 torr. The atmosphere of the

glove box was routinely checked by a light-bulb test, and the oxygen and

moisture content inside the box was kept between 1 and 5 ppm. After being

dried in the oven overnight, the glassware was assembled hot and evacuated

immediately, or directly placed in the port of the glove-box, evacuated and

assembled in the glove-box. The glassware used for the experiments was made

with virtually greaseless Fisher-Porter Solv-seal glass joints. High vacuum

valves on the flasks were purchased from Kimble-Kontes. Infrared spectra were

collected on a Nicolet Nexus 870 Fourier transform spectrometer.

2.2.2. Materials

Hexane and methylene chloride (Fisher) were purified by using a solvent

system manufactured by PureSolvTM. Deuterated methylene chloride (99.9%)

and deuterated chloroform (99.8%) were purchased from Cambridge Isotopes,

distilled three times over freshly activated 4 Å molecular sieves and stored under

argon in foil-wrapped storage tubes in the glove box. Aldrich products BBr3,

BCl3, and PCl5 were used as received. [PCl2N]3, AlCl3, AlBr3, and InCl3 (Aldrich) and GaCl3 (Strem) were purified via sublimation and stored in the glove-box.

2.2.3. NMR Spectroscopy

Some of the NMR spectra were taken by Dr. Deepa Savant. NMR samples were prepared in the glove-box and all NMR tubes were flame sealed under vacuum. In order to minimize the presence of protonated impurities, NMR

. samples of [PCl2N]3 MX3 were made within 24 hours of the adduct’s preparation.

The NMR spectra were either taken immediately after the NMR samples were

prepared or the tube was kept frozen (liquid nitrogen) until the spectra were

taken. Routine NMR spectra were obtained using Varian Gemini 300 MHz or

INOVA 400 MHz instruments at 25 °C. VT NMR data were obtained on a Varian

INOVA 400 MHz NMR spectrometer with a 5 mm switchable probe. Proton NMR

spectra were referenced to the residual proton resonance of the deuterated

solvent. External references were used for the other nuclei: 0.15 M H3PO4

31 solution in deuterated solvent (0 ppm) for the P spectra, and 1 M AlCl3 solution in deuterated water (0 ppm) for the 27Al spectra, respectively. 31P NMR spectra were collected with continuous decoupling because of the nuclear Overhauser effect (NOE). WinDNMR software15 was used for simulating the 31P VT NMR

. spectra of [PCl2N]3 MX3.

2.2.4. X-ray Crystallography

X-ray crystallography was performed by Dr. Matthew J. Panzner, Dr. Doug

A. Medvetz and Brian D. Wright. In the glove box, the air-sensitive crystals were put into Paratone oil on a slide. The slide was transported from the glove-box to

the instrument in a desiccator that was wrapped in aluminum foil because of the

light sensitivity of the crystals. The crystals were immediately mounted in low

light and the data collection took place with the laboratory lights turned off.

Crystal structure data sets were collected on a Bruker Apex CCD

diffractometer with graphite-monochromated Mo Kα radiation (λ = 0.71073Å).

Unit cell determination was achieved by using reflections from three different

orientations. An empirical absorption correction and other corrections were done

using multi-scan SADABS. Structure solution, refinement and modeling were

accomplished using the Bruker SHELXTL package.16 The structures were

obtained by full-matrix least-squares refinement of F2 and the selection of

appropriate atoms from the generated difference map.

2.2.5. Mass spectrometry

Mass spectrometry was performed by Vincenzo Scionti. Samples were prepared in the glove box and transferred to the spectrometer in a desiccator.

MS spectra were acquired with a SYNAPT HDMSTM Q/ToF mass spectrometer

(Waters, Beverly, MA) equipped with a z-spray electrospray source. The instrument was operated at a voltage of 3.5 kV, sample cone voltage of 35 V and extraction cone voltage of 3.5 V; the desolvation gas flow was 800 L/h (N2) and

the source temperature was 90 °C. The sample flow rate was set at 10 μL/min.

The concentration of the electrosprayed samples was 0.2 mg/mL in dry CHCl3.

. 2.2.6. Preparations of [PCl2N]3 MX3

. . [PCl2N]3 AlCl3 and [PCl2N]3 GaCl3 were synthesized following our

11 . published procedures. [PCl2N]3 AlBr3 was synthesized with a slight modification

of the said procedures by using AlBr3. In order to avoid protonated impurities,

high vacuum line and glove box techniques were used as much as possible

instead of the Schlenk line, and the above mentioned precautions were taken in

. the preparation of NMR samples. Because the three [PCl2N]3 MX3 (MX3 = AlCl3,

AlBr3 or GaCl3) adducts are light sensitive, exposure to light was minimized throughout all phases of the work. For AlCl3 and AlBr3, the adduct syntheses can be done using either hexane or CH2Cl2 as solvent. However adduct formation was observed only in hexane for GaCl3. Caution: It has been reported that AlBr3

reacts exothermically with CH2Cl2. We have never observed such a reaction in

these systems when following our published procedures.17

. 31 [PCl2N]3 AlBr3: Yield: 87%. MP: 174-175 °C. P NMR (CDCl3) at 0 °C: δ 26.7

27 ppm (d), 16.7 ppm (t). Al NMR (CDCl3) at 30 °C: δ 100.6 ppm (b, s).

. 31 [PCl2N]3 AlCl3: Yield: 90%. MP: 128-130 °C. P NMR (CDCl3) at 0 °C: δ 26.8

27 ppm (d), 16.6 ppm (t). Al NMR (CDCl3) at 30 °C: δ 100.9 ppm (b, s).

. 31 [PCl2N]3 GaCl3: Yield: 80%. MP: 126-127 °C. P NMR (CDCl3) at -55 °C: δ 25.28

ppm (d), δ 16.08 ppm (t).

2.3. Results and Discussion

The reaction of MX3 (MX3 = AlCl3, AlBr3 or GaCl3) and [PCl2N]3 with

rigorous exclusion of water gave 1:1 complexes as colorless crystals (Equation 35

2.1). Hexane was a useful solvent for the preparation of all three adducts but only the AlCl3 and AlBr3 adducts could be prepared in CH2Cl2. A published

. assertion that the adduct [PCl2N]3 GaCl3 could not be prepared may have been

18 due to the use of an inappropriate solvent. That work used CH2Cl2 throughout

. as the solvent. [PCl2N]3 AlBr3 had been prepared in nonpolar CS2 and our IR spectral data is in agreement with the data in this report.9a Contrary to a previous

9i report, we were unable to isolate compounds of other stoichiometries with AlCl3.

However the previous work was done in air. No adducts other than the 1:1 could be isolated with AlBr3.

Cl Cl MX P 3 N N MX3 + [PCl2N]3 Cl Cl P P Cl N MX = AlCl , AlBr , GaCl Cl 3 3 3 3 (2.1)

. The three [PCl2N]3 MX3 adducts had melting points that were different from those of their respective reagents. The adducts are insoluble in hexane, have some solubility in aromatic solvents and have good solubility in CH2Cl2 and

CHCl3.

. The three [PCl2N]3 MX3 adducts were water and light sensitive in solution

. and in the solid state. It was not possible to obtain completely pure [PCl2N]3 MX3 adducts, especially in the chlorinated solvents. Electrospray ionization mass

. + spectrometry spectra of the three [PCl2N]3 MX3 show (H[PCl2N]3) cation in the 36

positive mode. NMR spectra also showed the presence of, at least, traces of

. . [PCl2N]3 HMX4 impurities. [PCl2N]3 HMX4 species will be discussed in Chapter III.

The impurities were observed in spite of the fact that the NMR tubes were

prepared in a glove box (whose atmosphere was regularly tested) and flame

sealed under vacuum, and the NMR spectra were either taken immediately after

the NMR samples were prepared or the tube was kept frozen until the spectra

. were taken. We now understand that the presence of the [PCl2N]3 HMX4

. byproducts in the NMR studies of [PCl2N]3 MX3 appears to be largely due to the

fact that we must flame-seal the NMR tubes. The heating of the tube liberates

. . water, which reacts with [PCl2N]3 MX3 to give the [PCl2N]3 HMX4 impurities. (We

have tried to use NMR tubes with vacuum-tight Teflon valves for the variable

temperature work but the Teflon shrinks at the low temperatures and leaks

occur.) In addition, the combination of chloromethanes with AlCl3 or AlBr3 give

very reactive species, sometimes called superelectrophiles, which may account

19 for the higher prevalence of impurities in CH2Cl2 and CHCl3. It has been

reported that AlBr3 reacts exothermically with CH2Cl2 to give AlCl3 and

20 . CH2BrCl. We observed no such reactions of [PCl2N]3 AlBr3 with CH2Cl2.

The reactions of [PCl2N]3 with other Lewis acids were examined. It is

clear that only stronger Lewis acids21 form complexes with the weak base

[PCl2N]3. A BCl3 adduct has been proposed as an intermediate in the BCl3

5 initiated ROP of [PCl2N]3 but such an adduct could not be isolated, even in

hexane. Adducts of [PCl2N]3 could not be isolated with the Lewis acids BBr3,

15 InCl3, and PCl5. Because a reaction that involved SbF5 and [PCl2 N]3 gave 37 evidence by NMR for the formation of PF2 groups, reactions of [PCl2N]3 with other fluoride containing Lewis acids were not examined. Even after repeated attempts that included the use of freshly distilled SbCl5 in an all glass vessel, the only complex we have been able to isolate from the reaction of SbCl5 with

[PCl2N]3 was of structure 4 (Chart 2.1), which forms in the presence of water.

This will be described in Chapter V.

2.3.1. X-ray Crystal Structures

. The thermal ellipsoid plot for the crystal structure of [PCl2N]3 AlBr3,

. . [PCl2N]3 AlCl3 and [PCl2N]3 GaCl3 are given in the Figures 2.1, 2.2, and 2.3

. respectively. Selected distances and angles of the three [PCl2N]3 MX3 are given

. . in Table 2.1. The asymmetric units of [PCl2N]3 AlCl3 and [PCl2N]3 AlBr3 contain

. half of two different molecules whereas that of [PCl2N]3 GaCl3 contains two different molecules. In each case, the only statistically significant differences between the different molecules are in the dihedral angles of the nonplanar rings.

. The three [PCl2N]3 MX3 molecules have structure 3 (Chart 2.1). The Al-N

. bonds of [PCl2N]3 AlCl3 (1.983(3) and 1.970(3), average = 1.977 Å) are shorter

. than those of [PCl2N]3 AlBr3 (1.995(3) and 1.992(3), average = 1.994 Å). The

. latter distance is only slightly shorter than the Ga-N bonds of [PCl2N]3 GaCl3

(2.050(3) and 2.044(3), average = 2.047 Å). The distances between the group

13 and the nitrogen atoms are in the range of dative bonds (M = Al, 1.94-2.10

Å22; M = Ga, 1.95-2.20 Å18,23 in four-coordinate compounds). When compared to distances in other MCl3 adducts of nitrogen-containing bases, the M-N bonds of 38

. both [PCl2N]3 MCl3 (M = Al, Ga) are relatively long and suggest weaker

interactions. In addition, the Al-N distances can be compared to those computed

. . for [PH2N]3 AlF3 at 1.901 Å and for [P(OH)2N]3 AlF3 at 1.896 or 1.949 Å

(depending on the level of theory).24 In these two adducts, both the Lewis acid

. and the Lewis base are stronger than those in the three [PCl2N]3 MX3 reported

herein.

. The phosphazene rings in the [PCl2N]3 MX3 adducts have slight chair-like

structures in which the nitrogen atom bound to the Group 13 element (N(1)) and

the opposite phosphorus atom are below and above the plane of the remaining

ring atoms (Figures 2.1 (b), 2.2 (b) and 2.3(b)). The nitrogen atom bound to MX3

is bent away from this plane (dihedral angles: AlCl3: 19.7˚ and 17.5˚, AlBr3: 21.2° and 19.3˚, GaCl3: 21.6˚ and 20.0˚) to a greater extent than the opposite

phosphorus atom (dihedral angles are AlCl3: 11.3˚ and 3.5˚, AlBr3: 13.8° and

11.5˚, GaCl3: 7.68˚ a nd 13.9˚). Because of the large difference of the latter

. dihedral angle for the two molecules of [PCl2N]3 AlCl3 and the two molecules of

. [PCl2N]3 GaCl3, packing forces would appear to be at least partially responsible for the ring bending.

. In other ways, the structures of the three [PCl2N]3 MX3 adducts are similar.

. The distribution of multiple bond character in the rings of [PCl2N]3 MX3 is more

accurately shown in Equation 1 than in drawing 3. The P-N bonds that flank the

. M-N bond show single bond character, both at 1.6521(14) Å in [PCl2N]3 AlCl3,

. both at 1.6532(15) in [PCl2N]3 AlBr3 and ranging 1.648(3)-1.650(3)Å (average =

. 1.649 Å) in [PCl2N]3 GaCl3. The remaining P-N bonds show multiple bond

. character ranging 1.561(2)-1.572(2)Å (avg. 1.567 Å) for [PCl2N]3 AlCl3, 1.562(2)-

. 1.575(2) (average = 1.569 Å) for [PCl2N]3 AlBr3 and 1.566(4)-1.576(3)Å (avg. =

. 1.570 Å) for [PCl2N]3 GaCl3. Though there may be a slight alternation in the

multiply bonded P-N distances, the values are all within experimental error of one

another. These distances are similar to those in [PCl2N]3 (1.5795(16) –

1.5822(17) Å, average = 1.581 Å25). The P-N-P angle at the nitrogen atom bound to MX3 (all within 1.1° of 117.1°) is smaller than the P-N-P angles at the free nitrogen atoms in the adducts (all within 1.1° of 124.5°) or in the free ring

(average = 121.2°25). All N-P-N angles in the three adducts (all within 0.8° of

115.9°) decrease ~2° from those in the free ring (average = 118.41°)25. Similar

changes in ring geometry to those described above have been observed for

12,26 adducts of [PCl2N]3 and other phosphazene rings.

(a)

(b)

. Figure 2.1. (a) Thermal ellipsoid plot for the crystal structure of [PCl2N]3 AlBr3, (b) . Chair-like structure of [PCl2N]3 AlBr3.

(a)

(b)

. Figure 2.2. Thermal ellipsoid plot for the crystal structure of [PCl2N]3 AlCl3, (b) . Chair-like structure of [PCl2N]3 AlCl3.

(a)

(b)

. Figure 2.3. Thermal ellipsoid plot for the crystal structure of [PCl2N]3 GaCl3, (b) . Chair-like structure of [PCl2N]3 GaCl3.

. Table 2.1. Selected distances (Å) and angles in [PCl2N]3, [PCl2N]3 AlBr3, . . [PCl2N]3 AlCl3 and [PCl2N]3 GaCl3.

a . . . [PCl2N]3 [PCl2N]3 AlBr3 [PCl2N]3 AlCl3 [PCl2N]3 GaCl3 Al(1)-N(1) 1.995(3) Al(1)-N(1) 1.983(3) Ga(1)-N(1) 2.050(3) Al(2)-N(4) 1.992(3) Al(2)-N(3) 1.970(3) Ga(2)-N(4) 2.044(3)

P-N distances that flank the nitrogen atom that is bound to MX3 P(1)-N(1) 1.6527(15) P(1)-N(1) 1.6515(15) P(1)-N(1) 1.644(3) N(1)-P(1)#1 1.6527(15) N(1)-P(1)#1 1.6515(15) P(2)-N(1) 1.650(3) N(4)-P(3)#2 1.6520(15) N(3)-P(3) 1.6527(14) P(4)-N(4) 1.646(3) P(3)-N(4) 1.6520(15) P(3)#1-N(3) 1.6527(14) P(5)-N(4) 1.644(3) P-N distances Other P-N bond distances P(2)-N(1) 1.575(3) P(1)-N(2) 1.562(2) P(1)-N(2) 1.561(2) P(1)-N(3) 1.567(3) P(2)-N(2) 1.575(4) P(2)-N(2)#1 1.576(2) P(2)-N(2)#1 1.572(2) P(2)-N(2) 1.567(3) P(1)-N(2) 1.575(4) P(2)-N(2) 1.576(2) P(2)-N(2) 1.572(2) P(3)-N(2) 1.571(3) P(3)-N(3) 1.563(2) P(3)-N(4) 1.560(2) P(3)-N(3) 1.576(3) P(4)-N(3) 1.577(2) P(4)-N(4) 1.574(2) P(4)-N(6) 1.562(3) P(4)-N(3)#2 1.577(2) P(4)-N(4)#1 1.574(2) P(5)-N(5) 1.563(4) P(6)-N(6) 1.568(4) P(6)-N(5) 1.576(4)

P-N-P angles for N bound to MX3 P(1)#1-N(1)-P(1) 117.01(17) P(1)#1-N(1)-P(1) 117.68(16) P(2)-N(1)-P(1) 118.3(2) P(3)#2-N(4)-P(3) 117.85(16) P(3)-N(3)-P(3)#1 117.18(15) P(4)-N(4)-P(5) 118.1(2) P-N-P angles Other P-N-P angles P(2)-N(1)-P(2’) 121.2(4) P(1)-N(2)-P(2) 123.77(17) P(1)-N(2)-P(2) 125.33(13) P(1)-N(3)-P(3) 123.9(2) P(1)-N(2)-P(2) 121.5(3) P(3)-N(3)-P(4) 124.71(14) P(3)-N(4)-P(4) 124.48(13) P(2)-N(2)-P(3) 124.2(2) P(5)-N(5)-P(6) 124.7(2) P(4)-N(6)-P(6) 125.0(2) N-P-N angles N-P-N angles N(2)-P(1)-N(2’) 118.3(2) N(2)-P(1)-N(1) 116.48(12) N(2)-P(1)-N(1) 116.48(11) N(2)-P(2)-N(1) 116.07(18) N(1)-P(2)-N(2) 118.5(3) N(2)-P(2)-N(2)#1 115.79(15) N(2)-P(2)-N(2)#1 115.40(15) N(3)-P(1)-N(1) 115.37(18) N(3)-P(3)-N(4) 116.14(12) N(4)-P(3)-N(3) 116.49(11) N(2)-P(3)-N(3) 115.87(18) N(3)-P(4)-N(3)#2 115.21(16) N(4)-P(4)-N(4)#1 115.44(15) N(6)-P(4)-N(4) 115.60(19) N(5)-P(5)-N(4) 116.11(19) N(6)-P(6)-N(5) 115.51(19) a. reference 23

2.3.2. NMR Studies

. A variety of NMR studies were carried out on [PCl2N]3 MX3. Figure 2.4

31 15 . shows the P NMR spectra of the three [PCl2 N]3 MX3 adducts and that of

15 27 15 . [PCl2 N]3 in C6D6 solution at 25 ºC. The spectral data of [PCl2 N]3 MX3

15 . indicate that the [PCl2 N]3 MX3 structures are fluxional in solution which is

15 . consistent with the behavior of most MX3-base adducts. If the [PCl2 N]3 MX3

adducts had rigid structures in solution, a triplet and a doublet resonances would

be observed in their 31P solution NMR spectra. However, only a singlet was

15 . 15 . observed in the spectra of [PCl2 N]3 AlCl3 and [PCl2 N]3 GaCl3. The spectrum

15 . of [PCl2 N]3 AlBr3 shows the two resonances expected for a rigid structure, but

the broadness of the spectrum indicates that an exchange process is taking

15 . place in [PCl2 N]3 AlBr3 as well. The exchange is fastest in the case

15 . [PCl2 N]3 GaCl3, as evidenced by the sharp singlet resonance.

31 15 15 . Figure 2.4. P NMR spectra at 25 ºC in C6D6 (a) [PCl2 N]3, (b) [PCl2 N]3 GaCl3, 15 . 15 . 27 (c) [PCl2 N]3 AlCl3, (d) [PCl2 N]3 AlBr3. 45

To study the fluxionality of the adducts without the added complications of

higher order coupling effects, 31P VT NMR spectra of unlabeled adducts were

31 . taken. Figure 2.5 shows the P VT NMR spectra of [PCl2N]3 AlBr3 in CDCl3

obtained at 25 °C, 0 °C, -20 °C, and -40 °C. The numbering scheme for the

atoms in the crystal structure (Figure 2.1) will be used to explain the NMR

spectra. At 25 °C, two resonances at 27.1 ppm for P(1) and P(1A), and 16.9

ppm for P(2) were observed, however the rate of exchange was greater than the

coupling constant and no coupling was seen. The J-coupling starts to appear at

0 °C, and the resonance at 26.7 ppm became a doublet and the resonance at

16.7 ppm became a triplet. The exchange was slow at -20 °C, and all the expected J-coupling were observed with a well resolved doublet at 26.5 ppm and a triplet at 16.5 ppm along with a singlet at 17.6 ppm. At -40 °C, the doublet was seen at 26.2 ppm, whereas the triplet was at 16.2 ppm and the singlet was at

17.3 ppm. The singlet was due to protonated impurities in the product.

31 . Figure 2.5. P VT NMR spectra of [PCl2N]3 AlBr3 in CDCl3 taken between -40 . and 25 °C. The singlet is [PCl2N]3 HAlBr4 (Chapter III).

31 . . P VT NMR spectra of [PCl2N]3 AlCl3 and [PCl2N]3 GaCl3 are shown in

. . Figures 2.6 and 2.7 respectively. [PCl2N]3 AlCl3 and [PCl2N]3 GaCl3 showed

. similar dynamic behavior to that of [PCl2N]3 AlBr3, although the exchange process

. . of [PCl2N]3 GaCl3 was found to be faster than those of [PCl2N]3 AlCl3 and

. 31 . [PCl2N]3 AlBr3. The saturation transfer study of P NMR of [PCl2N]3 AlCl3 was carried out to determine whether the singlet was involved in the exchange process. Selectively saturating the doublet resonance in the 31P NMR spectrum

. of [PCl2N]3 AlCl3 at -20 °C resulted in the saturation of the triplet resonance, but had no effect on the singlet resonance. This showed that the doublet and the triplet resonances are involved in the exchange process, whereas the singlet resonance is not. 47

31 . Figure 2.6. P VT NMR spectra of [PCl2N]3 AlCl3 in CDCl3 taken between -40 and . 25 °C. The singlet is [PCl2N]3 HAlCl4 (Chapter III).

31 . Figure 2.7. P VT NMR spectra of [PCl2N]3 GaCl3 in CDCl3 taken between -55 . and 35 °C. The singlet is [PCl2N]3 HGaCl4 (Chapter III). 48

Classically, fluxionality in MX3-base adducts occurs by dissociation of the

28 MX3 from the base. MX3 as the monomer or dimer can re-associate with the

base. This is shown in Figure 2.8 as the free MX3 route. Because [PCl2N]3 has

three nitrogen sites, exchange could be due to movement of MX3 among the

three sites. This is shown in Figure 2.8 as the bound MX3 route. The energy

involved in the exchange process for the free MX3 route should be significantly

greater than that of the bound MX3 route. In order to distinguish between the

. possibilities, activation parameters of the [PCl2N]3 MX3 exchange system were

obtained.

Cl Cl Cl Cl Cl Cl P MX3 P P N N N N MX N N 3 + Cl Cl Cl Cl Cl P P P P Cl P P Cl N Cl N Cl Cl N Cl Cl Free Bound MX MX3 3 MX3 Cl Cl Cl Cl P X3M P N N N N X X X 1/2 M M + Cl Cl Cl Cl X X X P P P P Cl N Cl Cl N Cl

. Figure 2.8. Possible scenarios for the fluxionality of [PCl2N]3 MX3.

. In order to derive the activation parameters of the [PCl2N]3 MX3 exchange systems, bandshape analyses were performed of the 31P VT NMR spectra of the

29 31 . systems. The P VT NMR spectra of [PCl2N]3 MX3 were simulated by using

15 . the WinDNMR software, Typical examples of the simulation for [PCl2N]3 AlBr3,

. . [PCl2N]3 AlCl3 and [PCl2N]3 GaCl3 are given in Figures 2.9, 2.10 and 2.11 49 respectively. To obtain a simulated spectrum, the chemical shift, the coupling constant, % population and line-width at half-height of each resonance was entered into the WinDNMR program and the rate constant value of the simulated spectrum was varied until the simulated spectrum visually matches the experimental spectrum at a specific temperature. The rate constant value that resulted in the match between the simulated and the experimental spectra is determined to be the rate constant of the exchange at that temperature. Tables

. showing the rate constants at various temperatures for [PCl2N]3 MX3 are given in

Tables 2.2, 2.3, and 2.4. Arrhenius plots and plots of ln(k/T) vs. 1/T using the

. rate constants gave the activation parameters for the [PCl2N]3 MX3 systems.

Activation energy, Ea of the adducts were obtained from Arrhenius plots using equation (2.2) and the ΔH‡ and ΔS‡ were obtained from the plots of ln(k/T) vs.

1/T using equations (2.3) and (2.4), respectively. In the equations mentioned above, R is the gas constant, kB is the Boltzmann’s constant, and h is the

Planck’s constant, respectively. Arrhenius plots and plots of ln(k/T) vs. 1/T of

. . [PCl2N]3 AlBr3 are shown in Figure 2.12, and similar plots for [PCl2N]3 AlCl3 and

. [PCl2N]3 GaCl3 are given in Figures 2.13 and 2.14.

(2.2)

(2.4)

31 . Figure 2.9. Simulation of P NMR spectrum of [PCl2N]3 AlBr3 at -40 °C in CDCl3 by WinDNMR Software. For clarity, the simulated spectrum is offset by about 2 ppm. The simulated spectrum was obtained with a rate constant of 6.

31 . Figure 2.10. Simulation of P NMR spectrum of [PCl2N]3 AlCl3 at -20 °C in CDCl3 by WinDNMR Software. For clarity, the simulated spectrum is offset by about 2 ppm. The simulated spectrum was obtained with a rate constant of 15.

31 . Figure 2.11. Simulation of P NMR spectrum of [PCl2N]3 GaCl3 at -55 °C in CDCl3 by WinDNMR Software. For clarity, the simulated spectrum is offset by about 3 ppm. The simulated spectrum was obtained with a rate constant of 50.

. Table 2.2. Rate constants of the exchange of [PCl2N]3 AlBr3 in CDCl3 derived from simulation of 31P NMR spectra at various temperatures.

T(°C) k -40 6 -20 65 0 195 25 610

. Table 2.3. Rate constants of the exchange of [PCl2N]3 AlCl3 in CDCl3 derived from simulation of 31P NMR spectra at various temperatures.

T(°C) k -20 15 0 15 30 155 40 880 55 1300

. Table 2.4. Rate constants of the exchange of [PCl2N]3 GaCl3 in CDCl3 derived from simulation of 31P NMR spectra at various temperatures.

T (°C) k -55 50 -50 65 -40 150 -20 360 0 3000 15 4500 25 8500 30 12000 35 20000

(a)

(b)

. Figure 2.12. (a) Arrhenius plot of [PCl2N]3 AlBr3 and (b) plot of ln(k/T) vs. 1/T of . [PCl2N]3 AlBr3. The data are in Table 2.2.

(a)

(b)

. Figure 2.13 (a) Arrhenius Plot of [PCl2N]3 AlCl3 and (b) Plot of ln(k/T) vs. 1/T of . [PCl2N]3 AlCl3. The data are in Table 2.3.

(a)

(b)

. Figure 2.14. (a) Arrhenius Plot of [PCl2N]3 GaCl3 and (b) Plot of ln(k/T) vs. 1/T of . [PCl2N]3 GaCl3. The data are in Table 2.4.

. Calculated activation parameters of [PCl2N]3 MX3 in CDCl3 solution are

‡ ‡ listed in Table 2.5. The values of Ea, ΔH , and ΔG in Table 2.5 were low and

roughly comparable to a hydrogen bond. The ΔH‡ values in Table 2.5 are about

four times smaller than those reported for the complete dissociation of MX3

complexes of amines and pyridines and those computed for complete

. . 28 dissociation of [PH2N]3 AlF3 and [P(OH)2N]3 AlF3. In agreement with the

saturation transfer experiment, these values suggest that the exchange in

. [PCl2N]3 MX3 is taking place through the intramolecular bound MX3 scenario

rather than through complete dissociation of the adduct (Figure 2.8). It is not

clear whether the MX3 can move directly from one nitrogen site to another of the

[PCl2N]3 ring, or whether MX3 binds to one or more lone pairs on the chlorine

atoms as it travels between the different nitrogen sites. Figure 2.15 shows two

possible intermediates for the bound MX3 scenario in the fluxionality of

. [PCl2N]3 MX3. As expected on the basis of their Lewis acidity towards hard

28 donors, ΔH values follow the sequence AlCl3 > AlBr3 > GaCl3.

. Table 2.5. Calculated activation parameters of the [PCl2N]3 MX3 exchange systems in CDCl3.

. . . [PCl2N]3 AlCl3 [PCl2N]3 AlBr3 [PCl2N]3 GaCl3

-1 -1 Ea (kJmol K ) 45.7 40.4 36.8 ΔH‡ (kJmol-1K-1) 43.3 38.3 34.6 ΔS‡ (Jmol-1K-1) -55.7 -61.3 -52.8 ΔG‡ (kJmol-1K-1) 59.9 56.5 50.4

Cl Cl X Cl Cl P X M P N N N N (or) X Cl Cl X Cl Cl P P P P M Cl N Cl Cl N Cl X X

Figure 2.15. Proposed intermediate for the bound MX3 scenario in the fluxionality . of [PCl2N]3 MX3.

. The results from the above NMR spectral studies for [PCl2N]3 MX3 can be

compared to those of other adducts of [PCl2N]3 and to studies of MX3 adducts of

borazines. Though activation parameters of exchange for adducts other than

. [PCl2N]3 MX3 have not been obtained, it appears that qualitatively the rate of

+ + + + exchange is in the order Me ≈ SiR3 < AlCl3 < AlBr3 < GaCl3 < Ag ≈ H , with

+ + 6,12 only Me and SiR3 showing static structures in solution (See also Chapter III).

An intramolecular exchange process in which the Lewis acid moves among the

three Lewis basic sites also was proposed to account for the solution fluxionality

. 30 . of [RBNR’]3 MX3 (MX3 = AlBr3 and GaCl3). It should be noted that [PCl2N]3 MX3

. and [RBNR’]3 MX3 have somewhat different structures. MX3 resides roughly in

. the plane of the [PCl2N]3 ring in [PCl2N]3 MX3 whereas AlBr3 is above the plane of

30,31 the [RBNR’]3 ring and is bound to the π-type system.

2.4. Conclusions

. Three [PCl2N]3 MX3 adducts have been synthesized from [PCl2N]3 and

. MX3. Only the strongest Lewis acids bind to [PCl2N]3. The [PCl2N]3 MX3 adducts

. are water and light sensitive and impurities of [PCl2N]3 HMX4 are difficult to avoid.

The adducts have been characterized by their physical properties and X-ray crystallography. VT NMR studies show that the adducts are fluxional in solution.

. Calculated activation parameters suggest that the exchange in [PCl2N]3 MX3 is

taking place through a scenario in which free MX3 is not generated. The fragility

. of [PCl2N]3 MX3 at or near room temperature suggests that such adducts are not

involved directly as intermediates in the high-temperature ROP of [PCl2N]3 to

give [PCl2N]n.

2.5. References

(1) Allcock, H. R. Chemistry and Applications of Polyphosphazenes, Wiley- Interscience: New York, 2003; Chapters 4 and 5.

(2) Hagnauer, G. L. J. Macromol. Sci-Chem. 1981, A16, 385-408.

(3) (a) Emsley, J.; Udy, P. B. Polymer 1972, I, 593-594. (b) Sulkowski, W. In Synthesis and Characterizations of Poly(organophosphazenes), Gleria, M.; De Jaeger, R., eds.; Nova Science: New York, 2004, Chapter 4.

(4) Boomishankar, R.; Ledger, J.; Jean-Baptiste Guilbaud, J.-B. Campbell, N. L.; Bacsa, J.; Bonar-Law, R.; Khimyak, Y. Z.; Steiner, A. Chem. Commun. 2007, 5152–5154.

(5) (a) Kayser Potts, M.; Hagnauer, G. L.; Sennett, M. S.; Davies, G. Macromolecules 1989, 22, 4235-4239. (b) Sennett, M. S.; Hagnauer, G. L.; Singler, R. E.; Davies, G. Macromolecules 1986, 19, 959-964.

(6) (a) Zhang, Y.; Tham, F. S.; Reed, C. A. Inorg. Chem. 2006, 45, 10446- 10448. (b) Zhang, Y.; Huynh, K.; Manners, I.; Reed, C. A. Chem. Commun. 2008, 494– 496.

(7) (a) Allcock, H. R. Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapter 10. (b) Bode, H.; Bach, H. Chem. Ber. 1942, 75B, 215-226. (c) Becke-Goerhring, M.; John, K. Z. Anorg. Allg. Chem. 1960, 304, 126-136.

(8) Allcock, H. R. Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapters 4, 10-12.

(9) (a) Coxon, G. E.; Sowerby, D. B. J. Chem. Soc. A 1969, 3012-3014. (b) Becke-Goehring, M.; Hohenschutz, H.; Appel, R. Z. Naturforsch. 1954, 9b, 678- 681. (c) Kravchenko, E. A.; Levin, B. V.; Bananyarly, S. I.; Toktomatov, T. A. Koord. Khim. 1977, 3, 374-379. (d) Kandemirli, F. Phosphorus, Sulfur, Silicon and the Related Elements 2003, 178, 2331-2342. (e) Hota, N. K.; Harris, R. O. J. Chem. Soc., Chem. Commun. 1972, 407-408. (f) Zhivukhin, S. M.; Kireev, V. V. Russ. J. Inorg. Chem. 1964, 9, 1439-1440. (g) Derbisher, G. V.; Babaeva, A. V. Russ. J. Inorg. Chem. 1965, 10, 1194-1195. (h) Baranwal, B. P.; Das, S. S.; Farva, U. Res. J. Chem. Environ. 2001, 5, 55-58. (i) Bode, H.; Bach, H. Chem. Ber. 1942, 75B, 215-226.

(10) (a) Bode, H.; Bütow, K.; Lienau, G. Chem. Ber. 1948, 81, 547-552. (b) Feakins, D.; Last, W. A.; Neemuchwala, N.; Shaw, R. A.; Chem. Ind. (London) 63, (c) Sayed, M. B. Internet J. Chem. 2002, (5), Paper No. 6.

(11) (a) Heston, A. J.; Tessier, C. A.; Panzner, M. J.; Youngs W. J. Phosphorus, Sulfur Silicon Relat. Elem. 2004, 179, 831-837. (b) Heston, A. J.; Panzner, M. J.; Youngs W. J.; Tessier, C. A. Inorg. Chem. 2005, 44, 6518-6520.

(12) Gonsior, M.; Antonijevic, S.; Krossing, I. Chem. Eur. J. 2006, 12, 1997-2008.

(13) Shriver, D. F.; Drexdon, M. A. The Manipulation of Air-Sensitive Compounds, 2nd ed.; Wiley: New York, 1986.

(14) Plesch, P. H. High Vacuum Techniques for Chemical Syntheses and Measurements, Cambridge University Press: New York, 1989.

(15) Reich, H. J. WINDNMR: NMR Spectrum Calculations Version 7.1.13; University of Wisconson, Madison, USA 2008.

(16) Sheldrick, G. M. SHELX97: Programs for Crystal Structural Analysis; University of Göttingen, Göttingen, Germany 1997.

(17) Reference 11(b).

(18) Rivard, E.; Lough, A. J.; Chivers, T.; Manners, I. Inorg. Chem. 2004, 43, 802-811.

(19) Akhrem, I.; Alexander Orlinkov, A. Chem. Rev. 2007, 107, 2037-2079.

(20) Mirda, D.; Rapp, D.; Kramer, G. M. J. Org. Chem., 1979, 44 (15), 2619- 2624.

(21) (a) Several scales of relative Lewis acidity have been proposed: Santelli, M.; Pons, J.-M. Lewis Acids and Selectivity in Organic Synthesis, CRC: New York, 1996, Chapter 1. (b) Olah, G. A.; Kobayashi, S.; Tashiro, M. J. Am. Chem. Soc. 1972, 94, 7448-7461. (c) Kobayashi, S.; Busujima, T.; Nagayama, S. Chem. Eur. J. 2000, 6, 3491-3494. (d) Chen, E. Y.-X.; Marks, T. J. Chem. Rev. 2000, 100, 1391-1434.

(22) (a) Schulz, S. Adv. Organomet. Chem. 2003, 49, 225-317. (b) Haaland, A. In Coordination Chemistry of Aluminum, Robinson, G. H., ed.; VCH: New York, 1993, 1-56. (c) Krossing, I.; Nöth, H.; Schwenk-Kircher, H.; Seifert, T.; Tacke, C. Eur. J. Inorg. Chem. 1998, 1925-1930. (d) Jonas, V.; Frenking, G.; Reetz, M. F. J. Am. Chem. Soc. 1994, 116, 8741-8753. (e) Haaland, A. Angew. Chem. Int. Ed. Engl. 1989, 28, 992-1007.

(23) Some recent examples: (a) Nogai, S.; Schwriewer, A.; Schmidbaur, H. Dalton Trans. 2003, 3165-3171. (b) Ogawa, A.; Fujimoto, H. Inorg. Chem. 2002,

41, 4888-4894. (c) Cheng, Q. M.; Stark, O.; Merz, M.; Fischer, R. A. J. Chem. Soc., Dalton Trans. 2002, 2933-2936. (d) Waltman, R. J.; Lengsfield, B.; Pacansky, J. Chem. Mater. 1997, 9, 2185-2196. (e) Luo, B.; Kucera, B. E.; Gladfelter, W. L. Chem. Commun. 2005, 3463-3465. (f) Carmalt, C. J.; Mileham, J. D.; White, A. J. P.; Williams, D. J. Dalton Trans. 2003, 4255-4260. (g) Tang, C. Y.; Downs, A. J.; Greene, T. M.; Marcahnt, S. Parsons, S. Inorg. Chem. 2005, 44, 7143-7150. (f) Tang, C. Y.; Downs, A. J.; Greene, Kettle, L.; Rankin, D. W. H.; Robertson, H. E.; Turner, A. R. Dalton Trans. 2006, 1204-1212. (g) Timoshkin, A. Y. Bettinger, H. F.; Schaefer, H. F. III Inorg. Chem. 2002, 41, 738- 747.

(24) Waltman, R. J.; Lengsfield, B.; Pacansky, J. Chem. Mater. 1997, 9, 2185- 2196.

(25) (a) Bullen, G. J. J. Chem. Soc. (A) Inorg. Phys. Theor. 1971, 1450-1453. (b) Bartlett, S. W.; Coles, S. J.; Davies, D. B.; Hursthouse, M. B.; Ibisoglu, H.; Kilic, A.; Shaw, R. A.; Un, I. Acta Cryst. 2006, B62, 321–329.

(26) (a) Chadrasekhar, V.; Venkatasbbaiah, K. In Applicative Aspects of Cyclophosphazenes, Gleria, M.; De Jaeger, R., eds.; Nova Science: New York, 2004, Chapter 7 (b) Allen, C. W. In The Chemistry of Inorganic Homo- and Heterocycles, Volume 2, Haiduc, I.; Sowerby, D. B. eds.; Academic: New York, 1987; Chapter 20.

(27) Heston, A. J. Lewis and Brønsted Acid Adducts of Hexachlorotriphosphazene and Carboxylate Derivatives of Disilanes. PhD Dissertation, University of Akron, Akron, OH, 2005.

(28) (a) Tuck, D. In Chemistry of Aluminium, Gallium, Indium and Thallium, Downs, A., ed.; Blackie Academic & Professional: London, 1993, Chapter 8. (b) Davydova, E. I.; Sevastianova, T. N.; Suvorov, A. V.; Timoshkin, A.Y. Coord. Chem. Rev. 2010, 254, 2031–2077. (c) Haarland, A. In Coordination Chemistry of Aluminum, Robinson, G. H. ed.; VCH: New York, 1993, Chapter 1. (d) Haarland, A. Angew. Chem. Int. Ed. Engl. 1989, 28, 992-1007.

(29) Sandstrom, J. Dynamic NMR Spectroscopy, Academic: New York, 1984; Chapter 6.

(30)(a) Anton, K.; Fuβstetter, H.; Nöth, H. Chem. Ber. 1981, 114, 2723-2730. (b) Anton, K.; Nöth, H. K. Chem. Ber. 1982, 115, 2668-2673. (c) Gemünd, B.; Günther, B.; Nöth, H. ARKIVOC 2008, (5), 136-152.

(31) Lisovenko, A.; Timoshkin, A. Inorg. Chem. 2010, 49, 10357–10369.

CHAPTER III

GROUP 13 SUPER ACID ADDUCTS OF [PCl2N]3

3.1. Introduction

Most phosphazene compounds, including the important

polyphosphazenes, are prepared from chlorophosphazenes.1 In order to

understand the difficulties in the synthesis, storage and handling of the parent

polymer [PCl2N]n, we have been studying the fundamental acid-base

chemistry of chlorophosphazenes. A poorly understood aspect of

chlorophosphazene chemistry is the role that Brønsted acids play. Various

Brønsted acids have been added to the ring-opening polymerization (ROP) of

[PCl2N]3 and [PCl2N]4 to give [PCl2N]n. The acids behave as

initiators/catalysts,2 retardants3 or show little effect. Unspecified Brønsted acids are impurities in freshly prepared mixtures of rings [PCl2N]n (n ≈ 3-6)

and linear oligomers,4,5 may be involved in the otherwise uncatalyzed ROP of

6 [PCl2N]3 and [PCl2N]4 to give polymeric [PCl2N]n, and lead to the degradation

7 of polymeric [PCl2N]n on prolonged storage.

The most obvious role for a Brønsted acid in the above chemistry would be to protonate the chlorophosphazenes. Most reports indicate that halogen- substituted phosphazenes have very low basicities. The basicities of [PCl2N]3

8,9,10 and [PCl2N]4 were reported as too weak to measure. Complexes between

11 12 the superacids HAlBr4, HClO4, and H[CB11R5X6] (R = H, Me, X; X = Cl,

13 Br) with [PCl2N]3 have been reported. Protonation at a nitrogen atom to

+ yield H[PCl2N]3 has been observed in all cases where X-ray crystal structures

have been obtained.

The superacids in this chapter are conjugate Brønsted–Lewis

14 superacids, which will be denoted as HMXm+1. They are prepared from the

combination of a Lewis acid MXm and a Brønsted acid HX. HAlBr4 mentioned

above is such an acid. There is no universal agreement on how to refer to

conjugate Brønsted–Lewis superacids. We use the general formula HMXm+1

. to refer to these superacids because the crystal structures of [PCl2N]3 HMXm+1

that we report below suggest that the acid can be defined as the two species

+ - H and MXm+1 , at least in the solid state. Other researchers name such superacids as HX/MXm or HX-MXm to emphasize their source and because the

+ - solutions of such acids usually contain more species than just H and MXm+1

.14

In our studies of the reactions of Group 13 Lewis acids MX3 (MX3 =

AlCl3, GaCl3, AlBr3) with [PCl2N]3, we have observed two types of products.

As described in Chapter II, and with the most rigorous exclusion of water, the

. 15 adducts [PCl2N]3 MX3 are the major products. When water is present or

. when HX is added, [PCl2N]3 HMX4 forms, where HMX4 are known

superacids.16 Herein we describe the syntheses and complete

. characterization of the three [PCl2N]3 HMX4. As mentioned above, our

. research group briefly communicated preliminary work on [PCl2N]3 HAlBr4.

The HMX4 species mentioned here are recognized as superacids. The

comparison of their acid strengths with those of selected superacids based on

a qualitative method is discussed in Chapter V.

3.2. Experimental

This section describes the general experimental methods, materials used,

characterization techniques and syntheses.

3.2.1. General Experimental Methods

All manipulations were performed under argon, nitrogen, or vacuum using

standard anaerobic techniques such as Schlenk, vacuum line and glove-box techniques.17,18 The vacuum line had an ultimate capability of 2x10-4 torr. The

atmosphere of the glove-box was routinely checked by a light-bulb test, and the

oxygen and moisture content inside the glove-box was kept between 1 and 5

ppm. All glassware was dried in the oven overnight (~120oC). Reaction apparati

were either assembled hot and were immediately subjected to vacuum on the

Schlenk line, or the hot glassware was placed in the port of the glove-box and

immediately evacuated before assembly in the glove-box. The glassware used for the experiments was made with virtually greaseless Fisher-Porter Solv-seal

glass joints. High vacuum valves on the flasks were purchased from Kimble-

Kontes. Infrared spectra were collected on a Nicolet Nexus 870 Fourier

transform spectrometer. Infrared samples were prepared in the glove-box,

transported from the glove-box to the spectrometer in a desiccator and were not

exposed to air until they were placed in the spectrometer.

. [PCl2N]3 HMX4 species are extremely light sensitive and exposure to light was kept at minimum throughout the entire synthesis and characterization process.

3.2.2. Materials

Hexane, chloroform, methylene chloride and chlorobenzene (Fisher) were purified by using a solvent system manufactured by PureSolvTM. Deuterated

methylene chloride (99.9%) and deuterated chloroform (99.8%) were purchased

from Cambridge Isotopes, distilled three times over freshly activated 4 Å

molecular sieves and stored under argon in foil-wrapped storage tubes in the

glove-box. [PCl2N]3 (Aldrich), and AlCl3, AlBr3, GaCl3 (Alfa Aesar) were purified

by sublimation and stored in the glove-box. BCl3 (1 M solution in heptane) from

. Aldrich was used as received. [PCl2N]3 MX3 were prepared as described in

Chapter II. HCl gas (Praxair, 99%) was purified by fractional vacuum distillation through two -78 °C (dry ice/acetone bath) traps and stored in a glass bulb

attached to the high vacuum line which was equipped with a manometer. To add

dry HCl to a reaction, the Schlenk flask containing the reaction mixture was

attached to the high vacuum line. The desired volume of HCl was measured and

the gas was condensed into the reaction flask at liquid N2 temperature. HBr gas

was purchased in a lecture bottle from Matheson Gas Products, Inc. and used as

received.

3.2.3. NMR Spectroscopy

Some of the NMR spectra were taken by Dr. Deepa Savant and Linlin Li.

NMR samples were prepared in the glove-box and all NMR tubes were flame sealed under vacuum. In order to minimize the presence of degradation

. products, NMR samples of [PCl2N]3 HMX4 were made within 24 hours of the

adduct’s preparation. The NMR spectra were either taken immediately after the

NMR samples were prepared or the tube was kept frozen (liquid nitrogen) until

the spectra were taken. Routine and variable temperature NMR (VT NMR)

spectra were obtained on a Varian INOVA 400 MHz NMR spectrometer with a 5

mm switchable probe. Proton NMR spectra were referenced to the residual

proton resonance of the deuterated solvent. External references were used for

31 the other nuclei: 0.15 M H3PO4 solution in deuterated solvent (0 ppm) for the P

27 spectra, and 1 M AlCl3 solution in deuterated water (0 ppm) for the Al spectra, respectively. 27Al and 31P NMR were collected with continuous decoupling

because of the nuclear Overhauser effect (NOE).

To identify the anions present in the products via solution NMR, the spectra of the sample before and after the addition of excess MX3 were taken.

To accomplish this, a NMR sample was prepared by dissolving 7 mg of

. [PCl2N]3 HMX4 in 0.7 mL of CDCl3, the NMR tube was flame-sealed and the spectra of the sample was taken. The tube was scored open in the glove-box, excess MX3 (3 mg) was added before the tube was resealed and the spectra of

the sample was taken on the same instrument.

3.2.4. X-ray crystallography

X-ray crystallography was performed by Dr. Matthew J. Panzner, Dr. Doug

A. Medvetz and Brian D. Wright. In the glove-box, crystals were put into

Paratone oil on a slide. The slide was transported from the glove-box to the instrument in a desiccator that was wrapped in aluminum foil. The crystals were immediately mounted in low light and immediately cooled to 100 K on the diffractometer. The data collection took place with the laboratory lights turned off.

Crystal structure data sets were collected on a Bruker Apex CCD diffractometer with graphite-monochromated Mo Kα radiation (λ = 0.71073Å).

Unit cell determination was achieved by using reflections from three different orientations. An empirical absorption correction and other corrections were done using multi-scan SADABS. Structure solution, refinement and modeling were accomplished using the Bruker SHELXTL package.19 The structures were

obtained by full-matrix least-squares refinement of F2 and the selection of

appropriate atoms from the generated difference map.

3.2.5. Mass spectrometry

For mass spectrometry, samples were prepared in the glove-box and

transferred to the spectrometer in a desiccator. MS spectra were acquired with a

SYNAPT HDMS™ Q/ToF mass spectrometer (Waters, Beverly, MA) equipped

with a z-spray electrospray source. The concentration of the electrosprayed

68 samples was 0.01 mg/mL in dry CHCl3. The sample flow rate was set at 10

μL/min.

For the positive mode, the instrument was operated at a voltage of 3.5 kV, sample cone voltage of 35 V and extraction cone voltage of 3.2 V; the desolvation gas flow was 800 L/h (N2); the source temperature and desolvation gas temperature were 90 °C and 250 °C.

. The settings used for the negative mode of [PCl2N]3 HGaCl4 are different

. . . from those used for [PCl2N]3 HAlCl4 and [PCl2N]3 HAlBr4. For [PCl2N]3 HGaCl4, the instrument was operated at a voltage of 3.5 kV, sample cone voltage of 40 V and extraction cone voltage of 4.0 V; the desolvation gas flow was 800 L/h (N2); the source temperature and desolvation gas temperature were 120 °C and 250

. . °C. For [PCl2N]3 HAlCl4 and [PCl2N]3 HAlBr4, the instrument was operated at a voltage of 3.5 kV, sample cone voltage of 30 V and extraction cone voltage of 3

V; the desolvation gas flow was 500 L/h (N2); the source temperature and desolvation gas temperature were 40 °C and 50 °C.

3.2.6. Syntheses

. . Syntheses of [PCl2N]3 HMX4 are described below. [PCl2N]3 HMX4 species are extremely light sensitive and exposure to light was kept at minimum throughout the entire synthesis and characterization process.

. 3.2.6.1. Synthesis of [PCl2N]3 [HAlCl4]

. Route 1. In the glove-box, [PCl2N]3 AlCl3 (10 mg, 0.02 mmol) was dissolved in

CDCl3 ( 0.7 mL) in an NMR tube. Gaseous HCl (excess) was bubbled in the tube

on the Schlenk line. The NMR tube was flame sealed and VT NMR studies were

31 conducted. P NMR (CDCl3): δ 18.76 ppm (s) at 25 °C, δ 18.42 ppm (s) at 0 °C,

1 δ 18.17 ppm (s) at -20 °C, and δ 17.92 ppm (s) at -40 °C. H NMR (CDCl3): δ

10.21 ppm (s) at 25 °C, δ 10.11 ppm (s) at 0 °C, δ 10.01 ppm (s) at -20 °C, and δ

27 9.92 ppm (s) at -40 °C. Al NMR (CDCl3): δ 102.84 ppm (s) at 25 °C, δ 102.93

ppm (s) and 97.44 ppm (s) at 0 °C, δ 102.97 ppm (s) and 97.94 ppm (s) at -20

°C, δ 103.05 ppm (s) and 97.67 ppm (s) at -40 °C.

. Route 2. In the glove-box, [PCl2N]3 AlCl3 (0.96 g, 2.0 mmol) was dissolved in

CHCl3 (20 mL) to give a colorless solution. In air, H2O (2 mmol) was added into

the flask via syringe and the reaction mixture was stirred overnight. The reaction

flask was left undisturbed in the dark for 360 days until colorless crystals were

observed on the wall of the flask. The volatiles were slowly removed in vacuo.

. Crystallographic analysis showed that the product crystals were [PCl2N]3 [HAlCl4].

Route 3. In the glove-box, AlCl3 (0.13 g, 1.0 mmol) was put in a Schlenk flask

and CHCl3 (20 mL) was added. In a storage tube, [PCl2N]3 (0.35 g, 1.0 mmol)

was dissolved in CHCl3 (10 mL). The storage tube was attached to the arm of

the Schlenk flask containing the AlCl3 solution. The Schlenk flask was attached

to the high vacuum line and HCl (0.50 L at 0.048 atm, 295 K; 1.0 mmol) was

condensed into the reaction flask at liquid N2 temperature. The flask was thawed

and the solution was stirred for 3 hours before the [PCl2N]3 solution was slowly

added to the flask. The flask was wrapped with aluminum foil and the reactants

were stirred overnight in the dark. A clear, slightly brown solution was observed

the following morning. The solution was stored in the dark for two days and no

further change was observed. The volatile components were slowly removed in

vacuo to give colorless crystals. Recrystalization in chlorobenzene afforded

better crystals. Yield: 90%. HRMS (ESI+) m/z for [H(PCl2N)3] calculated 345.7,

found 345.7, HRMS (ESI-) m/z for [AlCl4] calculated 166.9, found 166.9. See the

Appendix for X-ray crystallographic information.

Route 4. In the glove-box, [PCl2N]3 (0.69 g, 2.0 mmol) was dissolved in CHCl3

(20 mL) to give a colorless solution. AlCl3 (0.266 g, 2.0 mmol) was added and

the reaction was let to stir for 30 minutes. Due to light-sensitivity of the solution, the reaction flask was wrapped in aluminum foil and taken out of the glove-box.

The flask was attached to the high vacuum line and dry HCl (0.50 L at 0.096 atm,

295 K; 2 mmol) was condensed in to the flask. The reaction flask was thawed

and the solution was stirred overnight at room temperature. The volatiles were

slowly removed in vacuo to yield colorless crystals, which were characterized to

. be [PCl2N]3 HAlCl4. Yield: 90%.

. 3.2.6.2. Synthesis of [PCl2N]3 [HAlBr4]

. Route 1. In the glove-box, [PCl2N]3 AlBr3 (10 mg, 0.016 mmol) was dissolved in

CDCl3 (0.70 mL) in a NMR tube. Gaseous HBr (excess) was bubbled in the tube

on the Schlenk line. The NMR tube was flame sealed and VT NMR studies were

31 conducted. P NMR (CDCl3): δ 18.0 ppm (s) at 25 °C, δ 17.8 ppm (s) at 0 °C, δ

1 17.6 ppm (s) at -20 °C, δ 17.45 ppm (s) at -40 °C. H NMR (CDCl3): δ 10.19 ppm

(s) at 25 °C, δ 10.10 ppm (s) at 0 °C, δ 10.02 ppm (s) at -20 °C, δ 9.94 ppm (s) at

-40 °C.

. Route 2. In the glove-box, [PCl2N]3 AlBr3 (1.23 g, 2.0 mmol) was dissolved in

CHCl3 (20 mL) to give a colorless solution. In air, H2O (2 mmol) was added into

the flask via syringe and the reaction mixture was stirred overnight. The reaction

flask was left undisturbed in the dark for 360 days until colorless crystals were

observed on the wall of the flask. The volatiles were slowly removed in vacuo.

Crystallographic analysis showed that the product crystals were

. [PCl2N]3 [HAlBr4].

Route 3. In the glove-box, (PCl2N)3 (0.695 g, 2.0 mmol) was dissolved in CHCl3

(20 mL) to give a colorless solution. AlBr3 (0.533 g, 2.0 mmol) was added and the

reaction was let to stir for 30 minutes. The reaction flask was wrapped in

aluminum foil and taken out of the glove-box. The flask was attached to the

Schlenk line and HBr (excess) was bubbled in to the flask. The mixture was

stirred overnight at room temperature in the dark. The volatiles were slowly

. removed in vacuo to yield colorless crystals of [PCl2N]3 [HAlBr4]. Yield: 85%.

HRMS (ESI+) m/z for [H(PCl2N)3] calculated 345.7, found 345.7. See the

Appendix for X-ray crystallographic information.

. 3.2.6.3. Synthesis of [PCl2N]3 [HGaCl4]

Route 1. In the glove-box, (PCl2N)3 (0.695 g, 2.0 mmol) was dissolved in CHCl3

(20 mL) to give a colorless solution. GaCl3 (0.352 g, 2.0 mmol) was added and

the reaction was let to stir for 30 minutes. The reaction flask was wrapped in

aluminum foil and taken out of the glove-box. The flask was attached to the high

vacuum line and dry HCl (0.50 L at 0.096 atm, 295 K; 2.0 mmol) was distilled in

to the flask. The reaction mixture was thawed and stirred overnight at room

temperature in the dark. The volatiles were slowly removed in vacuo to yield

. 31 colorless crystals of [PCl2N]3 [HGaCl4]. Yield: 92%. P NMR (CDCl3): δ 19.75

ppm (s) at 25 °C, δ 19.19 ppm (s) at 0 °C, δ 18.26 ppm (s) at -20 °C, δ 18.09

1 ppm (s) at -40 °C. H NMR (CDCl3): δ 10.30 ppm (s) at 25 °C, δ 10.29 ppm (s) at

0 °C, δ 10.26 ppm (s) at -20 °C, δ 10.20 ppm (s) at -40 °C. HRMS (ESI+) m/z for

[H(PCl2N)3] calculated 345.7, found 345.7. HRMS (ESI-) m/z for [GaCl4] calculated 208.7, found 208.7. See the Appendix for X-ray crystallographic

information.

. Route 2. In the glove-box, [PCl2N]3 GaCl3 (1.05 g, 2.0 mmol) was dissolved in

CHCl3 (20 mL) to give a colorless solution. On the vacuum line, HCl (0.50 L at

0.096 atm, 295 K; 2.0 mmol) was distilled into the flask. The reaction mixture

was thawed and stirred overnight at room temperature in the dark. The volatiles

. were slowly removed in vacuo to yield colorless crystals of [PCl2N]3 [HGaCl4].

. 3.2.6.4. Attempted Synthesis of [PCl2N]3 [HBCl4]

In the glove-box, (PCl2N)3 (0.695 g, 2.0 mmol) was dissolved in CHCl3 (20

mL) to give a colorless solution. BCl3 in 1M solution of heptane (2 mL, 2.0 mmol)

was added and the reaction was let to stir for 30 minutes. The reaction flask was

wrapped in aluminum foil and taken out of the glove-box. The flask was attached

to the high vacuum line and dry HCl (0.50 L at 0.096 atm, 295 K; 2.0 mmol) was

distilled in to the flask. The reaction mixture was thawed and stirred overnight at

room temperature in the dark. The volatiles were slowly removed in vacuo to

yield unreacted [PCl2N]3.

. 3.2.6.5. Attempted ROP of [PCl2N]3 catalyzed by [PCl2N]3 [HAlCl4]

In the glove-box, [PCl2N]3 (0.695 g, 2.0 mmol) was dissolved in

chlorobenzene (15 mL) to give a colorless solution in a three inch long, medium- walled glass tube with an inner diameter of 10 mm and a constriction.

. [PCl2N]3 [HAlCl4] (1.03 g, 0.2 mmol) was added. The tube was flame-sealed and

the reaction was heated at 70 °C for 1 hour. No ROP was observed. Only the

starting material, [PCl2N]3 and black materials which appeared to be the

. degradation product of [PCl2N]3 [HAlCl4] were recovered.

3.3. Results and Discussion

. [PCl2N]3 HMX4 species develop as minor products in the reactions of

Group 13 Lewis acids MX3 (MX3 = AlCl3, AlBr3, GaCl3) with [PCl2N]3 under less

strict anaerobic conditions. We suspected that the M-X bond of MX3 produced

HX upon hydrolysis, which reacted with more MX3 to give HMX4, which in turn

protonated [PCl2N]3. In order to test this hypothesis, we set up a series of

experiments (Scheme 3.1). Addition of one equivalent of water to the solution of

. . [PCl2N]3 MX3 gave a mixture of [PCl2N]3 HMX4 (Scheme 3.1) and degradation

products. Deliberately adding one equivalent of HX to the solution of

. . [PCl2N]3 MX3 gave [PCl2N]3 HMX4 as the sole product (Scheme 3.1). Addition of

one equivalent of HX to the reaction of [PCl2N]3 and MX3 led to the same result

(Scheme 3.1). This suggested that the combination of MX3 with its hydrolysis

product, HX generates HMX4 species responsible for [PCl2N]3 protonation. The

order of addition of the reagents does not have any effect on the product

. formation of [PCl2N]3 HAlX4.

. . [PCl2N]3 MX3 + HX (or) H2O [PCl2N]3 HMX4

. [PCl2N]3 + MX3 + HX [PCl2N]3 HMX4

. MX3 + HX + [PCl2N]3 [PCl2N]3 HMX4

where MX = AlCl , AlBr or GaCl , and HX = HCl or HBr 3 3 3 3

. Scheme 3.1. A Series of experiments to investigate how [PCl2N]3 HMX4 species were formed.

Chloroform, methylene chloride and chlorobenzene are suitable solvents

for the reactions in Scheme 3.1. Because BCl3 is a catalyst or initiator in the

ROP of [PCl2N]3, the reaction of BCl3 and HCl with [PCl2N]3 was investigated and

. no [PCl2N]3 HBCl4 adduct formation was observed. As mentioned in Chapter II,

. . [PCl2N]3 BCl3 adduct was also not formed. [PCl2N]3 HMX4 adducts have

. . significantly greater light sensitivity than [PCl2N]3 MX3 adducts. [PCl2N]3 HGaCl4

. degrades most quickly with light. In fact, light sensitivity of [PCl2N]3 MX3 adducts

. might be due to the presence of [PCl2N]3 HMX4 impurities. Attempted ROP of

. [PCl2N]3 in the presence of [PCl2N]3 HAlCl4 as a catalyst or initiator at 70 °C gave

only a mixture of the starting material [PCl2N]3, and degradation products of

. [PCl2N]3 HAlCl4. It has been reported that protonated and methylated adducts of

[PCl2N]3 with carborane anions failed to catalyze or initiate the ROP of [PCl2N]3 at room temperature or at 160 °C.20

3.3.1. X-ray crystal structures

. The ball and stick structure of [PCl2N]3 HAlBr4 is shown in Figure 3.1, and

. . the thermal ellipsoid plots of [PCl2N]3 HAlCl4 and [PCl2N]3 HGaCl4 are shown in

Figures 3.2 and 3.3, respectively. Selected bond distances and angles are given

. . in Table 3.1. The asymmetric units of [PCl2N]3 HAlCl4 and [PCl2N]3 HGaCl4

. contain one single molecule whereas that of [PCl2N]3 HAlBr4 contains two

different molecules. The hydrogen atom was found in the structures of

. . . [PCl2N]3 HAlCl4 and [PCl2N]3 HGaCl4 but not in [PCl2N]3 HAlBr4. The distance between the ring nitrogen and a halide of the MX4 anion was 3.13 Å for both

. . . [PCl2N]3 HAlCl4 and [PCl2N]3 HGaCl4, and 3.36 Å for [PCl2N]3 HAlBr4. These

distances are consistent with N-H--X hydrogen bonds.

. Protonation distorts the [PCl2N]3 rings in the [PCl2N]3 HAlCl4 and

. [PCl2N]3 HGaCl4 adducts into slight chair-like structures in which the protonated

nitrogen atom (dihedral angles: AlCl3: 11.8˚ and GaCl3: 11.9˚) and the opposite

phosphorus atom (dihedral angles are AlCl3: 11.4˚ and GaCl3: 10.1˚ ) are bent

below and above the plane of the remaining ring atoms. On the other hand,

. [PCl2N]3 ring in [PCl2N]3 HAlBr4 adduct becomes slightly twisted upon

protonation. A similar twisted ring conformation has been reported in

. 13 [PCl2N]3 CH3(CHB11((CH)3)5Br6). Protonation also weakens the two ring P-N

bonds that involve the [PCl2N]3 nitrogen atom where protonation occurs. These

weakened P-N bonds show single bond character whereas the remaining P-N

bonds still show multiple bond character. The lengthened P-N bond distances

. range 1.6483(19)-1.6522(18) Å (average = 1.6502 Å) for [PCl2N]3 HAlCl4,

. 1.644(3)-1.652(3) Å (average = 1.648 Å) for [PCl2N]3 HGaCl4, and 1.631(16)-

. 1.689(18) Å (average = 1.660 Å) for [PCl2N]3 HAlBr4. The remaining P-N bonds

. range 1.5472(18)-1.5855(19) Å (average = 1.5662 Å) for [PCl2N]3 HAlCl4,

. 1.554(3)-1.580(3) Å (average = 1.568 Å) for [PCl2N]3 HGaCl4, and 1.530(16)-

. 1.586(14) Å (average = 1.569 Å) for [PCl2N]3 HAlBr4, and they are similar to the

21 bond distances in free [PCl2N]3 (1.575 Å ). The P-N-P angles at the protonated

. . nitrogen are 124.64(12)° for [PCl2N]3 HAlCl4, 124.83(19)° for [PCl2N]3 HGaCl4 and

. average of 124.2(10)° for [PCl2N]3 HAlBr4. These bond angles are slightly smaller than other P-N-P angles in the rings which range 126.01(12)-126.04(12)°

. (average = 126.02°) for [PCl2N]3 HAlCl4, 126.10(19)-126.2(2)° (average = 126.1°)

. for [PCl2N]3 HGaCl4, and 124.7(9)-126.4(8)° (average = 125.4°) for

. 21 [PCl2N]3 HAlBr4. The average P-N-P angle in a free [PCl2N]3 ring is 121.2° .

The average N-P-N angles that involve the protonated nitrogen (112.68° for

. . . [PCl2N]3 HAlCl4, 112.485° for [PCl2N]3 HGaCl4, and 113.25° for [PCl2N]3 HAlBr4) is smaller than the remaining N-P-N angles in the rings (115.73° for

. . . [PCl2N]3 HAlCl4 and [PCl2N]3 HGaCl4, 116.65° for [PCl2N]3 HAlBr4). All N-P-N

. angles in [PCl2N]3 HMX4 are smaller than the N-P-N angles in a free [PCl2N]3 ring

21 . (average = 118.4°). [PCl2N]3 MX3 species described in Chapter II undergo

. similar changes in ring geometry as [PCl2N]3 HMX4 species when compared to a

free [PCl2N]3.

. Figure 3.1. Ball and stick structure of [PCl2N]3 HAlBr4.

. Figure 3.2. Thermal ellipsoid plot for the crystal structure of [PCl2N]3 HAlCl4. N atoms are drawn in blue, C atoms in orange and Cl atoms in green.

. Figure 3.3. Thermal ellipsoid plot for the crystal structure of [PCl2N]3 HGaCl4. N atoms are drawn in blue, C atoms in orange and Cl atoms in green.

. Table 3.1. Selected distances (Å) and angles(°) in [PCl2N]3, [PCl2N]3 HAlCl4, . . [PCl2N]3 HGaCl4 and [PCl2N]3 HAlBr4.

a. Reference 22

3.3.2. NMR Studies

. VT NMR studies were carried out for all three [PCl2N]3 HMX4 adducts.

31 . . . The VT P NMR spectra of [PCl2N]3 HAlCl4, [PCl2N]3 HGaCl4 and [PCl2N]3 HAlBr4

taken between -40 and 25 °C in CDCl3 are shown in Figures 3.4, 3.5 and 3.6,

respectively. Based on the solid state structure, a doublet and a triplet is

31 . 31 expected in the P NMR spectra of the [PCl2N]3 HMX4. However, only one P resonance was observed as a sharp singlet from 25 °C to -40 °C for all three

adducts due to their fluxionality in solution. Line broadening was observed in the

31 . P VT NMR spectra of [PCl2N]3 HGaCl4. It is unclear whether this line

- broadening was caused by the nature of the GaCl4 anion or by the concentration

effect of the NMR sample. The rate of exchange was greater than the coupling

constant even at -40 °C, and the coupling expected from the solid state structure

was not observed even at that temperature. At 25 °C, 31P resonance was at

. . 18.76 ppm for [PCl2N]3 HAlCl4, 19.75 ppm for [PCl2N]3 HGaCl4, and 18.0 ppm for

. 31 [PCl2N]3 HAlBr4, and these P chemical shifts are very close to that of a free

[PCl2N]3 which is observed at 20.6 ppm. Fluxionality in solution was also

. observed for [PCl2N]3 MX3 systems (Chapter II) although the couplings in their

. 31 spectra was resolved at -40 °C. In all three [PCl2N]3 HMX4, the P resonance

slightly shifted downfield with the decrease in temperature. Going from 25 °C to -

. 40 °C, the net change in chemical shift for [PCl2N]3 HAlCl4 is 0.84 ppm, that for

. . [PCl2N]3 HGaCl4 is 1.66 ppm, and that for [PCl2N]3 HAlBr4 is 0.55 ppm.

1 . . . VT H NMR of [PCl2N]3 HAlCl4, [PCl2N]3 HGaCl4 and [PCl2N]3 HAlBr4 taken

between -40 and 25 °C in CDCl3 are shown in Figures 3.7, 3.8 and 3.9

. respectively. At 25 °C, a singlet was observed at 10.21 ppm for [PCl2N]3 HAlCl4,

. . at 10.30 ppm for [PCl2N]3 HGaCl4, and at 10.19 ppm for [PCl2N]3 HAlBr4. Similar

to the 31P NMR spectral data, the chemical shift of the singlet moved downfield

with decreasing temperature for all three adducts. For the net change in

temperature of 65 °C, the net changes in chemical shift were 0.29 ppm for

. . . [PCl2N]3 HAlCl4, 0.25 ppm for [PCl2N]3 HGaCl4, and 0.1 ppm for [PCl2N]3 HAlBr4,

respectively.

31 . Figure 3.4. P VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C.

31 . Figure 3.5. P VT NMR spectra of [PCl2N]3 HGaCl4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C.

31 . Figure 3.6. P VT NMR spectra of [PCl2N]3 HAlBr4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C.

1 . Figure 3.7. H VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken between -40

and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C.

1 . Figure 3.8. H VT NMR spectra of [PCl2N]3 HGaCl4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C.

1 . Figure 3.9. H VT NMR spectra of [PCl2N]3 HAlBr4 in CDCl3 taken between -40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C.

27 . VT Al NMR spectra of [PCl2N]3 HAlCl4 taken between -40 and 25 °C in

CDCl3 are shown in Figure 3.10. A singlet at 102.84 ppm was observed at 25 °C

and this resonance shifted slightly downfield with decreasing temperature, the

net change in chemical shift being 0.25 ppm from 25 °C to -40 °C.

27 . Figure 3.10. Al VT NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken between - 40 and 25 °C. (a) 25 °C, (b) 0 °C, (c) -20 °C and (d) -40 °C. The spectra were offset by ~ 4 ppm for clarity.

- - In the presence of excess MX3, MX4 can form the M2X7 anion. We have

- - seen only MX4 anions and not M2X7 anions in crystal structures of the reaction

. products. However, with excess MX3 in solution, [PCl2N]3 HMX4 species might

. give [PCl2N]3 HM2X7 as the sole product or at least give a mixture of

. . - [PCl2N]3 HM2X7 with [PCl2N]3 HMX4. M2X7 anions, if stable, are bulkier and less

- coordinating than MX4 and therefore, HM2X7 would be expected to be stronger

acids than HMX4. Because MX3 is used as an initiator in the solution state ROP

. of [PCl2N]3, it will be advantageous to know whether [PCl2N]3 HM2X7 will form in

. solution from [PCl2N]3 HMX4 in the presence of excess MX3. For

. 27 1 31 [PCl2N]3 HAlCl4, Al , H, and P NMR were used to investigate the effect of

27 excess AlCl3. Figure 3.11 shows the Al NMR spectra from such investigation.

. Figure 3.11(a) shows the spectrum of [PCl2N]3 HAlCl4 and the Figure 3.11(b)

shows the spectrum of the sample with the excess AlCl3. Comparing these two

spectra, we can see that the presence of excess AlCl3 increases the half-

27 linewidth (Δν1/2) of the Al resonance significantly. The increase in Δν1/2 has

- been attributed to the increase in the concentration of Al2Cl7 and to the chemical

- - 22 exchange between Al2Cl7 and AlCl4 . This increase in Δν1/2 might also be

- explained by the differences in symmetry between the AlCl4 anion in the less

- concentrated original sample and the Al2Cl7 anion in the more concentrated

1 sample. Similarly, increases in Δν1/2 of resonances are observed in the H and

31P spectra depicted in Figures 3.12 and 3.13.

. 1 31 For [PCl2N]3 HGaCl4, H, and P NMR are used to investigate the effect of

1 31 excess GaCl3. Figures 3.14 and 3.15 respectively show the H and P NMR

. spectra from such investigation. Similar to [PCl2N]3 HAlCl4 species, comparison

between the spectrum of the original sample and the spectrum of the sample with

excess GaCl3 shows that the presence of excess GaCl3 increases the Δν1/2 of

the 1H and 31P resonances.

27 . Figure 3.11. Al NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken at 30 °C to investigate the effect of excess AlCl3 concentration in the sample. (a) sample of . . [PCl2N]3 HAlCl4 with no excess AlCl3, (b) the same sample of [PCl2N]3 HAlCl4 with excess AlCl3.

1 . Figure 3.12. H NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken at 30 °C to investigate the effect of excess AlCl3 concentration in the sample. (a) sample of . . [PCl2N]3 HAlCl4 with no excess AlCl3, (b) the same sample of [PCl2N]3 HAlCl4 with excess AlCl3.

31 . Figure 3.13. P NMR spectra of [PCl2N]3 HAlCl4 in CDCl3 taken at 30 °C to investigate the effect of excess AlCl3 concentration in the sample. (a) sample of . . [PCl2N]3 HAlCl4 with no excess AlCl3, (b) the same sample of [PCl2N]3 HAlCl4 with excess AlCl3.

1 . Figure 3.14. H NMR spectra of [PCl2N]3 HGaCl4 in CDCl3 taken at 30 °C to investigate the effect of excess GaCl3 concentration in the sample. (a) sample of . . [PCl2N]3 HGaCl4 with no excess GaCl3, (b) the same sample of [PCl2N]3 HGaCl4 with excess GaCl3.

31 . Figure 3.15. P NMR spectra of [PCl2N]3 HGaCl4 in CDCl3 taken at 30 °C to investigate the effect of excess GaCl3 concentration in the sample. (a) sample of . . [PCl2N]3 HGaCl4 with no excess GaCl3, (b) the same sample of [PCl2N]3 HGaCl4 with excess GaCl3.

3.3.3. Mass Spectrometry

. [PCl2N]3 HMX4 adducts were studied with electrospray ionization mass spectrometry (ESI-MS) in both positive and negative modes in order to identify

. both the cationic and the anionic species. For [PCl2N]3 HAlCl4 and

. + [PCl2N]3 HGaCl4, (H[PCl2N]3) cation was detected in the positive mode, and

- - AlCl4 and GaCl4 were detected in the respective negative mode spectra. In

- order to detect AlCl4 , milder conditions and lower temperature were used

- . compared to the ones used for detecting GaCl4 . For [PCl2N]3 HAlBr4, even

+ - though the positive mode shows the cation (H[PCl2N]3) , AlBr4 anion was not

- detected in the negative mode. We suspected that AlBr4 might be even more

- fragile than AlCl4 because the Al atom is surrounded by four larger Br atoms in

the former and this can lead to relative instability of the resulting anion. Based

. on this assumption, we applied even milder conditions in ionizing [PCl2N]3 HAlBr4

- species in the negative mode but we still were not able to detect AlBr4 .

Figures 3.16, 3.17 and 3.18 show the ESI-MS in positive mode spectra of

. . . [PCl2N]3 HAlCl4, [PCl2N]3 HGaCl4 and [PCl2N]3 HAlBr4, respectively. The

+ theoretical isotopic distribution of (H[PCl2N]3) cation is shown on the top (a) and

the experimental spectrum of the adducts is shown on the bottom (b) in the

Figures. Experimental spectra match the theoretical both in the distribution

pattern and the mass of the peak detected. ESI-MS in negative mode spectrum

. . of [PCl2N]3 HAlCl4 and [PCl2N]3 HGaCl4 are shown in Figures 3.19 and 3.20,

respectively . Distribution patterns and the masses of the detected peaks match

between the top (a) spectra showing the theoretical isotope distribution of the

- - anions (AlCl4 and GaCl4 , respectively) and the bottom (b) spectra showing the

experimental spectra of the adducts.

(a)

(b)

. Figure 3.16. ESI Mass spectrum of [PCl2N]3 HAlCl4 in positive mode. (a) + theoretical isotope distribution for (H[PCl2N]3) , (b) experimental isotope distribution.

. Figure 3.17. ESI Mass spectrum of [PCl2N]3 HGaCl4 in positive mode. (a) + theoretical isotope distribution for (H[PCl2N]3) , (b) experimental isotope distribution.

(a)

(b)

. Figure 3.18. ESI Mass spectrum of [PCl2N]3 HAlBr4 in positive mode. (a) + theoretical isotope distribution for (H[PCl2N]3) , (b) experimental isotope distribution.

. Figure 3.19. ESI Mass spectrum of [PCl2N]3 HAlCl4 in negative mode, (a) - theoretical isotope distribution for AlCl4 , (b) experimental isotope distribution.

. Figure 3.20. ESI Mass spectrum of [PCl2N]3 HGaCl4 in negative mode. (a) - theoretical isotope distribution for GaCl4 , (b) experimental isotope distribution.

3.4. Conclusion

The reaction of [PCl2N]3 with MX3 under less strict anaerobic conditions or

. in the presence of HX give [PCl2N]3 HMX4 species (MX3 = AlCl3, AlBr3, and

. GaCl3). The attempt to isolate the [PCl2N]3 HBCl4 adduct was not successful.

The ease of formation of HMX4 from MX3 even with the presence of adventitious water suggest that MX3 catalyzed or initiated reactions reported in the literature might not be as straightforward because catalysis might be done either by MX3 or

. HMX4. In [PCl2N]3 HMX4, protonation distorts the [PCl2N]3 ring and weakens two ring bonds that flank the protonated nitrogen. Unlike in the solid state,

. [PCl2N]3 HMX4 in solution with excess MX3 might contain a mixture of anions

- 1 31 27 . other than MX4 . VT H, P and Al NMR show that the [PCl2N]3 HMX4 adducts

. are fluxional in solution. Similar to [PCl2N]3 MX3 adducts discussed in Chapter II,

. the fragility of the [PCl2N]3 HMX4 adducts at or below the room temperature rules out these adducts as intermediates that are directly involved in the high- temperature ROP of [PCl2N]3 to give [PCl2N]n. As observed for protonated

20 . adducts of [PCl2N]3 with carborane anions, [PCl2N]3 HMX4 did not catalyze or initiate the ROP of [PCl2N]3 at room temperature or at 70 °C.

3.5. References

(1) Allcock, H. R. Chemistry and Applications of Polyphosphazenes, Wiley- Interscience: New York, 2003; Chapters 4 and 5.

(2) (a) Ganapathiappan, S.; Dhathathreyan,K. S.; . Krishnamurthy, S. S. Macromolecules 1987, 20, 1501-1505. (b) Mujumdar, A. N.; Young, S,. G.; Merker,R. L.; Magill, J. H. Macromolecules 1990, 23,14-21. (c) Liu, H.; Stannett, V. T. Macromolecules 1990, 23, 140-144. (d) Luten , J.; van Steenis, J. H.; van Someren, R.; Kemmink , J.; Schuurmans-Nieuwenbroek, N.M.E.; Koning, G.A.; Crommelin, D.J.A.; van Nostrum, C.F.; Hennink, W.E. J. Controlled Release 2003, 89, 483–497. (3) Allcock, F. R.; Gardner, J. E.; Smeltz, K. M. Macromolecules 1975, 8, 36-42.

(4) Sayed, M. B. Internet J. Chem. 2002, 5, Paper No. 6.

(5) Liu, H. Q.; Stannett, V. T. Macromolecules 1990, 23, 140-144.

(6) (a) Emsley, J.; Udy, P. B. Polymer, 1972, I, 593-594. (b) Sulkowski, W. W. In Synthesis and Characterizations of Poly(organophosphazenes), Gleria, M.; De Jaeger, R., eds.; Nova Science: New York, 2004, Chapter 4.

(7) Andrianov, A. K.; Chen, J.; LeGolvan, M. P. Macromolecules 2004, 37, 414- 420.

(8) Allcock, H. R. Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapters 4, 10-12.

(9) Feakins, D.; Last, W. A.; Neemuchwala, N.; Shaw, R. A.; J. Chem. Soc. 1963, 2804-2811.

(10) Sayed, M. B. Internet J. Chem. 2002, (5), Paper No. 6.

(11) Heston, A. J.; Panzner, M.; Youngs W. J.; Tessier, C. A. Phosphorus, Sulfur Silicon Rel. Elem. 2004, 179, 831-837.

(12) Bode, H.; Bütow, K.; Lienau, G. Chem. Ber. 1948, 81, 547-552. (13) Zhang, Y.; Tham, F. S.; Reed, C. A. Inorg. Chem. 2006, 45, 10446-10448.

(14) Molnar, A.; Olah, G. A.; Surya Prakash, G. K.; Sommer, J. Superacids, 2nd ed.; Wiley: New York, 2009; Chapters 1-2.

(15) Heston, A. J.; Panzner, M.; Youngs W. J.; Tessier, C. A. Inorg. Chem. 2005, 44, 6518-6520.

(16) (a) Farcasiu, S. L.; Fisk, S. L.; Melchior, M. T.; Rose, K. D. J. Org. Chem. 1982, 47, 453. (b) Kramer, G. M. J. Org. Chem. 1975, 40, 298, 302. (c) O’Donnell, T. A. Superacids and Acidic Melts As Inorganic Chemical Reaction Media; VCH Publishers: New York, 1993.

(17) Shriver, D. F.; Drexdon, M. A. The Manipulation of Air-Sensitive Compounds, 2nd ed.; Wiley: New York, 1986.

(18) Plesch, P. H. High Vacuum Techniques for Chemical Syntheses and Measurements, Cambridge University Press: New York, 1989.

(19) Sheldrick, G. M. SHELX97: Programs for Crystal Structural Analysis; University of Göttingen, Göttingen, Germany 1997.

(20) Zhang, Y.; Huynh, K.; Manners, I.; Reed, C. A. Chem. Comm. 2008, 494- 496.

(21) (a) Bullen, G. J. J. Chem. Soc. (A) Inorg. Phys. Theor. 1971, 1450-1453. (b) Bartlett, S. W.; Coles, S. J.; Davies, D. B.; Hursthouse, M. B.; Ibisoglu, H.; Kilic, A.; Shaw, R. A.; Un, I. Acta Cryst. 2006, B62, 321–329.

(22) Gray, J. L.; Maciel, G. E. J. Am. Chem. Soc. 1981, 103, 7147-7151.

CHAPTER IV

CROWN ETHER COMPLEXES OF HPCl6

Reproduced in part with permission from [Tun, Z.; Panzner, M.; Scionti, V.;

Medvetz, D.; Wesdemiotis, C.; Youngs, W.; Tessier, C. J. Am. Chem. Soc. 2010,

132, 17059-17061]. Copyright [2010] American Chemical Society.

4.1. Introduction

Superacids are Brønsted acids that are more acidic than 100% sulfuric

1 acid (Hammet acidity function, Ho < -12). They exist in nonaqueous, weakly- basic solvents. Superacids have found uses in important organic transformations such as hydrocarbon cracking and isomerization, Friedel-Crafts chemistry and they appear to be involved in some cationic polymerization processes.1,2

An important class of superacids is the conjugate Brønsted–Lewis

superacids.1 These acids are generated from the reaction of a Brønsted acid HX

(X = halide) and a Lewis acid MXm; the fluorinated systems are the most studied.

Conceptionally, such superacids could be viewed as in Equation 4.1 where the

- - Lewis acid MXm converts X into the more weakly coordinating anion MXm+1 ,

thereby increasing the Brønsted acidity of the system.

+ - HX + MXm → [H ][MXm+1 ] (4.1)

However, Equation 4.1 is an over-simplification.1,3,4 Species other than H+ and

- MXm+1 usually also form from HX and MXm especially in solution and the species

formed are dependent on the stoichiometry.

Phosphazene polymers have many useful properties but are seldomly

used industrially.5 A major problem in phosphazene chemistry concerns the

difficulties and irreprodicibilities encountered in the synthesis and handling of the

parent [PCl2N]n polymer, from which most other polyphosphazenes are prepared.

A number of the problems seem to involve unspecified Brønsted acids.6,7,8 On

9 the basis of our work on the reactions of Lewis acids and [PCl2N]3, we suspect

that at least some of these issues may be due to the presence of a strong acid or

a superacid that is generated from the hydrolytically-unstable, Lewis-acid PCl5

and HCl. PCl5 is a reagent, catalyst or initiator in all syntheses of [PCl2N]n and

thereby could be an impurity. Therefore, as suggested by Equation 4.1, HPCl6 or

a related species could be generated from the reaction of PCl5 and HCl, the latter

of which is generated as a by-product during some syntheses of

chlorophosphazenes or from hydrolysis of P-Cl bonds. The effect of PCl5 and

HCl separately on the ring-opening polymerization synthesis of [PCl2N]n has

been considered but their combined action has not.10

11 HPCl6 salts of a few nitrogen bases are known. Therefore, it appears

that HPCl6 is at least a strong acid. Herein, we describe some of our efforts to

characterize the acidic compounds generated from the combination of HCl and

PCl5 in the presence of bases that are weaker than those already examined.

Though there are very few references to HPCl6 per se, a search of the Chemical

Abstracts database showed that the combination of the reagents HCl and PCl5

has been used in about 1160 one-step reactions, most of which are syntheses of

organic molecules. Therefore, an understanding of the chemistry HCl/PCl5 has

application to areas other than phosphazene chemistry.

Attempts to isolate HPCl6 from the reactions of gaseous HCl and PCl5 in

hydrocarbon and chlorocarbon solvents were unsuccessful. The work of

Andrianov and coworkers provided some inspiration.8 They noted the polymer

[PCl2N]n was stable in air for over four years if it was stored in diglyme. They suggested that diglyme forms a complex with the acidic impurities that form in

[PCl2N]n on prolonged storage. Therefore, the HCl/PCl5 system was examined in

the presence of ethers, in particular crown ethers.

4.2. Experimental

This section describes the general experimental methods, materials used,

characterization techniques and syntheses.

4.2.1. General Experimental Methods

All manipulations were carried out under vacuum or under dry and oxygen-free argon or nitrogen atmosphere, applying standard anaerobic techniques such as Schlenk, vacuum line and glove-box techniques.12,13 The

vacuum line had the ultimate capacity of 2x10-4 torr. The atmosphere of the

glove-box was routinely checked by a light-bulb test, and the oxygen and

99 moisture content inside the glove-box was kept between 1 and 5 ppm. After being dried in the oven overnight, the glassware was assembled hot and evacuated immediately, or directly placed in the port of the glove-box, evacuated and assembled in the glove-box. The glassware used for the experiments was made with virtually greaseless Fisher-Porter Solv-seal glass joints. High vacuum valves on the flasks were purchased from Kimble-Kontes.

4.2.2. Materials Used

PCl5 (Sigma Aldrich, reagent grade) and 18-crown-6 (Acros Organics,

99%) were dried on the vacuum line overnight and stored in the glove-box. 12-

Crown-4 (Sigma Aldrich, 98%) was dried on the vacuum line and stored under argon in a foil-wrapped storage tube in the glove-box. HCl gas (Praxair, 99%) was purified by fractional vacuum distillation through two -78 °C (dry ice/acetone bath) traps and stored in a glass bulb attached to the high vacuum line which was equipped with a manometer. To add dry HCl to a reaction, the Schlenk flask containing the reaction mixture was attached to the high vacuum line. The desired volume of HCl was measured and the gas was condensed into the reaction flask at liquid N2 temperature. Chloroform was purified using a

PureSolvTM system. Deuterated methylene chloride (99.9%) and deuterated chloroform (99.8%) were purchased from Cambridge Isotopes, distilled three times over regenerated 4 Å molecular sieves and stored under argon in foil- wrapped storage tubes in the glove-box.

100

4.2.3. NMR Spectroscopy

NMR samples were prepared in the glove-box and all NMR tubes were

flame sealed under vacuum. In order to minimize the presence of degradation

products, NMR samples were made within 24 hours of the complexes’

preparation. The NMR spectra were either taken immediately after the NMR

samples were prepared or the tube was kept frozen (liquid nitrogen) until the

spectra were taken. Routine and Variable Temperature NMR (VT NMR) spectra

were obtained on a Varian INOVA 400 MHz NMR spectrometer with a 5 mm

switchable probe. Proton NMR spectra were referenced to the residual proton

resonance in the deuterated solvent, and 13C NMR spectra were referenced to

resonance of the deuterated solvent. 31P NMR spectra were externally

referenced to phosphoric acid (0 ppm) and were collected with continuous

decoupling because of the nuclear Overhauser effect (NOE).

4.2.4. X-ray crystallography

X-ray crystallography was performed by Dr. Matthew J. Panzner and Dr.

Doug A. Medvetz. In the glove-box, crystals were put into Paratone oil on a

slide. The slide was transported from the glove-box to the instrument in a

desiccator that was wrapped in aluminum foil. The crystals were immediately

mounted in low light and the data collection took place with the laboratory lights

turned off.

101

Crystal structure data sets were collected on a Bruker Apex CCD

diffractometer with graphite-monochromated Mo Kα radiation (λ = 0.71073Å).

Unit cell determination was achieved by using reflections from three different

orientations. An empirical absorption correction and other corrections were done

using multi-scan SADABS. Structure solution, refinement and modeling were

accomplished using the Bruker SHELXTL package.14 The structures were

obtained by full-matrix least-squares refinement of F2 and the selection of appropriate atoms from the generated difference map.

4.2.5. Mass spectrometry

Mass spectrometry was performed by Vincenzo Scionti. Samples were prepared in the glove-box and transferred to the spectrometer in a desiccator.

MS spectra were acquired with a SYNAPT HDMSTM Q/ToF mass spectrometer

the source temperature was 90 °C. The sample flow rate was set at 10 μL/min.

The concentration of the electrosprayed samples was 0.2 mg/mL in dry CHCl3.

102

4.2.6. Syntheses

Syntheses of [H(12-crown-4)][PCl6] and [H(18-crown-6)2][PCl6] are described

below. [H(12-crown-4)][PCl6] and [H(18-crown-6)2][PCl6] have limited thermal

stability.

4.2.6.1. Synthesis of [H(12-crown-4)][PCl6]

In the glove-box, 12-crown-4 (0.69 g, 2.0 mmol) was dissolved in CHCl3

(20 mL) to give a colorless solution. PCl5 (0.42 g, 2.0 mmol) was added and the

reaction was let to stir for 30 minutes. On the vacuum line, HCl (2 mmol) was

distilled into the flask and the reaction mixture was stirred overnight. The

volatiles were slowly removed in vacuo to yield colorless crystals of [H(12-crown-

31 4)][PCl6]. Yield: 90%. P NMR (CD2Cl2) at 30 °C: δ -296.8 ppm (s), -80.9 ppm

(s), 85.9 ppm (s), 91.7 ppm (s), and 220.2 ppm (s). HRMS (ESI+) m/z for

[H(C2H4O)4] calculated 177.1127, found 177.1132.

4.2.6.2. Synthesis of [H(18-crown-6)2][PCl6]

In the glove-box, 18-crown-6 (1.06 g, 4.0 mmol) was dissolved in CHCl3

(20 mL) to give a colorless solution. PCl5 (0.42 g, 2.0 mmol) was added and the

reaction was let to stir for 30 minutes. On the high vacuum line, dry HCl (2

mmol) was distilled into the flask and the reaction mixture was stirred overnight.

The volatiles were slowly removed in vacuo to yield colorless crystals of [H(18-

31 crown-6)2][PCl6]. Yield: 93%. P NMR (CD2Cl2) at 30 °C: δ -296.8 ppm (s), -80.2

103

ppm (s), 86.8 ppm (s), 90.4 ppm (s), and 220.1 ppm (s). HRMS (ESI+) m/z for

[H(C2H4O)6] calculated 265.1651, found 265.1648.

4.3. Results and Discussion

Equations 4.2 and 4.3 show the reactions of HCl, PCl5 and two different

crown ethers in CHCl3.

HCl + PCl5 + 12-crown-4 → [H(12-crown-4)][PCl6] (4.2) 1

HCl + PCl5 + 2 (18-crown-6) → [H(18-crown-6)2][PCl6] (4.3) 2

The reaction with 12-crown-4 occurs in a 1:1:1 ratio whereas that with 18-crown-

6 occurs in a 1:1:2 ratio, irrespective of the initial stoichiometry of the reagents.

Complexes 1 and 2 were isolated as colorless crystals.

Complexes 1 and 2 are air-sensitive and have limited thermal stability.

+ MS data of freshly prepared 1 and 2 shows the H[OCH2CH2]n cation (n = 4 or 6,

respectively) and lower molercular weight fragments (Figure 4.1). In addition,

higher molecular weight [OCH2CH2]n and H[OCH2CH2]nH oligomers, indicative of

degradation are observed for freshly prepared 1. Such oligomers were observed

in MS studies of the free crown ethers.15 After storage in an argon-filled glove-

box for 3 days for 1 and 1-2 weeks for 2, both degrade to form colorless oils.

From NMR and mass spectral data, the oils largely consist of oligomers of

formula [OCH2CH2]n and H[OCH2CH2]nH. In air, 2 degrades to give crystals of

the known [H3O(18-crown-6)][H5O2][Cl]2 which was identified by its crystal structure.16

104

Figure 4.1. ESI MS in Positive Mode of (a) [H(12-Crown-4)][PCl6], (b) [H(18-Crown-6)2][PCl6] freshly made, and (c) [H(18-Crown-

6)2][PCl6] degraded. Top: from 30 to 200 m/z. Bottom: from 45 to 1050 m/z.

105

The crystal structures of 1 and 2 have been obtained and thermal ellipsoid

plots of the cationic portions are shown in Figures 4.2 and 4.3, respectively.

Disorder of a carbon and two oxygen atoms (O(5), C(8), and C(9)) in one of the

two 18-crown-6 molecules of 2 was observed. In both 1 and 2, the proton was

found and it is two-coordinate. The proton of 1 lies in the center of the 12-crown-

4 molecule, roughly midway between two oxygen atoms separated by 2.446 Å

(Figure 5.2). The short O-O distance in 1 is consistent with a strong O-H-O

hydrogen bond.17 The proton of 2 is somewhat closer to one of the two oxygen

atoms that are involved in a shorter intermolecular O-H-O hydrogen bond of

2.423 Å between two different 18-crown-6 molecules (Figure 4.3).

The structures of 1 and 2 are different from the structures of the respective

free or nearly free crown ethers. The crystal structure of free 12-crown-4, a liquid

at room temperature, was not found. However, in structures where 12-crown-4 is

involved only in weak non-covalent interactions, none of the oxygen atoms point

toward the center of the ring.18 In 2, one end of each of the two 18-crown-6

molecules is cupped towards the proton in a conformation that is very different

than in the free 18-crown-6. 19 Some lengthening of the O-C bonds that involve the oxygen atoms bound to the proton relative to the other O-C bonds is observed in both 1 and 2.

106

Figure 4.2. Thermal ellipsoid plot of the cation of 1 with ellipsoids at 50% and showing the position of the acidic hydrogen in the O-H-O hydrogen bond (O--O = 2.446 Å). O atoms are drawn in red and C atoms in grey. Other hydrogen atoms are omitted for clarity.

Figure 4.3. Thermal ellipsoid plot of the cation of 2 with ellipsoids at 50% and showing the position of the hydrogen atom in the O-H-O hydrogen bond (O--O = 2.423 Å). O atoms are drawn in red and C atoms in grey. Other hydrogen atoms are omitted for clarity.

107

In Chapter V, it will be shown that HPCl6 is a super acid. Superacid solutions often are a complex mixture of several species.1 The NMR spectra of 1 and 2 in CD2Cl2 are in agreement with this expectation. Figures 4.4 and 4.5 show 1H NMR spectra for 1 and 2, while Figures 4.6 and 4.7 show 13C NMR spectra of 1 and 2 respectively. The 1H NMR spectra for the acidic protons show pairs of resonances at 6.05 and 5.99 for 1 and 6.00 and 5.96 ppm for 2,

1 13 respectively. The H and C NMR spectra show resonances for the CH2 groups of the two crown ethers at 3.7 and 70.7 ppm, respectively for both compounds.

31 Figures 4.8 and 4.9 show the P NMR spectra of 1 and 2 taken in CD2Cl2 at 30

ºC. Most of the resonances in the 31P spectra of 1 and 2 can be assigned to

20 31 known species. The P spectrum of 1 showed signals at -80.22 (PCl5), 4.87

+ - + - (OPCl3), 86.57 (PCl4 Cl ), and 92.40 (PCl4 PCl6 ), and 220.47 (PCl3) ppm. The

31 - P spectrum of 2 at 30 ºC showed resonances at -296.94 (PCl6 ), -80.72 (PCl5),

+ - + - 5.18 (OPCl3), 85.13 (PCl4 Cl ), and 92.37 (PCl4 PCl6 ), and 220.12 (PCl3) ppm.

- - Apparently, PCl6 dissociates to PCl5 and Cl and PCl5 is known to be a source of

+ - - 21 31 PCl4 , PCl6 , Cl and PCl3. Variable-temperature P NMR spectra of 2 in Figure

4.10 show that as the temperature is lowered to -20ºC, the resonances assigned

- to PCl5 and PCl6 sharpen considerably, consistent with an equilibrium between

- - PCl6 , PCl5 and Cl .

108

1 Figure 4.4. H NMR spectrum of [H(12-crown-4)][PCl6] in CDCl3 at 30 °C.

1 Figure 4.5. H NMR spectrum of [H(18-crown-6)2][PCl6] in CDCl3 at 30 °C. 109

13 Figure 4.6. C NMR spectrum of [H(12-crown-4)][PCl6] in CDCl3 at 30 °C.

13 Figure 4.7. C NMR spectrum of [H(18-crown-6)2][PCl6] in CDCl3 at 30 °C.

110

31 Figure 4.8. P NMR spectrum of [H(12-crown-4)][PCl6] in CD2Cl2 at 30 °C.

31 Figure 4.9. P NMR spectrum of [H(18-crown-6)2][PCl6] in CD2Cl2 at 30 °C.

111

] 6 ][PCl 2 6) - crown

- [H(18 of spectra NMR P 20 °C, (b) at 30 °C. 30 at (b) 20 °C, 31 10 . . (a) at - 4 2 Cl 2 CD Figure Figure

112

4.4. Conclusion

In summary, we have synthesized and characterized two crown ether complexes of the little-known superacid HPCl6. The coordination chemistry of the proton is a topic of recent interest.22 Though numerous crown-ether complexes of oxonium ions have been isolated and characterized,23 complexes 1 and 2 appear to be the first crystallographically-characterized crown-ether complexes of otherwise uncomplexed protons. The reactions of HPCl6 and chlorophosphazenes will be described in Chapter V.

113

4.5. References

(1) Molnar, A.; Olah, G. A.; Surya Prakash, G. K.; Sommer, J. Superacids, 2nd ed.; Wiley: New York, 2009; Chapters 1-2.

(2) Some examples: a) Kennedy, J. P. J. Polym. Sci. Part A: Polym. Chem, 1999, 37, 2285–2293. b) Kolishetti, N.; Faust, R. Macromolecules 2008, 41, 3842-3851. c) Crivello, J. V. J. Polym. Sci. Part A: Polym. Chem, 2009, 47, 1825-1835.

(3) (a) Fărcaşiu, D. Acc. Chem. Res. 1982, 15, 46-51. (b) Snider, B. B. Acc. Chem. Res. 1980, 13, 426-432.

(4) (a) Gillespie, R. J.; Liang, J. J. Am. Chem. Soc. 1988, 110, 6053-6057. (b) Culmann, J.-C.; Fauconet,. M.; Jost, R.; Sommer, J. New J. Chem. 1999, 23, 863-867.

(5) Allcock, H. R. Chemistry and Applications of Polyphosphazenes, Wiley- Interscience: New York, 2003; Chapters 1-2.

(6) (a) Liu, H. Q.; Stannett, V. T. Macromolecules 1990, 23, 140-144. (b) Sayed, M. B. Internet J. Chem. 2002, 5, Paper No. 6.

(7) (a) Emsley, J.; Udy, P. B. Polymer 1972, 13, 593-4. (b) Sulkowski, W. W. in Phosphazenes: A Worldwide Insight, Gleria, M. De Jaeger, R., eds.; Nova Science: New York, 2004, Chapter 4.

(8) Andrianov, A. K.; Chen, J.; LeGolvan, M. P. Macromolecules 2004, 37, 414- 420.

(9) (a) Heston, A. J.; Panzner, M.; Youngs W. J.; Tessier, C. A. Phosphorus, Sulfur Silicon Rel. Elem. 2004, 179, 831-837. (b) Heston, A. J.; Panzner, M.; Youngs W. J.; Tessier, C. A. Inorg. Chem. 2005, 44, 6518-6520.

(10) Allcock, H. R.; Gardner, J. E.; Smeltz, K. E. Macromolecules 1975, 8, 36-42.

(11) Examples of compounds of general form [H(base)][PCl6] where “base” is a nitrogen containing compound: (a) Knachel, H. C.; Owens, S. D.; Lawrence, S. H.; Dolan, M. E.; Kerby, M. C.; Salupo, T. A. Inorg. Chem. 1986, 25, 4606-4608. (b) Rozinov, V. G.; Kolbina, V. E.; Dmitrichenko, M. Yu. Russ. J. Gen. Chem. 1997, 67, 483-484. (c) Kaupp, G.; Boy, J.; Schmeyers, J. J. Prakt. Chem./Chem.-Zeitung 1998, 340, 346-355. (d) Dillon, K. B.; Khabbass, N. D. A. H.; Ludman, C. J. Polyhedron, 1989, 8, 2623-2626.

(12) Shriver, D. F.; Drexdon, M. A. The Manipulation of Air-Sensitive Compounds, 2nd ed.; Wiley: New York, 1986.

114

(13) Plesch, P. H. High Vacuum Techniques for Chemical Syntheses and Measurements, Cambridge University Press: New York, 1989.

(14) Sheldrick, G. M. SHELX97: Programs for Crystal Structural Analysis; University of Göttingen, Göttingen, Germany 1997.

(15) (a) Selby, T. L.; Wesdemiotis, C.; Lattimer, R. L. J. Am. Soc. Mass Spectrom. 1994, 5, 1081-1092. (b) Lattimer, R. L. J. Am. Soc. Mass Spectrom. 1994, 5, 1072-1080.

(16) Atwood, J. L.; Bott, S. G.; Coleman, A. W.; Robinson, K. D.; Whetstone, S. B.; Means C. M. J. Am. Chem. Soc. 1987, 109, 8100-8101.

(17) (a) Emsley, J. Chem. Soc. Rev. 1980, 9, 91-124. (b) Perrin, C. L.; Nielson, J. B. Ann. Rev. Phys. Chem. 1997. 48, 511–544. (c) Gilli,P.; Pretto, L.; Bertolasi, V.; Gilli, G. Acc. Chem. Res. 2009, 42, 33-44.

(18) (a) Fonari, M. S.; Ganinb, E. V.; Wang, W.-J. Acta Cryst. 2005, C61, o431- o433. (b) Babaian, E. A.; Huff, M.; Tibbals, F. A.; Hrncir, D. C. J. Chem. Soc., Chem. Commun. 1990, 306-307.

(19) Dunitz, J. D.; Seiler, P. Acta Cryst. 1974, B30, 2739-2741.

(20) (a) Kleeman, S. G.; Fluck, E.; Tebby, J. C. in CRC Handbook of Phosphorus-31 Nuclear Magnetic Resonance Data, Tebby, J. C., ed.; CRC: Boca Raton, 1991; p. 54. (b) Germa, H.; Navech, J. in CRC Handbook of Phosphorus-31 Nuclear Magnetic Resonance Data, Tebby, J. C., ed.; CRC: Boca Raton, 1991; p. 185. (c) Brazier, J. F.; Lamandé, L.; Wolf, R. in CRC Handbook of Phosphorus-31 Nuclear Magnetic Resonance Data, Tebby, J. C., ed.; CRC: Boca Raton, 1991; p. 508. (d) Lamandé, L.; Koenig, M.; Dillon, K. in CRC Handbook of Phosphorus-31 Nuclear Magnetic Resonance Data, Tebby, J. C., ed.; CRC: Boca Raton, 1991; p. 556.

(21) (a) Suter, R. W. Knachel, H. C.; Petro, V. P.; Howatson, J. H.; Shore, S. G. J. Am. Chem. Soc. 1973, 95, 1474-1479. (b) Dillon, K. B.; Lynch, R. J.; Reeve, R. N.; Waddington, T. C. J. Inorg. Nucl. Chem. 1974, 36, 815-817. (c) Wiberg, N. Hollerman, A. F.; Wiberg, E. Inorganic Chemistry, Academic: New York, 2001; pp 705 and 707.

(22) Chambron, J.-C.; Meyer, M. Chem. Soc. Rev. 2009, 38, 1663-1673.

(23) Junk, P. C. New J. Chem. 2008, 762-773 and references cited therein.

115

CHAPTER V

REACTIONS OF GROUP 15 SUPERACIDS WITH CHLOROPHOSPHAZENES

5.1. Introduction

Polyphosphazenes are classically prepared by the ring-opening

polymerization of [PCl2N]3 to form [PCl2N]n, followed by the functionalization of

1 the polymeric [PCl2N]n. Allcock and Emsley have proposed two different

mechanisms for the ROP.1,2 According to Allcock’s more generally accepted

mechanism, a phosphazenium cation is formed in the first step with the loss of a chloride anion from [PCl2N]3 (Figure 5.1). The cation is then attacked by the lone pair of electrons on the nitrogen atom of a nearby [PCl2N]3, leading to the

breakage of a P-N bond and ultimately to the ring opening of [PCl2N]3. The

reactions of several Lewis acids with [PCl2N]3 have been studied in the quest for

3 a Lewis acid that can facilitate the chloride removal from [PCl2N]3.

116

Cl Cl Cl N Cl Cl N P P Cl heat Cl P P Cl N N o P (>250 C) N N P Cl Cl Cl Cl Cl Cl Cl N P P Cl N N P Cl Cl Cl Cl Cl N N P P P Cl P N N Cl P N N Cl P Cl Cl

1 Figure 5.1. Allcock’s mechanism of the ROP of [PCl2N]3 to give [PCl2N]n.

In this chapter, we will describe the reaction of [PCl2N]3 with the Group 15

Lewis acids SbCl5 and PCl5. Because SbCl5 is the strongest chloride ion

4 acceptor, second only to FeCl3 , we decided to investigate if it will remove the

chloride from [PCl2N]3. The interaction between SbCl5 and [PCl2N]3 has been

studied before by others but discrepancies exist as to the kind of product formed

from the interaction.5 In 1968, Coxon reported that there was no interaction

5 between SbCl5 and [PCl2N]3. Kravcheko claimed in 1977 that SbCl5 abstracted

. 5 the chloride from [PCl2N]3 and formed [P3N3Cl5] SbCl6 (Figure 5.2).

117

Cl SbCl6 P N N Cl Cl P P N Cl Cl

. Figure 5.2. [P3N3Cl5] SbCl6 proposed by Kravcheko as the product of the 5 interaction between SbCl5 and [PCl2N]3.

As described in Chapter III, the Lewis acid/Bronsted acid dichotomy was

observed in the Group 13 Lewis acid chemistry of chlorophosphazenes. It is

important to investigate if the same dichotomy is pertinent to the Group 15 Lewis

acid chemistry, especially with PCl5. Because PCl5 is used in one step or the

1 other in the syntheses of [PCl2N]3 and the polymeric [PCl2N]n (Figure 5.3), traces

of PCl5 can remain as impurities in both synthesized cyclic and polymeric

[PCl2N]n. During storage of [PCl2N]n, the P-Cl bond in PCl5 impurities can be

hydrolyzed by water impurities to give H-Cl. The HCl produced can react with

another PCl5 to give HPCl6. Studying how HPCl6 reacts with the cyclic [PCl2N]n

might help us determine if HPCl6 plays a role in the protonic impurities that are present in freshly made cyclics. In addition, if PCl6 is a strong enough acid, it

could account for the fact that protonic impurities cause the polymeric [PCl2N]n to

degrade.

The acidities of HPCl6 and HSbCl6 are not well documented even though

their fluoro-containing counterparts, HPF6 and HSbF6, are fully recognized as

6 7 superacids. In fact, HSbF6 is the strongest liquid superacid. Chapter IV

118 showed that HPCl6 is acidic enough to protonate crown ethers. In this chapter, we will discuss the interactions of SbCl5, PCl5, HSbCl6 and HPCl6 with cyclic

[PCl2N]m (m = 3, 4, 5, and 6) and polymeric [PCl2N]n. The letters m and n will be used to denote the degree of oligomerization or polymerization for the rings and the polymer, respectively. Applying the qualitative acidity scale that was

8 developed by Reed, we will also compare the acidity of HSbCl6 and HPCl6 with those of better known Group 13 superacids mentioned in Chapter III.

NH4Cl + PCl5 [PCl2N]3

o ROP o 214 C + 145 C "SiEt3 " -HCl rt melt ROP [PCl N] + [PCl2N]4 o [PCl2N]n 2 3 250 C

Condensations -X-Z BCl3 210oC Cl

X P N Z PCl5 Cl

Figure 5.3. Prevalent usage of PCl5 in the syntheses of chlorophosphazenes.

119

5.2. Experimental

This section describes the general experimental methods, materials used,

characterization techniques and syntheses.

5.2.1. General Experimental Methods

All manipulations were carried out under vacuum or under dry and

oxygen-free argon or nitrogen atmosphere, applying standard anaerobic

techniques such as Schlenk, vacuum line and glove-box techniques.9 The

vacuum line had the ultimate capacity of 2x10-4 torr. The atmosphere of the

glove-box was routinely checked by a light-bulb test, and the oxygen and

moisture content inside the glove-box was kept between 1 and 5 ppm. After

being dried in the oven overnight, the glassware was assembled hot and

evacuated immediately, or directly placed in the port of the glove-box, evacuated

and assembled in the glove-box. The glassware used for the experiments was made with virtually greaseless Fisher-Porter Solv-seal® glass joints. The high vacuum valves on the flasks were purchased from Kimble-Kontes. Infrared spectra were collected on a Nicolet Nexus 870 Fourier transform spectrometer.

Infrared samples were prepared in the glove-box, transported from the glove-box to the spectrometer in a desiccator and were not exposed to air until they were placed in the spectrometer.

Due to the light sensitivity of the HSbCl6 complexes of the cyclic [PCl2N]n

(n = 3, 4, 5, and 6) and the polymeric [PCl2N]n, exposure to light was kept at

absolute minimum in the syntheses and handling of those compounds. 120

5.2.2. Materials

Chloroform, methylene chloride and hexane (Fisher) were purified by

using a solvent system manufactured by PureSolvTM. Deuterated methylene

chloride (99.9%) and deuterated chloroform (99.8%) were purchased from

Cambridge Isotopes, distilled three times onto freshly activated 4 Å molecular sieves and stored under argon in foil-wrapped storage tubes in the glove-box.

SbCl5 (Sigma Aldrich) was used as received unless otherwise stated. PCl5

(Sigma Aldrich, reagent grade) was dried on the vacuum line overnight and

stored in the glove box. [PCl2N]3 (Aldrich, 99.99%) was purified via sublimation

and stored in the glove-box. [PCl2N]4 (a gift from Prof. Chris Allen, University of

Vermont), [PCl2N]5-6 (a gift from David Bowers, University of Akron), and

polymeric [PCl2N]n (a gift from Supat Moolsin, Sujeewani Ekanayake, and David

Bowers, University of Akron) were pumped overnight on the high-vacuum line

and stored in the glove box. AlCl3, AlBr3, and GaCl3 (Alfa Aesar) were purified by sublimation and stored in the glove-box. HCl gas (Praxair, 99%) was purified by fractional vacuum distillation through two -78 °C (dry ice/acetone bath) traps and stored in a glass bulb attached to the high vacuum line. HBr gas was purchased in a lecture bottle from Matheson Gas Products, Inc. and used as received. Tri- n-octylamine was purchased from Acros Organics, vacuum dried on the high- vacuum line for one week and stored in the glove-box. A literature procedure was followed in preparing tri-n-octylammonium chloride.10 Tri-n-octylammonium bromide was synthesized with a slight modification of the said procedure by using HBr in lieu of HCl. 121

5.2.3. NMR Spectroscopy

NMR samples were prepared in the glove-box and all NMR tubes were

flame sealed under vacuum. In order to minimize the presence of degradation

products, NMR samples were made within 24 hours of the preparation of the

adducts. The NMR spectra were either taken immediately after the NMR samples were prepared or the tube was kept frozen (liquid nitrogen) until the spectra were taken. Routine NMR spectra were obtained using Varian Gemini

300 MHz or INOVA 400 MHz instruments at 25°C. VT NMR data were obtained on a Varian INOVA 400 MHz NMR spectrometer with a 5 mm switchable probe.

Proton NMR spectra were referenced to the residual proton resonance of the deuterated solvent. An external reference (0.15 M H3PO4 solution in deuterated solvent (0 ppm)) was used for the 31P spectra. 31P NMR spectra were collected

with continuous decoupling because of the nuclear Overhauser effect (NOE).

5.2.4. X-ray crystallography

In the glove-box, crystals were put into paratone® oil on a slide. The slide was transported from the glove-box to the instrument in a desiccator that was wrapped in aluminum foil. The crystals were immediately mounted in low light and the data collection took place with the laboratory lights turned off.

Crystal structure data sets were collected on a Bruker Apex CCD diffractometer with graphite-monochromated Mo Kα radiation (λ = 0.71073Å).

Unit cell determination was achieved by using reflections from three different

122

orientations. An empirical absorption correction and other corrections were done

using multi-scan SADABS. Structure solution, refinement and modeling were

accomplished using the Bruker SHELXTL package.11 The structures were

obtained by full-matrix least-squares refinement of F2 and the selection of

appropriate atoms from the generated difference map. X-ray crystallography was done by Dr. Matthew J. Panzner.

5.2.5. Mass Spectrometry

For mass spectrometry, samples were prepared in the glove-box and transferred to the spectrometer in a desiccator. MS spectra were acquired with a

SYNAPT HDMS™ Q/ToF mass spectrometer (Waters, Beverly, MA) equipped with a z-spray electrospray source. For the positive mode, the instrument was operated at a voltage of 3.5 kV, sample cone voltage of 35 V and extraction cone voltage of 3.2 V; the desolvation gas flow was 800 L/h (N2); the source temperature and desolvation gas temperature were 90 °C and 250 °C. The sample flow rate was set at 10 μL/min. For the negative mode, the instrument was operated at a voltage of 3.5 kV, sample cone voltage of 40 V and extraction cone voltage of 4.0 V; the desolvation gas flow was 800 L/h (N2); the source

temperature and desolvation gas temperature were 120 °C and 250 °C. The

sample flow rate was set at 10 μL/min. The concentration of the electrosprayed

samples was 0.01 mg/mL in CHCl3. Mass spectrometry experiments were

performed by Vincenzo Scionti.

123

5.2.6. Syntheses

Due to the light sensitivity of the HSbCl6 complexes of the cyclic [PCl2N]n

(n = 3, 4, 5, and 6) and the polymeric [PCl2N]n, exposure to light was kept at absolute minimum in the syntheses and handling of those compounds.

. 5.2.6.1. Synthesis of [PCl2N]3 [HSbCl6]

Route 1. The glassware used for this synthetic route is shown in Figure 5.4. In the glove-box, SbCl5 (0.2 mL, 2 mmol) was put in the flask A via a syringe.

[PCl2N]3 (6.9 g, 2.0 mmol) and hexane (20 mL) were put in a storage tube and the storage tube was attached to the reaction flask as shown in Figure 5.3. The reaction vessel was taken out of the glove-box and attached to the high vacuum line. SbCl5 in the flask A was frozen at liquid nitrogen temperature and the constriction 1 was closed by flame-sealing. SbCl5 from the flask A was thawed and condensed into the flask B at -77 °C (dry ice/acetone bath) while any HCl gas and other volatile impurities were distilled into a trap on the vacuum line at -

196 °C (liquid nitrogen bath). Constriction 2 was flame-sealed. In order to remove any dissolved Cl2 contaminants, condensed SbCl5 in flask B was subjected three times to freeze-pump-thaw cycle using an ice/ethanol bath (-22

°C) for freezing. The contents of the storage tube were added to the flask B while SbCl5 in flask B was chilled at -22 °C (ice/ethanol bath). The reaction assembly was taken into the glove-box where the storage tube was replaced by a cap. The reaction flask was wrapped in aluminum foil and stored undisturbed

124

in the dark for 4 days to promote crystal growth. After 4 days, colorless crystals

had formed on the wall of the flask from a black solution. X-ray crystallography

. analysis of the unit cell showed that the crystals were [PCl2N]3 [HSbCl6].

. Figure 5.4. Glassware used for the attempted synthesis of [PCl2N]3 SbCl5. The . reaction yielded [PCl2N]3 HSbCl6 instead.

Route 2. In the glove-box, (PCl2N)3 (0.86 g, 1.5 mmol) was dissolved in CHCl3

(20 mL) to give a colorless solution. The flask was taken out of the glove-box and into a glove-bag where SbCl5 (0.15 mL, 1.5 mmol) was added to the flask via a syringe, and the reaction was stirred for 30 minutes. Due to light-sensitivity of the solution, the reaction flask was wrapped in aluminum foil. The flask was attached to the high vacuum line and dry HCl (0.50 L at 0.072 atm, 295 K; 1.5 mmol) was condensed into the flask. The reaction was stirred overnight. The

125

volatiles were slowly removed in vacuo to yield colorless crystals of

. 31 [PCl2N]3 [HSbCl6]. Yield: 95%. P NMR (CDCl3): δ 18.95 ppm (s) at 30 °C, δ

18.56 ppm (s) at 0 °C, δ 18.27 ppm (s) at -20 °C, δ 17.99 ppm (s) at -40 °C, δ

1 17.77 ppm (s) at -60 °C and δ 17.59 ppm (s) at -80 °C. H NMR (CDCl3): δ 9.14

ppm (s) at 25 °C, δ 9.09 ppm (s) at 0 °C, δ 8.99 ppm (s) at -20 °C, δ 8.88 ppm (s)

+ at -40 °C, and δ 8.79 ppm (s) at -60 °C. HRMS (ESI+) m/z for (H[PCl2N]3) calculated 345.7515, found 345.7466, HRMS (ESI-) m/z for [SbCl6] calculated

330.7169, found 330.7177. See the Appendix for X-ray crystallographic

information. Upon storage under argon for ~ 40 days, the product degraded to

give colorless crystals. Crystallographic analysis of the degradation product

showed the co-crystallization of (PCl2N)3 with SbCl3. See the Appendix for X-ray

crystallographic information.

. 5.2.6.2. Synthesis of [PCl2N]4 [HSbCl6]

In the glove-box, (PCl2N)4 (0.93 g, 2.0 mmol) was dissolved in CHCl3 (25

mL) to give a colorless solution. In the glove-bag, SbCl5 (0.2 mL, 2.0 mmol) was

added to the flask via a syringe, and the reaction was stirred for 30 minutes. Due

to light-sensitivity of the solution, the reaction flask was wrapped in aluminum foil.

The flask was attached to the high vacuum line and dry HCl (0.50 L at 0.096 atm,

295 K; 2.0 mmol) was condensed into the flask, and the reaction mixture was

stirred overnight. A fine white precipitate was observed. The volatiles were

126

. slowly removed in vacuo to yield colorless crystals of [PCl2N]4 [HSbCl6]. Yield:

31 90%. P NMR (CDCl3): δ -5.8 ppm (s) at 30 °C, and δ -3.6 ppm (s) and -6.1

1 ppm (s) at -40 °C. H NMR (CDCl3): δ 8.2 ppm (s) at -40 °C. See the Appendix

for X-ray crystallographic information.

. . 5.2.6.3. Synthesis of a mixture of [PCl2N]5 [HSbCl6] and [PCl2N]6 [HSbCl6]

In the glove-box, (PCl2N)5-8 (1.39 g, 11.9 mmol) was dissolved in CHCl3

(20 mL) to give a colorless solution. The reaction flask was taken out of the

glove-box and into a glove-bag where SbCl5 (0.2 mL, 2.0 mmol) was added via

syringe to give a yellowish brown solution. The reaction was stirred for 30 minutes with the reaction flask wrapped in aluminum foil. The flask was taken

out of the glove-bag and attached to the high vacuum line where dry HCl (0.50 L

at 0.096 atm, 295 K; 2.0 mmol) was condensed into the flask. The reaction was

stirred in the dark for 1 hr. A small amount of a white precipitate was observed.

Stirring was stopped and the reaction was allowed to sit undisturbed and away

from light overnight. The volatiles were slowly removed in vacuo to yield a brown

viscous material. The product was characterized by 1H and 31P NMR, and

31 HRMS. Yield: 85%. P NMR (CDCl3) at 30 °C: δ -17.0 ppm (m), -16.8 ppm (m),

1 -16.3 ppm (d), -15.5 ppm (d), and -13.7 ppm (t). H NMR (CDCl3) at 30 °C: δ

8.74 ppm (s). After the reaction flask was left undisturbed for three months in the

. . glove-box, colorless crystals of [PCl2N]5 [HSbCl6] and [PCl2N]6 [HSbCl6] formed

127 amid the brown viscous material. See the Appendix for X-ray crystallographic information.

5.2.6.4. The reaction of polymeric [PCl2N]n with HSbCl6

In the glove-box, polymeric (PCl2N)n (0.06 g, 0.52 mmol) was dissolved in

CHCl3 (20 mL) to give a colorless solution. The reaction flask was taken out of the glove-box and into a glove-bag where SbCl5 (5 µL, 50 µmol) was added via syringe and the reaction was stirred for 30 minutes with the reaction flask wrapped in aluminum foil. The flask was taken out of the glove-bag and attached to the high vacuum line where excess dry HCl (0.50 L at 0.024 atm, 295 K; 0.5 mmol) was condensed into the flask. The reaction was stirred overnight with the reaction flask wrapped in aluminum foil. The volatiles were slowly removed in

31 vacuo to yield a brown viscous material. Yield: 60%. P NMR (CDCl3) at 30 °C:

δ -19.73 ppm (m), -11.68 ppm (m), -9.22 ppm (m), 7.38 ppm (m), and 17.99 ppm

1 (m). H NMR (CDCl3) at 30 °C: δ 6.41 ppm (s). After storing undisturbed under argon, small crystals were observed in the flask. X-ray crystallography analysis

. showed that the crystals were of HSbCl6 3H2O.

128

5.2.6.5. The reaction of a mixture of cyclic [PCl2N]m with HPCl6, where m = 3, 4, 5

or 6

In the glove-box, cyclic (PCl2N)m (2.0 mmol) was dissolved in CHCl3 (20 mL) to give a colorless solution. PCl5 (0.416 g, 2.0 mmol) was added and the

reaction was stirred for 30 minutes with the reaction flask wrapped in aluminum

foil. The flask was attached to the high vacuum line and dry HCl (0.50 L at 0.096

atm, 295 K; 2.0 mmol) was condensed into the flask. The reaction was stirred

overnight with the reaction flask wrapped in aluminum foil. The volatiles were

slowly removed in vacuo. By 1H and 31P NMR, unreacted starting materials

cyclic (PCl2N)n and PCl5 were isolated.

5.2.6.6. The reaction of polymeric [PCl2N]n with HPCl6

In the glove-box, polymeric (PCl2N)n (0.137 g, 1.19 µmol) was dissolved in

CHCl3 (20 mL) to give a colorless solution. PCl5 (0.022, 0.1 mmol) was added

and the reaction was stirred for 30 minutes with the reaction flask wrapped in aluminum foil. The flask was taken out of the glove-box and attached to the high vacuum line where excess dry HCl (0.50 L at 0.048 atm, 295 K; 1.0 mmol) was condensed into the flask. The reaction was stirred overnight with the reaction flask wrapped in aluminum foil. The volatiles were slowly removed in vacuo to

1 yield brown viscous material. Yield: 60%. H NMR (CDCl3) at 30 °C: δ 7.32 ppm

(s), 7.26 ppm (m), 7.19 ppm (m), 7.13 ppm (m), and 7.08 ppm (s).

129

5.2.6.7. Synthesis of tri-n-octylammonium tetrachloaluminate

In the glove-box, tri-n-octylammonium chloride (0.38 g, 1.0 mmol) was dissolved in CH2Cl2 (20 mL) to give a colorless solution. AlCl3 (0.13 g, 1.0 mmol)

was added to the flask to give a colorless solution. The reaction was stirred

overnight. The reaction flask was taken out of the glove-box and the volatiles

were slowly removed in vacuo to yield a colorless solid. Yield: 90%. 1H NMR

(CD2Cl2) at 30 °C: δ 6.65 ppm (s), 3.16 (m), 1.75(m), 1.35 (m). IR neat oil,

-1 ν(NH): 3132 cm (s).

5.2.6.8. Synthesis of tri-n-octylammonium tetrachlorogallate

In the glove-box, tri-n-octylammonium chloride (0.38 g, 1.0 mmol) was dissolved in CH2Cl2 (20 mL) to give a colorless solution. GaCl3 (0.17 g, 1.0

mmol) was added to the flask to give a pink tinted solution. The reaction was

stirred overnight. The reaction flask was taken out of the glove-box and the

volatiles were slowly removed in vacuo to yield a colorless solid. Yield: 90%. 1H

NMR (CD2Cl2) at 30 °C: δ 6.76 ppm (s), 3.16 (m), 1.75 (m) 1.35 (m). IR neat oil,

-1 ν(NH): 3127 cm (s).

130

5.2.6.9. Synthesis of tri-n-octylammonium tetrabromoaluminate

In the glove-box, tri-n-octylammonium bromide (0.869 g, 2.0 mmol) was dissolved in CH2Cl2 (20 mL) to give a yellow solution. AlBr3 (0.533 g, 2.0 mmol)

was added to the flask to give a yellow solution. The reaction was stirred

overnight. The reaction flask was taken out of the glove-box and the volatiles

were slowly removed in vacuo to yield a dark brown viscous material. Yield:

1 85%. H NMR (CD2Cl2) at 30 °C: δ 8.20 ppm (s), 7.72 (m), 7.57 (m), 4.21 (m),

-1 3.16 (m), 1.75 (m), 1.35 (m). IR neat oil, ν(NH): 3074 cm (s).

5.2.6.10. Synthesis of tri-n-octylammonium hexachloroantimonate

In the glove-box, Tri-n-octylammonium chloride (0.38 g, 1.0 mmol) was

dissolved in CH2Cl2 (20 mL) to give a colorless solution. The reaction flask was

taken out of the glove-box and into a glove-bag where SbCl5 (0.1 mL, 1.0 mmol)

was added to the flask via a syringe to give a colorless solution. The reaction

was stirred overnight. The flask was taken out of the glove-bag and the volatiles

were slowly removed in vacuo to yield a colorless solid. Yield: 93%. IR neat oil,

-1 ν(NH): 3058 cm (s).

131

5.2.6.11. Synthesis of tri-n-octylammonium phosphorushexachloride

In the glove-box, tri-n-octylammonium chloride (0.78 g, 2.0 mmol) was

dissolved in CH2Cl2 (20 mL) to give a colorless solution. PCl5 (0.42 g, 2.0 mmol)

was added to the flask to give a colorless solution. The reaction was stirred

overnight. The volatiles were slowly removed in vacuo to yield a white material.

1 Yield: 85%. H NMR (CD2Cl2) at 30 °C: δ 10.0 ppm (s), 3.02 (m), 1.76 (m), 1.31

-1 (m). IR neat oil, ν(NH): 3055 cm (s).

5.3. Results and Discussion

The reaction of cyclic [PCl2N]n (n = 3, 4, 5, and 6) and the polymeric [PCl2N]n with

HSbCl6 will be discussed first, followed by the discussion of the reactions of

cyclic [PCl2N]n (n = 3, 4, 5, and 6) and the polymeric [PCl2N]n with HPCl6.

Qualitative comparison of the acidities of HSbCl6 and HPCl6 with known

superacids will follow last.

. 5.3.1. [PCl2N]3 HSbCl6

The reaction of SbCl5 with [PCl2N]3 in hexane, shown in Scheme 5.1, did

5 not remove a chloride ion from [PCl2N]3 as proposed in the literature. The

. reaction of SbCl5 with [PCl2N]3 did not form [PCl2N]3 SbCl5 unlike the reactions of

Group 13 Lewis acids with [PCl2N]3 (Chapter II). It instead gave a low yield of

. [PCl2N]3 HSbCl6 as colorless crystals presumably because a small amount of

adventitious water was present. Reacting SbCl5, HCl and [PCl2N]3 in CHCl3 gave 132

. . [PCl2N]3 HSbCl6 as colorless crystals (Scheme 5.1). [PCl2N]3 HSbCl6 was

characterized by x-ray crystallography, 1H and 31P VT NMR and high resolution

. mass spectrometry. [PCl2N]3 HSbCl6 degraded to give colorless crystals upon storage under argon in the glove-box for about 40 days. Crystallographic analysis of the degradation product showed a co-crystal of (PCl2N)3 with SbCl3

- (see below). Pentavalent SbCl6 appears to have been reduced into trivalent

- 31 SbCl3. Similar degradation of PCl6 into PCl3 was observed in the P NMR spectra of [H(12-crown-4)][PCl6] and [H(18-crown-6)2][PCl6] (Chapter IV).

Cl Cl SbCl5 P N N Cl Cl P P N Cl Cl

. SbCl5 + [PCl2N]3 [PCl2N]3 SbCl5

H2O [H(PCl2N)3][SbCl6] [PCl2N]3 + SbCl3

SbCl + HCl + [PCl N] 5 2 3

Scheme 5.1. Reactions involving [PCl2N]3 with SbCl5 or HSbCl6.

. The thermal ellipsoid plots of [PCl2N]3 HSbCl6 and its degradation product

are shown in Figures 5.5 and 5.6, respectively. Comparison of selected bond

. distances and angles of [PCl2N]3 HSbCl6 with those in a free [PCl2N]3 ring is

given in Table 5.1. The hydrogen atom was not found in the structure of 133

. [PCl2N]3 HSbCl6, but the distance between the ring nitrogen and a chloride of the

SbCl6 anion (3.27 Ǻ) was consistent with N-H—Cl hydrogen bonds. Adduct

. formation did not distort the [PCl2N]3 ring in the [PCl2N]3 HSbCl6, unlike the ring in

the adducts discussed in Chapter II and Chapter III. Similar to the adducts

. discussed in the above mentioned chapters, [PCl2N]3 HSbCl6 showed

lengthening of the two P-N bonds in the ring that involve the nitrogen atom where

protonation occurred. These weakened P-N bonds [1.656(5)-1.664(5) Ǻ

(average = 1.660 Ǻ)] showed single bond character whereas the remaining P-N

bonds [1.540(5)-1.592(5) Ǻ (average = 1.567 Ǻ)] preserved the multiple bond

12 character found in free [PCl2N]3 (1.575 Ǻ ). The P-N-P angle at the protonated nitrogen [124.3°(3)] is narrower than other P-N-P angles in the ring [125.0(3)-

125.2(3) (average = 125.1(3))]. The average P-N-P angle in a free [PCl2N]3 ring

12 . is 121.2°. Similar changes in P-N-P angles were observed in [PCl2N]3 HMX4

. (Chapter III). All N-P-N angles in [PCl2N]3 HSbCl6 (average = 118.4°) are smaller

12 than the N-P-N angles in a free [PCl2N]3 ring (average = 118.4°).

. ESI mass spectra of [PCl2N]3 HSbCl6 were obtained in CHCl3 solutions that were exposed to air as little as possible. The mass spectra were obtained

. under high resolution conditions. ESI mass spectra of [PCl2N]3 HSbCl6 in positive

+ - mode (Figures 5.7) showed (H[PCl2N]3) cation. Similarly, the anion SbCl6 was

. detected in ESI mass spectra of [PCl2N]3 HSbCl6 in negative mode (Figures 5.8).

31 . VT P NMR spectra of [PCl2N]3 HSbCl6 in CD2Cl2 taken between -80 °C

. and 30 °C are shown in Figure 5.9. [PCl2N]3 HSbCl6 was extremely fluxional in

134

solution even at -80 °C and only a sharp singlet was observed in its 31P spectra

as opposed to a triplet and a doublet expected from the solid state structure. The

. fluxional behavior in solution of [PCl2N]3 HSbCl6 is consistent with those of

. 1 . [PCl2N]3 HMX4 described in Chapter III. VT H NMR spectra of [PCl2N]3 HSbCl6

31 in CD2Cl2 taken between -60 °C and 30 °C are shown in Figure 5.10. Both P

1 . and H resonances of [PCl2N]3 HSbCl6 shifted upfield with decrease in

. temperature following the trend observed for [PCl2N]3 HMX4 systems (Chapter

III).

. Figure 5.5. Thermal ellipsoid plot for the crystal structure of [PCl2N]3 HSbCl6. N atoms are drawn in blue, P atoms in orange and chlorine atoms in green.

135

. Figure 5.6. Degradation product in solid of [PCl2N]3 HSbCl6 showing the co- crystallization of [PCl2N]3 with SbCl3. N atoms are drawn in blue, P atoms in orange and chlorine atoms in green.

136

. Table 5.1. Selected distances (Ǻ) and angles in [PCl2N]3 and [PCl2N]3 HSbCl6.

a . [PCl2N]3 [PCl2N]3 HSbCl6 Hydrogen bond distance N(1)-Cl(8) 3.268 P-N distances that flank the nitrogen atom that is bound to HSbCl6 P(1)-N(1) 1.656(5) N(1)-P(2) 1.664(5)

Other P-N bond distances P-N distances P(2)-N(1) 1.575(3) P(1)-N(3) 1.549(5) P(2)-N(2) 1.575(4) P(2)-N(2) 1.540(5) P(1)-N(2) 1.575(4) P(3)-N(3) 1.585(5) P(3)-N(2) 1.592(5)

P-N-P angles for N bound to HSbCl6 P(2)-N(1)-P(1) 124.3(3)

Other P-N-P angles P-N-P angles P(2)-N(2)-P(3) 125.0(3) P(2)-N(1)-P(2’) 121.2(4) P(1)-N(3)-P(3) 125.2(3) P(1)-N(2)-P(2) 121.5(3)

N-P-N angles N-P-N angles N(2)-P(1)-N(2’) 118.3(2) N(3)-P(1)-N(1) 113.0(3) N(1)-P(2)-N(2) 118.5(3) N(2)-P(2)-N(1) 112.7(3) N(3)-P(3)-N(2) 114.7(3) a. reference 11

137

. Figure 5.7. High resolution ESI mass spectrum of [PCl2N]3 HSbCl6 in the positive + mode. (a) Theoretical isotope distribution for H[PCl2N]3 , (b) experimental isotope distribution.

. Figure 5.8. High resolution ESI Mass spectrum of [PCl2N]3 HSbCl6 in the negative - mode, (a) theoretical isotope distribution for SbCl6 , (b) experimental isotope distribution.

138

31 . Figure 5.9. P VT NMR spectra of [PCl2N]3 HSbCl6 in CD2Cl2 taken between -80 and 30 °C. (a) 30 °C, (b) 0 °C, (c) -20 °C, (d) -40 °C, (e) -60 °C, and (f) -80 °C.

1 . Figure 5.10. H VT NMR spectra of [PCl2N]3 HSbCl6 in CD2Cl2 taken between -60 and 30 °C. (a) 30 °C, (b) 0 °C, (c) -20 °C, (d) -40 °C, and (e) -60 °C.

139

. 5.3.2. [PCl2N]4 HSbCl6

The reaction of [PCl2N]4, SbCl5 and HCl in CHCl3 resulted in

. [PCl2N]4 HSbCl6 (Equation 5.1).

CHCl3 . [PCl2N]4 + SbCl5 + HCl [PCl2N]4 [HSbCl6]

(5.1)

. The thermal ellipsoid plot of [PCl2N]4 HSbCl6 is shown in Figure 5.11 and

selected bond distances and bond angles are given in Table 5.2. The hydrogen

. atom was found in the structure of [PCl2N]4 HSbCl6, and the distance between

the ring nitrogen and a chloride of the SbCl6 anion (3.22 Ǻ) was consistent with

N-H—Cl hydrogen bonds. Protonation lengthened the two P-N bonds in the ring

that involve the nitrogen atom where protonation occurred. The weakened P-N

bond distances were 1.647(3) Ǻ and 1.651(3) Ǻ whereas the remaining P-N

bonds range 1.540(3)-1.584(3) Ǻ (average = 1.566 Ǻ). Similar P-N bond

. weakening has been reported in [PMe2N]4 [HM(CO)5I] (M = Cr or Mo) and

. 13 [PMe2N]4 [H2MCl4] (M = Pt or Co).

31 . P NMR spectra of [PCl2N]4 HSbCl6 in CDCl3 showed fluxional behavior in

solution (Figure 5.12). At 30 °C, a single resonance was observed at -5.8 ppm.

At -40 °C, two singlets at -3.6 ppm and -6.1 ppm are observed. In 1H NMR

spectrum in CDCl3, a singlet was observed at 8.2 ppm only at -40 °C and not at

30 °C.

140

. 6 HSbCl . 4 N] 2 Thermal ellipsoid plot for the crystal structure of [PCl of structure crystal the for plot ellipsoid Thermal

. 1

Figure 5.1 Figure

141

. Table 5.2. Selected distances (Ǻ) and angles in [PCl2N]4 and [PCl2N]4 HSbCl6.

. [PCl2N]4 in boat structure [PCl2N]4 HSbCl6 Hydrogen bond distance and angle N(1)-Cl(8) 3.222(3) N(1)-H(1)-Cl(1) 159.3

P-N distances that flank the nitrogen atom that is bound to HSbCl6 P(2)-N(2) 1.647(3) P(3)-N(2) 1.651(3)

Other P-N bond distances P-N distances P(1)-N(1)#1 1.5710(12) P(1)-N(4) 1.572(3) P(1)-N(1) 1.5711(12) P(1)-N(1) 1.584(3) P(1)-N(1)#2 1.5710(12) P(2)-N(1) 1.585(3) P(3)-N(3) 1.540(3) P(4)-N(4) 1.574(3) P(4)-N(3) 1.578(3)

P-N-P angles for N bound to HSbCl6 P-N-P angle P(2)-N(2)-P(3) 123.5(2) P(1)#2-N(1)-P(1) 130.91(8) Other P-N-P angles P(2)-N(1)-P(1) 136.0(2) P(3)-N(3)-P(4) 143.9(2) P(1)-N(4)-P(4) 126.6(2) N-P-N angles N-P-N angle N(4)-P(1)-N(1) 117.23(17) N(1)#1-P(1)-N(1) 120.46(8) N(1)-P(2)-N(2) 112.16(18) N(3)-P(3)-N(2) 111.24(18) N(4)-P(4)-N(3) 116.90(17)

142

, and and , 40 °C - taken (a) at at (a) taken 3 in CDCl

6 HSbCl . 4 N] 2 P VT NMR spectra of [PCl of spectra NMR P VT 31

. . 2 30 °C

5.1 Figure (b) at

143

. . 5.3.3. [PCl2N]5 HSbCl6 and [PCl2N]6 HSbCl6

The reaction of SbCl5, HCl and cyclic [PCl2N]m where m = 5 – 8, gave a brown viscous material (equation 5.2).

CHCl3 . . [PCl2N]5-8 + SbCl5 + HCl [PCl2N]5 [HSbCl6] + [PCl2N]6 [HSbCl6] + others

(5.2)

Proton NMR spectrum of the material in CDCl3 at 30 °C showed the presence of an acidic proton at 8.74 ppm as a broad resonance (Figure 5.13).

31 The P NMR spectrum in CDCl3 at 30 °C shown in Figure 5.14 is very complex.

In order to assign the observed resonances to the corresponding phosphorus species, either a 2D 31P-31P homonuclear 2DJ study of the product needs to be performed or the reaction needs to be repeated with pure cyclic [PCl2N]n starting materials. However, the purpose of this preliminary study is to determine if there is any interaction between SbCl5 and HCl with the cyclic [PCl2N]n, and the 1D

NMR data show that there is an interaction. After storing the product undisturbed

. . for 3 months, crystals of [PCl2N]5 HSbCl6 and [PCl2N]6 HSbCl6 had formed amid the brown viscous material.

. . The crystals of [PCl2N]5 HSbCl6 and [PCl2N]6 HSbCl6 were characterized

. by x-ray crystallography. The thermal ellipsoid plot of [PCl2N]5 HSbCl6 is shown in Figure 5.15, and the hydrogen atom can be found in the structure.

. Comparison of selected bond distances and bond angles of [PCl2N]5 HSbCl6 with

144

14 those of [PCl2N]5 is given in Table 5.3. The distance between the ring nitrogen

- and a chloride of the SbCl6 anion (3.239(3) Ǻ) was consistent with N-H—Cl

. hydrogen bonds. [PMe2N]5 [H2CuCl4] structure has been reported to show similar

P-N bond weakening upon protonation.13 The ball and stick plot of the structure

. of [PCl2N]6 HSbCl6 is shown in Figure 5.16. The asymmetric unit of

. [PCl2N]6 HSbCl6 contains two molecules. The crystal structure showed much

thermal motion, especially at the positions of chloride anions. The unit cell of free [PCl2N]6 was reported in 1968 but the structure of free [PCl2N]6 has never

been solved. Attempts in our group to acquire a satisfactory structure of [PCl2N]6

has not been successful. Although the smaller cyclic [PCl2N]n (n = 3, 4, 5) have

rigid structures, the polymeric [PCl2N]n is a very flexible material. Because the

flexibility increases with the increase in ring size, we might be observing the

onset of elasticity at [PCl2N]6.

145

1 . Figure 5.13. H NMR spectrum of [PCl2N]5-7 HSbCl6 in CDCl3 taken at 30 °C.

31 . Figure 5.14. P NMR spectrum of [PCl2N]5-7 HSbCl6 in CDCl3 taken at 30 °C.

146

. Figure 5.15. Thermal ellipsoid plot for the crystal structure of [PCl2N]5 HSbCl6.

147

Table 5.3. Selected distances (Ǻ) and angles in the crystal structures of [PCl2N]5 . and [PCl2N]5 HSbCl6.

a . [PCl2N]5 [PCl2N]5 HSbCl6 Hydrogen bond distance and angle N(3)-Cl(11) 3.239(3) N(3)-H(3)-Cl(11) 178.0 P-N distances that flank the nitrogen atom that is bound to HSbCl6 P(3)-N(3) 1.653(2) P(4)-N(3) 1.648(2)

Other P-N bond distances P-N distances P(1)-N(5) 1.561(3) P(1)-N(1) 1.564(3) P(1)-N(1) 1.565(3) P(1)-N(5) 1.576(3) P(2)-N(2) 1.551(3) P(2)-N(1) 1.560(3) P(2)-N(1) 1.561(3) P(2)-N(2) 1.572(3) P(3)-N(2) 1.558(3) P(3)-N(2) 1.520(3) P(3)-N(3) 1.564(3) P(4)-N(4) 1.534(3) P(4)-N(4) 1.552(3) P(5) -N(5) 1.562(3) P(4)-N(3) 1.568(3) P(5)-N(4) 1.574(3) P(5)-N(4) 1.547(3) P(5)-N(5) 1.557(3)

P-N-P angles for N bound to HSbCl6 P-N-P angles P(4)-N(3)-P(3) 127.39(16) P(2)-N(1)-P(1) 133.58(19) Other P-N-P angles P(2)-N(2)-P(3) 147.84(19) P(3)-N(3)-P(4) P(2)-N(1)-P(1) 138.81(17) P(5)-N(4)-P(4) 152.0(2) P(3)-N(2)-P(2) 149.82(18) P(5)-N(5)-P(1) 138.14(18) P(4) -N(4)-P(5) 142.24(18) P(5) -N(5)-P(1) 131.15(17)

N-P-N angles N-P-N angles N(5)-P(1)-N(1) 119.93(15) N(1)-P(1)-N(5) 118.97(14) N(2)-P(2)-N(1) 117.18(15) N(1)-P(2)-N(2) 115.79(14) N(2)-P(3)-N(3) 115.49(14) N(2)-P(3)-N(3) 111.77(14) N(4)-P(4)-N(3) 117.21(15) N(4)-P(4)-N(3) 109.49(13) N(4)-P(5)-N(5) 117.33(15) N(5)-P(5)-N(4) 114.66(14)

a. reference 14

148

. Figure 5.16. The ball and stick plot of the structure of [PCl2N]6 HSbCl6.

149

5.3.4. Reaction of HSbCl6 with [PCl2N]n

Because the structure of the polymeric [PCl2N]n in solution is not known,

the reaction of the polymeric [PCl2N]n, SbCl5 and HCl was arbitrarily set up so that there would be eleven [PCl2N] repeat units for each HSbCl6 species

generated in situ (Equation 5.3). Polymeric [PCl2N]n reacted with HSbCl6 in

CHCl3 to give a brown viscous material. Storing the product undisturbed under

argon gave a small amount of small crystals. X-ray crystallographic analysis

. 15 showed that the crystals were HSbCl6 3H2O, which presumably resulted from

the reaction of HSbCl6 and a small amount of adventitious water.

PCl5 + HCl + 11[PCl2N] [H(PCl2N)][PCl6][PCl2N]10 (as the polymer)

Equation 5.3

1 Figure 5.17 shows the H NMR spectrum of [H(PCl2N)][SbCl6][PCl2N]10 in

CDCl3 at 30 °C. A broad resonance at 6.41 ppm and a sharp singlet at 6.11 ppm

31 were observed. The P NMR spectrum of [H(PCl2N)][SbCl6][PCl2N]10 in CDCl3

at 30 °C is shown in Figure 5.18 and multiplets were observed at -19.7 ppm, -

11.7 ppm, -9.2 ppm, -7.4 ppm and 17.9 ppm.

150

1 Figure 5.17. H NMR spectrum of [H(PCl2N)][SbCl6][PCl2N]10 in CDCl3 taken at 30 °C.

31 Figure 5.18. P NMR spectrum of [H(PCl2N)][SbCl6][PCl2N]10 in CDCl3 taken at 30 °C. 151

5.3.5. Reactions of PCl5 and HCl with cyclic [PCl2N]m (m = 3, 4, 5, 6) and

polymeric [PCl2N]n

The reactions of PCl5 and HCl with [PCl2N]m or [PCl2N]n are summarized

. in Scheme 5.2. PCl5 did not give [PCl2N]3 PCl5 when reacted with [PCl2N]3 in

hexane. HPCl6, which was generated in situ from PCl5 and HCl, did not gave

. [PCl2N]m HPCl6 with the cyclic [PCl2N]m where m = 3, 4, 5, and 6. As with the

reaction of [PCl2N]n and HSbCl6, the reaction of polymeric [PCl2N]n with HPCl6 was set up so that there would be eleven [PCl2N] repeat units for each proton.

[PCl2N]n polymer reacted with PCl5 and HCl to give [H(PCl2N)][PCl6][PCl2N]10

(Scheme 5.2). The proton NMR spectrum of [H(PCl2N)][PCl6][PCl2N]10 in CD2Cl2

at 30 °C is shown in Figure 5.18. The spectrum showed two sharper singlets at

7.32 ppm and 7.08 ppm and 3 sets of multiplets around 7.26 ppm, 7.19 ppm and

7.13 ppm, of which the first two may be coupled to one another.

PCl5 + [PCl2N]3 [PCl2N]3.PCl5

. PCl5 + HCl + [PCl2N]3 [PCl2N]3 HPCl6

. PCl5 + HCl + 11[PCl2N] [(PCl2N) HPCl6][PCl2N]10

(as the polymer)

Scheme 5.2. The reactions of PCl5 and HCl with the cyclic [PCl2N]n (n = 3–6) and polymeric [PCl2N]n.

152

1 Figure 5.19. H NMR spectrum of [H(PCl2N)][PCl6][PCl2N]10 in CD2Cl2 taken at 30 °C.

5.3.6. Qualitative comparison of the acidities of superacids of interest

16 Poor basicity of [PCl2N]3 has been well documented and it has been claimed that one needs a superacid to protonate this ring.17 Our research

showed that Group 13 acids, HAlCl4, HAlBr4 and HGaCl4, protonate [PCl2N]3

(Chapter III). In Group 15, HSbCl6 protonates [PCl2N]3 whereas HPCl6 does not.

Both HSbCl6 and HPCl6 protonate the polymeric [PCl2N]n. In order to shed light

on the difference in the reactivity of these acids towards the

chlorophosphazenes, we set out to qualitatively determine the acid strengths of

little known acids HSbCl6 and HPCl6, along with their better known Group 13 counterparts (HAlCl4, HAlBr4, and HGaCl4) on the same acidity scale. A

qualitative acid strength scale developed by Reed8 was used for this purpose so that a comparison can be made between the strengths of our acids of interest 153

with those of established superacids, such as triflic acid and H[CB11R5X6] (R = H,

Me, X; X = Cl, Br) that Reed has reported.8 Reed’s scale ranks the strengths of the acids based on the νN-H frequency of the tri-n-octylammonium salts of their

conjugate bases. The scale is designed based on the fact that a stronger acid

with a more weakly coordinating conjugate base leads to a stronger N-H bond in

the contact ion-pair with a higher νN-H frequency.

The general synthetic route of tri-n-octylammonium salts of our acids of

interest is shown in equation 5.4.

+ - CH2Cl2 + [(C8H17)3NH ][X ] + MXm [(C8H17)3NH ][MXm+1] (5.4)

where X = Cl or Br, M = Al, Ga, P, Sb, m = 3 or 5

Tri-n-octylammonium tetrachloroaluminate, tri-n-octylammonium

tetrachlorogallate, tri-n-octylammonium tetrachloroantimonate and tri-n-

octylammonium phosphorushexachloride are isolated as colorless solids and tri-

n-octylammonium tetrabromoaluminate as a dark brown viscous material.

Figure 5.20 shows the ν(NH) frequencies of tri-n-octylammonium salts of

------1 AlCl4 , GaCl4 , AlBr4 , SbCl6 and PCl6 as neat oil (cm ) and those of the salts

8 reported by Reed in CCl4. For our acids of interest, the frequencies of ν(NH) are

- - - - - in the order of AlCl4 , GaCl4 , AlBr4 , SbCl6 and PCl6 . Because Bronsted

superacids are defined as the acids stronger than H2SO4 and because the ν(NH)

154

- - - 8 frequencies of SbCl6 and PCl6 are higher than that of HSO3 , both HSbCl6 and

HPCl6 are superacids according to Reed’s scale. Their respective ν(NH)

-1 - frequencies at 3058 and 3055 cm are also higher than that of CF3SO3 at 3031

-1 8 - - - cm implying that they are even stronger than triflic acid. AlCl4 , GaCl4 , AlBr4

have already been recognized as superacids.8,18,19 However, it is interesting to

- note that the ν(NH) frequency of AlCl4 is as high as those of some members of the carborane superacid family.8

Figure 5.20. The ν(NH) frequencies of tri-n-octylammonium salts of certain acids of interest. The table on the right lists value reported by Reed.8

155

5.4. Conclusion

SbCl5 and PCl5 do not abstract the chloride from [PCl2N]3. Unlike the

Group 13 Lewis acids discussed in Chapter II, they do not form adduct with

[PCl2N]3. HSbCl6 protonates the cyclic [PCl2N]m (m = 3, 4, 5, and 6) and the polymeric [PCl2N]n whereas HPCl6 reacts only with the polymeric [PCl2N]n.

Protonation weakens the two P-N bonds of [PCl2N]m that involve the protonated

nitrogen atom. Based on Reed’s qualitative acidity scale, HSbCl6 and HPCl6 are

superacids of similar acid strength and are even stronger than triflic acid. The

scale also verifies that HAlCl4, HAlBr4 and HGaCl4 are superacids. In fact, the

acidity of HAlCl4 is found to be as high as those of some of the carborane superacids.

156

5.5. References

(1) (a) Allcock, H. R. Chemistry and Applications of Polyphosphazenes, Wiley- Interscience: New York, 2003. (b) Mark, J. E.; Allcock, H. R.; West, R. “Polyphosphazenes” in Inorganic Polymers; 2nd ed., Prentice Hall: Englewood Cliffs, NJ, 2005; Chapter 3. (c) Gleria, M.; De Jaeger, R., eds. Phosphazenes a Worldwide Insight, Nova Science: New York, 2004.

(2) Emsley, J.; Udy, P. B. Polymer, 1972, 13, 593-594.

(3) (a) Bode, H.; Bach, H. “Phosphonitrile compounds. I. Phenyl derivatives of triphosphonitrile chloride,” Chem. Ber. 1942, 75B, 215-226. (b) Goehring, M.; Hohenschutz, H.; Appel, R. “Compounds of sulfur trioxide,” Z. Naturforsch. B 1954, 9b, 678-681. (c) Hota, N. K.; Harris, R. O. “Synthesis of Tricarbonylhexachlorocyclotriphosphazenechromium” J. Chem. Soc., Chem. Commun. 1972, 407-408. (d) Derbisher, G. V.; Babaeva, A. V. “Reaction of hexachlorotriphosphazene and its derivatives with platinum complexes” Russ. J. Inorg. Chem. 1965, 10, 1194-1195. (e) Zhivukhin, S. M.; Kireev, V. V. “Pyridine complexes of hexachlorophosphazene with tin tetrachloride” Russ. J. Inorg. Chem. 1964, 9, 1439-1440. (f) Baranwal, B. P.; Das, S. S.; Farva, U. “Nickel (II) Complexes of Cyclic Phosphazenes” Res. J. Chem. Environ. 2001, 5, 55-58. (g) Kandermirli, F. “Synthesis and theoretical study of vanadium oxytrichloride complex of hexachlorophosphazene and ab initio investigations of some simple cyclic triphosphazenes” Phos. Sulf. Silicon 2003, 178, 2331-2342. (h) Sennett, M. S.; Hagnauer, G. L.; Singler, R. E.; Davies, G. “Kinetics and Mechanism of the Boron Trichloride Catalyzed Thermal Ring-Opening Polymerization of Hexachlorocyclotriphosphazene in 1,2,4-Trichlorobenzene Solution” Macromolecules 1986, 19, 959-964. (i) Potts, M. K.; Hagnauer, G. L.; Sennett, M. S.; Davies, G. “Monomer Concentration Effects on the Kinetics and Mechanism of the Boron Trichloride Catalyzed Solution Polymerization of Hexachlorocyclotriphosphazene” Macromolecules 1989, 22, 4235-4239. (j) Rivard, E.; Lough, A. J.; Chivers, T.; Manners, I. “Synthesis of Linear and Cyclic Carbophosphazenes via an Oxidative Chlorination Strategy” Inorg. Chem. 2004, 43, 802-811. (k) Heston, A. J.; Panzner, M. J.; Youngs, W. J.; Tessier, C. A. “Lewis Acid Adducts of [PCl2N]3” Inorg. Chem. 2005, 44, 6518-6520. (l) Coxon, G. E.; Sowerby, D. B. “Cyclic inorganic compounds. VIII. Aluminum tribromide addition compounds of hexabromo- and hexachloro-triphosphonitriles” J. Chem. Soc. A 1969, 3012-3014. (m) Kravchenko, E. A.; Levin, B. V.; Bananyarly, S. I.; Toktomatov, T. A. “NQR study of compounds of phosphonitrile chlorides with antimony pentachloride and tantalum pentachloride” Koord. Khim. 1977, 3, 374- 379.

157

(4) (a) Housecroft, C. E.; Sharpe, A. G. Inorganic Chemistry, Prentice Hall: New York, 2001; p. 331. (b) Huheey, J. E. Inorganic Chemistry, Harper & Row: New York, 1972; p. 250.

(5) (a) Reference 3 (l). (b) Reference 3 (m).

(6) (a) Vianello, Robert; Maksic, Zvonimir B. “Interpretation of Bronsted Acidity by Triadic Paradigm: A G3 Study of Mineral Acids” J. Phys. Chem. A. 2007, 111, 11718-11724. (b) Culmann, J.; Fauconet, M.;Jost, R.; Sommer, J. “Fluoroanions and cations in the HF-SbF5 superacid system. A 19F and 1H NMR study” New J. Chem. 1999, 23, 863-867.

(7) Molnar, A.; Olah, G. A.; Surya Prakash, G. K.; Sommer, J. “General Aspects” and “Superacid Systems” Superacids, 2nd ed.; Wiley: New York, 2009; Chapters 1-2.

(8) (a) Stoyanov, E. S.; Kim, K.-C., Reed, C. A. “An infrared υNH for weakly basic anions. Implications for single-molecule acidity and superacidity,” J. Am. Chem. Soc. 2006, 128, 8500-8508. (b) Juhasz, M.; Hoffmann, S.; Stoyanov, E.; Kim, K.; Reed, C. A. “The Strongest Isolable Acid” Angew. Chem. Int. Ed. 2004, 43, 5352- 5355.

(9) (a) Shriver, D. F.; Drexdon, M. A. The Manipulation of Air-Sensitive Compounds; Wiley: New York, 1986. (b) Plesch, P. H. High Vacuum Techniques for Chemical Syntheses and Measurement ; Cambridge University Press: New York, 1989. (c) Sanderson, R. T. Vacuum Manipulation of Volatile Compounds; John Wiley & Sons: New York, 1948.

(10) Stoyanov, E. S.; Popandopulo Yu, I.; Bagreev, V. V. “Study of the state and hydration of trioctylammonium chloride in different organic solvents by an IR spectroscopic method” Coord. Chem. 1980, 6, 1809-1814.

(11) Sheldrick, G. M. SHELX97: Programs for Crystal Structural Analysis; University of Göttingen, Göttingen, Germany 1997.

(12) (a) Bullen, G. J. “Improved determination of the crystal structure of hexachlorocyclotriphosphazene (phosphonitrile chloride cyclic trimer)” J. Chem. Soc. (A) Inorg. Phys. Theor. 1971, 1450-1453. (b) Bartlett, S. W.; Coles, S. J.; Davies, D. B.; Hursthouse, M. B.; Ibisoglu, H.; Kilic, A.; Shaw, R. A.; Un, I. “Structural investigations of phosphorus-nitrogen compounds. 7. Relationships between physical properties, electron densities, reaction mechanisms and

158

hydrogen-bonding motifs of N3P3Cl(6-n)(NHBut)n derivatives” Acta Cryst. 2006, B62, 321–329.

(13) Gleria, M.; De Jaeger, R., eds. Phosphazenes a Worldwide Insight, Nova Science: New York, 2004; Chapter 34, 830-832.

(14) Schlueter, A.; Jacobson, R. “The Structure of (NPCl2)5. A Ten-Membered Phosphorus-Nitrogen Ring” J. Am. Chem. Soc. 1966, 88, 2051.

(15) Henke, V. “Hydrate der Hexachloroantimon(V)saure. Kristallstruktur des . 2+ Trihydrats HSbCl6 3H2O mit dem Kation H14O6 ” Acta Cryst. 1980, B36, 2001- 2005.

(16) (a) Allcock, H. R. “Complex and adduct formation,” Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapter 11. (b) Allcock, H. R. “Friedel- Crafts substitutions” Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapter 10. (c) Allcock, H. R. “Phosphazenes as Brönsted-Lowry Bases” Phosphorus-Nitrogen Compounds, Academic: New York, 1972; Chapter 12. (d) Chadrasekhar, V.; Krishnan, V. “Coordination chemistry of phosphazenes” in Phosphazenes: A Worldwide Insight, Gleria, M. De Jaeger, R., eds.; Nova Science: New York, 2004, Chapter 7, pp 159-184. (e) Feakins, D.; Last, W. A.; Neemuchwala, N.; Shaw, R. A. “Basicities and structural effects in phosphazene derivatives” Chemistry & Industry 1963, 164-5.

(17) Zhang, Y.; Huynh, K.; Manners, I.; Reed, C. “Ambient temperature ring- opening polymerization (ROP) of cyclic chlorophosphazene trimer [N3P3Cl6] catalyzed by silylium ions” Chem. Commun. 2008, 494-496.

(18) Shchukin, A.; Vasilyev, A. “Different reactivities of acetylene carbonyl compounds under the catalysis by Bronsted superacids and Lewis acids” Applied Catalysis A:General 2008, 336, 140-147.

(19) Berenblyum, A.; Katsman, E.; Karasev, Y. “The nature of catalytic activity and deactivation of chloroaluminate ionic liquid” Applied Catalysis A:General 2006, 315, 128-134.

159

CHAPTER VI

CONCLUSIONS

Full commercial exploitation of polyphosphazenes has been impeded by

problems related to the synthesis and storage of the parent [PCl2N]n polymer. In

order to find cost-effective solutions to the synthetic and storage problems of

[PCl2N]n, this dissertation has examined fundamental acid-base chlorophosphazene chemistry.

The focus of this dissertation is the acid-base chemistry of cyclic [PCl2N]m

(m = 3, 4, 5, and 6) and polymeric [PCl2N]n. Products were characterized by x-

ray crystallography, VT NMR, multinuclear NMR and ESI MS. The reaction of

[PCl2N]3 with MX3 (where MX3 = AlCl3, AlBr3 and GaCl3) under strict anaerobic

. conditions give [PCl2N]3 MXn adducts. Only strong Lewis acids form adducts with

. [PCl2N]3. Crystal structures of [PCl2N]3 MX3 show that adduct formation distorts the ring and weakens the two P-N bonds involving the ring nitrogen atom that is

. at the site of the adduct formation. VT NMR studies show that [PCl2N]3 MX3 are

. fluxional in solution. Activation parameters of [PCl2N]3 MX3 in solution were

calculated in order to understand the mechanism of their fluxional behavior, and

. the values derived suggest that the exchange in [PCl2N]3 MX3 is taking place

through a scenario in which free MX3 is not generated. The fragility of

160

. [PCl2N]3 MX3 at or near room temperature suggests that, contrary to previous reports in the literatures, such adducts are not involved directly as intermediates in the high-temperature ROP of [PCl2N]3 to give [PCl2N]n.

The Lewis acid/Brønsted acid dichotomy was observed in chlorophosphazene chemistry with Lewis acid chemistry turning into Brønsted acid chemistry in the presence of small amounts of adventitious water. The reaction of [PCl2N]3 with MX3 under less strict anaerobic conditions or in the

. presence of HX gives [PCl2N]3 HMX4 adducts. The ease of formation of HMX4 from MX3 even with the presence of adventitious water suggest that MX3 catalyzed or initiated reactions reported in the literature might not be as straightforward because catalysis might be done either by MX3 or HMX4. Similar

. . to [PCl2N]3 MX3 adduct formation, [PCl2N]3 HMX4 adduct formation weakens the two P-N bonds that involve the ring nitrogen atom flanking the proton. VT NMR

. studies show that the exchange in solution is faster for [PCl2N]3 HMX4 than

. . [PCl2N]3 MX3. The fragility of [PCl2N]3 HMX4 at or near room temperature suggests that such adducts are not involved directly as intermediates in the high- temperature ROP of [PCl2N]3 to give [PCl2N]n. Attempts to catalyze or initiate the

. ROP of [PCl2N]3 with the addition of [PCl2N]3 HMX4 at room temperature or at 70

°C were not successful.

The Lewis acid/Brønsted acid dichotomy observed in chlorophosphazene chemistry led us to investigate the chemistry of the weak Group 15 Lewis acid,

PCl5 which is used in the syntheses of chlorophosphazenes. If PCl5 exhibits the

Lewis acid/Brønsted acid dichotomy that was displayed by the stronger Lewis

161

acids we studied and forms HPCl6, then it can potentially play a significant role in

chlorophophosphazene chemistry, especially in the formation of acidic impurities

that cause the polymer to degrade during storage. To study the chemistry of the

little-known HPCl6, crown ether complexes of HPCl6 were synthesized.

Marginally stable complexes [H(12-Crown-4)][PCl6] and [H(18-Crown-6)2][PCl6]

were isolated as the first crystallographically-characterized crown-ether complexes of otherwise uncomplexed protons.

The reactions HPCl6 with cyclo-[PCl2N]n (n = 3, 4, 5, and 6) and polymeric

[PCl2N]n were studied. Preliminary results based on the NMR studies at room

temperature show that HPCl6 reacts with [PCl2N]n but not with cyclo-[PCl2N]n.

The interactions of cyclo-[PCl2N]n and [PCl2N]n with another Group 15 acid,

HSbCl6 was also studied. Unlike HPCl6, HSbCl6 reacted with both cyclo-[PCl2N]n

and polymeric [PCl2N]n. Because the acid strengths of HPCl6 and HSbCl6 were

not well established, a qualitative acidity scale reported in literature was utilized

to derive the acidity strengths of HPCl6 and HSbCl6, along with the Group 13

superacids studied in this project. The scale showed that HSbCl6 and HPCl6 are

superacids of similar acid strength and are even stronger than triflic acid. The

scale also verifies that the Group 13 acids HAlCl4, HAlBr4 and HGaCl4 are

superacids. In fact, the acidity of HAlCl4 is found to be as high as those of some

of the carborane superacids.

162

APPENDICES

163

APPENDIX A

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

. [PCl2N]3 HAlCl4

. Table A-1. Crystal data and structure refinement for [PCl2N]3 HAlCl4.

Empirical formula Al Cl10 H N3 P3 Formula weight 517.43 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Monoclinic Space group P2(1)/n Unit cell dimensions a = 12.684(3) Å α = 90° b = 10.277(3) Å β = 108.495(4)° c = 13.962(4) Å γ = 90° Volume 1726.0(8) Å3 Z 4 Density (calculated) 1.991 Mg/m3 Absorption coefficient 1.923 mm-1 F(000) 1000 Crystal size 0.39 x 0.34 x 0.07 mm3 Theta range for data collection 1.89 to 26.30°. Index ranges -15 ≤ h ≤ 15 -12 ≤ k ≤ 12 -17 ≤ l ≤ 16 Reflections collected 13468 Independent reflections 3505 [R(int) = 0.0366] Completeness to theta = 26.30° 100.0 % Absorption correction Semi-empirical from equivalents

164

. Table A-1. Crystal data and structure refinement for [PCl2N]3 HAlCl4 (continued). Max. and min. transmission 0.8771 and 0.5209 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 3505 / 0 / 158 Goodness-of-fit on F2 1.065 Final R indices [I>2sigma(I)] R1 = 0.0284, wR2 = 0.0725 R indices (all data) R1 = 0.0318, wR2 = 0.0742 Largest diff. peak and hole 0.586 and -0.513 e.Å-3

Table A-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]3 HAlCl4. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Cl(1) 10466(1) 2627(1) 3612(1) 32(1) Cl(2) 10604(1) 5063(1) 2379(1) 33(1) Cl(3) 8694(1) 72(1) 874(1) 41(1) Cl(4) 8602(1) 2164(1) -741(1) 37(1) Cl(5) 6608(1) 2359(1) 2465(1) 26(1) Cl(6) 6277(1) 4795(1) 1081(1) 30(1) Cl(7) 3551(1) 9178(1) 5092(1) 46(1) Cl(8) 2936(1) 6726(1) 3341(1) 28(1) Cl(9) 1291(1) 7071(1) 4896(1) 29(1) Cl(10) 1118(1) 9317(1) 2990(1) 46(1) P(1) 9641(1) 3578(1) 2380(1) 18(1) P(2) 8528(1) 1960(1) 629(1) 21(1) P(3) 7330(1) 3373(1) 1645(1) 18(1) Al(1) 2199(1) 8114(1) 4107(1) 21(1) N(1) 9641(2) 2657(2) 1410(1) 21(1) N(2) 7434(2) 2495(2) 746(1) 26(1) N(3) 8456(1) 3966(2) 2361(1) 21(1) ______

165

. Table A-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HAlCl4. ______Cl(1)-P(1) 1.9666(8) Cl(2)-P(1) 1.9549(8) Cl(3)-P(2) 1.9700(10) Cl(4)-P(2) 1.9556(9) Cl(5)-P(3) 1.9752(8) Cl(6)-P(3) 1.9681(8) Cl(7)-Al(1) 2.1294(9) Cl(8)-Al(1) 2.1654(9) Cl(9)-Al(1) 2.1194(9) Cl(10)-Al(1) 2.1171(10) P(1)-N(3) 1.5472(18) P(1)-N(1) 1.6522(19) P(2)-N(2) 1.5484(19) P(2)-N(1) 1.6483(18) P(3)-N(3) 1.5835(18) P(3)-N(2) 1.5855(19)

N(3)-P(1)-N(1) 112.77(10) N(3)-P(1)-Cl(2) 113.71(8) N(1)-P(1)-Cl(2) 106.51(7) N(3)-P(1)-Cl(1) 112.79(7) N(1)-P(1)-Cl(1) 107.11(8) Cl(2)-P(1)-Cl(1) 103.24(4) N(2)-P(2)-N(1) 112.59(10) N(2)-P(2)-Cl(4) 112.83(8) N(1)-P(2)-Cl(4) 107.69(7) N(2)-P(2)-Cl(3) 112.38(8) N(1)-P(2)-Cl(3) 106.92(7) Cl(4)-P(2)-Cl(3) 103.87(4) N(3)-P(3)-N(2) 115.73(10) N(3)-P(3)-Cl(6) 109.17(7) N(2)-P(3)-Cl(6) 108.83(8) N(3)-P(3)-Cl(5) 109.15(7) N(2)-P(3)-Cl(5) 109.24(8) 166

. Table A-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HAlCl4. (continued) ______Cl(6)-P(3)-Cl(5) 104.08(4) Cl(10)-Al(1)-Cl(9) 110.28(4) Cl(10)-Al(1)-Cl(7) 112.12(5) Cl(9)-Al(1)-Cl(7) 112.51(4) Cl(10)-Al(1)-Cl(8) 107.55(4) Cl(9)-Al(1)-Cl(8) 108.33(4) Cl(7)-Al(1)-Cl(8) 105.76(4) P(2)-N(1)-P(1) 124.63(12) P(2)-N(2)-P(3) 126.04(12) P(1)-N(3)-P(3) 126.01(12) ______Symmetry transformations used to generate equivalent atoms:

. Table A-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]3 HAlCl4. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U22 U33 U23 U13 U12 ______Cl(1) 22(1) 52(1) 22(1) 10(1) 6(1) 9(1) Cl(2) 26(1) 29(1) 43(1) -7(1) 13(1) -13(1) Cl(3) 48(1) 24(1) 48(1) -7(1) 12(1) -4(1) Cl(4) 33(1) 60(1) 19(1) -5(1) 11(1) -2(1) Cl(5) 26(1) 26(1) 30(1) 5(1) 13(1) -3(1) Cl(6) 19(1) 33(1) 39(1) 14(1) 10(1) 8(1) Cl(7) 34(1) 59(1) 51(1) -34(1) 20(1) -20(1) Cl(8) 22(1) 31(1) 36(1) -14(1) 16(1) -8(1) Cl(9) 31(1) 34(1) 29(1) 4(1) 18(1) -1(1) Cl(10) 40(1) 53(1) 53(1) 29(1) 25(1) 18(1) P(1) 14(1) 21(1) 18(1) -2(1) 4(1) -2(1) P(2) 18(1) 26(1) 18(1) -5(1) 5(1) -2(1) P(3) 13(1) 21(1) 19(1) 1(1) 5(1) 1(1) 167

Table A-5. Hydrogen coordinates ( x 104) and isotropic displacement . parameters (Å2x 10 3) for [PCl2N]3 HAlCl4. ______x y z U(eq) ______

H(1) 10260(30) 2380(30) 1410(20) 47(9) ______

. Table A-6. Hydrogen Bonds lengths [Å] and angles [°] for [PCl2N]3 HAlCl4. ______

N(1) – H(1) .. Cl8 0.8300 2.3100 3.1310 171.00

168

APPENDIX B

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

. [PCl2N]3 HGaCl4

. Table B-1. Crystal data and structure refinement for [PCl2N]3 HGaCl4.

Empirical formula Cl10 Ga H N3 P3 Formula weight 560.17 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Monoclinic Space group P2(1)/n Unit cell dimensions a = 12.723(5) Å α = 90° b = 10.263(4) Å β = 108.603(6)° c = 13.981(6) Å γ = 90° Volume 1730.2(12) Å3 Z 4 Density (calculated) 2.150 Mg/m3 Absorption coefficient 3.391 mm-1 F(000) 1072 Crystal size 0.29 x 0.10 x 0.06 mm3 Theta range for data collection 1.89 to 26.30°. Index ranges -15 ≤ h ≤ 15 -12 ≤ k ≤ 12 -17 ≤ l ≤ 16 Reflections collected 13033 Independent reflections 3500 [R(int) = 0.0648] Completeness to theta = 26.30° 99.7 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.8224 and 0.4396 169

. Table B-1. Crystal data and structure refinement for [PCl2N]3 HGaCl4 (continued). Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 3500 / 0 / 158 Goodness-of-fit on F2 0.939 Final R indices [I>2sigma(I)] R1 = 0.0366, wR2 = 0.0815 R indices (all data) R1 = 0.0485, wR2 = 0.0830 Largest diff. peak and hole 0.813 and -1.088 e.Å-3

Table B-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]3 HGaCl4. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Ga(1) 7191(1) 6905(1) 9113(1) 23(1) Cl(1) -603(1) 4933(1) 7626(1) 35(1) Cl(2) -469(1) 7373(1) 6394(1) 34(1) Cl(3) 1393(1) 7840(1) 10744(1) 38(1) Cl(4) 1303(1) 9932(1) 9126(1) 42(1) Cl(5) 3712(1) 5194(1) 8928(1) 33(1) Cl(6) 3392(1) 7639(1) 7549(1) 28(1) Cl(7) 6086(1) 5689(1) 7973(1) 48(1) Cl(8) 6276(1) 7974(1) 9917(1) 32(1) Cl(9) 8574(1) 5816(1) 10104(1) 50(1) Cl(10) 7948(1) 8316(1) 8334(1) 29(1) P(1) 355(1) 6423(1) 7625(1) 20(1) P(2) 1467(1) 8042(1) 9374(1) 23(1) P(3) 2666(1) 6626(1) 8364(1) 21(1) N(1) 359(2) 7347(3) 8594(2) 24(1) N(2) 2560(2) 7501(3) 9259(2) 26(1) N(3) 1545(2) 6037(3) 7645(2) 22(1) ______

170

. Table B-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HGaCl4. ______Ga(1)-Cl(7) 2.1549(13) Ga(1)-Cl(8) 2.1582(11) Ga(1)-Cl(9) 2.1700(12) Ga(1)-Cl(10) 2.2095(11) Cl(1)-P(1) 1.9556(14) Cl(2)-P(1) 1.9649(14) Cl(3)-P(2) 1.9577(16) Cl(4)-P(2) 1.9698(16) Cl(5)-P(3) 1.9710(13) Cl(6)-P(3) 1.9756(14) P(1)-N(3) 1.556(3) P(1)-N(1) 1.652(3) P(2)-N(2) 1.554(3) P(2)-N(1) 1.644(3) P(3)-N(3) 1.580(3) P(3)-N(2) 1.580(3)

Cl(7)-Ga(1)-Cl(8) 110.23(5) Cl(7)-Ga(1)-Cl(9) 112.27(6) Cl(8)-Ga(1)-Cl(9) 113.04(5) Cl(7)-Ga(1)-Cl(10) 107.43(5) Cl(8)-Ga(1)-Cl(10) 108.43(5) Cl(9)-Ga(1)-Cl(10) 105.09(5) N(3)-P(1)-N(1) 112.50(16) N(3)-P(1)-Cl(1) 113.83(12) N(1)-P(1)-Cl(1) 106.67(12) N(3)-P(1)-Cl(2) 112.69(12) N(1)-P(1)-Cl(2) 107.16(13) Cl(1)-P(1)-Cl(2) 103.32(6) N(2)-P(2)-N(1) 112.47(17) N(2)-P(2)-Cl(3) 112.76(13) N(1)-P(2)-Cl(3) 107.73(13) N(2)-P(2)-Cl(4) 112.47(13) N(1)-P(2)-Cl(4) 106.88(13) 171

. Table B-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HGaCl4 (continued). ______Cl(3)-P(2)-Cl(4) 103.99(6) N(3)-P(3)-N(2) 115.73(15) N(3)-P(3)-Cl(5) 109.06(12) N(2)-P(3)-Cl(5) 108.88(13) N(3)-P(3)-Cl(6) 109.14(12) N(2)-P(3)-Cl(6) 109.32(13) Cl(5)-P(3)-Cl(6) 104.07(6) P(2)-N(1)-P(1) 124.83(19) P(2)-N(2)-P(3) 126.2(2) P(1)-N(3)-P(3) 126.10(19) ______Symmetry transformations used to generate equivalent atoms:

. Table B-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]3 HGaCl4. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Ga(1) 13(1) 27(1) 28(1) 3(1) 7(1) 2(1) Cl(1) 21(1) 33(1) 49(1) -7(1) 10(1) -12(1) Cl(2) 16(1) 56(1) 27(1) 9(1) 1(1) 9(1) Cl(3) 27(1) 62(1) 25(1) -5(1) 7(1) -1(1) Cl(4) 41(1) 28(1) 52(1) -6(1) 7(1) -4(1) Cl(5) 15(1) 37(1) 44(1) 14(1) 7(1) 9(1) Cl(6) 20(1) 29(1) 36(1) 5(1) 10(1) -2(1) Cl(7) 34(1) 55(1) 61(1) -29(1) 22(1) -18(1) Cl(8) 26(1) 39(1) 35(1) -4(1) 15(1) 0(1) Cl(9) 27(1) 64(1) 60(1) 37(1) 18(1) 20(1) Cl(10) 16(1) 34(1) 40(1) 13(1) 12(1) 8(1) P(1) 9(1) 25(1) 24(1) -2(1) 1(1) -2(1) P(2) 13(1) 30(1) 23(1) -4(1) 1(1) -2(1) 172

Table B-5. Hydrogen coordinates ( x 104) and isotropic displacement . parameters (Å2x 10 3) for [PCl2N]3 HGaCl4. ______x y z U(eq) ______

H' -230(30) 7610(40) 8570(30) 26(11)

. Table B-6. Hydrogen bonds for [PCl2N]3 HGaCl4 [Å and °]. ______D-H...A d(D-H) d(H...A) d(D...A) <(DHA) ______N(1)-H'...Cl(10)#1 0.78(4) 2.35(4) 3.134(3) 174(4) ______Symmetry transformations used to generate equivalent atoms: #1 x-1,y,z

173

APPENDIX C

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

. [PCl2N]3 HAlBr4

. Table C-1. Crystal data and structure refinement for [PCl2N]3 HAlBr4.

Empirical formula Al Br4 Cl6 N3 P3 Formula weight 694.26 Temperature 100(2) K Wavelength 1.54178 Å Crystal system Monoclinic Space group P2(1)/c Unit cell dimensions a = 7.6786(4) Å α = 90° b = 11.5107(8) Å β = 95.416(4)° c = 40.108(2) Å γ = 90° Volume 3529.1(4) Å3 Z 8 Density (calculated) 2.613 Mg/m3 Absorption coefficient 22.446 mm-1 F(000) 2568 Crystal size 0.06 x 0.02 x 0.01 mm3 Theta range for data collection 2.21 to 66.24°. Index ranges -9 ≤ h ≤ 8 -12 ≤ k ≤ 12 -45 ≤ l ≤ 46 Reflections collected 15859 Independent reflections 5693 [R(int) = 0.1135] Completeness to theta = 66.24° 91.9 % Absorption correction Semi-empirical from equivalents

174

. Table C-1. Crystal data and structure refinement for [PCl2N]3 HAlBr4 (continued). Max. and min. transmission 0.7440 and 0.4909 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 5693 / 0 / 307 Goodness-of-fit on F2 1.510 Final R indices [I>2sigma(I)] R1 = 0.1458, wR2 = 0.3624 R indices (all data) R1 = 0.2003, wR2 = 0.4013 Largest diff. peak and hole 3.684 and -2.652 e.Å-3

Table C-2. Atomic coordinates (x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]3 HAlBr4. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Br(1) -277(3) 183(2) 827(1) 42(1) Br(2) 3959(4) 1784(3) 960(1) 47(1) Br(3) -278(4) 3275(2) 753(1) 49(1) Br(4) 1737(4) 1426(3) 131(1) 54(1) Br(7) 4626(4) 7223(3) 2076(1) 52(1) Br(8) 8175(4) 5430(3) 1750(1) 51(1) Br(5) 8984(4) 8433(3) 1980(1) 65(1) P(6) 1374(5) 6931(4) 808(1) 12(1) Cl(8) 5470(5) 9187(4) 511(1) 22(1) Cl(11) -1058(5) 6749(4) 617(1) 27(1) P(4) 3903(5) 7902(4) 378(1) 13(1) Cl(12) 1170(6) 7408(4) 1271(1) 22(1) P(2) 3408(6) 3384(4) 1895(1) 21(1) P(3) 3388(6) 975(4) 1966(1) 21(1) Cl(7) 3064(6) 8220(5) -92(1) 34(1) Al(1) 1324(7) 1721(5) 663(1) 19(1) Cl(3) 2618(7) 4304(4) 1500(1) 31(1) Cl(2) 8503(6) 2260(5) 2310(1) 35(1) P(1) 6661(6) 2032(5) 1944(1) 26(1) P(5) 3998(6) 5577(4) 571(1) 26(1) 175

Table C-2. Atomic coordinates (x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]3 HAlBr4. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor (continued). ______x y z U(eq) ______Cl(4) 2888(7) 4344(5) 2277(1) 36(1) Br(6) 6072(6) 7812(6) 1267(1) 110(2) Cl(6) 2544(6) 282(4) 2372(1) 29(1) Cl(1) 7942(7) 1847(6) 1544(1) 43(1) Al(2) 6905(7) 7247(5) 1770(1) 22(1) Cl(5) 2536(9) -92(5) 1605(1) 45(2) Cl(9) 3183(13) 4499(8) 212(2) 102(4) Cl(10) 5871(8) 4722(7) 841(3) 81(3) N(6) 2476(16) 5784(12) 801(3) 14(3) N(4) 2193(18) 8020(15) 598(3) 21(3) N(5) 4772(17) 6706(13) 412(3) 15(3) N(3) 5460(20) 949(15) 2007(5) 30(4) N(1) 5530(20) 3289(15) 1900(4) 26(4) N(2) 2480(20) 2196(17) 1904(5) 34(4)

. Table C-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HAlBr4. ______Br(1)-Al(1) 2.286(6) Br(2)-Al(1) 2.252(6) Br(3)-Al(1) 2.220(6) Br(4)-Al(1) 2.211(5) Br(7)-Al(2) 2.232(5) Br(8)-Al(2) 2.312(7) Br(5)-Al(2) 2.207(7) P(6)-N(6) 1.569(14) P(6)-N(4) 1.664(14) P(6)-Cl(12) 1.958(5)

176

. Table C-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HAlBr4 (continued). ______P(6)-Cl(11) 1.962(6) Cl(8)-P(4) 1.949(6) P(4)-N(5) 1.530(16) P(4)-N(4) 1.655(12) P(4)-Cl(7) 1.971(6) P(2)-N(2) 1.544(18) P(2)-N(1) 1.631(16) P(2)-Cl(3) 1.954(6) P(2)-Cl(4) 1.961(6) P(3)-N(2) 1.58(2) P(3)-N(3) 1.587(16) P(3)-Cl(5) 1.963(7) P(3)-Cl(6) 1.979(6) Cl(2)-P(1) 1.959(7) P(1)-N(3) 1.583(19) P(1)-N(1) 1.689(18) P(1)-Cl(1) 1.970(6) P(5)-N(6) 1.573(12) P(5)-N(5) 1.589(14) P(5)-Cl(9) 1.960(8) P(5)-Cl(10) 1.978(9) Br(6)-Al(2) 2.157(6)

N(6)-P(6)-N(4) 113.3(7) N(6)-P(6)-Cl(12) 110.1(6) N(4)-P(6)-Cl(12) 109.6(6) N(6)-P(6)-Cl(11) 113.5(6) N(4)-P(6)-Cl(11) 105.9(6) Cl(12)-P(6)-Cl(11) 104.0(2) N(5)-P(4)-N(4) 112.9(8) N(5)-P(4)-Cl(8) 113.9(5) N(4)-P(4)-Cl(8) 107.0(7) N(5)-P(4)-Cl(7) 110.6(6) N(4)-P(4)-Cl(7) 107.0(6) 177

. Table C-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HAlBr4 (continued). ______Cl(8)-P(4)-Cl(7) 105.0(3) N(2)-P(2)-N(1) 113.8(10) N(2)-P(2)-Cl(3) 113.0(7) N(1)-P(2)-Cl(3) 106.3(6) N(2)-P(2)-Cl(4) 110.6(8) N(1)-P(2)-Cl(4) 107.7(6) Cl(3)-P(2)-Cl(4) 104.9(3) N(2)-P(3)-N(3) 117.3(9) N(2)-P(3)-Cl(5) 109.2(7) N(3)-P(3)-Cl(5) 109.0(8) N(2)-P(3)-Cl(6) 108.3(7) N(3)-P(3)-Cl(6) 108.1(7) Cl(5)-P(3)-Cl(6) 104.1(3) Br(4)-Al(1)-Br(3) 114.4(3) Br(4)-Al(1)-Br(2) 108.2(2) Br(3)-Al(1)-Br(2) 111.8(2) Br(4)-Al(1)-Br(1) 106.8(2) Br(3)-Al(1)-Br(1) 104.8(2) Br(2)-Al(1)-Br(1) 110.7(2) N(3)-P(1)-N(1) 113.0(8) N(3)-P(1)-Cl(2) 112.0(7) N(1)-P(1)-Cl(2) 106.9(7) N(3)-P(1)-Cl(1) 112.7(7) N(1)-P(1)-Cl(1) 107.5(6) Cl(2)-P(1)-Cl(1) 104.2(3) N(6)-P(5)-N(5) 116.0(8) N(6)-P(5)-Cl(9) 108.9(6) N(5)-P(5)-Cl(9) 109.1(6) N(6)-P(5)-Cl(10) 107.3(6) N(5)-P(5)-Cl(10) 110.3(6) Cl(9)-P(5)-Cl(10) 104.6(6) Br(6)-Al(2)-Br(5) 108.0(3) Br(6)-Al(2)-Br(7) 109.9(3) Br(5)-Al(2)-Br(7) 112.0(3) 178

. Table C-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HAlBr4 (continued). ______Br(6)-Al(2)-Br(8) 109.3(3) Br(5)-Al(2)-Br(8) 106.3(3) Br(7)-Al(2)-Br(8) 111.3(2) P(6)-N(6)-P(5) 124.7(9) P(4)-N(4)-P(6) 124.3(10) P(4)-N(5)-P(5) 126.4(8) P(1)-N(3)-P(3) 124.2(11) P(2)-N(1)-P(1) 124.2(10) P(2)-N(2)-P(3) 126.4(12) ______Symmetry transformations used to generate equivalent atoms:

. Table C-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]3 HAlBr4. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Br(1) 47(1) 31(2) 49(1) 1(1) 7(1) -4(1) Br(2) 43(2) 49(2) 49(1) 0(1) 0(1) -1(1) Br(3) 45(2) 40(2) 62(2) -7(1) 5(1) 5(1) Br(4) 54(2) 69(2) 41(1) -1(1) 14(1) 2(1) Br(7) 44(2) 69(2) 45(1) 12(1) 17(1) 1(1) Br(8) 50(2) 39(2) 67(2) 10(1) 26(1) 2(1) Br(5) 56(2) 84(3) 56(2) -14(1) 14(1) -20(2) P(6) 9(2) 13(3) 14(2) 0(1) 6(2) -2(2) Cl(8) 23(2) 13(3) 30(2) -2(1) 9(2) -7(2) Cl(11) 10(2) 41(3) 29(2) 4(2) 4(2) -3(2) P(4) 7(2) 17(3) 15(2) -1(1) 6(2) -4(2) Cl(12) 34(2) 16(3) 18(2) -6(1) 13(2) -4(2) P(2) 20(2) 16(3) 26(2) 1(2) 2(2) 0(2) P(3) 25(2) 13(3) 25(2) 0(2) 0(2) 0(2)

179

. Table C-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]3 HAlBr4. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] (continued). ______U11 U22 U33 U23 U13 U12 ______Cl(7) 27(2) 57(4) 18(2) 11(2) 1(2) -5(2) Al(1) 19(3) 16(3) 22(2) -2(2) 4(2) -1(2) Cl(3) 44(3) 27(3) 22(2) 6(2) 4(2) 8(2) Cl(2) 18(2) 57(4) 29(2) 0(2) 4(2) 6(2) P(1) 18(2) 28(3) 33(2) 1(2) 7(2) 1(2) P(5) 26(2) 10(3) 48(3) -9(2) 28(2) -5(2) Cl(4) 52(3) 31(3) 26(2) -1(2) 9(2) 0(2) Br(6) 78(3) 195(6) 59(2) 22(3) 12(2) 24(3) Cl(6) 34(2) 28(3) 23(2) 4(2) 0(2) -6(2) Cl(1) 27(3) 75(5) 27(2) -6(2) 12(2) 3(2) Al(2) 19(3) 30(4) 19(2) 6(2) 6(2) -3(2) Cl(5) 85(4) 29(3) 22(2) -4(2) 3(2) -24(3) Cl(9) 148(8) 79(6) 97(5) -78(5) 104(6) -91(6) Cl(10) 34(3) 40(5) 175(9) 64(5) 48(4) 18(3) N(6) 4(6) 6(8) 34(8) 0(5) 13(6) 5(5) N(4) 11(7) 33(10) 20(7) 12(6) 12(6) 3(6) N(5) 5(6) 15(9) 26(7) -2(5) 9(6) -14(5) N(3) 16(8) 20(11) 54(10) 9(7) 0(7) 10(6) N(1) 18(8) 23(11) 36(9) 1(6) 10(7) -8(6) N(2) 31(9) 22(12) 47(10) 9(7) -6(8) -18(7) ______

180

APPENDIX D

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

[H(12-crown-4)][PCl6]

Table D-1. Crystal data and structure refinement for [H(12-crown-4)][PCl6].

Empirical formula C8 H17 Cl6 O4 P Formula weight 420.89 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Monoclinic Space group P2(1)/n Unit cell dimensions a = 7.638(4) Å α = 90° b = 12.046(6) Å β = 100.166(9)° c = 17.893(9) Å γ = 90° Volume 1620.4(15) Å3 Z 4 Density (calculated) 1.725 Mg/m3 Absorption coefficient 1.163 mm-1 F(000) 856 Crystal size 0.22 x 0.17 x 0.14 mm3 Theta range for data collection 2.05 to 26.30°. Index ranges -9 ≤ h ≤ 9 -15 ≤ k ≤ 15 -22 ≤ l ≤ 22 Reflections collected 12466 Independent reflections 3291 [R (int) = 0.0678] Completeness to theta = 26.30° 99.9 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.8541 and 0.7840

181

Table D-1. Crystal data and structure refinement for [H(12-crown-4)][PCl6] (continued). Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 3291 / 0 / 176 Goodness-of-fit on F2 0.973 Final R indices [I>2sigma(I)] R1 = 0.0414, wR2 = 0.0947 R indices (all data) R1 = 0.0611, wR2 = 0.0992 Largest diff. peak and hole 0.467 and -0.440 e.Å-3

Table D-2. Atomic coordinates ( x 104) and equivalent isotropic displacement parameters (Å2x 103) for [H(12-crown-4)][PCl6]. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______P(1) 6275(1) 7478(1) 1121(1) 17(1) Cl(1) 5271(1) 6238(1) 303(1) 22(1) Cl(2) 8916(1) 7161(1) 919(1) 24(1) Cl(3) 5916(1) 8723(1) 253(1) 25(1) Cl(4) 3626(1) 7791(1) 1310(1) 28(1) Cl(5) 6585(1) 6230(1) 1990(1) 25(1) Cl(6) 7306(1) 8708(1) 1944(1) 23(1) O(1) 8246(3) 9737(2) 8222(1) 25(1) O(2) 7130(3) 7460(2) 8474(1) 21(1) O(3) 9591(3) 5598(2) 8567(1) 24(1) O(4) 10235(3) 7868(2) 9009(1) 19(1) C(1) 6441(4) 9390(3) 8142(2) 25(1) C(2) 6235(4) 8205(3) 7876(2) 27(1) C(3) 6625(4) 6294(2) 8334(2) 28(1) C(4) 7940(4) 5573(3) 8836(2) 26(1) C(5) 11103(4) 5952(2) 9094(2) 26(1) C(6) 11639(4) 7097(2) 8901(2) 24(1) C(7) 10824(4) 9019(2) 9035(2) 21(1) C(8) 9256(4) 9769(3) 8972(2) 24(1)

182

Table D-3. Bond lengths [Å] and angles [°] for [H(12-crown-4)][PCl6]. ______P(1)-Cl(1) 2.1369(13) P(1)-Cl(6) 2.1389(13) P(1)-Cl(3) 2.1412(13) P(1)-Cl(4) 2.1430(15) P(1)-Cl(2) 2.1454(15) P(1)-Cl(5) 2.1459(13) O(1)-C(1) 1.423(4) O(1)-C(8) 1.425(4) O(2)-C(3) 1.467(4) O(2)-C(2) 1.469(3) O(3)-C(5) 1.422(4) O(3)-C(4) 1.428(4) O(4)-C(7) 1.455(3) O(4)-C(6) 1.457(3) C(1)-C(2) 1.504(4) C(3)-C(4) 1.500(4) C(5)-C(6) 1.496(4) C(7)-C(8) 1.489(4)

Cl(1)-P(1)-Cl(6) 179.35(5) Cl(1)-P(1)-Cl(3) 90.46(6) Cl(6)-P(1)-Cl(3) 89.96(6) Cl(1)-P(1)-Cl(4) 89.79(5) Cl(6)-P(1)-Cl(4) 90.71(5) Cl(3)-P(1)-Cl(4) 89.27(4) Cl(1)-P(1)-Cl(2) 89.69(5) Cl(6)-P(1)-Cl(2) 89.81(5) Cl(3)-P(1)-Cl(2) 90.37(4) Cl(4)-P(1)-Cl(2) 179.37(5) Cl(1)-P(1)-Cl(5) 89.24(6) Cl(6)-P(1)-Cl(5) 90.35(6) Cl(3)-P(1)-Cl(5) 178.97(5) Cl(4)-P(1)-Cl(5) 89.74(4) Cl(2)-P(1)-Cl(5) 90.61(4) 183

Table D-3. Bond lengths [Å] and angles [°] for [H(12-crown-4)][PCl6] (continued). C(1)-O(1)-C(8) 117.2(2) C(3)-O(2)-C(2) 112.8(2) C(5)-O(3)-C(4) 116.4(2) C(7)-O(4)-C(6) 112.4(2) O(1)-C(1)-C(2) 110.8(2) O(2)-C(2)-C(1) 109.9(2) O(2)-C(3)-C(4) 108.9(3) O(3)-C(4)-C(3) 108.9(3) O(3)-C(5)-C(6) 110.3(3) O(4)-C(6)-C(5) 108.6(3) O(4)-C(7)-C(8) 109.6(2) O(1)-C(8)-C(7) 110.5(2) ______Symmetry transformations used to generate equivalent atoms:

Table D-4. Anisotropic displacement parameters (Å2x 103) for [H(12-crown-

4)][PCl6]. The anisotropic displacement factor exponent takes the form: -2π2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______P(1) 22(1) 10(1) 17(1) 1(1) 3(1) 0(1) Cl(1) 28(1) 13(1) 23(1) -3(1) -2(1) -1(1) Cl(2) 23(1) 20(1) 29(1) -4(1) 5(1) 1(1) Cl(3) 35(1) 16(1) 24(1) 8(1) 1(1) -1(1) Cl(4) 26(1) 18(1) 42(1) -2(1) 13(1) 1(1) Cl(5) 39(1) 14(1) 21(1) 4(1) 1(1) -4(1) Cl(6) 34(1) 13(1) 21(1) -3(1) 3(1) -3(1) O(1) 32(1) 21(1) 22(1) 4(1) 6(1) 3(1) O(2) 25(1) 12(1) 25(1) -2(1) -1(1) 2(1) O(3) 26(1) 20(1) 26(1) -5(1) 1(1) 3(1) O(4) 24(1) 7(1) 23(1) -2(1) 0(1) 0(1) 184

Table D-4. Anisotropic displacement parameters (Å2x 103) for [H(12-crown-

4)][PCl6]. The anisotropic displacement factor exponent takes the form: -2π2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] (continued). ______U11 U22 U33 U23 U13 U12 ______C(1) 28(2) 21(2) 26(2) 5(1) 3(2) 7(1) C(2) 28(2) 27(2) 21(2) 2(2) -7(2) 7(2) C(3) 29(2) 14(2) 38(2) -8(1) 0(2) -6(1) C(4) 32(2) 15(2) 30(2) 2(1) 4(2) -5(1) C(5) 32(2) 13(2) 30(2) -1(1) 0(2) 5(1) C(6) 22(2) 20(2) 27(2) -2(1) 1(2) 9(1) C(7) 29(2) 10(2) 24(2) -2(1) 4(2) -2(1) C(8) 35(2) 13(2) 25(2) -4(1) 5(2) -3(1) ______

185

APPENDIX E

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

[H(18-crown-6)2][PCl6]

Table E-1. Crystal data and structure refinement for [H(18-crown-6)2][PCl6].

Empirical formula C24 H49 Cl6 O12 P Formula weight 773.30 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Triclinic Space group P-1 Unit cell dimensions a = 8.8731(7) Å α= 92.6260(10)° b = 11.6179(9) Å β= 96.3030(10)° c = 18.3623(14) Å γ = 109.9780(10)° Volume 1761.2(2) Å3 Z 2 Density (calculated) 1.458 Mg/m3 Absorption coefficient 0.588 mm-1 F(000) 812 Crystal size 0.32 x 0.20 x 0.08 mm3 Theta range for data collection 1.87 to 26.30°. Index ranges -11 ≤ h ≤ 11 -14 ≤ k ≤ 14 -22 ≤ l ≤ 22 Reflections collected 14197 Independent reflections 7063 [R(int) = 0.0258] (b) Completeness to theta = 26.30° 99.0 % Absorption correction Semi-empirical from equivalents

186

Table E-1. Crystal data and structure refinement for [H(18-crown-6)2][PCl6] (continued). Max. and min. transmission 0.9545 and 0.8342 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 7063 / 0 / 414 Goodness-of-fit on F2 1.084 Final R indices [I>2sigma(I)] R1 = 0.0347, wR2 = 0.0901 R indices (all data) R1 = 0.0431, wR2 = 0.0924 Largest diff. peak and hole 0.400 and -0.384 e.Å-3

Table E-2. Atomic coordinates ( x 104) and equivalent isotropic displacement parameters (Å2x 103) for [H(18-crown-6)2][PCl6]. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Cl(1) 9955(1) 8157(1) 72(1) 21(1) Cl(2) 7440(1) 9392(1) 17(1) 26(1) Cl(3) 10376(1) 10296(1) 1179(1) 24(1) Cl(4) 10037(1) 8161(1) 4930(1) 21(1) Cl(5) 7435(1) 9292(1) 4689(1) 22(1) Cl(6) 10353(1) 10131(1) 3867(1) 21(1) P(1) 10000 10000 0 16(1) P(2) 10000 10000 5000 16(1) O(1) 5797(2) 5615(1) 3209(1) 20(1) O(2) 8381(2) 6848(1) 2411(1) 23(1) O(3) 8215(2) 4655(1) 1504(1) 23(1) O(4) 8006(2) 2485(1) 2218(1) 22(1) O(5) 5663(2) 1667(1) 3271(1) 22(1) O(6) 5745(2) 3876(1) 4183(1) 24(1) O(7A) 2247(3) 4567(2) 3660(2) 21(1) O(7B) 1908(5) 4560(4) 3135(3) 18(2) O(8) 2949(2) 7069(1) 3632(1) 22(1) O(9) 3651(2) 8454(1) 2387(1) 22(1)

187

Table E-2. Atomic coordinates ( x 104) and equivalent isotropic displacement parameters (Å2x 103) for [H(18-crown-6)2][PCl6]. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. (continued) ______x y z U(eq) ______O(10) 3323(2) 6894(1) 1081(1) 24(1) O(11) 4147(2) 4732(1) 1200(1) 25(1) O(12) 3899(2) 3678(1) 2608(1) 22(1) C(1) 5696(2) 6589(2) 2735(1) 21(1) C(2) 7395(2) 7447(2) 2697(1) 24(1) C(3) 8174(2) 6690(2) 1628(1) 22(1) C(4) 9093(2) 5896(2) 1391(1) 22(1) C(5) 9033(3) 3848(2) 1314(1) 27(1) C(6) 8050(3) 2561(2) 1450(1) 25(1) C(7) 7214(3) 1251(2) 2374(1) 25(1) C(8) 6938(2) 1217(2) 3164(1) 23(1) C(9) 5443(3) 1765(2) 4029(1) 24(1) C(10) 6452(3) 2999(2) 4418(1) 27(1) C(11) 6777(3) 5110(2) 4370(1) 25(1) C(12) 5975(3) 5917(2) 4007(1) 25(1) C(13A) 1220(5) 5034(4) 3211(3) 24(1) C(13B) 959(9) 5033(7) 3555(5) 22(2) C(14) 1315(3) 6288(2) 3514(1) 31(1) C(15) 3206(2) 8351(2) 3645(1) 21(1) C(16) 2740(2) 8753(2) 2909(1) 21(1) C(17) 3148(2) 8700(2) 1667(1) 22(1) C(18) 3954(2) 8198(2) 1118(1) 23(1) C(19) 3886(2) 6353(2) 513(1) 23(1) C(20) 3314(2) 4983(2) 556(1) 22(1) C(21) 3761(3) 3453(2) 1266(1) 26(1) C(22) 4552(3) 3274(2) 1996(1) 25(1) C(23) 2312(2) 2903(2) 2726(1) 27(1) C(24) 1920(3) 3323(2) 3441(1) 33(1) ______

188

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6]. ______Cl(1)-P(1) 2.1380(5) Cl(2)-P(1) 2.1400(5) Cl(3)-P(1) 2.1468(5) Cl(4)-P(2) 2.1466(5) Cl(5)-P(2) 2.1391(5) Cl(6)-P(2) 2.1420(5) P(1)-Cl(1)#1 2.1380(5) P(1)-Cl(2)#1 2.1400(5) P(1)-Cl(3)#1 2.1468(5) P(2)-Cl(5)#2 2.1391(5) P(2)-Cl(6)#2 2.1420(5) P(2)-Cl(4)#2 2.1466(5) O(1)-C(12) 1.469(2) O(1)-C(1) 1.479(2) O(1)-H' 1.08(3) O(2)-C(2) 1.417(2) O(2)-C(3) 1.425(2) O(3)-C(5) 1.420(2) O(3)-C(4) 1.423(2) O(4)-C(6) 1.420(2) O(4)-C(7) 1.423(2) O(5)-C(8) 1.426(2) O(5)-C(9) 1.430(2) O(6)-C(11) 1.414(2) O(6)-C(10) 1.427(2) O(7A)-C(24) 1.404(3) O(7A)-C(13A) 1.420(5) O(7B)-C(13B) 1.423(9) O(7B)-C(24) 1.569(5) O(8)-C(14) 1.409(2) O(8)-C(15) 1.426(2) O(9)-C(17) 1.422(2)

189

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______O(9)-C(16) 1.422(2) O(10)-C(19) 1.415(2) O(10)-C(18) 1.420(2) O(11)-C(20) 1.419(2) O(11)-C(21) 1.421(2) O(12)-C(23) 1.435(2) O(12)-C(22) 1.450(2) C(1)-C(2) 1.508(3) C(1)-H(1A) 0.9900 C(1)-H(1B) 0.9900 C(2)-H(2A) 0.9900 C(2)-H(2B) 0.9900 C(3)-C(4) 1.505(3) C(3)-H(3A) 0.9900 C(3)-H(3B) 0.9900 C(4)-H(4A) 0.9900 C(4)-H(4B) 0.9900 C(5)-C(6) 1.500(3) C(5)-H(5A) 0.9900 C(5)-H(5B) 0.9900 C(6)-H(6A) 0.9900 C(6)-H(6B) 0.9900 C(7)-C(8) 1.497(3) C(7)-H(7A) 0.9900 C(7)-H(7B) 0.9900 C(8)-H(8A) 0.9900 C(8)-H(8B) 0.9900 C(9)-C(10) 1.502(3) C(9)-H(9A) 0.9900 C(9)-H(9B) 0.9900 C(10)-H(10A) 0.9900 C(10)-H(10B) 0.9900 C(11)-C(12) 1.497(3)

190

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______C(11)-H(11A) 0.9900 C(11)-H(11B) 0.9900 C(12)-H(12A) 0.9900 C(12)-H(12B) 0.9900 C(13A)-C(14) 1.506(4) C(13A)-H(13A) 0.9900 C(13A)-H(13B) 0.9900 C(13B)-C(14) 1.390(8) C(13B)-H(13C) 0.9900 C(13B)-H(13D) 0.9900 C(14)-H(14A) 0.9900 C(14)-H(14B) 0.9900 C(15)-C(16) 1.511(3) C(15)-H(15A) 0.9900 C(15)-H(15B) 0.9900 C(16)-H(16A) 0.9900 C(16)-H(16B) 0.9900 C(17)-C(18) 1.503(3) C(17)-H(17A) 0.9900 C(17)-H(17B) 0.9900 C(18)-H(18A) 0.9900 C(18)-H(18B) 0.9900 C(19)-C(20) 1.505(3) C(19)-H(19A) 0.9900 C(19)-H(19B) 0.9900 C(20)-H(20A) 0.9900 C(20)-H(20B) 0.9900 C(21)-C(22) 1.500(3) C(21)-H(21A) 0.9900 C(21)-H(21B) 0.9900 C(22)-H(22A) 0.9900 C(22)-H(22B) 0.9900 C(23)-C(24) 1.497(3) C(23)-H(23A) 0.9900

191

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______C(23)-H(23B) 0.9900 C(24)-H(24A) 0.9900 C(24)-H(24B) 0.9900 Cl(1)#1-P(1)-Cl(1) 180.0 Cl(1)#1-P(1)-Cl(2)#1 90.292(19) Cl(1)-P(1)-Cl(2)#1 89.708(19) Cl(1)#1-P(1)-Cl(2) 89.708(19) Cl(1)-P(1)-Cl(2) 90.292(19) Cl(2)#1-P(1)-Cl(2) 180.00(3) Cl(1)#1-P(1)-Cl(3)#1 90.029(18) Cl(1)-P(1)-Cl(3)#1 89.971(18) Cl(2)#1-P(1)-Cl(3)#1 89.71(2) Cl(2)-P(1)-Cl(3)#1 90.29(2) Cl(1)#1-P(1)-Cl(3) 89.971(18) Cl(1)-P(1)-Cl(3) 90.029(18) Cl(2)#1-P(1)-Cl(3) 90.29(2) Cl(2)-P(1)-Cl(3) 89.71(2) Cl(3)#1-P(1)-Cl(3) 180.0 Cl(5)#2-P(2)-Cl(5) 180.000(1) Cl(5)#2-P(2)-Cl(6)#2 90.212(19) Cl(5)-P(2)-Cl(6)#2 89.788(19) Cl(5)#2-P(2)-Cl(6) 89.788(19) Cl(5)-P(2)-Cl(6) 90.212(19) Cl(6)#2-P(2)-Cl(6) 180.0 Cl(5)#2-P(2)-Cl(4)#2 89.848(19) Cl(5)-P(2)-Cl(4)#2 90.152(19) Cl(6)#2-P(2)-Cl(4)#2 90.175(18) Cl(6)-P(2)-Cl(4)#2 89.825(18) Cl(5)#2-P(2)-Cl(4) 90.152(19) Cl(5)-P(2)-Cl(4) 89.848(19) Cl(6)#2-P(2)-Cl(4) 89.825(18) Cl(6)-P(2)-Cl(4) 90.175(18) Cl(4)#2-P(2)-Cl(4) 180.000(1) C(12)-O(1)-C(1) 116.64(14)

192

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______C(12)-O(1)-H' 117.4(14) C(1)-O(1)-H' 106.7(14) C(2)-O(2)-C(3) 113.60(15) C(5)-O(3)-C(4) 112.08(15) C(6)-O(4)-C(7) 110.93(15) C(8)-O(5)-C(9) 112.33(15) C(11)-O(6)-C(10) 113.50(16) C(24)-O(7A)-C(13A) 110.4(3) C(13B)-O(7B)-C(24) 108.1(5) C(14)-O(8)-C(15) 115.17(15) C(17)-O(9)-C(16) 111.37(14) C(19)-O(10)-C(18) 111.81(15) C(20)-O(11)-C(21) 112.78(15) C(23)-O(12)-C(22) 116.06(15) C(23)-O(12)-H' 128.3(11) C(22)-O(12)-H' 115.6(11) O(1)-C(1)-C(2) 108.00(16) O(1)-C(1)-H(1A) 110.1 C(2)-C(1)-H(1A) 110.1 O(1)-C(1)-H(1B) 110.1 C(2)-C(1)-H(1B) 110.1 H(1A)-C(1)-H(1B) 108.4 O(2)-C(2)-C(1) 113.07(16) O(2)-C(2)-H(2A) 109.0 C(1)-C(2)-H(2A) 109.0 O(2)-C(2)-H(2B) 109.0 C(1)-C(2)-H(2B) 109.0 H(2A)-C(2)-H(2B) 107.8 O(2)-C(3)-C(4) 108.94(16) O(2)-C(3)-H(3A) 109.9 C(4)-C(3)-H(3A) 109.9 O(2)-C(3)-H(3B) 109.9 C(4)-C(3)-H(3B) 109.9 H(3A)-C(3)-H(3B) 108.3

193

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______O(3)-C(4)-C(3) 108.62(16) O(3)-C(4)-H(4A) 110.0 C(3)-C(4)-H(4A) 110.0 O(3)-C(4)-H(4B) 110.0 C(3)-C(4)-H(4B) 110.0 H(4A)-C(4)-H(4B) 108.3 O(3)-C(5)-C(6) 109.33(16) O(3)-C(5)-H(5A) 109.8 C(6)-C(5)-H(5A) 109.8 O(3)-C(5)-H(5B) 109.8 C(6)-C(5)-H(5B) 109.8 H(5A)-C(5)-H(5B) 108.3 O(4)-C(6)-C(5) 109.35(17) O(4)-C(6)-H(6A) 109.8 C(5)-C(6)-H(6A) 109.8 O(4)-C(6)-H(6B) 109.8 C(5)-C(6)-H(6B) 109.8 H(6A)-C(6)-H(6B) 108.3 O(4)-C(7)-C(8) 110.08(16) O(4)-C(7)-H(7A) 109.6 C(8)-C(7)-H(7A) 109.6 O(4)-C(7)-H(7B) 109.6 C(8)-C(7)-H(7B) 109.6 H(7A)-C(7)-H(7B) 108.2 O(5)-C(8)-C(7) 109.73(16) O(5)-C(8)-H(8A) 109.7 C(7)-C(8)-H(8A) 109.7 O(5)-C(8)-H(8B) 109.7 C(7)-C(8)-H(8B) 109.7 H(8A)-C(8)-H(8B) 108.2 O(5)-C(9)-C(10) 112.66(16) O(5)-C(9)-H(9A) 109.1 C(10)-C(9)-H(9A) 109.1 O(5)-C(9)-H(9B) 109.1 194

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______C(10)-C(9)-H(9B) 109.1 H(9A)-C(9)-H(9B) 107.8 O(6)-C(10)-C(9) 108.29(17) O(6)-C(10)-H(10A) 110.0 C(9)-C(10)-H(10A) 110.0 O(6)-C(10)-H(10B) 110.0 C(9)-C(10)-H(10B) 110.0 H(10A)-C(10)-H(10B) 108.4 O(6)-C(11)-C(12) 107.60(17) O(6)-C(11)-H(11A) 110.2 C(12)-C(11)-H(11A) 110.2 O(6)-C(11)-H(11B) 110.2 C(12)-C(11)-H(11B) 110.2 H(11A)-C(11)-H(11B) 108.5 O(1)-C(12)-C(11) 107.28(16) O(1)-C(12)-H(12A) 110.3 C(11)-C(12)-H(12A) 110.3 O(1)-C(12)-H(12B) 110.3 C(11)-C(12)-H(12B) 110.3 H(12A)-C(12)-H(12B) 108.5 O(7A)-C(13A)-C(14) 111.9(3) O(7A)-C(13A)-H(13A) 109.2 C(14)-C(13A)-H(13A) 109.2 O(7A)-C(13A)-H(13B) 109.2 C(14)-C(13A)-H(13B) 109.2 H(13A)-C(13A)-H(13B) 107.9 C(14)-C(13B)-O(7B) 112.4(6) C(14)-C(13B)-H(13C) 109.1 O(7B)-C(13B)-H(13C) 109.1 C(14)-C(13B)-H(13D) 109.1 O(7B)-C(13B)-H(13D) 109.1 H(13C)-C(13B)-H(13D) 107.9 C(13B)-C(14)-O(8) 118.6(4) O(8)-C(14)-C(13A) 109.0(2) 195

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______C(13B)-C(14)-H(14A) 122.8 O(8)-C(14)-H(14A) 109.9 C(13A)-C(14)-H(14A) 109.9 C(13B)-C(14)-H(14B) 82.6 O(8)-C(14)-H(14B) 109.9 C(13A)-C(14)-H(14B) 109.9 H(14A)-C(14)-H(14B) 108.3 O(8)-C(15)-C(16) 113.82(16) O(8)-C(15)-H(15A) 108.8 C(16)-C(15)-H(15A) 108.8 O(8)-C(15)-H(15B) 108.8 C(16)-C(15)-H(15B) 108.8 H(15A)-C(15)-H(15B) 107.7 O(9)-C(16)-C(15) 108.84(16) O(9)-C(16)-H(16A) 109.9 C(15)-C(16)-H(16A) 109.9 O(9)-C(16)-H(16B) 109.9 C(15)-C(16)-H(16B) 109.9 H(16A)-C(16)-H(16B) 108.3 O(9)-C(17)-C(18) 109.77(16) O(9)-C(17)-H(17A) 109.7 C(18)-C(17)-H(17A) 109.7 O(9)-C(17)-H(17B) 109.7 C(18)-C(17)-H(17B) 109.7 H(17A)-C(17)-H(17B) 108.2 O(10)-C(18)-C(17) 108.60(16) O(10)-C(18)-H(18A) 110.0 C(17)-C(18)-H(18A) 110.0 O(10)-C(18)-H(18B) 110.0 C(17)-C(18)-H(18B) 110.0 H(18A)-C(18)-H(18B) 108.4 O(10)-C(19)-C(20) 109.00(16) O(10)-C(19)-H(19A) 109.9 C(20)-C(19)-H(19A) 109.9 196

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______O(10)-C(19)-H(19B) 109.9 C(20)-C(19)-H(19B) 109.9 H(19A)-C(19)-H(19B) 108.3 O(11)-C(20)-C(19) 108.52(16) O(11)-C(20)-H(20A) 110.0 C(19)-C(20)-H(20A) 110.0 O(11)-C(20)-H(20B) 110.0 C(19)-C(20)-H(20B) 110.0 H(20A)-C(20)-H(20B) 108.4 O(11)-C(21)-C(22) 109.11(16) O(11)-C(21)-H(21A) 109.9 C(22)-C(21)-H(21A) 109.9 O(11)-C(21)-H(21B) 109.9 C(22)-C(21)-H(21B) 109.9 H(21A)-C(21)-H(21B) 108.3 O(12)-C(22)-C(21) 112.41(17) O(12)-C(22)-H(22A) 109.1 C(21)-C(22)-H(22A) 109.1 O(12)-C(22)-H(22B) 109.1 C(21)-C(22)-H(22B) 109.1 H(22A)-C(22)-H(22B) 107.9 O(12)-C(23)-C(24) 109.65(17) O(12)-C(23)-H(23A) 109.7 C(24)-C(23)-H(23A) 109.7 O(12)-C(23)-H(23B) 109.7 C(24)-C(23)-H(23B) 109.7 H(23A)-C(23)-H(23B) 108.2 O(7A)-C(24)-C(23) 122.7(2) C(23)-C(24)-O(7B) 91.1(2) O(7A)-C(24)-H(24A) 106.7 C(23)-C(24)-H(24A) 106.7 O(7B)-C(24)-H(24A) 100.2 O(7A)-C(24)-H(24B) 106.7 C(23)-C(24)-H(24B) 106.7 197

Table E-3. Bond lengths [Å] and angles [°] for [H(18-crown-6)2][PCl6] (continued). ______O(7B)-C(24)-H(24B) 141.5 H(24A)-C(24)-H(24B) 106.6 ______symmetry transformations used to generate equivalent atoms: #1 -x+2,-y+2,-z #2 -x+2,-y+2,-z+1

Table E-4. Anisotropic displacement parameters (Å2x 103) for [H(18-crown-

6)2][PCl6]. The anisotropic displacement factor exponent takes the form: -2π2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Cl(1) 31(1) 15(1) 20(1) 4(1) 4(1) 11(1) Cl(2) 21(1) 24(1) 34(1) 3(1) 6(1) 7(1) Cl(3) 37(1) 23(1) 16(1) 2(1) 3(1) 16(1) Cl(4) 26(1) 17(1) 24(1) 3(1) 5(1) 11(1) Cl(5) 16(1) 23(1) 25(1) 3(1) 2(1) 7(1) Cl(6) 25(1) 22(1) 17(1) 3(1) 5(1) 10(1) P(1) 20(1) 14(1) 17(1) 3(1) 4(1) 7(1) P(2) 16(1) 16(1) 17(1) 1(1) 3(1) 7(1) O(1) 23(1) 16(1) 20(1) 3(1) 4(1) 6(1) O(2) 21(1) 29(1) 19(1) 2(1) 4(1) 8(1) O(3) 21(1) 20(1) 33(1) 9(1) 12(1) 10(1) O(4) 27(1) 21(1) 21(1) 7(1) 6(1) 8(1) O(5) 22(1) 25(1) 21(1) 5(1) 5(1) 11(1) O(6) 28(1) 19(1) 26(1) 4(1) 0(1) 9(1) O(7A) 23(1) 19(1) 22(2) 2(1) 0(1) 9(1) O(7B) 23(2) 15(2) 20(4) 5(2) 10(2) 10(2) O(8) 19(1) 19(1) 27(1) 3(1) 0(1) 8(1) O(9) 24(1) 28(1) 20(1) 5(1) 3(1) 16(1) O(10) 28(1) 22(1) 25(1) 5(1) 9(1) 10(1) O(11) 27(1) 18(1) 26(1) 2(1) -6(1) 6(1)

198

Table E-4. Anisotropic displacement parameters (Å2x 103) for [H(18-crown-

6)2][PCl6]. The anisotropic displacement factor exponent takes the form: -2π2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] (continued). ______U11 U22 U33 U23 U13 U12 ______O(12) 19(1) 18(1) 27(1) 2(1) 1(1) 2(1) C(1) 26(1) 18(1) 25(1) 7(1) 5(1) 13(1) C(2) 28(1) 19(1) 23(1) 2(1) 5(1) 7(1) C(3) 23(1) 20(1) 21(1) 6(1) 4(1) 6(1) C(4) 23(1) 22(1) 21(1) 7(1) 6(1) 6(1) C(5) 30(1) 29(1) 31(1) 12(1) 15(1) 18(1) C(6) 34(1) 28(1) 23(1) 8(1) 12(1) 19(1) C(7) 26(1) 19(1) 31(1) 8(1) 9(1) 9(1) C(8) 23(1) 21(1) 28(1) 8(1) 7(1) 11(1) C(9) 32(1) 22(1) 22(1) 8(1) 10(1) 13(1) C(10) 33(1) 27(1) 23(1) 6(1) 0(1) 15(1) C(11) 30(1) 21(1) 19(1) 0(1) 2(1) 5(1) C(12) 34(1) 19(1) 21(1) -1(1) 8(1) 8(1) C(13A) 24(2) 23(2) 24(2) -4(2) -5(2) 10(2) C(13B) 21(4) 31(4) 22(4) -4(4) 9(4) 18(3) C(14) 22(1) 24(1) 46(1) -3(1) 9(1) 7(1) C(15) 22(1) 19(1) 24(1) 0(1) 4(1) 8(1) C(16) 21(1) 19(1) 27(1) 2(1) 4(1) 10(1) C(17) 21(1) 20(1) 26(1) 7(1) 1(1) 9(1) C(18) 24(1) 25(1) 23(1) 8(1) 5(1) 9(1) C(19) 23(1) 31(1) 18(1) 4(1) 5(1) 13(1) C(20) 22(1) 28(1) 17(1) 0(1) 1(1) 10(1) C(21) 30(1) 16(1) 30(1) -1(1) 2(1) 5(1) C(22) 25(1) 21(1) 32(1) 4(1) 5(1) 10(1) C(23) 22(1) 21(1) 30(1) 8(1) -3(1) -2(1) C(24) 22(1) 15(1) 61(2) 0(1) 13(1) 5(1)

199

Table E-5. Hydrogen coordinates ( x 104) and isotropic displacement

parameters (Å2x 10 3) for [H(18-crown-6)2][PCl6]. ______x y z U(eq) ______H(1A) 5060 7046 2944 26 H(1B) 5155 6220 2236 26 H(2A) 7347 8107 2383 28 H(2B) 7898 7836 3196 28 H(3A) 8582 7500 1428 26 H(3B) 7011 6296 1438 26 H(4A) 9224 5966 864 26 H(4B) 10182 6168 1681 26 H(5A) 10111 4104 1613 32 H(5B) 9191 3883 789 32 H(6A) 6936 2336 1191 30 H(6B) 8537 1979 1258 30 H(7A) 7887 752 2272 29 H(7B) 6164 895 2053 29 H(8A) 6649 363 3303 27 H(8B) 7942 1730 3481 27 H(9A) 5731 1118 4280 29 H(9B) 4288 1620 4062 29 H(10A) 6484 2963 4957 32 H(10B) 7573 3239 4299 32 H(11A) 7838 5245 4198 30 H(11B) 6956 5301 4911 30 H(12A) 4901 5767 4169 30 H(12B) 6644 6793 4137 30 H(13A) 89 4460 3176 29 H(13B) 1532 5084 2709 29 H(13C) -201 4595 3375 26 H(13D) 1153 4873 4076 26 H(14A) 686 6627 3162 37 H(14B) 851 6226 3983 37 H(15A) 4364 8819 3813 26 200

Table E-5. Hydrogen coordinates ( x 104) and isotropic displacement parameters (Å2x 10 3) for [H(18-crown-6)2][PCl6] (continued). ______x y z U(eq) ______H(15B) 2571 8559 4008 26 H(16A) 1568 8331 2746 26 H(16B) 2965 9651 2952 26 H(17A) 3441 9599 1643 26 H(17B) 1959 8314 1549 26 H(18A) 3743 8478 628 28 H(18B) 5138 8499 1269 28 H(19A) 5083 6690 569 27 H(19B) 3465 6542 29 27 H(20A) 2133 4661 575 27 H(20B) 3535 4576 115 27 H(21A) 4149 3081 863 31 H(21B) 2573 3044 1229 31 H(22A) 4400 2391 2016 30 H(22B) 5729 3738 2042 30 H(23A) 2268 2041 2734 32 H(23B) 1505 2939 2318 32 H(24A) 747 2896 3445 39 H(24B) 2484 3003 3833 39 H' 4840(30) 4780(20) 2976(15) 67(9)

Table E-6. Torsion angles [°] for [H(18-crown-6)2][PCl6]. ______C(12)-O(1)-C(1)-C(2) 82.38(19) C(3)-O(2)-C(2)-C(1) 82.5(2) O(1)-C(1)-C(2)-O(2) 58.9(2) C(2)-O(2)-C(3)-C(4) -172.18(16) C(5)-O(3)-C(4)-C(3) -178.14(16) O(2)-C(3)-C(4)-O(3) 75.5(2)

201

Table E-6. Torsion angles [°] for [H(18-crown-6)2][PCl6] (continued). ______C(4)-O(3)-C(5)-C(6) 179.71(16) C(7)-O(4)-C(6)-C(5) -174.44(16) O(3)-C(5)-C(6)-O(4) -66.9(2) C(6)-O(4)-C(7)-C(8) -170.76(16) C(9)-O(5)-C(8)-C(7) -174.54(16) O(4)-C(7)-C(8)-O(5) 73.6(2) C(8)-O(5)-C(9)-C(10) 89.9(2) C(11)-O(6)-C(10)-C(9) -165.68(16) O(5)-C(9)-C(10)-O(6) 74.0(2) C(10)-O(6)-C(11)-C(12) 172.58(16) C(1)-O(1)-C(12)-C(11) -154.96(16) O(6)-C(11)-C(12)-O(1) -61.7(2) C(24)-O(7A)-C(13A)-C(14) 169.5(2) C(24)-O(7B)-C(13B)-C(14) 158.9(4) O(7B)-C(13B)-C(14)-O(8) -48.8(8) O(7B)-C(13B)-C(14)-C(13A) 26.8(6) C(15)-O(8)-C(14)-C(13B) -174.7(4) C(15)-O(8)-C(14)-C(13A) 157.2(2) O(7A)-C(13A)-C(14)-C(13B) -62.8(9) O(7A)-C(13A)-C(14)-O(8) 53.1(4) C(14)-O(8)-C(15)-C(16) -68.0(2) C(17)-O(9)-C(16)-C(15) 174.20(15) O(8)-C(15)-C(16)-O(9) -58.5(2) C(16)-O(9)-C(17)-C(18) -171.46(16) C(19)-O(10)-C(18)-C(17) 173.16(16) O(9)-C(17)-C(18)-O(10) 68.3(2) C(18)-O(10)-C(19)-C(20) 174.20(16) C(21)-O(11)-C(20)-C(19) -176.42(16) O(10)-C(19)-C(20)-O(11) -69.2(2) C(20)-O(11)-C(21)-C(22) -174.02(17) C(23)-O(12)-C(22)-C(21) 73.5(2) O(11)-C(21)-C(22)-O(12) 65.9(2) C(22)-O(12)-C(23)-C(24) 170.77(17) C(13A)-O(7A)-C(24)-C(23) 69.1(4) 202

Table E-6. Torsion angles [°] for [H(18-crown-6)2][PCl6] (continued). ______C(13A)-O(7A)-C(24)-O(7B) 31.1(3) O(12)-C(23)-C(24)-O(7A) 44.2(3) O(12)-C(23)-C(24)-O(7B) 66.4(2) C(13B)-O(7B)-C(24)-O(7A) -54.0(5) C(13B)-O(7B)-C(24)-C(23) 157.2(5) ______Symmetry transformations used to generate equivalent atoms: #1 -x+2,-y+2,-z #2 -x+2,-y+2,-z+1

Table E-7. Hydrogen bonds for [H(18-crown-6)2][PCl6] (Å and °). ______D-H...A d(D-H) d(H...A) d(D...A) <(DHA) ______O(1)-H'...O(12) 1.08(3) 1.36(3) 2.4275(18) 167(3) ______Symmetry transformations used to generate equivalent atoms: #1 -x+2,-y+2,-z #2 -x+2,-y+2,-z+1

203

APPENDIX F

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

. [PCl2N]3 HSbCl6

. Table F-1. Crystal data and structure refinement for [PCl2N]3 HSbCl6.

Empirical formula Cl12 N3 P3 Sb Formula weight 682.09 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Orthorhombic Space group Pna2(1) Unit cell dimensions a = 16.0656(17) Å α = 90° b = 10.0854(11) Å β = 90° c = 11.7766(12) Å γ = 90° Volume 1908.1(3) Å3 Z 4 Density (calculated) 2.374 Mg/m3 Absorption coefficient 3.363 mm-1 F(000) 1284 Crystal size 0.14 x 0.10 x 0.08 mm3 Theta range for data collection 2.38 to 28.27°. Index ranges -21 ≤ h ≤ 21 -12 ≤ k ≤ 13 -15 ≤ l ≤ 15 Reflections collected 16343 Independent reflections 4572 [R(int) = 0.0623] Completeness to theta = 28.27° 98.6 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.7747 and 0.6503

204

. Table F-1. Crystal data and structure refinement for [PCl2N]3 HSbCl6 (continued). Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 4572 / 1 / 172 Goodness-of-fit on F2 1.039 Final R indices [I>2sigma(I)] R1 = 0.0412, wR2 = 0.0802 R indices (all data) R1 = 0.0491, wR2 = 0.0824 Absolute structure parameter 0.51(2) Largest diff. peak and hole 0.644 and -0.708 e.Å-3

Table F-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]3 HSbCl6. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Sb(1) 632(1) 3053(1) 3772(1) 14(1) Cl(1) 7405(1) -183(2) 10976(1) 23(1) Cl(2) 8798(1) 1914(2) 11174(1) 26(1) Cl(3) 7335(1) 190(2) 6895(2) 27(1) Cl(4) 8800(1) 2195(2) 6908(2) 23(1) Cl(5) 5593(1) 2324(2) 9021(1) 26(1) Cl(6) 6537(1) 5001(1) 9247(1) 22(1) Cl(7) 479(1) 3993(2) 1963(1) 22(1) Cl(8) 363(1) 901(2) 2977(2) 26(1) Cl(9) -809(1) 3365(2) 4082(1) 22(1) Cl(10) 959(1) 5147(2) 4549(2) 28(1) Cl(11) 2063(1) 2626(2) 3477(1) 22(1) Cl(12) 736(1) 2052(2) 5583(2) 37(1) P(1) 7823(1) 1431(2) 10267(1) 12(1) P(2) 7822(1) 1638(2) 7780(1) 14(1) P(3) 6724(1) 3087(1) 9115(1) 13(1) N(1) 8167(3) 998(5) 8994(4) 15(1) N(2) 7208(3) 2791(5) 7963(4) 17(1) N(3) 7177(3) 2572(5) 10226(4) 16(1) ______205

. Table F-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HSbCl6. ______Sb(1)-Cl(7) 2.3445(17) Sb(1)-Cl(10) 2.3609(17) Sb(1)-Cl(11) 2.3645(14) Sb(1)-Cl(9) 2.3646(15) Sb(1)-Cl(12) 2.3652(18) Sb(1)-Cl(8) 2.4030(17) Cl(1)-P(1) 1.949(2) Cl(2)-P(1) 1.958(2) Cl(3)-P(2) 1.956(2) Cl(4)-P(2) 1.960(2) Cl(5)-P(3) 1.976(2) Cl(6)-P(3) 1.959(2) P(1)-N(3) 1.549(5) P(1)-N(1) 1.656(5) P(2)-N(2) 1.540(5) P(2)-N(1) 1.664(5) P(3)-N(3) 1.585(5) P(3)-N(2) 1.592(5)

Cl(7)-Sb(1)-Cl(10) 90.79(6) Cl(7)-Sb(1)-Cl(11) 92.39(6) Cl(10)-Sb(1)-Cl(11) 90.17(6) Cl(7)-Sb(1)-Cl(9) 89.11(5) Cl(10)-Sb(1)-Cl(9) 92.25(6) Cl(11)-Sb(1)-Cl(9) 177.14(6) Cl(7)-Sb(1)-Cl(12) 177.66(7) Cl(10)-Sb(1)-Cl(12) 90.94(7) Cl(11)-Sb(1)-Cl(12) 89.18(6) Cl(9)-Sb(1)-Cl(12) 89.25(6) Cl(7)-Sb(1)-Cl(8) 89.57(6) Cl(10)-Sb(1)-Cl(8) 177.46(6) Cl(11)-Sb(1)-Cl(8) 87.30(6) Cl(9)-Sb(1)-Cl(8) 90.27(6) Cl(12)-Sb(1)-Cl(8) 88.76(7) 206

. Table F-3. Bond lengths [Å] and angles [°] for [PCl2N]3 HSbCl6 (continued). N(3)-P(1)-N(1) 113.0(3) N(3)-P(1)-Cl(1) 113.8(2) N(1)-P(1)-Cl(1) 106.43(19) N(3)-P(1)-Cl(2) 111.6(2) N(1)-P(1)-Cl(2) 106.98(19) Cl(1)-P(1)-Cl(2) 104.43(10) N(2)-P(2)-N(1) 112.7(3) N(2)-P(2)-Cl(3) 112.5(2) N(1)-P(2)-Cl(3) 107.56(19) N(2)-P(2)-Cl(4) 111.7(2) N(1)-P(2)-Cl(4) 107.11(19) Cl(3)-P(2)-Cl(4) 104.80(11) N(3)-P(3)-N(2) 114.7(3) N(3)-P(3)-Cl(6) 109.1(2) N(2)-P(3)-Cl(6) 109.1(2) N(3)-P(3)-Cl(5) 109.9(2) N(2)-P(3)-Cl(5) 109.1(2) Cl(6)-P(3)-Cl(5) 104.32(10) P(1)-N(1)-P(2) 124.3(3) P(2)-N(2)-P(3) 125.0(3) P(1)-N(3)-P(3) 125.2(3) ______Symmetry transformations used to generate equivalent atoms:

207

Table F-4. Anisotropic displacement parameters (Å2x 103) for . [PCl2N]3 HSbCl6. The anisotropic displacement factor exponent takes the form: - 22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Sb(1) 10(1) 16(1) 16(1) 1(1) 0(1) 2(1) Cl(1) 24(1) 15(1) 29(1) 8(1) 10(1) 4(1) Cl(2) 18(1) 36(1) 24(1) -5(1) -8(1) -1(1) Cl(3) 36(1) 24(1) 21(1) -5(1) -5(1) -2(1) Cl(4) 21(1) 26(1) 22(1) 7(1) 10(1) 4(1) Cl(5) 17(1) 31(1) 30(1) 3(1) -2(1) -7(1) Cl(6) 28(1) 10(1) 28(1) 1(1) -3(1) 5(1) Cl(7) 19(1) 31(1) 17(1) 5(1) 0(1) -4(1) Cl(8) 15(1) 16(1) 48(1) -5(1) -9(1) 1(1) Cl(9) 14(1) 29(1) 23(1) 7(1) 2(1) 5(1) Cl(10) 24(1) 26(1) 34(1) -13(1) -10(1) 8(1) Cl(11) 9(1) 23(1) 32(1) -6(1) 1(1) 1(1) Cl(12) 26(1) 59(1) 27(1) 21(1) 0(1) 11(1) P(1) 13(1) 13(1) 12(1) 2(1) -1(1) 1(1) P(2) 15(1) 14(1) 12(1) 2(1) 2(1) 2(1) P(3) 12(1) 12(1) 15(1) 3(1) -1(1) 2(1) N(1) 19(2) 20(2) 8(3) 4(2) -3(2) 7(2) N(2) 19(3) 19(3) 11(3) 7(2) 0(2) 3(2) N(3) 16(3) 14(3) 16(3) 3(2) 4(2) 2(2)

208

APPENDIX G

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

. THE DEGRADATION PRODUCT OF [PCl2N]3 HSbCl6

Table G-1. Crystal data and structure refinement for the degradation product of . [PCl2N]3 HSbCl6.

Empirical formula Cl12 N3 P3 Sb2 Formula weight 803.86 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Triclinic Space group P-1 Unit cell dimensions a = 6.248(4) Å α = 98.254(12)° b = 11.255(8) Å β = 97.078(12)° c = 14.593(10) Å γ = 92.304(12)° Volume 1006.1(12) Å3 Z 2 Density (calculated) 2.842 Mg/m3 Absorption coefficient 5.354 mm-1 F(000) 792 Crystal size 0.06 x 0.06 x 0.02 mm3 Theta range for data collection 1.83 to 28.50°. Index ranges -8 ≤ h ≤ 8 -15 ≤ k ≤ 14 -19 ≤ l ≤ 19 Reflections collected 8593 Independent reflections 4555 [R(int) = 0.0663] Completeness to theta = 28.50° 89.3 %

209

Table G-1. Crystal data and structure refinement for the degradation product of . [PCl2N]3 HSbCl6 (continued). Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.898 and 0.733 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 4555 / 0 / 181 Goodness-of-fit on F2 1.123 Final R indices [I>2sigma(I)] R1 = 0.0677, wR2 = 0.1613 R indices (all data) R1 = 0.0825, wR2 = 0.1694 Largest diff. peak and hole 2.304 and -1.945 e.Å-3

Table G-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for the degradation product of [PCl2N]3 HSbCl6. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Sb(1) 673(1) 8829(1) 3702(1) 12(1) Sb(2) 4829(1) 3025(1) 4501(1) 13(1) Cl(1) 6263(4) 5581(2) 2097(2) 18(1) Cl(2) 10628(4) 5703(2) 1316(2) 23(1) Cl(3) 2738(4) 7260(2) -603(2) 21(1) Cl(4) 7033(4) 7203(2) -1455(2) 17(1) Cl(5) 10830(4) 9738(2) 1193(2) 20(1) Cl(6) 6657(4) 10239(2) 2084(2) 18(1) Cl(7) 2569(4) 9452(2) 5249(2) 15(1) Cl(8) 3754(4) 8014(2) 3156(2) 19(1) Cl(9) -614(4) 7026(2) 4144(2) 18(1) Cl(10) 2838(4) 4634(2) 4026(2) 23(1) Cl(11) 7374(4) 3214(2) 3477(2) 21(1) Cl(12) 2551(4) 1552(2) 3451(2) 17(1) P(1) 7859(4) 6508(2) 1320(2) 12(1) P(2) 5922(4) 7400(2) -228(2) 13(1) P(3) 7961(4) 8961(2) 1282(2) 11(1) 210

Table G-3. Bond lengths [Å] and angles [°] for for the degradation product of . [PCl2N]3 HSbCl6. ______Sb(1)-Cl(8) 2.343(3) Sb(1)-Cl(9) 2.356(3) Sb(1)-Cl(7) 2.411(3) Sb(2)-Cl(11) 2.336(3) Sb(2)-Cl(10) 2.374(3) Sb(2)-Cl(12) 2.380(3) Cl(1)-P(1) 1.975(3) Cl(2)-P(1) 1.986(4) Cl(3)-P(2) 1.990(4) Cl(4)-P(2) 1.986(4) Cl(5)-P(3) 1.989(3) Cl(6)-P(3) 1.987(3) P(1)-N(2) 1.564(9) P(1)-N(1) 1.602(8) P(2)-N(3) 1.582(8) P(2)-N(2) 1.592(9) P(3)-N(3) 1.584(9) P(3)-N(1) 1.593(8) Cl(8)-Sb(1)-Cl(9) 94.71(9) Cl(8)-Sb(1)-Cl(7) 92.16(9)

211

Table G-3. Bond lengths [Å] and angles [°]for the degradation product of . [PCl2N]3 HSbCl6 (continued). ______Cl(9)-Sb(1)-Cl(7) 90.79(9) Cl(11)-Sb(2)-Cl(10) 93.59(10) Cl(11)-Sb(2)-Cl(12) 94.96(10) Cl(10)-Sb(2)-Cl(12) 92.78(10) N(2)-P(1)-N(1) 118.0(4) N(2)-P(1)-Cl(1) 108.9(3) N(1)-P(1)-Cl(1) 108.7(3) N(2)-P(1)-Cl(2) 108.7(4) N(1)-P(1)-Cl(2) 109.0(3) Cl(1)-P(1)-Cl(2) 102.48(16) N(3)-P(2)-N(2) 118.2(4) N(3)-P(2)-Cl(4) 108.4(3) N(2)-P(2)-Cl(4) 108.8(4) N(3)-P(2)-Cl(3) 108.2(3) N(2)-P(2)-Cl(3) 109.9(4) Cl(4)-P(2)-Cl(3) 102.10(15) N(3)-P(3)-N(1) 118.7(4) N(3)-P(3)-Cl(6) 108.7(3) N(1)-P(3)-Cl(6) 107.8(3) N(3)-P(3)-Cl(5) 109.8(3) N(1)-P(3)-Cl(5) 108.5(3) Cl(6)-P(3)-Cl(5) 101.98(15) P(3)-N(1)-P(1) 120.0(5) P(1)-N(2)-P(2) 122.5(5) P(2)-N(3)-P(3) 120.8(5) ______Symmetry transformations used to generate equivalent atoms:

212

Table G-4. Anisotropic displacement parameters (Å2x 103) for the degradation . product of [PCl2N]3 HSbCl6. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Sb(1) 11(1) 12(1) 11(1) 0(1) -1(1) 1(1) Sb(2) 12(1) 11(1) 14(1) 1(1) -2(1) -1(1) Cl(1) 24(1) 13(1) 16(1) 4(1) 3(1) -5(1) Cl(2) 17(1) 17(1) 33(1) -3(1) 2(1) 2(1) Cl(3) 13(1) 24(1) 22(1) -3(1) -2(1) -3(1) Cl(4) 19(1) 18(1) 13(1) 0(1) 0(1) -3(1) Cl(5) 18(1) 21(1) 21(1) 5(1) 1(1) -9(1) Cl(6) 23(1) 11(1) 20(1) 0(1) 1(1) 6(1) Cl(7) 12(1) 20(1) 11(1) -1(1) -2(1) 2(1) Cl(8) 16(1) 22(1) 19(1) 0(1) 5(1) 4(1) Cl(9) 18(1) 16(1) 19(1) 4(1) 0(1) -2(1) Cl(10) 17(1) 13(1) 35(1) 2(1) -7(1) 0(1) Cl(11) 14(1) 26(1) 23(1) 7(1) 2(1) -2(1) Cl(12) 19(1) 14(1) 18(1) 1(1) -2(1) -3(1) P(1) 12(1) 9(1) 12(1) 0(1) -1(1) -2(1) P(2) 14(1) 11(1) 12(1) 2(1) -3(1) -3(1) P(3) 14(1) 8(1) 10(1) 0(1) -2(1) -2(1) N(1) 16(4) 12(4) 9(4) -3(3) 0(3) -2(3) N(2) 34(5) 8(4) 17(4) 2(3) -6(4) -9(3) N(3) 24(5) 7(4) 18(4) 0(3) -5(3) -7(3)

213

APPENDIX H

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

. [PCl2N]4 HSbCl6

. Table H-1. Crystal data and structure refinement for [PCl2N]4 HSbCl6.

Empirical formula Cl14 H N4 P4 Sb Formula weight 798.98 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Monoclinic Space group P2(1)/c Unit cell dimensions a = 8.0123(6) Å α= 90° b = 25.992(2) Å β = 104.6710(10)° c = 11.4064(9) Å γ = 90° Volume 2298.0(3) Å3 Z 4 Density (calculated) 2.309 Mg/m3 Absorption coefficient 3.104 mm-1 F(000) 1512 Crystal size 0.27 x 0.14 x 0.06 mm3 Theta range for data collection 1.57 to 26.30°. Index ranges -9 ≤ h ≤ 9, -32 ≤ k ≤ 32 -14 ≤ l ≤13 Reflections collected 17686 Independent reflections 4640 [R(int) = 0.0435] Completeness to theta = 26.30° 99.6 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.8357 and 0.4879

214

. Table H-1. Crystal data and structure refinement for [PCl2N]4 HSbCl6 (continued). Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 4640 / 0 / 208 Goodness-of-fit on F2 1.084 Final R indices [I>2sigma(I)] R1 = 0.0346, wR2 = 0.0808 R indices (all data) R1 = 0.0401, wR2 = 0.0837 Largest diff. peak and hole 1.653 and -1.194 e.Å-3

Table H-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]4 HSbCl6. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Sb(1) 3308(1) 4043(1) 2193(1) 16(1) Cl(1) -2033(1) 6796(1) 4650(1) 22(1) Cl(2) -2853(1) 7206(1) 2002(1) 23(1) Cl(3) -1089(1) 5168(1) 2858(1) 27(1) Cl(4) 1476(1) 5811(1) 4869(1) 30(1) Cl(5) 5090(1) 5861(1) 2025(1) 36(1) Cl(6) 1860(2) 6327(1) 229(1) 32(1) Cl(7) 4040(1) 7602(1) 4027(1) 23(1) Cl(8) 1573(1) 7559(1) 1427(1) 25(1) Cl(9) 642(1) 3826(1) 2594(1) 28(1) Cl(10) 1872(1) 4689(1) 788(1) 27(1) Cl(11) 3778(2) 4661(1) 3772(1) 30(1) Cl(12) 4769(1) 3416(1) 3577(1) 22(1) Cl(13) 2758(1) 3451(1) 578(1) 26(1) Cl(14) 5950(1) 4275(1) 1778(1) 33(1) P(1) -1038(1) 6845(1) 3235(1) 15(1) P(2) 261(1) 5808(1) 3129(1) 17(1) P(3) 2852(1) 6181(1) 1957(1) 17(1) P(4) 2190(1) 7183(1) 2995(1) 15(1) N(1) -856(4) 6290(1) 2704(3) 17(1) 215

Table H-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]4 HSbCl6. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. (continued) ______x y z U(eq) ______N(2) 1694(4) 5714(1) 2339(3) 22(1) N(3) 2998(4) 6644(1) 2819(3) 18(1) N(4) 640(4) 7183(1) 3610(3) 16(1)

. Table H-3. Bond lengths [Å] and angles [°] for [PCl2N]4 HSbCl6. ______Sb(1)-Cl(13) 2.3540(10) Sb(1)-Cl(14) 2.3619(11) Sb(1)-Cl(12) 2.3622(10) Sb(1)-Cl(9) 2.3632(10) Sb(1)-Cl(11) 2.3710(10) Sb(1)-Cl(10) 2.4042(10) Cl(1)-P(1) 1.9762(13) Cl(2)-P(1) 1.9839(14) Cl(3)-P(2) 1.9660(14) Cl(4)-P(2) 1.9769(15) Cl(5)-P(3) 1.9595(14) Cl(6)-P(3) 1.9658(15) Cl(7)-P(4) 1.9708(14) Cl(8)-P(4) 1.9874(14) P(1)-N(4) 1.572(3) P(1)-N(1) 1.584(3) P(2)-N(1) 1.545(3) P(2)-N(2) 1.647(3) P(3)-N(3) 1.540(3) P(3)-N(2) 1.651(3) P(4)-N(4) 1.574(3)

216

. Table H-3. Bond lengths [Å] and angles [°] for [PCl2N]4 HSbCl6 (continued). ______P(4)-N(3) 1.578(3) N(2)-H(2) 0.8600

Cl(13)-Sb(1)-Cl(14) 90.54(4) Cl(13)-Sb(1)-Cl(12) 92.05(4) Cl(14)-Sb(1)-Cl(12) 89.57(4) Cl(13)-Sb(1)-Cl(9) 89.78(4) Cl(14)-Sb(1)-Cl(9) 178.91(4) Cl(12)-Sb(1)-Cl(9) 91.45(4) Cl(13)-Sb(1)-Cl(11) 177.68(4) Cl(14)-Sb(1)-Cl(11) 90.08(4) Cl(12)-Sb(1)-Cl(11) 90.18(4) Cl(9)-Sb(1)-Cl(11) 89.55(4) Cl(13)-Sb(1)-Cl(10) 88.33(4) Cl(14)-Sb(1)-Cl(10) 89.41(4) Cl(12)-Sb(1)-Cl(10) 178.92(4) Cl(9)-Sb(1)-Cl(10) 89.56(4) Cl(11)-Sb(1)-Cl(10) 89.44(4) N(4)-P(1)-N(1) 117.23(17) N(4)-P(1)-Cl(1) 107.95(12) N(1)-P(1)-Cl(1) 110.41(13) N(4)-P(1)-Cl(2) 110.57(13) N(1)-P(1)-Cl(2) 106.27(13) Cl(1)-P(1)-Cl(2) 103.57(6) N(1)-P(2)-N(2) 112.16(18) N(1)-P(2)-Cl(3) 112.65(13) N(2)-P(2)-Cl(3) 102.78(13) N(1)-P(2)-Cl(4) 114.23(13) N(2)-P(2)-Cl(4) 108.40(14) Cl(3)-P(2)-Cl(4) 105.80(7) N(3)-P(3)-N(2) 111.24(18) N(3)-P(3)-Cl(5) 112.67(13) N(2)-P(3)-Cl(5) 104.35(13) N(3)-P(3)-Cl(6) 115.82(14) 217

. Table H-3. Bond lengths [Å] and angles [°] for [PCl2N]4 HSbCl6 (continued). ______N(2)-P(3)-Cl(6) 107.10(14) Cl(5)-P(3)-Cl(6) 104.79(7) N(4)-P(4)-N(3) 116.90(17) N(4)-P(4)-Cl(7) 107.02(13) N(3)-P(4)-Cl(7) 107.20(13) N(4)-P(4)-Cl(8) 110.89(13) N(3)-P(4)-Cl(8) 109.81(13) Cl(7)-P(4)-Cl(8) 104.14(6) P(2)-N(1)-P(1) 136.0(2) P(2)-N(2)-P(3) 123.5(2) P(2)-N(2)-H(2) 118.3 P(3)-N(2)-H(2) 118.3 P(3)-N(3)-P(4) 143.9(2) P(1)-N(4)-P(4) 126.6(2) ______Symmetry transformations used to generate equivalent atoms:

. Table H-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]4 HSbCl6. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Sb(1) 15(1) 16(1) 18(1) -2(1) 6(1) 2(1) Cl(1) 20(1) 31(1) 20(1) 0(1) 13(1) -2(1) Cl(2) 22(1) 24(1) 22(1) 2(1) 6(1) 7(1) Cl(3) 21(1) 16(1) 47(1) 1(1) 14(1) -4(1) Cl(4) 29(1) 34(1) 25(1) 6(1) 3(1) 6(1) Cl(5) 14(1) 30(1) 66(1) -13(1) 16(1) 2(1) Cl(6) 41(1) 35(1) 22(1) -5(1) 9(1) -7(1) Cl(7) 18(1) 24(1) 29(1) -7(1) 9(1) -6(1) Cl(8) 27(1) 28(1) 23(1) 8(1) 11(1) 5(1) 218

. Table H-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]4 HSbCl6. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] (continued). ______U11 U22 U33 U23 U13 U12 ______Cl(9) 16(1) 44(1) 24(1) 3(1) 8(1) 2(1) Cl(10) 35(1) 22(1) 21(1) 1(1) 3(1) 7(1) Cl(11) 36(1) 26(1) 24(1) -10(1) -1(1) 9(1) Cl(12) 20(1) 20(1) 25(1) 2(1) 4(1) 3(1) Cl(13) 26(1) 26(1) 24(1) -10(1) 4(1) 6(1) Cl(14) 23(1) 41(1) 39(1) 0(1) 14(1) -9(1) P(1) 14(1) 17(1) 15(1) 1(1) 8(1) 1(1) P(2) 14(1) 15(1) 24(1) 1(1) 8(1) 0(1) P(3) 11(1) 19(1) 23(1) -4(1) 8(1) -1(1) P(4) 15(1) 16(1) 17(1) 0(1) 8(1) -1(1) N(1) 16(2) 18(2) 20(2) 0(1) 8(1) -2(1) N(2) 20(2) 14(2) 36(2) -3(2) 16(2) 1(1) N(3) 16(2) 19(2) 19(2) 0(1) 6(1) -1(1) N(4) 18(2) 17(2) 17(2) -2(1) 9(1) -1(1) ______

Table H-5. Hydrogen coordinates ( x 104) and isotropic displacement . parameters (Å2x 10 3) for [PCl2N]4 HSbCl6. ______x y z U(eq) ______H(2) 1847 5406 2113 26 ______

219

. Table H-6. Hydrogen bonds for [PCl2N]4 HSbCl6 [Å and °]. ______D-H...A d(D-H) d(H...A) d(D...A) <(DHA) ______N(2)-H(2)...Cl(10) 0.86 2.40 3.222(3) 159.3 ______Symmetry transformations used to generate equivalent atoms:

220

APPENDIX I

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

. [PCl2N]5 HSbCl6

. Table I-1. Crystal data and structure refinement for [PCl2N]5 HSbCl6.

Empirical formula Cl16 H N5 P5 Sb Formula weight 914.86 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Monoclinic Space group P2(1)/c Unit cell dimensions a = 12.2164(6) Å α = 90° b = 14.2115(7) Å β = 106.2380(10)° c = 15.7543(8) Å γ = 90° Volume 2626.0(2) Å3 Z 4 Density (calculated) 2.314 Mg/m3 Absorption coefficient 2.988 mm-1 F(000) 1736 Crystal size 0.35 x 0.16 x 0.09 mm3 Theta range for data collection 1.74 to 26.30°. Index ranges -15 ≤ h ≤ 15 -17 ≤ k ≤ 17 -19 ≤ l ≤ 19 Reflections collected 20455 Independent reflections 5316 [R(int) = 0.0395] Completeness to theta = 26.30° 99.7 % Absorption correction Semi-empirical from equivalents

221

. Table I-1. Crystal data and structure refinement for [PCl2N]5 HSbCl6 (continued). Max. and min. transmission 0.7748 and 0.4211 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 5316 / 0 / 244 Goodness-of-fit on F2 1.022 Final R indices [I>2sigma(I)] R1 = 0.0270, wR2 = 0.0546 R indices (all data) R1 = 0.0322, wR2 = 0.0570 Largest diff. peak and hole 0.492 and -0.453 e.Å-3

Table I-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]5 HSbCl6. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Sb(1) 3858(1) 7660(1) 5598(1) 14(1) Cl(1) 10818(1) 7239(1) 3393(1) 37(1) Cl(2) 10435(1) 7235(1) 1341(1) 37(1) Cl(3) 9480(1) 5130(1) 3659(1) 27(1) Cl(4) 7550(1) 4698(1) 1936(1) 26(1) Cl(5) 7938(1) 6151(1) 5039(1) 23(1) Cl(6) 5562(1) 5505(1) 3819(1) 24(1) Cl(7) 7704(1) 8831(1) 4995(1) 25(1) Cl(8) 5610(1) 9293(1) 3369(1) 24(1) Cl(9) 9691(1) 9527(1) 3716(1) 26(1) Cl(10) 7673(1) 9975(1) 2062(1) 24(1) Cl(11) 3721(1) 7424(1) 4066(1) 25(1) Cl(12) 5439(1) 6618(1) 5968(1) 25(1) Cl(13) 2565(1) 6407(1) 5512(1) 29(1) Cl(14) 2314(1) 8720(1) 5193(1) 23(1) Cl(15) 5156(1) 8887(1) 5603(1) 31(1) Cl(16) 3976(1) 7903(1) 7090(1) 36(1) P(1) 9600(1) 7307(1) 2250(1) 18(1) P(2) 8282(1) 5760(1) 2696(1) 16(1) 222

Table I-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]5 HSbCl6. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. (continued) ______x y z U(eq) ______P(3) P(4) 6890(1) 8425(1) 3783(1) 14(1) P(5) 8492(1) 8894(1) 2758(1) 16(1) N(1) 8821(2) 6416(2) 2127(2) 18(1) N(2) 7373(2) 6231(2) 3097(2) 20(1) N(3) 6291(2) 7403(2) 3869(2) 14(1) N(4) 7680(2) 8318(2) 3184(2) 18(1) N(5) 9029(2) 8311(2) 2135(2) 18(1)

. Table I-3. Bond lengths [Å] and angles [°] for [PCl2N]5 HSbCl6. ______Sb(1)-Cl(16) 2.3410(8) Sb(1)-Cl(15) 2.3555(8) Sb(1)-Cl(14) 2.3579(8) Sb(1)-Cl(13) 2.3598(8) Sb(1)-Cl(12) 2.3728(8) Sb(1)-Cl(11) 2.3958(8) Cl(1)-P(1) 1.9912(12) Cl(2)-P(1) 1.9794(12) Cl(3)-P(2) 2.0007(11) Cl(4)-P(2) 1.9782(11) Cl(5)-P(3) 1.9809(11) Cl(6)-P(3) 1.9597(11) Cl(7)-P(4) 1.9775(11) Cl(8)-P(4) 1.9556(11) Cl(9)-P(5) 1.9996(11) Cl(10)-P(5) 1.9863(11) P(1)-N(1) 1.564(3)

223

. Table I-3. Bond lengths [Å] and angles [°] for [PCl2N]5 HSbCl6 (continued). ______P(1)-N(5) 1.576(3) P(2)-N(1) 1.560(3) P(2)-N(2) 1.572(3) P(3)-N(2) 1.520(3) P(3)-N(3) 1.653(2) P(4)-N(4) 1.534(3) P(4)-N(3) 1.648(2) P(5)-N(5) 1.562(3) P(5)-N(4) 1.574(3)

Cl(16)-Sb(1)-Cl(15) 92.01(3) Cl(16)-Sb(1)-Cl(14) 89.82(3) Cl(15)-Sb(1)-Cl(14) 90.87(3) Cl(16)-Sb(1)-Cl(13) 91.17(3) Cl(15)-Sb(1)-Cl(13) 176.78(3) Cl(14)-Sb(1)-Cl(13) 89.67(3) Cl(16)-Sb(1)-Cl(12) 91.58(3) Cl(15)-Sb(1)-Cl(12) 87.74(3) Cl(14)-Sb(1)-Cl(12) 178.06(3) Cl(13)-Sb(1)-Cl(12) 91.64(3) Cl(16)-Sb(1)-Cl(11) 179.36(3) Cl(15)-Sb(1)-Cl(11) 87.97(3) Cl(14)-Sb(1)-Cl(11) 89.54(3) Cl(13)-Sb(1)-Cl(11) 88.86(3) Cl(12)-Sb(1)-Cl(11) 89.06(3) N(1)-P(1)-N(5) 118.97(14) N(1)-P(1)-Cl(2) 106.68(11) N(5)-P(1)-Cl(2) 105.34(10) N(1)-P(1)-Cl(1) 110.36(11) N(5)-P(1)-Cl(1) 110.07(10) Cl(2)-P(1)-Cl(1) 104.21(6) N(1)-P(2)-N(2) 115.79(14) N(1)-P(2)-Cl(4) 107.48(10) N(2)-P(2)-Cl(4) 108.48(11) 224

. Table I-3. Bond lengths [Å] and angles [°] for [PCl2N]5 HSbCl6 (continued). ______N(1)-P(2)-Cl(3) 111.51(10) N(2)-P(2)-Cl(3) 109.55(10) Cl(4)-P(2)-Cl(3) 103.21(5) N(2)-P(3)-N(3) 111.77(14) N(2)-P(3)-Cl(6) 115.01(11) N(3)-P(3)-Cl(6) 103.08(9) N(2)-P(3)-Cl(5) 113.86(11) N(3)-P(3)-Cl(5) 106.68(10) Cl(6)-P(3)-Cl(5) 105.52(5) N(4)-P(4)-N(3) 109.49(13) N(4)-P(4)-Cl(8) 116.11(11) N(3)-P(4)-Cl(8) 104.54(10) N(4)-P(4)-Cl(7) 112.92(11) N(3)-P(4)-Cl(7) 107.03(10) Cl(8)-P(4)-Cl(7) 106.07(5) N(5)-P(5)-N(4) 114.66(14) N(5)-P(5)-Cl(10) 107.40(11) N(4)-P(5)-Cl(10) 110.99(10) N(5)-P(5)-Cl(9) 111.43(10) N(4)-P(5)-Cl(9) 109.09(10) Cl(10)-P(5)-Cl(9) 102.60(5) P(2)-N(1)-P(1) 138.81(17) P(3)-N(2)-P(2) 149.82(18) P(4)-N(3)-P(3) 127.39(16) P(4)-N(4)-P(5) 142.24(18) P(5)-N(5)-P(1) 131.15(17) ______Symmetry transformations used to generate equivalent atoms:

225

. Table I-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]5 HSbCl6. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Sb(1) 15(1) 14(1) 13(1) 1(1) 6(1) 1(1) Cl(1) 23(1) 28(1) 48(1) -6(1) -10(1) 2(1) Cl(2) 43(1) 28(1) 59(1) -7(1) 42(1) -4(1) Cl(3) 26(1) 30(1) 28(1) 9(1) 10(1) 13(1) Cl(4) 32(1) 18(1) 33(1) -9(1) 16(1) -4(1) Cl(5) 26(1) 26(1) 17(1) 1(1) 3(1) 7(1) Cl(6) 23(1) 13(1) 38(1) -1(1) 12(1) -2(1) Cl(7) 34(1) 23(1) 19(1) -6(1) 8(1) -7(1) Cl(8) 25(1) 17(1) 32(1) 6(1) 13(1) 7(1) Cl(9) 22(1) 25(1) 31(1) -7(1) 7(1) -7(1) Cl(10) 26(1) 17(1) 32(1) 6(1) 12(1) 3(1) Cl(11) 19(1) 41(1) 16(1) -5(1) 7(1) 4(1) Cl(12) 18(1) 24(1) 32(1) 8(1) 7(1) 6(1) Cl(13) 20(1) 18(1) 51(1) 6(1) 14(1) -1(1) Cl(14) 27(1) 20(1) 25(1) 4(1) 12(1) 10(1) Cl(15) 34(1) 20(1) 47(1) -9(1) 23(1) -10(1) Cl(16) 34(1) 63(1) 14(1) 0(1) 9(1) 7(1) P(1) 16(1) 18(1) 24(1) -2(1) 10(1) 0(1) P(2) 18(1) 14(1) 18(1) 0(1) 8(1) 3(1) P(3) 16(1) 12(1) 16(1) 0(1) 7(1) 2(1) P(4) 17(1) 11(1) 16(1) -1(1) 8(1) 0(1) P(5) 16(1) 13(1) 21(1) -1(1) 9(1) -2(1) N(1) 19(1) 19(1) 18(1) -1(1) 7(1) -1(1) N(2) 25(2) 20(2) 18(1) 1(1) 9(1) 8(1) N(3) 14(1) 12(1) 20(1) -1(1) 10(1) -1(1) N(4) 22(1) 14(1) 20(1) -2(1) 12(1) -1(1) N(5) 19(1) 18(1) 21(1) -2(1) 10(1) -1(1) ______

226

Table I-5. Hydrogen coordinates ( x 104) and isotropic displacement parameters (Å2x . 10 3) for [PCl2N]5 HSbCl6. ______x y z U(eq) ______H(3) 5611 7423 3926 17 ______

. Table I-6. Hydrogen bonds for [PCl2N]5 HSbCl6 [Å and °]. ______D-H...A d(D-H) d(H...A) d(D...A) <(DHA) ______N(3)-H(3)...Cl(11) 0.86 2.38 3.239(3) 178.0 ______Symmetry transformations used to generate equivalent atoms:

227

APPENDIX J

SUPPLEMENTARY MATERIALS FOR THE X-RAY CRYSTAL STRUCTURE OF

. [PCl2N]6 HSbCl6

. Table J-1. Crystal data and structure refinement for [PCl2N]6 HSbCl6.

Empirical formula Cl18 H N6 P6 Sb Formula weight 1030.74 Temperature 100(2) K Wavelength 0.71073 Å Crystal system Monoclinic Space group P2/c Unit cell dimensions a = 31.268(5) Å α = 90° b = 8.1567(12) Å β = 114.166(3)° c = 25.882(4) Å γ = 90° Volume 6022.5(15) Å3 Z 8 Density (calculated) 2.274 Mg/m3 Absorption coefficient 2.843 mm-1 F(000) 3920 Crystal size 0.16 x 0.09 x 0.05 mm3 Theta range for data collection 1.72 to 25.00°. Index ranges -37 ≤ h ≤ 37 -9 ≤ k ≤9 -30 ≤ l ≤ 21 Reflections collected 93117 Independent reflections 10575 [R(int) = 0.0635] Completeness to theta = 25.00° 99.6 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.8616 and 0.6559 228

. Table J-1. Crystal data and structure refinement for [PCl2N]6 HSbCl6 (continued). Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 10575 / 0 / 559 Goodness-of-fit on F2 1.097 Final R indices [I>2sigma(I)] R1 = 0.2253, wR2 = 0.4799 R indices (all data) R1 = 0.2272, wR2 = 0.4806 Largest diff. peak and hole 10.219 and -4.494 e.Å-3

Table J-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]6 HSbCl6. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______Sb(1) 1054(1) 6017(3) 3894(1) 15(1) Sb(2) 3947(1) 5945(3) 2866(1) 22(1) Cl(1) 1173(4) -1866(13) 77(4) 33(2) Cl(2) 1622(4) 1355(12) 668(5) 36(2) Cl(3) -67(3) -149(16) 922(4) 38(3) Cl(4) 247(4) 3147(14) 614(5) 36(2) Cl(5) 598(3) -170(13) 2489(4) 27(2) Cl(6) 343(3) 3453(12) 2097(4) 24(2) Cl(7) 2095(5) 1970(20) 3670(6) 75(6) Cl(8) 2173(6) 3013(18) 2579(11) 97(8) Cl(9) 2383(5) -2595(17) 3428(5) 49(3) Cl(10) 2639(4) -760(20) 2538(7) 75(6) Cl(11) 1599(6) -4969(15) 1244(7) 64(4) Cl(12) 849(5) -3294(16) 1568(6) 49(3) Cl(13) 4657(3) 3402(12) 1769(4) 25(2) Cl(14) 4395(4) -212(14) 1910(5) 36(2) Cl(15) 2944(5) 1830(20) 1714(8) 70(5) Cl(16) 2805(7) 3174(19) 541(9) 125(11) Cl(17) 2315(4) -494(17) -89(5) 48(3) Cl(18) 2516(5) -2408(15) 1016(5) 44(3) 229

Table J-2. Atomic coordinates ( x 104) and equivalent isotropic displacement . parameters (Å2x 103) for [PCl2N]6 HSbCl6. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor (continued). ______x y z U(eq) ______Cl(19) 3336(9) -4951(19) -375(9) 99(8) Cl(20) 4061(7) -3440(30) 698(9) 94(7) Cl(21) 3436(5) 1407(17) -894(6) 55(3) Cl(22) 3828(5) -1930(17) -1074(6) 51(3) Cl(23) 4741(4) 3026(16) 364(5) 44(3) Cl(24) 5069(4) -218(18) 1011(5) 46(3) Cl(25) 1811(4) 5288(16) 4540(7) 65(5) Cl(26) 879(3) 3191(10) 3716(3) 16(2) Cl(27) 1304(5) 6016(11) 3138(5) 39(3) Cl(28) 1233(4) 8820(11) 4033(4) 30(2) Cl(29) 765(4) 5990(12) 4602(4) 30(2) Cl(30) 293(3) 6703(11) 3226(4) 24(2) Cl(31) 4274(5) 5916(14) 3865(4) 42(3) Cl(32) 4693(3) 6608(11) 2896(5) 26(2) Cl(33) 3786(4) 8748(12) 2854(5) 33(2) Cl(34) 3206(4) 5196(15) 2830(8) 59(4) Cl(35) 4073(4) 3299(17) 2826(3) 50(4) Cl(36) 3645(5) 5979(12) 1850(4) 43(3) P(1) 1233(3) -495(12) 728(4) 20(2) P(2) 506(3) 990(13) 972(4) 19(2) P(3) 794(3) 1707(11) 2161(4) 11(2) P(4) 1809(3) 1623(13) 2858(5) 22(2) P(5) 2097(4) -1615(15) 2670(5) 35(3) P(6) 1490(4) -2980(13) 1613(5) 30(2) P(7) 4202(3) 1614(12) 1395(4) 17(2) P(8) 3177(3) 1584(13) 1112(5) 28(2) P(9) 2844(4) -1539(14) 566(5) 30(2) P(10) 3428(6) -2948(15) 94(6) 43(3) P(11) 3771(4) -561(16) -481(5) 34(3) P(12) 4496(4) 870(17) 493(5) 33(3) 230

. Table J-3. Bond lengths [Å] and angles [°] for [PCl2N]6 HSbCl6. ______Sb(1)-Cl(29) 2.349(10) Sb(1)-Cl(28) 2.347(9) Sb(1)-Cl(30) 2.364(9) Sb(1)-Cl(25) 2.349(11) Sb(1)-Cl(26) 2.370(8) Sb(1)-Cl(27) 2.387(10) Sb(2)-Cl(35) 2.204(15) Sb(2)-Cl(33) 2.339(10) Sb(2)-Cl(34) 2.361(11) Sb(2)-Cl(32) 2.363(9) Sb(2)-Cl(31) 2.361(11) Sb(2)-Cl(36) 2.402(11)

231

. Table J-3. Bond lengths [Å] and angles [°] for [PCl2N]6 HSbCl6 (continued). ______Cl(1)-P(1) 1.966(13) Cl(2)-P(1) 1.983(15) Cl(3)-P(2) 1.974(14) Cl(4)-P(2) 1.999(15) Cl(5)-P(3) 1.966(13) Cl(6)-P(3) 1.964(12) Cl(7)-P(4) 1.937(16) Cl(8)-P(4) 1.944(16) Cl(9)-P(5) 1.961(16) Cl(10)-P(5) 1.988(18) Cl(11)-P(6) 1.981(17) Cl(12)-P(6) 1.978(17) Cl(13)-P(7) 1.991(13) Cl(14)-P(7) 1.924(14) Cl(15)-P(8) 1.982(18) Cl(16)-P(8) 1.953(18) Cl(17)-P(9) 2.010(17) Cl(18)-P(9) 1.972(16) Cl(19)-P(10) 1.985(19) Cl(20)-P(10) 2.00(2) Cl(21)-P(11) 1.975(19) Cl(22)-P(11) 1.963(16) Cl(23)-P(12) 2.000(18) Cl(24)-P(12) 1.957(16) P(1)-N(6) 1.57(3) P(1)-N(1) 1.57(3) P(2)-N(1) 1.54(3) P(2)-N(2) 1.58(3) P(3)-N(2) 1.54(3) P(3)-N(3) 1.64(3) P(4)-N(4) 1.51(3) P(4)-N(3) 1.64(3) P(5)-N(5) 1.57(4) P(5)-N(4) 1.58(3) 232

. Table J-3. Bond lengths [Å] and angles [°] for [PCl2N]6 HSbCl6 (continued). ______P(6)-N(6) 1.58(3) P(6)-N(5) 1.56(4) P(7)-N(12) 1.57(3) P(7)-N(7) 1.60(3) P(8)-N(8) 1.56(3) P(8)-N(7) 1.66(3) P(9)-N(9) 1.51(4) P(9)-N(8) 1.55(3) P(10)-N(10) 1.58(4) P(10)-N(9) 1.66(5) P(11)-N(11) 1.57(4) P(11)-N(10) 1.58(4) P(12)-N(11) 1.56(4) P(12)-N(12) 1.57(3)

Cl(29)-Sb(1)-Cl(28) 91.9(4) Cl(29)-Sb(1)-Cl(30) 88.9(4) Cl(28)-Sb(1)-Cl(30) 89.3(3) Cl(29)-Sb(1)-Cl(25) 92.2(5) Cl(28)-Sb(1)-Cl(25) 91.7(4) Cl(30)-Sb(1)-Cl(25) 178.5(5) Cl(29)-Sb(1)-Cl(26) 90.7(3) Cl(28)-Sb(1)-Cl(26) 177.4(4) Cl(30)-Sb(1)-Cl(26) 90.3(3) Cl(25)-Sb(1)-Cl(26) 88.7(4) Cl(29)-Sb(1)-Cl(27) 176.8(4) Cl(28)-Sb(1)-Cl(27) 89.3(4) Cl(30)-Sb(1)-Cl(27) 88.2(4) Cl(25)-Sb(1)-Cl(27) 90.6(6) Cl(26)-Sb(1)-Cl(27) 88.1(3) Cl(35)-Sb(2)-Cl(33) 176.8(4) Cl(35)-Sb(2)-Cl(34) 86.3(4) Cl(33)-Sb(2)-Cl(34) 92.8(4) Cl(35)-Sb(2)-Cl(32) 91.9(3) 233

. Table J-3. Bond lengths [Å] and angles [°] for [PCl2N]6 HSbCl6 (continued). ______Cl(33)-Sb(2)-Cl(32) 88.9(3) Cl(34)-Sb(2)-Cl(32) 178.2(4) Cl(35)-Sb(2)-Cl(31) 92.0(4) Cl(33)-Sb(2)-Cl(31) 91.0(4) Cl(34)-Sb(2)-Cl(31) 91.0(6) Cl(32)-Sb(2)-Cl(31) 89.3(4) Cl(35)-Sb(2)-Cl(36) 87.6(3) Cl(33)-Sb(2)-Cl(36) 89.3(4) Cl(34)-Sb(2)-Cl(36) 91.1(6) Cl(32)-Sb(2)-Cl(36) 88.5(4) Cl(31)-Sb(2)-Cl(36) 177.8(5) N(6)-P(1)-N(1) 120.8(19) N(6)-P(1)-Cl(1) 110.6(13) N(1)-P(1)-Cl(1) 106.5(13) N(6)-P(1)-Cl(2) 105.3(13) N(1)-P(1)-Cl(2) 109.8(17) Cl(1)-P(1)-Cl(2) 102.3(6) N(1)-P(2)-N(2) 114.9(17) N(1)-P(2)-Cl(3) 111.4(17) N(2)-P(2)-Cl(3) 110.1(13) N(1)-P(2)-Cl(4) 108.4(16) N(2)-P(2)-Cl(4) 109.7(13) Cl(3)-P(2)-Cl(4) 101.4(6) N(2)-P(3)-N(3) 111.3(17) N(2)-P(3)-Cl(6) 116.3(12) N(3)-P(3)-Cl(6) 102.4(12) N(2)-P(3)-Cl(5) 112.6(13) N(3)-P(3)-Cl(5) 108.3(12) Cl(6)-P(3)-Cl(5) 105.1(5) N(4)-P(4)-N(3) 109.8(17) N(4)-P(4)-Cl(7) 115.3(14) N(3)-P(4)-Cl(7) 105.2(15) N(4)-P(4)-Cl(8) 115.0(14) N(3)-P(4)-Cl(8) 107.1(13) 234

. Table J-3. Bond lengths [Å] and angles [°] for [PCl2N]6 HSbCl6 (continued). ______Cl(7)-P(4)-Cl(8) 103.7(11) N(5)-P(5)-N(4) 115.2(18) N(5)-P(5)-Cl(9) 107.1(13) N(4)-P(5)-Cl(9) 109.8(14) N(5)-P(5)-Cl(10) 110.4(16) N(4)-P(5)-Cl(10) 109.7(15) Cl(9)-P(5)-Cl(10) 104.0(8) N(6)-P(6)-N(5) 112.7(19) N(6)-P(6)-Cl(11) 110.8(14) N(5)-P(6)-Cl(11) 106.9(14) N(6)-P(6)-Cl(12) 112.8(14) N(5)-P(6)-Cl(12) 109.5(16) Cl(11)-P(6)-Cl(12) 103.6(8) N(12)-P(7)-N(7) 109.8(18) N(12)-P(7)-Cl(14) 115.1(14) N(7)-P(7)-Cl(14) 108.9(14) N(12)-P(7)-Cl(13) 113.4(14) N(7)-P(7)-Cl(13) 103.1(12) Cl(14)-P(7)-Cl(13) 105.8(6) N(8)-P(8)-N(7) 107.4(16) N(8)-P(8)-Cl(16) 115.8(15) N(7)-P(8)-Cl(16) 105.3(13) N(8)-P(8)-Cl(15) 117.9(13) N(7)-P(8)-Cl(15) 106.0(15) Cl(16)-P(8)-Cl(15) 103.4(12) N(9)-P(9)-N(8) 119(2) N(9)-P(9)-Cl(18) 107.5(17) N(8)-P(9)-Cl(18) 111.7(14) N(9)-P(9)-Cl(17) 107.5(18) N(8)-P(9)-Cl(17) 108.2(14) Cl(18)-P(9)-Cl(17) 101.7(7) N(10)-P(10)-N(9) 113(2) N(10)-P(10)-Cl(19) 113.6(17) N(9)-P(10)-Cl(19) 106.0(13) 235

. Table J-3. Bond lengths [Å] and angles [°] for [PCl2N]6 HSbCl6 (continued). ______N(10)-P(10)-Cl(20) 111.5(18) N(9)-P(10)-Cl(20) 112.2(17) Cl(19)-P(10)-Cl(20) 99.4(12) N(11)-P(11)-N(10) 118(2) N(11)-P(11)-Cl(21) 112.0(18) N(10)-P(11)-Cl(21) 104.1(17) N(11)-P(11)-Cl(22) 104.9(16) N(10)-P(11)-Cl(22) 113.0(18) Cl(21)-P(11)-Cl(22) 103.7(8) N(11)-P(12)-N(12) 116(2) N(11)-P(12)-Cl(24) 107.6(15) N(12)-P(12)-Cl(24) 112.3(14) N(11)-P(12)-Cl(23) 111.3(18) N(12)-P(12)-Cl(23) 107.3(15) Cl(24)-P(12)-Cl(23) 102.0(8) P(2)-N(1)-P(1) 134(2) P(3)-N(2)-P(2) 136(2) P(4)-N(3)-P(3) 127(2) P(4)-N(4)-P(5) 139(2) P(5)-N(5)-P(6) 131(2) P(6)-N(6)-P(1) 136(2) P(7)-N(7)-P(8) 132(2) P(8)-N(8)-P(9) 137(2) P(9)-N(9)-P(10) 126(2) P(10)-N(10)-P(11) 134(3) P(11)-N(11)-P(12) 132(3) P(7)-N(12)-P(12) 135(2) ______Symmetry transformations used to generate equivalent atoms:

236

. Table J-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]6 HSbCl6. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Sb(1) 15(1) 13(1) 12(1) -3(1) 1(1) -2(1) Sb(2) 20(1) 18(1) 33(1) 0(1) 18(1) 4(1) Cl(1) 40(6) 25(5) 35(5) -12(4) 17(5) 6(4) Cl(2) 55(7) 15(5) 34(5) 4(4) 14(5) -3(5) Cl(3) 21(5) 56(7) 28(5) 5(5) 1(4) -20(5) Cl(4) 35(6) 34(6) 33(5) 18(5) 9(5) 16(5) Cl(5) 25(5) 30(5) 28(5) 12(4) 13(4) 2(4) Cl(6) 15(4) 31(5) 24(5) 10(4) 7(4) 12(4) Cl(7) 55(8) 86(11) 35(7) -28(7) -31(6) 41(8) Cl(8) 73(10) 39(8) 230(20) 52(11) 113(14) 8(7) Cl(9) 62(8) 50(7) 34(6) 21(6) 18(6) 23(6) Cl(10) 29(6) 131(15) 81(10) 51(10) 40(7) 45(8) Cl(11) 111(13) 22(6) 75(10) -8(6) 54(10) 7(7) Cl(12) 61(8) 40(7) 64(8) -5(6) 44(7) -22(6) Cl(13) 16(4) 32(5) 28(5) -3(4) 9(4) -6(4) Cl(14) 35(6) 31(6) 33(5) 10(5) 5(4) 3(5) Cl(15) 47(7) 74(10) 121(13) -62(10) 65(9) -35(7) Cl(16) 101(14) 37(8) 126(17) 42(10) -67(13) -36(9) Cl(17) 44(7) 58(8) 27(5) -2(5) -2(5) -20(6) Cl(18) 59(7) 36(6) 50(7) 6(5) 36(6) -6(6) Cl(19) 190(20) 36(8) 115(15) -34(9) 104(16) -56(11) Cl(20) 83(12) 110(15) 101(14) 75(12) 52(11) 67(12) Cl(21) 70(9) 41(7) 59(8) 15(6) 30(7) 12(7) Cl(22) 57(8) 52(8) 59(8) -34(7) 38(7) -14(6) Cl(23) 45(7) 52(7) 41(6) 0(6) 23(5) -17(6) Cl(24) 25(5) 68(8) 51(7) 9(6) 22(5) 17(6) Cl(25) 28(6) 37(7) 78(10) -16(7) -31(6) 9(5) Cl(26) 23(4) 8(4) 18(4) 1(3) 7(3) -4(3) Cl(27) 76(8) 7(4) 68(7) -8(5) 65(7) -9(5) Cl(28) 40(6) 8(4) 30(5) -9(4) 2(4) -12(4) 237

. Table J-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]6 HSbCl6. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] (continued). ______U11 U22 U33 U23 U13 U12 ______Cl(29) 56(6) 19(5) 18(4) -1(4) 20(4) 4(5) Cl(30) 16(4) 19(4) 25(5) 0(4) -4(4) -5(4) Cl(31) 83(9) 27(5) 24(5) -3(4) 30(6) -4(6) Cl(32) 14(4) 19(4) 49(6) 11(4) 16(4) -1(4) Cl(33) 31(5) 17(5) 60(7) -1(5) 28(5) 1(4) Cl(34) 29(6) 33(6) 131(13) 12(8) 48(8) 0(5) Cl(35) 46(6) 102(10) 1(4) -10(5) 8(4) -74(7) Cl(36) 62(8) 14(5) 27(5) 2(4) -7(5) 2(5) P(1) 25(5) 24(5) 11(4) -1(4) 9(4) 10(4) P(2) 15(4) 31(5) 12(4) -1(4) 5(4) 0(4) P(3) 10(4) 13(4) 12(4) -1(3) 6(3) 1(3) P(4) 11(4) 21(5) 35(6) 8(4) 8(4) 4(4) P(5) 48(7) 27(6) 39(6) 11(5) 29(6) 16(5) P(6) 49(7) 19(5) 27(5) -2(4) 20(5) 0(5) P(7) 20(5) 20(5) 16(4) 0(4) 12(4) -1(4) P(8) 15(5) 20(5) 35(6) 9(5) -2(4) -8(4) P(9) 37(6) 27(6) 31(6) -10(5) 19(5) -13(5) P(10) 81(10) 19(6) 46(7) -1(5) 42(7) -2(6) P(11) 37(6) 46(7) 21(5) -13(5) 15(5) -5(5) P(12) 23(5) 50(7) 28(6) 5(5) 12(5) 6(5) N(1) 26(18) 60(20) 19(16) -14(16) 9(14) 28(17) N(2) 34(17) 17(16) 4(13) -17(12) 8(13) 8(13) N(3) 14(15) 1(13) 70(20) 3(15) 21(16) -2(12) N(4) 20(16) 27(18) 22(16) -8(14) 13(14) 6(14) N(5) 60(30) 15(16) 31(18) 27(14) 27(18) 37(17) N(6) 27(17) 11(15) 25(17) 10(13) 6(14) 3(13) N(7) -1(13) 10(15) 50(20) -2(14) -12(13) 8(11) N(8) 16(15) 12(15) 31(18) -2(13) 11(13) -1(12) N(9) 190(50) -19(12) 28(19) -26(13) 50(30) -30(20) N(10) 50(20) 40(20) 50(20) 20(20) 40(20) 0(20) 238

. Table J-4. Anisotropic displacement parameters (Å2x 103) for [PCl2N]6 HSbCl6. The anisotropic displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ] (continued). ______U11 U22 U33 U23 U13 U12 ______N(11) 27(19) 50(30) 30(20) 0(18) -4(16) 19(18) N(12) 23(17) 32(19) 18(16) 1(14) 9(13) 1(14)

. Table J-5. Short Contacts/Hydrogen bonds for [PCl2N]6 HSbCl6 [Å and °]. ______D-H...A d(D-H) d(H...A) d(D...A) <(DHA) ______N(3)-H(3)...Cl(27) 0.88 2.31 3.18(3) 168.2 N(7)-H(7)...Cl(36) 0.88 2.40 3.26(3) 167.5 N(9)-H(9)...Cl(16)#1 0.88 2.45 3.29(3) 159.2 ______Symmetry transformations used to generate equivalent atoms: #1 x,y-1,z

239