Group 13 Organometallic Chemistry: Sterically

Home , Aromaticity, Decamethyldizincocene, Digallane, Grignard reagent, Hapticity, Hyperconjugation

GROUP 13 ORGANOMETALLIC CHEMISTRY:

STERICALLY DEMANDING LIGANDS, METAL-METAL BONDING, AND

METALLOAROMATICY

BRANDON QUILLIAN

(Under the Direction of Gregory H. Robinson)

ABSTRACT

The syntheses and molecular structures of several organometallic group 13 compounds

and complexes are presented herein. The organometallic chemistry of RLi (R = 2,6-(4-t-

BuC6H4)2C6H3-) and R´Li (R´ = 2,6-(4-Me-C6H4)2C6H3-) was examined on group 13 halides to

yield a number of new compounds 1-8: RGaCl2(OEt2) (1), R2GaCl (2), RAlBr2(OEt2) (3),

[RAlCl(OEt2)]2O (4), R3In (5), [RGaCl3][Li(OEt2)2] (6), [RInCl3][Li(OEt2)(THF)] (7), R3In.

Compounds 5 and 8 are notable as the first tris-m-terphenyl-group 13 compounds, while 4 is an interesting oxo-bridged-di(m-terphenyl-aluminum chloride) complex with exceptionally long

AlCl bonds. Sodium metal reduction of 1 provides a rare catenated tri-gallium complex,

[R3Ga3][Na(OEt2)]3 (9).

Additionally, the organometallic chemistry at the group 13group 4 interface was

explored, wherein three new compounds were isolated: Cp2Hf(ER)2 (10, E = Ga; 11, E = In; R =

2,6-(2,4,6-i-Pr3C6H2)2C6H3-) and (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (R = 2,6-(4-t-

BuC6H4)2C6H3-) (12). Compounds 10 and 11 contain the first reported group 13Hf bonds, while

compound 12 is the only compound with gallium engaged in bonding with two zirconium atoms.

Extending the organometallic chemistry of m-terphenyl ligands to the group 4

metallocenes gave the first m-terphenyltitanium(III) radical Cp2TiR´ (13) and the first m-

terphenylzirconocene(IV) compound, Cp2ZrR(Cl) (14) (R = 2,6-(4-t-BuC6H4)2C6H3-).

This research project also involved the study of heterometallic aromaticity, which ultimately produced the first gallepin, bis(gallepin)2·TMEDA (18), by the reaction of 2,2-

dilithio-Z-stilbene(TMEDA)2 (16) and GaCl3. The aromatic nature of the gallepin was evaluated using Nucleus-Independent Chemical Shifts (NICS) and compared to that of borepins.

Additionally, the -donor properties of N-heterocyclic carbenes were evaluated on mesityl-group 13 dihalides, wherein several new carbene-mesityl-group 13 dihalide adducts were prepared: MesGaCl2(:L) (19), MesAlBr2(:L) (20), MesInBr2(:L) (21) (Mes = 2,4,6-Me3C6H2-; :L

= :C 2). Potassium graphite reduction of 19 yielded a rare meso-digallane, [MesGaCl(:L)]2 (22),

with four-coordinate gallium atoms, while reduction with potassium metal unexpectedly

produced an unprecedented neutral Ga6-octahedron cluster, Mes4Ga6(:L)2 (23). NICS calculations were used to support its aromatic properties and compared with that of the

-2 thoroughly studied dianionic hexaborate octahedron, [B6H6] .

In conjunction with these studies a new detailed synthetic protocol to prepare

Arduengo’s carbene (26) from adamantylammonium chloride was established and full single

crystal X-ray structural analysis reported.

INDEX WORDS: alkali metal reduction, aluminum, aromaticity, computations,

cyclopentadienyl, gallepin, gallium, group 4, group 13, hafnium, indium,

main group metals, mesityl, metallocene, metalloaromaticity, metalmetal bonds, m-terphenyl, N-heterocyclic carbene, Nucleus-Independent

Chemical Shifts, organometallic, sterically demanding ligands, titanium, zirconium

GROUP 13 ORGANOMETALLIC CHEMISTRY:

STERICALLY DEMANDING LIGANDS, METAL-METAL BONDING, AND

METALLOAROMATICY

BRANDON QUILLIAN

B.S., Armstrong Atlantic State University, 2003

A Dissertation Submitted to the Graduate Faculty of The University of Georgia in Partial

Fulfillment of the Requirements for the Degree

DOCTOR OF PHILOSOPHY

ATHENS, GEORGIA

2008

Brandon Quillian

GROUP 13 ORGANOMETALLIC CHEMISTRY:

STERICALLY DEMANDING LIGANDS, METAL-METAL BONDING, AND

METALLOAROMATICY

BRANDON QUILLIAN

Major Professor: Gregory H. Robinson

Committee: George F. Majetich Robert S. Phillips

Electronic Version Approved:

Maureen Grasso Dean of the Graduate School The University of Georgia December 2008

DEDICATION

I dedicate this dissertation to my wife, Jennifer Quillian, whose loyalty and sacrifice gave me the strength to carry on in my desperate moments, and to my daughter, Kyleigh, whose smile and laughter consoled me. To those who were not able to witness my greatest accomplishment, my mother and father, Rosa Mae Rucker and Charles Edward Quillian, who gave me this precious life but left this world long before I ever knew them. To my Aunt Fannie whom raised me in my parents’ stead.

ACKNOWLEDGEMENTS

I owe great gratitude to my wife whose perseverance and patience never waned. It is with her support and understanding that I am able to complete The University of Georgia doctoral program in chemistry. Special thanks goes out to my committee members, Dr. George Majetich and Dr. Robert S. Phillips, for your guidance and support. I would also like to thank Dr.

Yuzhong Wang. His ingenuity, knowledge, and guidance were invaluable assets. Last but not least, I would also like to thank Dr. Gregory H. Robinson for giving me the opportunity to become a better scientist and motivation and support throughout my years at UGA.

TABLE OF CONTENTS

Page

ACKNOWLEDGEMENTS...... v

LIST OF TABLES...... viii

LIST OF FIGURES ...... x

CHAPTER

1 INTRODUCTION ...... 1

1.1 Purpose of Study...... 1

1.2 Organometallic Chemistry History and Origins...... 2

1.3 General Organometallic Synthetic Techniques...... 5

1.4 Chemistry and Properties of the Group I, II, 13 Elements...... 6

1.5 Sterically Demanding m-Terphenyl Ligands ...... 19

1.6 Main Group MetalMetal Multiple Bonding...... 22

1.7 Metalloaromaticity...... 33

2 RESULTS AND DISCUSSIONS ...... 39

2.1 Less-sterically Demanding m-TerphenylGroup 13 Complexes...... 39

2.2 Organometallic Group 13Group 4 Complexes ...... 68

2.3 m-Terphenyl Group 4 Metallocenes ...... 81

2.4 Gallepins ...... 89

2.5 Examinations of Carbenes in Group 13 Chemistry...... 104

2.6 A New Synthetic Procedure for Arduengo’s Carbene...... 126

3 Conclusion...... 133

3.1 Concluding Remarks...... 133

4 EXPERIMENTAL...... 137

4.1 General Background ...... 137

4.2 Preparation and Characterization of Starting Materials...... 139

4.3 Syntheses of m-TerphenylGroup 13 Complexes...... 143

4.4 Syntheses of Organometallic Group 13Group 4 Complexes...... 147

4.5 Syntheses of m-Terphenyl Group 4 Metallocenes...... 148

4.6 Syntheses of Gallepins and Precursor...... 149

4.7 Syntheses of CarbeneGroup 13 complexes...... 151

4.8 Synthesis of Arduengo’s Carbene ...... 153

REFERENCES ...... 155

APPENDICES

A CRYSTALLOGRAPHIC DATA...... 172

B RESEARCH PUBLICATIONS ...... 284

vii

LIST OF TABLES

Page

Table 2.1: Selected bond distances [Å] and angles [°] for RGaCl2(OEt2) (1)...... 45

Table 2.2: Selected bond distances [Å] and angles [°] for R2GaCl (2)...... 46

Table 2.3: Selected bond distances [Å] and angles [°] for RAlBr2(OEt2) (3)...... 48

Table 2.4: Selected bond distances [Å] and angles [°] for [RAlCl(OEt2)]2O (4)...... 50

Table 2.5: Selected bond distances [Å] and angles [°] for R3In (5)...... 54

Table 2.6: Selected bond distances [Å] and angles [°] for [RGaCl3][Li(OEt2)2] (6)...... 58

Table 2.7: Selected bond distances [Å] and angles [°] for [RInCl3][Li(OEt2)(THF)] (7)...... 61

Table 2.8: Selected bond distances [Å] and angles [°] for R3In (8)...... 62

Table 2.9: Selected bond distances [Å] and angles [°] for [R3Ga3][Na(OEt2)]3 (9) ...... 66

Table 2.10: Selected bond distances [Å] and angles [°] for Cp2Hf(GaR)2 (10)...... 72

Table 2.11: Selected bond distances [Å] and angles [°] for Cp2Hf(InR)2 (11) ...... 73

Table 2.12: Selected bond distances [Å] and angles [°] for (C10H8)(ZrCp)2(μH)(μCl)(μGaR)

(12) ...... 77

Table 2.13: Selected bond distances [Å] and angles [°] for Cp2TiR(13)...... 85

Table 2.14: Selected bond distances [Å] and angles [°] for Cp2Zr(R)(Cl) (14)...... 88

Table 2.15: Selected bond distances [Å] and angles [°] for 2,2-dilithio-Z-stilbene(TMEDA)2,

(16) ...... 95

Table 2.16: Selected bond distances [Å] and angles [°] for [spiro-[6,6]-bis-

stilbenylgallium][Li(OEt2)] (17) ...... 97

viii

Table 2.17: Selected bond distances [Å] and angles [°] for bis(gallepin)2·TMEDA (18) ...... 101

Table 2.18: NICS, NICS, and NICSzz for seven-membered rings in 18, 18Cl(NMe3), 18Cl,

Gallepin, and Borepin...... 103

Table 2.19: NICS, NICS, and NICSzz for phenyl rings in 18, 18Cl(NMe3), and 18Cl...... 104

Table 2.20: Selected bond distances [Å] and angles [°] for MesGaCl2(:L) (19) ...... 112

Table 2.21: Selected bond distances [Å] and angles [°] for MesAlBr2(:L) (20)...... 113

Table 2.22: Selected bond distances [Å] and angles [°] for [MesInBr2(:L)] (21) ...... 115

Table 2.23: Selected bond distances [Å] and angles [°] for [MesGaCl(:L)]2 (22) ...... 118

Table 2.24: Selected bond distances [Å] and angles [°] for Mes4Ga6(:L)2 (23)...... 122

Table 2.25: Bond order for various bonds are calculated at the PW91PW91/6-31G*//B3LYP/6-

311+G** for Ga6Ph4(:L)2 (:L = :C(HNCH)2) (23a)...... 125

Table 2.26: Selected bond distances [Å] and angles [°] for Arduengo’s carbene (AdL:) (26)...130

LIST OF FIGURES

Page

Figure 1.1: Anion of Zeise’s Salt ...... 3

Figure 1.2: Structure of Ferrocene...... 5

Figure 1.3: Beryllium chain polymer with three-center two-electron bonds ...... 7

Figure 1.4: Electron deficient three-center two-electron bonds of diborane, B2H6 ...... 8

Figure 1.5: Schlenk equilibrium of Grignard reagent in solution...... 10

Figure 1.6: Structure of B12 icosahedral unit...... 12

Figure 1.7: Octahedral AlF3 and AlCl3 dimer ...... 16

Figure 1.8: Structures of [Ph3Al]2 and (Mes)3Al...... 19

Figure 1.9: Structures of common m-terphenyl ligands...... 20

Figure 1.10: Depiction of dissociation/dimerization in solution and solid and donor-acceptor

bonding model for R2Sn=SnR2 (R = -CH(SiMe3)2 ...... 24

Figure 1.11: Molecular structure of tetrakis[bis(trimethylsilyl)methyl]dialane, R2AlAlR2 ...... 26

Figure 1.12: Bonding model for the heavier main group metallynes ...... 27

Figure 1.13: Schematic depiction and single crystal X-ray structure of gallyne, Na2[RGaGaR]

2,6-(2,4,6-i-Pr3C6H2)2C6H3-)...... 29

Figure 1.14: Structures of [Mg(Priso)]2 and [Mg(Nacnac)]2 ...... 31

Figure 1.15: Structures of compounds containing group 12 metalmetal bonds...... 32

Figure 1.16: Schematic depiction of CbFe(CO)3...... 34

Figure 1.17: Single crystal X-ray structure of Na[GaR]3 ...... 34

2- Figure 1.18: Orbital description of [H3Ga3] ...... 35

Figure1.19: Structure of K2[Ga4R2] ( R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-)...... 36

Figure 1.20: Structure of Na2[Ga4R4](THF)2 (R = t-Bu3Si-)...... 37

Figure 2.1: Structures of 2,6-(4-t-BuC6H4)2C6H3- (R) and 2,6-(4-Me-C6H4)2C6H3- (R´) ...... 40

Figure 2.2: Molecular structure of RGaCl2(OEt2) (1)...... 45

Figure 2.3: Molecular structure of R2GaCl (2)...... 46

Figure 2.4: Molecular structure of RAlBr2(OEt2) (3) ...... 48

Figure 2.5: Molecular structure of [RAlCl(OEt2)]2O (4) ...... 50

Figure 2.6 Table for torsion angles (deg) and Newman projection of 4: “looking down the

AlOAl vector”...... 51

Figure 2.7: “No bond/double bond” resonance model for -halomethyl ethers ...... 52

Figure 2.8: The “no-bond/double-bond” resonance model for 4...... 53

Figure 2.9: Molecular structure of R3In (5)...... 54

Figure 2.10: Molecular structure of [RGaCl3][Li(OEt2)2] (6) ...... 58

Figure 2.11: Molecular structure of [RInCl3][Li(OEt2)(THF)] (7)...... 61

Figure 2.12: Molecular structure of R3In (8)...... 62

Figure 2.13: Space filling model of R3In (8) ...... 63

Figure 2.14: Molecular structure of [R3Ga3][Na3(OEt)3] (9)...... 66

Figure 2.15: Molecular structure of Cp2Hf(GaR)2 (10) ...... 72

Figure 2.16: Molecular structure of Cp2Hf(InR)2 (11)...... 73

Figure 2.17: DFT level calculated HOMO, HOMO-1 and HOM-2 orbitals for Cp2M(ER)2

compounds...... 74

Figure 2.18: Molecular structure of (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) ...... 77

Figure 2.19: PW91PW91/LANL2DZ optimized structure of (C10H8)(CpZr)2(μ-H)(μ-Cl)(μ-GaR)

(R = 2,6-Me2C6H3) (12a)...... 78

Figure 2.20: ChemDraw representation of 12 depicting with bridging and localized chloride and

hydride ligands...... 79

Figure 2.21: Space filling model of (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) ...... 80

Figure 2.22: Molecular structure of Cp2TiR (13)...... 85

Figure 2.23: Molecular structure of Cp2Zr(R)(Cl) (14) ...... 88

Figure 2.24: Tropylium ion localized cation and delocalized cation, borepin, and gallepin ...... 90

Figure 2.25: Molecular structure of 2,2-dibromo-Z-stilbene (15) ...... 92

Figure 2.26: Molecular structure of 2,2-dilithio-Z-stilbene(TMEDA)2 (16)...... 95

Figure 2.27: Molecular structure of [spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17)...... 97

Figure 2.28: Molecular structure of bis(gallepin)2·TMEDA, (18)...... 100

Figure 2.29: B3LYP/LANL2DZ optimized geometries of 18Cl(NMe3) and 18Cl ...... 102

Figure 2.30: General carbene shown as singlet state and Arduengo’s carbene...... 104

Figure 2.31: General N-heterocyclic carbene depicting electron with drawing effects of the -

nitrogen and -donation into the empty p-orbital of carbenic carbon...... 105

Figure 2.32: Molecular structure of MesGaCl2(:L) (19) ...... 112

Figure 2.33: Molecular structure of MesAlBr2(:L) (20)...... 113

Figure 2.34: Molecular structure of MesInBr2(:L) (21) ...... 115

Figure 2.35: A view of the unit cell of [MesInBr2(:L)][InBr3(:L)] (21)...... 116

Figure 2.36: Molecular structure of [MesGaCl(:L)]2 (22) ...... 118

Figure 2.37: Molecular structure of Mes4Ga6(:L)2 (23)...... 122

xii

Figure 2.38: The B3LYP/6-311+G** optimized geometry of Ga6Ph4(:L)2 (:L = :C(HNCH)2)

(23a) ...... 125

Figure 2.39: Molecular structure of glyoxal-bis-(1-adamantyl)imine (24)...... 128

Figure 2.40: Molecular structure of Arduengo’s carbene (AdL:) (26) ...... 130

Figure 2.41: A view of the unit cell of Arduengo’s carbene (AdL:) (26) ...... 131

xiii

CHAPTER 1

INTRODUCTION

1.1 Purpose of Study

All of chemistry is centered around the chemical bond. Probably the least well-studied bonding scenario, however, is the metalmetal bond. In fact metalmetal bonding was once considered impossible curiosities. The organometallic community has embraced this challenge and has put forth a large number of reports that has expanded the scope and knowledge of our understanding of such bonding. Regarding main group metalmetal bonding, these investigations were not seriously embarked upon until fairly recently. Hence, this field of organometallic chemistry remains relatively underdeveloped. We continue in this quest to obtain organometallic compounds containing main group metalmetal bonds so as to provide new insights into the fundamental principles of structure and bonding.

Another aspect of this research project focuses on aromaticity. This theory, once reserved for carbon, has transcended its founding principles and no more is the prerequisites of 4n+2 - electrons and a planar cyclic structure mandatory. Indeed, aromaticity is far more intricate than previously suggested and has been observed in three-dimensions, 4n -electron systems, and metallic species. The latter of these has been a concentrate in organometallic chemistry. In particular, reports of compounds containing all metallic aromatic rings (metalloaromatic) have rejuvenated the discussion of aromaticity. Although some exquisite examples of organometallic compounds exhibiting metalloaromaticity have been published, this genre of chemistry is still

severely underdeveloped. Hence, an alternative purpose of this study was to prepare

organometallic compounds that exhibit metalloaromaticity and heterometallic aromaticity (cyclic compounds with at least one metallic atom that display aromatic properties).

1.2 Organometallic Chemistry History and Origins

Organometallic chemistry is the combination of two disparate chemical disciplinestraditional organic chemistry and inorganic chemistry. Surprisingly, organometallic chemistry is a relatively quiescent topic in both organic and inorganic textbooks, being mentioned with a fleeting paragraph. This is appalling due to the ubiquitous nature of organometallic compounds in both disciplines.

Compounds possessing at least one direct carbonmetal bond are considered organometallic. The ubiquitous Grignard reagents are quintessential examples. Because metalloids (B, Si, Ge, P, As, Se, Te) are not strictly metallic, categorizing compounds with

carbonmetalloid bonds as either organometallic or organic may seem ambiguous. This dilemma

may be elegantly resolved by J. S. Thayer’s interpretation, which proposed that a compound

containing a metalloid less electronegative than carbon may be considered organometallic.1

The origins of organometallic chemistry can be traced back to an organoarsenic

compound prepared by Cadet de Gassicourt in 1760 known as “Cadet’s fuming arsenical liquid”,

1 which was later identified as (CH3)4As2 by Robert Bunsen (1837-1843). These accounts have

been summarized in a recent essay.2 In 1827 W. C. Zeise reported another organometallic

complex, K[C2H4PtCl3]•H2O (Zeise’s salt), which is considered by most to be the first organometallic compound (arsenic is considered a metalloid). The structure and bonding of

Zeise’s salt was steeped in controversy and would not be resolved until its single crystal X-ray

structure was reported 85 years later,3 which revealed an ethylene molecule -bound to a Pt atom in a side-on fashion (Figure 1.1).4 Zeise’s salt is notable as the first report of an organic molecule bonded to a metal through -electrons and brought about the concept of hapticity.5

- Cl Cl H Pt H H Cl

Figure 1.1. Anion of Zeise’s Salt

The focus of organometallic chemistry began to shift to the main group elements with the

6 isolation of the first organozinc compound, diethylzinc ((C2H5)2Zn), by Edward Frankland in

1849 (Though zinc, a group 12 element, formally resides in the d-block section of the periodic table, its chemistry is more similar to that of the group II elements. With a filled d-orbital (d10s2 electronic configuration), the two s-electrons dominate its chemistry. In fact, zinc behaves more like beryllium than any of the transition metals). Not only were organozinc compounds notable as the first organo-main group compounds but they were also the first to have appreciable synthetic utility. The zenith of organozinc chemistry did not last for long because in 1900 Victor

Grignard discovered organomagnesium compounds, which quickly replaced organozinc compounds in synthetic protocols due to facile preparation, ease of handling, and reaction efficacy.

During the period of 1900-1950, there was a lull in the development of organometallic chemistry until a seemingly accidental discovery sparked the birth of modern-day organometallic

chemistry. In 1951 Kealy and Pauson attempted to synthesize fulvalene (H4C5=C5H4) by reaction

of cyclopentadienyl magnesium bromide, CpMgBr (Cp = C5H5) with anhydrous iron(III)

chloride (Eq.1.1). However, the reaction did not produce the desired fulvalene, but instead gave

7 an orange air-stable compound with a molecular formula of C10H10Fe. It is noteworthy that in

1952 Miller and co-workers independently synthesized the identical compound by reaction of

cyclopentadiene with metallic iron in the presence of metal oxides (Eq. 1.2).8

X fulvalene (1.1) 3 MgBr + FeCl3

(C5H5)2Fe + 1/2C10H10 + 3 MgBrCl

Metal oxide 2 + Fe (C5H5)2Fe + H2 (1.2)

The structural assignment of C10H10Fe was quite a quandary as spectroscopic data did correlate with the initial assessment, wherein it was thought that two Cp ligands were -bound to

an iron center. In 1952, two groups, Wilkinson et al.9 and Fischer et al.10,11, independently

postulated that the Cp ligands were bound to the iron atom in a novel -fashion, wherein the

cyclic array of p-orbitals on the Cp ligands overlapped the d-orbitals of the metal to form a

“sandwiched” iron complex. This “sandwich” description was confirmed by spectroscopic

evidence, i.e. only one CH stretch in the infrared spectrum, diamagnetism, and an effectively

zero dipole moment. Its structure was unambiguously characterized by single crystal X-ray

crystallographic analysis in 1956 and confirmed its structure.12 This renowned compound is of course ferrocene (Figure 1.2). It is interesting to note that the term “ferrocene” replaced the formal name of dicyclopentadienyliron because Friedel-Crafts acylations of this compound were readily achieved. This line of reasoning mimicked the vernacular of benzene, wherein “ene” evokes aromaticity.

Organometallic chemistry has blossomed into a flourishing division of chemistry today that has its own set of journals, books, and monograms. It is an interdisciplinary study that is encountered in organic, inorganic, computational, physical, and biological chemistries. The storied history of organometallic chemistry is quite unique with its periods of inactivity and moments of eureka, however today it is well established. It is safe to say that new insights into organometallic chemistry will be revealed in the impending future.

Figure 1.2. Structure of Ferrocene

1.3 General Organometallic Synthetic Techniques

Organometallic chemistry is not much different from other synthetic chemical

disciplines. The major difference is dealing with air- and moisture-sensitive materials, which

require some special techniques. In general, however, organometallic compounds are prepared

by three common methods: 1) reaction of metal or metal derivative with an organic reagent, 2)

oxidations/reductions, and 3) metathesis reactions of nucleophilic organic reagents with metal

halides.

Due the inherent instability of metalcarbon bonds, organometallic species readily

hydrolyze, thus special synthetic measures known as Schlenk techniques13 have been developed

to strictly exclude air and moisture. Bench-top reactions are performed on a double manifold

system (Schlenk line) equipped with purified nitrogen or argon gas and vacuum pump. Glassware

is cleaned with great scrutiny and stored and dried in a 180°C oven, while solvents are rigorously

dried, freshly distilled, and degassed prior to use. Because glassware is stored in air, all reaction

vessels are repeatedly purged and flushed with argon. To avoid exposure to air, dripping funnels,

syringes, or a long flexible tubes known as cannulas are commonly used to transfer reagents.

In conjunction with Schlenk line techniques a dry box is commonly utilized to weigh

reactants, conduct experiments that require solid reagent transfer, store air- and moisture-

sensitive reagents, and prepare samples for characterization.

The most practical means to unambiguously characterized organometallic compounds is

by single crystal X-ray crystallographic analysis, however, 1H- 13C-nuclear magnetic resonance

spectroscopy (NMR), infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-vis),

electron spin resonance spectroscopy (ESR), elemental analysis (EA), and mass spectrometry

(MS) can be indispensable aids. All characterization techniques require that the sample be

prepared expeditiously in sealed sampling vessels to avoid decomposition.

1.4 Chemistry and Properties of the Group I, II, 13 Elements

The group I, II, and 13 elements were routinely employed in this research project. The

purpose of this section is to provide some background on the fundamental properties of these elements and insights into their chemistry.

Group 13 organometallic chemistry would be difficult to pursue without utilizing its

lower valent neighborsthe group I and II elements. These elements not only provide a method

to form carbonmetal bonds, by which the very nomenclature of organometallic is derived, but they also provide excellent reducing agents. All of the group I and II elements are metals (alkali metals and alkaline earth metals, respectively) and primarily form ionic complexes. However, beryllium, the smallest of the group II elements, is somewhat of an anomaly. Large charge density resides about beryllium and contributes significantly to its peculiar behavior. For example, beryllium chemistry is dominated by covalent bonds and has a common coordination number of four, whereas magnesium and calcium are commonly hexa-coordinate, and strontium and barium can even eclipse this high-coordination number. Moreover, beryllium compounds routinely form polymeric electron-deficient bonds (Figure 1.3) termed “three-centered two- electron bonds” (3c-2e bonds).

R R R Be Be Be Be R R R

R = Halide or -CH3

Figure 1.3. Beryllium chain polymer showing three-center two-electron bonds

Lipscomb rationalized 3c-2e bonds in his seminal studies of borohydrides.14,15 Diborane,

B2H6, is a quintessential example. It consists of four terminal BH bonds and two bridging 3c-2e

BHB bonds, which have adequate orbital overlap between the two boron sp3-hybridized orbitals and spherical bridging hydrogen s-orbitals (Fig. 1.4). The terminal BH bond distances

(1.192 Å) are considerably shorter than the bridging BHB bonds (1.329 Å), evidence that the

terminal covalent bonds are much stronger.16 This bonding scenario has also been observed in

metallic clusters, organometallic species, and metal halides.17-19

s-orbital sp3-orbital H H H B B H H H

Figure 1.4. Electron deficient three-center two-electron bonds of diborane, B2H6

The ability to form highly reactive carbon-metal bonds is perhaps the most remarkable shared characteristic between the group I and II elements. In particular, organolithiums or organomagnesiums are routinely used to synthesize organo-group 13 halides (RmEXn, R = alkyl,

aryl, E = BTl, X = halide, m = 1-3, n = 3 - m) via metathesis reactions with group 13 salts, EX3

(Eq. 1.3), which serve as intermediates for more intricate chemistry.

RLi + EX3 REX2 + LiX (1.3)

RMgX + EX3 REX2 + MgX2

Organolithium compounds, RLi, may be prepared by reaction of two equivalents of

lithium metal with an organic halide (RX) (Eq. 1.4), by deprotonation of organic residues with

highly reactive alkyllithium compounds such as n-butyllithium (n-BuLi) (Eq. 1.5), or by metal-

halogen exchange reaction between organic halides (RX) (Eq. 1.6).

RX + 2Li RLi + LiX (1.4)

RLi + R'H RH + R'Li (1.5)

RLi + R'X RX + R'Li (1.6)

RX + Mg RMgX (1.7)

Organomagnesium halides (Grignard reagents), RMgX, are prepared by reaction of

magnesium metal with an organic halide, wherein magnesium metal oxidatively inserts into the

CX bond (Eq. 1.7). Of special note, a thin layer of magnesium oxide must be removed from the metal in order to initiate the reaction by a process known as “activation”. Sonication, agitation, and/or catalyst (1,2-dibromoethane) are several techniques used to activate magnesium metal.

Once the metal is activated, the reaction is generally highly exothermic as long as air and moisture is excluded at all times.

Organomagnesium compounds are frequently written as RMgX, and for most purposes this representation is suffice, however in solution a complex equilibrium (Schlenk equilibrium) is a more accurate depiction (Figure 1.5).20

RX + Mg

X R RMg MgR RMgX XMg MgR R2Mg + MgX2 X X

X + - RMg + RMgX2 Mg MgR2 X

Figure 1.5 Equilibrium of Grignard reagent in solution

Organolithiums are more reactive than their magnesium counterparts, yet they are easily handled and tend to avoid side reactions such as non-specific CH activation, which is often observed for Grignard reagents. Many organomagnesium and organolithium reagents are commercially available, and if stored properly, they are stable for months. The choice to use either organolithium or magnesium reagents depends on ease of preparation, commercial availability, specific reaction conditions, and substrates involved.

Alkali or alkaline earth metal reductions of organo-group 13 halides have been established as an effective strategy to obtain compounds with metalmetal bonds. A detailed

discussion of this chemistry is provided in the proceeding chapters. Due to more robust reactivity

and lower reduction potentials, alkali metal reductions are cited more often than their alkaline

earth metal counterparts in these procedures because the third ionization energies of the group 13

elements are very large (2704-3659 kJ/mol). The group I metals (alkali metals) more readily

donate their electron and as the column descends relative reactivity increases due to poorer

internal shielding of the d-orbitals; hence rubidium and cesium are extremely reactive metals.

Counterintuitively, lithium is the least reactive but has the lowest reduction potential of the group

(Caution: group I metals are highly sensitive to water and moisture, and in some instances even explosive, thus great care should always be practiced when handling them).

A commonly employed reducing agent in organometallic synthetic procedures is potassium graphite (KC8), which is part of a larger class of molecules called inclusion compounds or “lamellar” compounds. Potassium graphite may be conveniently prepared by melting potassium metal with graphite (Eq. 1.8), wherein the potassium metal readily inserts into the well-separated (3.35 Å) sheets of graphite.

K + 8 C (graphite) KC8 (1.8)

In some instances, reductions of organometallic halides with potassium graphite have shown able to elicit group 13 metal-metal bonding, where the otherwise sodium or potassium metal reductions could not (vide infra). This is primarily because metalmetal bonds are kinetically stabilized, thus the reduction rate of the organometallic substrate is vitally important.

Because these reductions are heterogeneous, the large surface area of potassium graphite allows for excellent interaction with the solubilized organometallic substrate. On the other hand, sodium or potassium metal is usually divided by hand into tiny pieces and is extremely difficult to approach the size of potassium graphite. Of course, this lowers the rate of reduction because of less interaction between metal and the solubilized substrate.

It has been demonstrated that the metal reductant may also influence the structure and bonding of complexes containing group 13 metalmetal bonds. For example, reduction of

RGaCl2 (R2,6-(2,4,6-i-Pr3C6H2)2C6H3-) with sodium metal provides a galliumgallium triple

bond (digallyne) Na2[RGaGaR however when potassium metal is employed a tetragallium

22 dianion, K2[Ga4R2], with a planar cyclic Ga4 metallic core is formed (vide infra). The size of

the alkali metal reductant was cited as critical to the different formations, as they interact

strongly with the group 13 elements. Interestingly, computations have proposed that lithium can

interact with gallium more strongly than either sodium or potassium.23 In some instances, however, differences in reducing metal provide essentially identical final products. This is observed when RGaCl2 (R = 2,6-Mes2C6H3, Mes =2,4,6-Me3C6H2-) is reduced with either

24 25 sodium or potassium, which forms isoelectronic cyclotrigallenes, M2[GaR]3 (M = Na, K, Mes

= 2,4,6-Me3C6H2-), regardless of which metal is used.

1.4.2 The Group 13 Elements

With exception of boron, a metalloid, the group 13 elements are metals. Boron, the

lightest of the group 13 elements, is a black solid with a metallic luster and consisting of a

number of allotropes. Most notable is the naturally occurring B12-icosahedron (Fig.1.6). Boron is very distinct from the rest of the group 13 elements being more similar to silicon. This disparate nature of boron from its group 13 members and close similarity to silicon is demonstrated by comparing their electronegativity values (Pauling electronegativity; B = 2.040, Si = 1.900; Al =

1.61, Ga = 1.81, In = 1.78,), atomic radii (B = 0.85 Å Si = 1.10 Å; Al = 1.25, Ga, 1.30, In, 1.81), and the fact that both boron and silicon have semiconductor properties.

= B

Figure 1.6. Structure of B12 icosahedral unit

Aluminum, the second lightest group 13 element, is a strong, silvery-white metal that is

prized for its light weight. Though aluminum is quite plentiful, it was once arduously difficult to

extract from its ubiquitous ores and once more treasured than gold. Today aluminum is produced

on an industrial scale by the Hall-Héroult process,26 whereby alumina is dissolved in molten

cryolite and subjected to electrolysis. A pound of aluminum today cost about a dollar, whereas

gold is now traded at $800/oz.

Gallium is a silvery, low-melting metal (30°C) that expands on solidification. Similar to

mercury, it is a liquid just above room temperature and commonly used in high-temperature thermometers, however, gallium is not as toxic as mercury. Interestingly, the trend of increasing atomic radius with column descent is at odds when transitioning from Al (1.48 Å) to Ga (1.26

Å).

Indium and thallium are also lowmeting metals, though not to the extent of gallium, and

are easily malleable. Interestingly, indium is slightly radioactive, decaying with -emission,

however its half-life is more that 400 trillion years, thus it is relatively safe to handle. Thallium,

on the other hand, is a highly toxic element that was commonly used in rat poisons. This practice

has been discontinued in the United States.

The chemistry of the group 13 elements varies from element to element, principally due

to internal electronic configurations. For instance, boron and aluminum contains only s and p

orbitals, while indium, gallium, and thallium contains a full compliment of d10 electrons.

Thallium also includes a filled f14 orbital, which contributes significantly to its anomalous

chemistry. There are, however, prevailing common characteristic between these elements. With

three valance electrons, the +3 oxidation state is favored for this group. Lower oxidation states

(+1 and +2) can also be obtained at very low temperatures but have a propensity to

disproportionate to metal and the +3 oxidation state with increasing temperature (Eq. 1.9).

Utilizing sterically demanding ligands has been an effective method to stabilize low-valent group

13 organometallic compounds (vide infra). Of the lower oxidation states, the +1 oxidation state

is more often observed, being somewhat common for In and readily obtained for Tl. In fact, Tl+3

is oxidizing due in part to the “inert pair” effect, which occurs when a pair of electrons in the low

energy s-orbital becomes difficult to ionize. This effect is more prevalent for the heavier p-block

main group elements (Sn, Pb, Sb, Bi, Te).

3 MX MX + M 3 (1.9)

Perhaps the most dominant feature of group 13 chemistry is the highly Lewis acidic

nature of the elements. Because trivalent group 13 species are commonly sp2-hybridized with trigonal planar geometry, the unoccupied p-orbital makes them powerful Lewis acids that readily accepts electron density from Lewis bases to obtain closed shelled, four-coordinate, Lewis acid/base adducts, R3MLB. Coordination numbers of three and four are common for the group

13 elements, however higher-orders can be obtained, especially for the heavier members with d-

shell (Ga, In, Tl) valances.

1.4.3 The Group 13 Halides

The group 13 metal(III) halides, MX3, are important starting materials for the synthesis of

organo-group 13 halides, RMX2 or R2MX, which frequently serve as intermediates in a number

of synthetic protocols. All of the group 13 trihalides, MX3, are known except for TlI3, and their geometries vary with element, halide, and physical state. All boron halides, BX3, are trivalent

monomers, due to effective overlap of the non-bonding electrons on the halides with the empty

p-orbital of boron. As a consequence, the acidity of the boron atom gradually increases as orbital

overlap lessens. Thus, BF3 is less acidic than BI3. Conversely, an opposite trend is observed for the heavier EX3 (E = Al, Ga, In, Tl, X = halide) members, which preclude np -bonding,

wherein Lewis acidity drops off as the electronegativity of the halide diminishes. Interestingly,

aluminum(III) fluoride (AlF3) and aluminum(III) chloride (AlCl3) (Fig.1.7) have polymeric

octahedral structures (AX6) with infinite lattices in the solid state, however in the liquid or gas

states aluminum chloride exist as a dimer, Al2Cl6, with two AlClAl bridges (Fig. 1.7). AlBr3

and AlI3 share this dimeric nature in all states. Surprisingly, although gallium is only one period

below aluminum, its halides are monomers (GaX3), similar to those of boron. Indium(III)

halides, InX3 (X = F, Cl, Br), are more similar in structure to AlCl3, but the structure of InI3 is

unknown. As alluded to earlier, Tl is considerably different from the metallic group 13 members

and this is reflected in its halides, as Tl(III) halides, TlX3 (X = Cl, Br), are fairly unstable and

readily disproportionate to a mixture salts Tl(TlCl4), Tl(TlX6),Tl2Cl3. TlF3 is known to have a 9-

coordinate tricapped trigonal prismatic structure.

The group 13 metal monohalides, MX, are also useful regents in synthetic protocols. In

particular, Linti27 and Schnöckel28 have employed putative in situ generated “GaI” and “AlI” to

synthesize a number of high-order group 13 clusters. The group 13 monohalides are known for

all of the metals, however TlX is by far more stable. Both InX and TlX are commercially

available.

Cl F F Cl Cl Al Al Al

F F Cl Cl Cl F

Figure 1.7. AlF6 octahedron and AlCl3 dimer

1.4.4 Simple Organometallic Chemistry of the Group 13 Elements

The organometallic chemistry of the group 13 elements dates back to the middle 18th

century with the isolation of the sesquihalides of aluminum, which are mixtures of mono- and di-

ethylaluminum halides, (C2H5)AlI2 and (C2H5)2AlI. Today group 13 organometallic chemistry is

quite developed, thus all aspects cannot be addressed; however, a discussion on the extensively

studied simple R3M compounds (R = alkyl, aryl; M = group 13 metal) provides some seminal

discoveries of this chemistry.

All R3M (R = alkyl) are pyrophoric liquids with the exception of trimethylindium, Me3In,

which forms colorless crystals.29 They are well-established and some are even commercially

available. While most of the heavier trialky-group 13 compounds (Ga, In, Tl) are monomeric in

solution, trialkylindium and thallium compounds form tetrameric aggregates in the solid state.

30 Me3Al and Et3Al, on the other hand, are dimeric, [AlMe3]2, and contain bridging alkyl 3c-2e

bonds between two aluminum atoms. When first hypothesized, the 3c-2e bonding model for

31,32 AlMe3 was highly controversial, however spectroscopic evidence supports its dimeric nature.

In particular, this was corroborated by 1H NMR experiments, in which the single broad signal

that was observed for Me3Al at room temperature separated into two distinct signals at -70˚C,

evidence of two different chemical environments. The single crystal X-ray structure of trimethylaluminum unambiguously confirms its structure.33

Due to their Lewis acidity, trialkylaluminum compounds are very useful as co-catalysts in Ziegler-Natta olefin polymerizations. For this reason, they are produce in large-scale by a process known as hydroalumination, which involves reaction of aluminum metal with terminal olefins in the presence of hydrogen gas at elevated temperatures and pressures (Eq. 1.10).

2 Al + 3H2 + 6 RCH=CH2 2 (RCH2CH2)3Al (1.10)

Trialkylaluminum compounds also have utility as alkylating agents, usually transferring only one alkyl group. Ligand transfer is also a convenient method to covert trialkylgalliums and indiums into mono- and di-alkyl-group 13 halides, R2EX and REX2, respectively, by

30 disproportionation reactions with EX3 (E = group 13 metal, X = halides) (Eq. 1.11).

2 R3E + EX3 3 R2EX or (1.11) R E + 2 EX 3 REX 3 3 2

The organometallic chemistry of gallium is not so dissimilar from that of aluminum.

Perhaps, the most interesting difference is that organogallium chemistry usually precludes 3c-2e bonding that is commonly observer in organoaluminum chemistry. Gallium can be perfectly stable with only a sextet of electrons. The first organogallium compounds, Et3Ga and

Et3Ga(OEt2), were prepared by Dennis in 1932 and spawned the genesis of the organogallium

34 chemistry. While triethylgallium, Et3Ga, was prepared by a redox reaction of diethyl mercury,

Et2Hg, with metallic gallium (Eq. 1.12), triethylgallium etherate, Et3Ga(OEt2) was obtained by a metathesis reaction of ethylmagnesium bromide, EtMgBr, with GaBr3 in diethyl ether

(Eq.1.13).35

3 HgEt + 2 Ga 165°C, 200 hr 2 Et Ga + 3 Hg 2 3 (1.12)

Et2O, -196°C Et Ga Et O + 3 MgBr 3 EtMgBr + GaBr3 3 • 2 2 (1.13)

The early endeavors into trialkyl-group 13 chemistry led to the inevitable investigations

36-39 of triaryl-group 13 compounds, Ar3E. Largely these compounds are monomeric, and unlike their trialkyl-group 13 counterparts, donor molecules are seldom incorporated into their structures due to the favorable steric and electronic effects afforded by the aryl substituents.

Steric factors in particular have profound implications on bonding and structure in triarylaluminum compounds. For instance, triphenylaluminum, Al2Ph6, (Fig. 1.8) is dimeric with

two Al–C–Al bridges about tetrahedral aluminum centers, whereas trimesitylaluminum, Mes3Al

(Mes = 2,4,6-Me3C6H2), (Fig. 1.8) is monomeric with the three ligands configured in a propeller-

like arrangement about a trigonal planar aluminum atom. Steric considerations have now been

well-recognized in low-valent group 13 organometallic chemistry. Indeed, it has been

demonstrated that minor changes to ligand steric effects can have a great impact on structure and

bonding.

C H C6H5 6 5 Al Al Al C6H5 C6H5

Figure 1. 8. Structures of [Ph3Al]2 and (Mes)3Al

1.5 Sterically Demanding m-Terphenyl Ligands

Sterically demanding ligands have played a prominent role in the development of group

13 organometallic chemistry. The innate ability to kinetically stabilize low-valent main group

species by inhibiting decomposition pathways is a desirable characteristic that is often utilized to

obtain compounds with main group metalmetal bonds. The m-terphenyl class of ligands is

prolific in this regard. Hart and coworkers developed a one-pot synthesis of m-terphenyls by reaction of 2,6-dibromoiodobenzene with an arylmagnesium halide, ArMgX (Eq. 1.14).40

Although this reaction protocol provided m-terphenyls in good yield, the laborious preparation of

the starting materials, primarily 2,6-dibromoiodobenzene, presented a less than desirable reaction

scheme. Hart later published an improved synthesis for m-terphenyls by reaction of n-BuLi with

1,3-dichlorobenzene followed by addition of an aryl magnesium halide reagent. Quenching the reaction with iodine affords the 1-iodo-m-terphenyl derivative in good yield (Eq 1.15).41 This

simple preparative procedure, however, is limited to symmetrical m-terphenyls.

I I

Br Br Ar Ar + ArMgX (1.14)

LI MgX I

Cl Cl Cl Cl Aryl Aryl Ar Ar n-BuLi 3 ArMgX I2

(1.5)

This protocol can be extended to an array of aryl groups but largely those with ortho substitution have been chosen to study in low-valent main group organometallic chemistry. The steric properties of these ligands are decidedly dominated by the degree substitution at this position, and it appears that the isopropyl functionality is optimal for steric loading. It has been shown that introduction of more bulky tert-butyl groups creates exceedingly close CH contacts with the metal centers,42 causing excessive steric pressure that can often lead to undesirable side

reactions such alkyl group transfer to the metal center or insertion reactions via CH bond

activation.43 Three notable m-terphenyl ligands are shown in Figure 1.9.

2,6-Mes2C6H3- 2,6-(2,6-i-Pr3C6H2)2C6H3- 2,6-(2,4,6-i-Pr3C6H2)2C6H3-

Figure 1. 9. Structures of three common m-terphenyl ligands

The degree of substitution on m-terphenyl ligands has profound implications on the structure and bonding of the respective organometallic complexes. Even the simple bis(m-

terphenyl)gallium halides, R2GaX (R = m-terphenyl; X = halide), are dramatically affected by

the steric properties of the ligand. For example, the coordination environment around the gallium

center in (2,6-Ph2C6H3)2GaI is distorted trigonal planar with a CGaC bond angle of

44 134.3(3)°, while the more sterically imposing (2,6-Mes2C6H3)2GaX (Mes = 2,4,6-Me3C6H2-, X

= Cl,45 Br46) compounds assume a “T-shaped” gallium coordination sphere with CGaC bond

angles of 153.5(5)°. This bond angle is nearly 20° larger than the corresponding bond angle in

(2,6-Ph2C6H3)2GaI and a substantial larger (33.5°) than the 120° anticipated for trigonal planar

geometry. It is noteworthy that the sterically more imposing bis(m-terphenyl)gallium halide (2,6-

(2,4,6-i-Pr3C6H2)2C6H3)2GaX (X = halide), with isopropyl functionally at the ortho-position of

outer phenyl rings, has not been isolated. The added steric encumbrance may be too great to

accommodate two of these large ligands about the gallium atom.

The substituents at the paraposition of the flanking phenyl rings also play a significant

role in the structure and bonding. Power and coworkers demonstrated that when ArLi (Ar = 2,6-

47 (2,4,6-i-Pr3C6H2)2C6H3-) is allowed to react with In(I)Br a monovalent indium diyl, ArIn:, is

produced in both solid and liquid states; however, utilizing a modified ligand, wherein the para- isopropyl group is absent from the flanking phenyl rings, the indium diyls are permitted to dimerize in the solid state to produce a compound with a formal indiumindium double bond

48 (diindane), Ar´InInAr´, (Ar´ = 2,6-(2,6-i-Pr2C6H2)2C6H3-). Substituents on the central phenyl

ring may also alter structure and bonding in compounds containing main group metalmetal

bonds. For example, the SnSn bond distance (2.6675(4) Å) in Ar´SnSnAr´49 (Ar´ = 2,6-(2,6-i-

˝ ˝ ˝ Pr2C6H2)2C6H3-) is 0.4 Å shorter than that in the analogous compound, Ar SnSnAr (Ar = 2,6-

50 (2,6-i-Pr2C6H2)2-4-SiMe3-C6H2-), with the ligand having a trimethylsilyl group at the para-

position of the central phenyl ring. The trans-bent core of Ar´SnSnAr´49 also had a significantly

larger SnSnC bond angle (125.24(7)°) when compared to that in Ar˝SnSnAr˝ (99.25(14)°). The

authors attributed these structural changes to electronic differences between the two ligands. In

effect, addition of the SiMe3 ligand to the central phenyl ring changes the electronic character of

the Sn atoms enough that the small energy difference between two structures is surmounted.

Thus, not only is the degree of steric (i.e. Me, i-Pr, t-Bu) substitution important, but also its

location on the m-terphenyl ligand, as steric and electronic properties of the ligand are ultimately

transferred to the metal and contributes to structure and bonding.

1.6 Main Group MetalMetal Multiple Bonding

Compounds with CC single and multiple bonds are ubiquitous, and the literature, in general, is replete with reports of compounds containing homonuclear and heteronuclear multiple bonds of the second row elements (C, N, O). In contrast, the development of the analogous chemistry of the heavier main group elements has only emerged over the last 30 years. Perhaps the early prognostications by Pitzer51,52 and Mulliken22 which predicted, “…elements whose

principle quantum number is equal or greater than three were not capable of forming multiple

bonds…”, further discouraged investigations into this realm of chemistry. Notwithstanding this

bleak prospect for main group metalmetal multiple bonding, in 1976 Lappert and coworkers isolated and unambiguously characterized a compound containing the first Sn=Sn double bond

53 (distannene), R2Sn=SnR2 (R = CH(SiMe3)2) and proved that the heavier main group congeners

were indeed capable of multiple bonding. The structure of the first distannene contained two

pyramidal Sn atoms of trans-bent geometry with a Sn=Sn bond distance of 2.768(1) Å, which

was shorter than that found in elemental tin (2.80 Å). The key to the stabilization of this intriguing compound was the considerable steric bulk and attractive electronic properties inherent to the ligands.

Following this seminal discovery the strategy of employing sterically demanding ligands to stabilize compounds containing main group metalmetal multiple bonds was promptly embraced. Early investigations in this regard were focused on the heavier main group metalmetal double bonds (dimetallenes) of the group 14 elements, R2E=ER2 (R = alkyl or aryl;

E = Si,54,55 Ge,56 Sn,53 Pb57), and group 15 elements, RE=ER (R = alkyl, aryl; E = As,58-60

60,61 60,62 63 48 Sb, Bi ). The group 13 congeners RE=ER (E = Ga, In; R = 2,6-(2,6-i-Pr2C6H3)2C6H3-), have only recently been experimentally realized. The / bonding mode for ethene can be applied well for the group 15 dimetallenes; however, less so as the column descends because the

-bond gradually weakens due to enhanced s-character. The group 15 dimetallenes begin to resemble more of a EE single bond with n-electron pairs localized at the metal centers.

Computational studies have suggested that group 15 dimetallenes possess stronger -bonding but weaker -bonding when compared to their group 14 congeners. 64 The smaller size of pnictogens and interatomic electronic repulsion of the lone pairs found in group 15 dimetallenes may contribute to this affect. 64

The bonding model for the group 1365,66 and 1464 dimetallenes is fundamentally different from that of the second row elements, which is clearly demonstrated by their trans-bent geometries. This variance from the first row elements is attributed to the lowering of the -* energy gap as the column descends, which permits orbital mixing. As the metals acquire more s- character and concomitant formation of nonbonding electron pairs, the pp -bond weakens. In essence, the group 13 and 14 dimetallenes are formed in the solid state by weak association of

two RM: units through donor-acceptor bonds. If the trend for carbon is referenced, the group 13

and 14 metallic double bonds are comparatively weaker and longer than expected as a

consequence of this unique bonding mode. As an illustrative example of this weak association,

distannene is a dimer of two R2Sn: units in the solid state, wherein a lone pair of electrons

2 residing in the sp -hybridized orbital of a discrete R2Sn: unit donates into the empty p-orbital of

another R2Sn: moiety (Fig. 1.10), however in solution, the weakly held dimers readily dissociate into stannanediyl monomers (R2Sn:). This dimerization is responsible for the trans-bent

geometries of the dimetallenes. The out-of-plane angles (° EER) become more

perpendicular, with respect to the E=E bond, as the column descends and has become somewhat

of a visual indicator of EE bond strength. Large out-of–plane angles correlates to higher bond

dissociation energies.

R Sn 5sp2 R R R R Sn R Sn Sn R R Sn R R

Solution Solid state

Figure 1.10 Depiction of dissociation/dimerization in solution and solid states and donor- acceptor bonding model for R2Sn=SnR2 (R = -CH(SiMe3)2)

1.6.2 Group 13 MetalMetal Bonds

Reports of compounds possessing group 13 double bonds, RE=ER (E = Ga,63 In;48 R =

2,6-(2,6-i-Pr2C6H3)2C6H3-), have only been established this decade. In fact, the aluminum

analogue remains elusive. However, it is worth mentioning that the product of a suspected [2+4]

Diels-Alder cycloaddition reaction between toluene and a dialuminene intermediate, RAl=AlR,

suggests a transient Al=Al double bond.67

The lag in development of the organometallic chemistry involving group 13 multiple bonds is not surprising since the first purported compound containing an AlAl single bond was

first reported in 1976,68 yet this account was dubious as it lacked vital single crystal X-ray

structural analysis. It would be twelve years later (1988) that Uhl prepared the first structurally

characterized compound containing a group 13 metalmetal bond,

tetrakis[bis(trimethylsilyl)methyl]dialane, R2AlAlR2 (R = -CH(SiMe3)2) (AlAl = 2.660(1) Å)

69 (Fig. 1.11), by potassium reduction of R2AlCl (Eq. 1.16 ). Soon thereafter, Uhl also prepared the analogous digallane, R2GaGaR2 (R = -CH(SiMe3)2) (GaGa =2.541(1) Å), by allowing RLi

70 to react with Ga2Br4•(dioxane)2 (Eq. 1.17). This simplistic approach was ingenious, as the

staring material, Ga2Br4•(dioxane)2, already contained a GaGa single bond, and the task simply

became addition of the ligands while maintaining the labile bond. Utilizing a similar protocol,

71 Uhl also synthesized the first diindane, R2InInR2 (R = -CH(SiMe3)2), and thus completed the

series of compounds containing the first group 13 EE single bonds (Eq. 1.18). Notably, all of

2 these compounds were isostructural, consisting of a planar C2E-EC2 core of two sp hybridized group 13 metals bound together. The two proximal empty p-orbitals on the group 13 metals can

·- 72 readily accept an additional electron from lithium to give radical anions [R2EER2] (E = Ga,

Al73) with short EE bond distances (Al = 2.53 Å; Ga = 2.40 Å) and bond orders of 1.5.

2 K R R 2 R2AlCl Al Al -2 KCl R R (1.16) R = -CH(SiMe3)2

R R Ga Br (dioxane) + 4 RLi Ga Ga 2 4• 2 -4 LiBr R R (1.17) R = -CH(SiMe3)2

R R In2Br4•(TMEDA)2 + 4 RLi In In -4 LiBr (1.18) R = -CH(SiMe3)2 R R

Figure 1.11. Molecular structure of tetrakis[bis(trimethylsilyl)methyl]dialane, R2AlAlR2

1.6.3 Main Group Metal Triple Bonds

The more ambitious task of synthesizing heavier main group triple bonds (dimetallynes),

R-EE-R, was pursued utilizing an array of sterically imposing ligands. From the onset, the classification and description of dimetallynes was difficult to assess because the structure and bonding of these heavier alkyne analogues is significantly different from that of carbon triple bonds. Whereas a classical /2 model adequately depicts multiple bonding for the first row elements, the bonding mode of the heavier group 14 alkyne analogues departs from this

conventional description. Instead, the triple bonds of heavier analogues are essentially identical

to that put forth for the distannene (two donor-acceptor bonds) (Fig. 1.10), but are augmented by

an additional pp -bond (Fig. 1.12). This bonding arrangement results in a “slipped” or “trans- bent” triple bond, as opposed to linear, and has been a common structural manifestation for all dimetallynes isolated to date (Ga,21 Al,74 Si,75 Ge76,77, Sn,49 Pb78).

donor-acceptor bond

R R

-bond EE R R donor-acceptor bond

Figure 1.12. Bonding model for the heavier main group metallynes

One example of the perplexity of assigning “triple bond” nomenclature to the heavier

78 analogues is easily found in the description of RPbPbR (R = 2,6-(2,6-i-Pr2C6H3)2C6H3-), which

was stated as “the first stable heavier group 14 element analogue of an alkyne”. Indeed, it was

the first report of a group 14 compound with a general formula of REER, however the Pb–Pb

bond distance (3.1881(1) Å) was significantly longer than the average PbPb (diplumbanes)

79 80 single bond distances (2.85 Å av.) found in Ph3Pb–PbPh3 and Ph3Pb–Pb(p-tol)3. Subsequent

computational studies on model diplumbylenes, RPbPbR (R = H, Ar), suggested that the dihedral

angle of the trans-bent Pb–Pb–C core (~90°) was a result of a non-bonding pair of electrons on

each lead atom. Thus, the claimed experimental PbPb triple bond was merely a novel Pb–Pb

single bond.81

This discussion would be remiss if the gallium alkyne analogue were not discussed

because the synthesis and isolation of the first digallyne, Na2[RGaGaR] (R = 2,6-(2,4,6-i-

21 82,83 Pr3C6H2)2C6H3-) (Fig. 1.13), by the Robinson group, was a monumental, yet provocative,

achievement. As with all new concepts that challenge conventional wisdom, the nature of the

Ga–Ga bond sparked a spirited debate that was contested84-86 and defended66,87-91 with volleying

reports. Objections to the formulation of a triple bond were founded on fundamental issues

regarding structure and bonding, i.e. the Ga–Ga bond distance of 2.319(3) Å, the trans-bent C–

Ga–Ga–C array, and the Wiberg Bond Index (WBI) bond order of 1.13. Although the Ga–Ga

bond distance is the shortest on record, it is only marginally shorter than Ga–Ga single bond

distances reported for other relevant compounds (2.395-2.778 Å).22,70,72,92-94 Notwithstanding, the

Ga–Ga bond distance of the digallyne is shorter than twice its covalent radii (2.42 Å).

Furthermore, it seems that the implicit presumption that increased bond multiplicity correlates to

a net decrease in bond length is a concept that is reserved for carbon. For example, the Pb=Pb

57 double bond distance (3.0515(3) Å) in RPb=PbR (R = 2,4,6-i-Pr3C6H2-) is more than 0.2 Å

79 longer that the average Pb–Pb single bond distances (2.85 Å) in Ph3Pb–PbPh3 and Ph3Pb–Pb(p-

80 tol)3. The longer Pb=Pb bond distance was never a factor to challenge its validity as a double

bond. Moreover, E=E bond distances in the heavier group 14 dimetallenes, R2E=ER2 (E = Si, Ge,

64 Sn), are only marginally shorter than those of their respective dimetallanes R3E-ER3.

The trans-bent geometry of the C–Ga–Ga–C core seems to be a futile objection to the formulation of the gallyne; as previously discussed, this seems to be a common geometry for all

of the heavier main group alkyne analogues. Finally, pertaining to the WBI values for the gallyne

(1.13), it is granted that the GaGa triple bond in the digallyne is weaker because of the unique

bonding mode for the dimetallynes, however it should also be considered that WBI bond order

values are commonly smaller than the formal bond order values. Even for simple and well-

established compounds such as HF and H2O, the WBI bond orders are significantly lower than

1.0 (0.67 and 0.76, respectively). Clearly, these compounds contain “true” single bonds!

Ga Ga Na

Figure 1.13. Schematic depiction and single crystal X-ray structure of gallyne, Na2[RGaGaR]

(R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-)

To date, the chemistry community has accepted the triple bond formulation for the

digallyne. The recently reported isoelectronic/isostructural aluminum analogue of the gallyne by the Power group,74 in which the term “dialuminyne” was used to evoke the connotation of an

aluminumaluminum triple bond, strengthens the argument for the gallyne triple bond

formulation. If the “dialuminyne” is regarded an aluminum–aluminum triple bond, shouldn’t the

digallyne garner the same consideration?

1.6.2 Group II and 12 MetalMetal Bonding

Recently there has been a surge of activity in the quest to synthesize compounds with

group II and group 12 metalmetal bonds. The major obstacle in producing compounds with

metalmetal bonds of these divalent elements is stabilizing the +1 oxidation state and protecting

the coordination spheres from donor molecules. Although the +1 oxidation state for mercury is

well known, as well as reports of Hg–Hg bonds,95,96 there has been a paucity of reports of

compounds containing Zn or Cd metalmetal bonds.97,98 Furthermore, reports of compounds

with group II (Be, Mg, Ca, Sr, Ba) metal–metal bonds were nonexistent. Fortunately, recently a

few unambiguously characterized compounds containing group II and group 12 metalmetal bonds have been reported.

Organomagnesium chemistry has been extensively studied; hence it is surprising that a molecular species containing an Mg–Mg bond was not isolated earlier. Although it has been proposed that dimagnesium complexes RMgMgX (R = CH3, H; X = halide) with “strong”

MgMg bonds are generated in production of Grignard regents99 and that a dimagnesium

species, HMgMgH, is detected in matrices;100 an unambiguously characterized compound

containing a Mg–Mg bond remained more of an curiosity than reality for sometime. Ultimately,

Jones101 and coworkers synthesized the first stable dimagnesium compounds containing

metalmetal bonds using bulky guanidinate and -diketiminate ligands to protect the labile bond,

- [Mg(Priso)]2 (Priso = [(Ar)NC(N-i-Pr)N(AR)] ; Ar = 2,6-i-Pr2C6H3-), and [Mg(nacnac)]2

i 101 (Nacnac = [{(2,6-Pr 2C6H3)N(Me)C}2CH)] (Figure 1.14). Surprisingly, the Mg–Mg bond

distances in these compounds (2.8508(12) and 2.8457(8) Å, respectively) are longer than the sum

of two magnesium covalent radii (2.72 Å), yet are shorter than those of diatomic or elemental

magnesium. These compounds are the only specimens that contain group II metalmetal bonds.

Ar Ar Ar Ar

N N N N Mg Mg Mg Mg

N N N N

Ar Ar Ar Ar

Ar = 2,6-i-Pr2C6H3

Figure 1.14. Structures of [Mg(Priso)]2 and [Mg(Nacnac)]2

Carmona and coworker’s unexpected isolation of decamethyldizincocene, Zn2(5-

C5Me5)2, by reaction of Zn(C5Me5)2 with diethyl zinc, Zn(C2H5)2, (Eq. 1.19) was the first structurally characterized compound containing a ZnZn bond.102 The structure of this fascinating compound displayed two pentamethylzincocene fragments, Zn(5-C5Me), bound together by a linear Zn–Zn bond. Indeed, the most striking feature of this compound was the short Zn–Zn bond distance (2.305(3) Å), which was shorter than twice the Pauling’s single bond metallic radius (2.50 Å).

Zn Zn + + Zn(C2H5)2 Zn (1.19) Zn

C2H5

This landmark discovery set the stage for further investigations into synthesizing compounds with group 12 metal–metal bonds. Our group synthesized the second compound containing a ZnZn bond using a bulky -diketiminate ligand, RZnZnR (R= [{(2,6-

i 103 Pr 2C6H3)N(Me)C}2CH]), which had a ZnZn bond distance of 2.3586(7) Å. This distance is

slightly longer than that in Zn2(5-C5Me5)2 (2.305(3) Å), but still shorter than the sum of two Zn

covalent radii. The pursuit for compounds containing group 12 metal–metal bonds was

complemented with the isolation of the first structurally characterized compound containing a

104 Cd–Cd bond, RCd–CdR (R = 2,6-(2,6-i-Pr2C6H3)2C6H3-), followed by preparations of isostructural Zn and Hg analogues (Figure 1.15).105

Ar Ar Ar Ar

N N

Zn Zn M M

N N

Ar Ar Ar Ar

Ar = 2,6-(i-Pr-C6H3)2C6H3 M = Zn, Cd, Hg; Ar = 2,6-(i-Pr-C6H3)2C6H3

Figure 1.15. Structures of compounds containing group 12 metalmetal bonds

To end, initially it was deemed that metalmetal bonding for the heavier main group

elements was impossible; today however, by utilizing sterically demanding ligands with

attractive steric and electronic effects, molecular species containing such bonds are known from

group 2 to group 15 elements. Furthermore, the structure and bonding of the heavier main group

multiple bonded species deviates greatly from that of carbon multiple bonds. In fact, one is

drawn to the reality that the characteristics of carbon multiple bonding are an exception rather

than the rule. Finally, with the recently synthesized compounds containing MgMg bonds, the

continuation for the molecular species containing main group metalmetal bonds will

undoubtedly be focused on the remainder of group II elements.

1.7 Metalloaromaticity

Aromaticity has been traditionally described as a number of Hückel’s 4n + 2 -electrons

delocalized in a planar cyclic structure that results in enhance stabilization energy greater than

that of conjugation alone. It is encountered early on in chemical scholarship. To avoid confusion

the concept is routinely explained in simple terms and enforced with strict stipulations that act as

litmus tests to readily recognize aromaticity. This early training is further augmented with

unambiguous examples of aromatic compounds, which are carbon-based molecules with

inclusion of O, S, and N. Though this early instruction may serve well to simplify aromatic

characteristics, in reality subtle intricacies of aromaticity can be difficult to assess with these

rudimentary principles. In some instances, novel compounds exhibiting unusual aromatic

properties can be difficult to appraise based solely on physical, structural, and chemical

properties. Because aromaticity cannot be measured quantitatively, new theoretical techniques

such as Nucleus-independent Chemical Shifts (NICS),106-108 which utilizes geometrical sensitive

magnetic criteria, have been developed to further aid in deciphering aromaticity.

Indeed, aromaticity has transcended its initial boundaries of carbon and its neighbors and has been observed in compounds containing transition and main group metals. The first of these metallic aromatic compounds can be traced to the study of the enhanced stability of the

109 antiaromatic cyclobutadiene ligand (Cb) in CbFe(CO)3 (Fig.1.16) by Bursten, which ultimately proposed that traditional aromatic behavior is induced into the Cb ring by an FeC4H4

-interaction. The term metalloaromaticity was used to describe the unique and unprecedented

bonding scenario.

Fe C C O C O

Figure 1.16. Schematic depiction of CbFe(CO)3

The literal connotation of metalloaromaticitywherein all-metallic ring systems exhibit

aromatic behaviorwas first experimentally realized by the Robinson group with the synthesis

24 25 and isolation of the cyclotrigallenes, M2[GaR]3 (M = Na, K, R = 2,6-Mes2C6H3, Mes = 2,4,6-

46 Me3C6H2-) by alkali metal reduction of RGaCl2. The cyclotrigallenes consist of an essentially

equilateral triangular arrangement of three trigonal planar gallium atoms (GaGaGa bond angle

~ 60°) with two alkali metal cations resting above and below the Ga3-ring. The GaGa bond

distance in the cyclotrigallenes average 2.43 Å and is slightly shorter than an average GaGa

single bond distance (~2.5 Å) (Fig. 1.17).

- 2 e Ga Ga

Figure 1.17. Schematic depiction and single crystal X-ray structure of tricyclogallene, Na[GaR]3

+ The cyclotrigallenes are comparable to the isoelectronic cyclopropenium ion, R3C3 , in

+ that both are 2-electron aromatic speciesalbeit in a different mode. While R3C3 affords delocalization of two -electrons of an olefin segment through an carbocation, the tricyclogallenes gain aromaticity by delocalizing two electrons donated from the alkali metals into the cyclic array of empty p-orbitals on the three proximal gallium atoms. This affords an - electron cloud above and below the Ga3-ring (Fig. 1.18). It should be noted that the alkali metals are not close enough to engage in metalmetal bonding with the gallium atoms, but they are integrally assimilated in the structure of the tricyclogallenes. Moreover, the characteristic features of aromaticity were adequately displayed in the cyclotrigallenes, i.e. bond length equalization, aromatic stabilization energies, and magnetic susceptibility exaltations.

Computational studies also supported the existence of a ring current through NICS calculations

2- 106 (-45.4 ppm) on a model cyclotrigallene, [H3Ga3] .

It should also be noted that the isoelectronic tricycloaluminene, [R3Al3]Na2 (R = 2,6-

Mes2C6H3), has also been synthesized. Its structure and bonding parallels that of the cyclotrigallenes.74

2- Figure 1.18. Orbital description of [H3Ga3] showing HOMO -electron cloud above and below the Ga3-ring

Aromaticity can be very subtle as traditional constraints become evermore irrelevant. A

prime example of this is apparent in the unsuspecting aromatic species, K2[Ga4R2] (R = 2,6-

22 (2,4,6-i-Pr3C6H2)2C6H3) (Fig. 1.19), which contained an essentially square planar Ga4-ring

comprised of two “naked” gallium atoms with a singlet pair of electrons and two of them ligated.

This compound also possessed two potassium atoms that resided above and below the Ga4 plane,

slightly favoring the opposing ligand substituted gallium atoms. The GaGa bond distances were

virtually equivalent at 2.46 Å.

Unfortunately, the purpose of this report was to denounce the formulation of the gallyne

by showing that the alkali metals contribute significantly to its structure and bonding and

disregarded a more important property of this compoundmetalloaromaticity. The aromatic

properties of this compounds were not reported until three years after its initial report.65 Quite surprisingly, quantum chemical calculations showed that this compound was not only a 2- aromatic system, but simultaneously it was also -antiaromatic in terms of electron counting

(eight total electrons).110 This uniquely stunning result further signified the conflicting nature of

aromaticity.

Ga Ga

2 e-

Ga Ga

2- Figure 1.19. Structure of [Ga4R2] ( R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-)

The dianionic tetragallium compound, Na2[Ga4R4](THF)2 (R = t-Bu3Si-) (Fig. 2.20), is perhaps the unlikeliest compound to exhibit metalloaromaticity.111 Several structural features of

this compound are counterintuitive to aromaticity, i.e., the Ga4 ring is puckered in a butterfly

conformation and the GaGa bond distances differ in an alternating fashion (2.4238(6) and

2.416(1) Å), yet the authors deduced it to be a 2-electron aromatic system. The non-planarity of

the ring was dismissed as a consequence of ligand steric interactions of the supersilyl groups,

while the alternating GaGa bond lengths were viewed as menial distortions. They, however, described the compound by two different modes of bonding. In one description, the two Na

atoms donate their one electron entirely to the Ga4 cluster, resulting in the prescribed 2-electron

aromatic system. In an alternate formulation, the two Na atoms transfer their electron only

partially and become an integral part of the structure by GaNa metalmetal bonding, resulting

is a 10-electron Ga4Na2 cluster that is consistent with Wade-Mingos 2n +2 cluster electron rules.

112,113 As of yet, there has not been a careful theoretical investigation on the aromatic properties

of this compound to discern rather which of the two different bonding possibilities are correct.

THF

R Na Ga Ga R Ga Ga R Na R THF

R = t-Bu Si- 3

Figure 1.20. Structure of Na2[Ga4R4](THF)2 (R = t-Bu3Si-)

In conclusion, group 13 compounds that display metalloaromaticity are few, yet comprise of interesting and varied structural arrays. The prevailing characteristic has been electron donation from alkali metals that allow for delocalization through a cyclic arrangement of the proximal group 13 unoccupied p-orbitals. Furthermore, these compounds have shown that aromaticity can be unexpected, and may be overlooked if not thoroughly examined.

CHAPTER 2

RESULTS AND DISCUSSIONS

2.1 Syntheses and Structures of Less-sterically Demanding m-TerphenylGroup 13 Complexes

2.1.1 Introduction

The organometallic chemistry of low-valent group 13 species has long been a focus for this laboratory. In particular, reductions of m-terphenyl-group 13 halides, REX2 (R = m-

terphenyl, E = group 13 element, X = halide) have been an effective strategy to synthesize

compounds containing metalmetal bonds. Studies have shown that by manipulating the

electronic and steric properties of the m-terphenyl ligand, the structure and bonding of a given organometallic compound or complex may be dramatically altered. Since the bulkiest of these ligands, 2,6-Mes2C6H3-, 2,6-(2,6-i-Pr2C6H2)2C6H3-, 2,6-(2,4,6-i-Pr3C6H2)2C6H3-, have been

extensively examined for their ability to kinetically stabilize complexes possessing main group

metalmetal bonds, we set out to gain further insight into the significance of ortho-substitution,

or the lack thereof, on the flanking phenyl rings.

Two m-terphenyl ligands lacking ortho-substituents on the flanking phenyl rings, 2,6-(4-

t-BuC6H4)2C6H3- (R) and 2,6-(4-Me-C6H4)2C6H3- (R´), were examined on group 13 halides to

ascertain the stability and structural properties of their respective ligand–metal complexes and

later evaluated on their ability to stabilize group 13 metalmetal bonds. Structural

representations of R and R´ are shown in Figure 2.1. From a steric aspect, these ligands are

deceptively similar, however electronically they differ significantly due to varied contributions

of -donor inductive effects afforded by the para-substituents, primarily due to enhanced

hyperconjugation of the t-butyl group versus methyl.

R R 2,6-(4-Me-C H ) C H - 2,6-(4-t-BuC6H4)2C6H3- 6 4 2 6 3

Figure 2.1. Structures of 2,6-(4-t-BuC6H4)2C6H3- (R), and 2,6-(4-Me-C6H4)2C6H3- (R´)

The respective 1-iodo-m-terphenyl derivatives (RI or R´I) are synthesized in good yield by literature protocol (65-85%) (Refer to section 1.5 (Eq. 1.15) for a detailed scheme).41 A

modified lithiation procedure in hexane employing n-BuLi at -78°C affords the lithium

analogues (RLi or R´Li) as white to off-white powders in excellent yield (96-98%) (Eq. 2.1). The

lithium derivatives are sparingly soluble in diethyl ether, hexanes, and toluene, and form thick

slurries at -78°C. Though they are highly soluble in tetrahydrofuran at room temperature, fine

black particulate matter is formed on standing for short periods, suggesting some degree of

decomposition. However, placing the lithium derivatives at -78°C before addition of THF

appears to lessen decomposition.

RI or RI n-BuLi, Hexane, RLi or RLi -78°C (2.1)

2.1.2 Syntheses of 2,6-Di(4-t-butylpheny)phenyl-Group 13 Complexes

Reactions of RLi (R = 2,6-(4-t-BuC6H4)2C6H3-) with group 13 salts (GaCl3, AlCl3, AlBr3,

InCl3) were performed in diethyl ether at -78°C. RLi was generally transferred to the respective group 13 salts to control stoichiometry and avoid excessive ligation. Unless otherwise stated, all of the m-terphenyl-group 13 complexes are air and moisture sensitive and were characterized by single crystal X-ray crystallography, 1H NMR, elemental analysis, and melting point determination.

Compounds 1-5 (RGaCl2(OEt2) (1), R2GaCl (2), RAlBr2(OEt2) (3), O[AlClR(OEt2)]2 (4),

R3In (5)) were obtained as colorless crystals by reaction of RLi (R = 2,6-(4-t-BuC6H4)2C6H3-) with their respective group 13 halides (Eq. 2.2). These compounds have fairly high thermal stabilities, however compound 5 is exceptional, melting above 288°C. While compounds 1-3 were prepared in a straightforward manner, the isolations of 4 and 5 were unexpected and deserve special synthetic discussion.

In an attempt to synthesize R2AlCl, two equivalents of RLi were allowed to react with

AlCl3, instead the reaction produced an organometallic oxo-bridged-dialuminum chloride etherate, O[AlClR(OEt2)]2 (4), (Eq 2.2). The reaction mechanism for the formation of 4 is not well understood, however it appears that the reaction was either contaminated with trace amounts of H2O, or the ethereal solvent was activated. The latter proposition may be ascribed to the strong Lewis acid properties of AlCl3, which has been well documented as an ether cleavage

114 reagent. To eliminate the possibility of H2O incursion, the reaction was repeated as described with a particular emphasis to restrict H2O exclusion. Nevertheless, a similar conclusion was drawn as 4 was once again isolated. Similarly, switching to AlBr3 in place of AlCl3 provides the isoelectronic/isostructural bromide analogue of 4.

RAlBr2Et2O (3)

AlBr3 Et2O,-78°C

1/2 AlX3 R2GaCl (2) 1/2 GaCl 3 Et O,-78°C O[AlXR(OEt )] (4) Et O,-78°C 2 2 2 2 X = Cl, Br RLi

GaCl3 InCl3 Et2O,-78°C Et2O,-78°C

RGaCl2Et2O (1) R3In (5)

(Eq. 2.2)

The unexpected formation of R3In (5) by reaction of RLi with a slurry of InCl3 in a 1:1

ratio is intriguing. Even after several attempts, the anticipated 1:1 product, RInCl2, could not be prepared. Perhaps the heterogeneous reaction conditions promoted the formation of 5, wherein the more soluble RLi reacts multiply with the partially soluble InCl3. Interestingly, unlike

compounds 1-4, compound 5 can be handled in air without apparent signs of decomposition.

This is probably due to the substantial shielding afforded by the three bulky m-terphenyl ligands,

which envelop the indium atom.

2.1.3 Molecular Structures of 2,6-Di(4-t-butylpheny)phenylGroup 13 Complexes

Single crystal X-ray analysis of compounds 1-5 reveals an array of structurally interesting

molecules. Their structures are shown in Figures 2.22.6, respectively. Compounds 1 and 3 are

m-terphenylgroup 13 etherates with tetrahedral metal centers, whereas 2 is a trigonal planar

bis(m-terphenyl)gallium chloride, and compound 4 is a rare oxo-bridged di(m-

terphenylaluminum chloride). Compound 5 compliments these complexes and is notable as the

first report of a tris(m-terphenyl)group 13 compound.

The structure of RGaCl2(OEt2) (1) (Fig. 2.2) reveals the first structurally characterized m-

terphenylgallium dihalide etherate, RGaX2(OEt2). Although RGaCl2(OEt2) (R = 2,6-(2,4,6-i-

115 Pr3C6H2)2C6H3-) was previously reported, no corroborating structural data was presented.

Several structural features of 1 merit discussion. Specifically, the pseudo-tetrahedral geometry around the four coordinate gallium atom in 1 is expressed by the large C(1)Ga(1)Cl(1) and

C(1)Ga(1)Cl(2) bond angles, 123.49(12)° and 118.72(13)°, respectively, which greatly exceed the expected value for tetrahedral geometry (109.5°) and are more closely associated with trigonal planar geometry. As anticipated, the remaining bond angles are smaller; however, the

O(1)Ga(1)Cl(4) bond angle (95.05(11)°) is unusually small.

Since 1 is the first structurally characterized m-terphenyl-gallium etherate, special attention is drawn to the galliumether interaction. As expected, the weak coordination of the diethyl ether molecule in 1 creates a significant longer Ga(1)–O(1) bond distance (2.041(4) Å) when compared to the Ga–O -bond distance (1.7833(17) Å) found in R2GaOH (R = 2,6-

116 Mes2C6H3-). For comparison purposes, the GaO bond distance in 1 is also longer that the

116 bridging Ga–O–Ga bond distances (GaO = 1.938(2) and 1942(2) Å) in [RGa(Cl)(μ-OH)]2.

The Ga(1)C(1) bond distance (1.98(5) Å) in 1 is comparable to other m-terphenylgallium

dihalides (1.930(8) to 1.985(1) Å) on the high side of the range.44,46,117 The Ga(1)Cl(1) and

Ga(1)Cl(2) bond distances (2.205(2) and 2.1872(13) Å, respectively) are quite similar to the

terminal GaCl bond distance (2.290-2.172 Å) in the m-terphenylgallium dichloride dimer, [2,6-

46 Mes2C6H3GaCl2]2, but somewhat shorter than its bridging GaCl bond distances (2.333(5) and

2.324(4) Å).

The single crystal X-ray structure of the bis(m-terphenyl)gallium complex, R2GaCl (2)

(Fig. 2.3), reveals a three coordinate gallium atom in an seriously distorted trigonal planar environment. The geometry about the gallium atom in 2 is consistent with that in (2,6-

44 Ph2C6H3)2GaI, but contrasts with the “T-shaped” coordination around the gallium center in the

45 46 similar (2,6-Mes2C6H3)2GaX (X = Cl, Br ) compounds. This is almost certainly the

consequence of steric hindrance in the latter. This can be placed in a simple perspective, wherein

the less bulky m-terphenyl ligands utilized in 2 and (2,6-Ph2C6H3)2GaI require significantly

smaller C(1)–Ga(1)–C(27) bond angles (137.37(12)° and (134.3(3)°), respectively) to

accommodate the two ligands, whereas the more sterically encumbered “T-shaped” bis(m-

terphenyl)gallium halides warrant a significantly wider CGaC bond angle (153.5°) to lessen

steric interactions. Similar to previously reported bis-m-terphenyl galliums, the two m-terphenyl ligands in 2 adequately shield the gallium center so as to preclude solvent coordination. The

Ga(1)–C(1) and Ga(1)–C(27) bond lengths in 2, 1.981(3) and 1.997(3) Å, respectively, lie in the

range (1.971(12) Å 1.988(6) Å and 1.984 Å) of most bis-m-terphenyl galliums;44,46 however, a

slight variance is detected in the two GaC bond distances (2.001(16) and 1.956(16) Å) in (2,6-

Mes2C6H3)2GaCl, which places those in 2 somewhere in between. Interestingly, although 2 is substantially less crowded than (2,6-Mes2C6H3)2GaCl, the GaCl bond distance in 2 (2.2537(10)

Å) is substantially longer (2.177(5) Å). The exact cause of this inconsistency is unclear.

Figure 2.2 Molecular structure of RGaCl2(OEt2) (1)

Table 2.1 Selected bond distances [Å] and angles [°] for RGaCl2(OEt2) (1) Atoms Distance Atoms Angle Ga(1)C(1) 1.985(5) C(1)Ga(1)O(1) 105.89(15) Ga(1)O(1) 2.041(4) C(1)Ga(1)Cl(1) 123.49(12) Ga(1)Cl(1) 2.1872(13) C(1)Ga(1)Cl(2) 118.72(13) Ga(1)Cl(2) 2.2238(14) Cl(1)Ga(1)Cl(2) 106.70(6)

Figure 2.3. Molecular structure of R2GaCl (2)

Table 2.2 Selected bond distances [Å] and angles [°] for R2GaCl (2) Atoms Distance Atoms Angle Ga(1)C(1) 1.981(3) C(1)Ga(1)C(27) 137.37(12) Ga(1)C(27) 1.997(3) C(1)Ga(1)Cl(1) 106.69(9) Ga(1)Cl(1) 2.2537(10) C(27)Ga(1)Cl(1) 115.76(9)

The structure of RAlBr2(OEt2) (3) (Fig. 2.4) is isoelectronic with RGaCl2(OEt2) (1). Both structures are m-terphenylgroup 13 etherates and share a common four-coordinate distorted tetrahedral environment about the metal centers. Similar to that in 1, the C(1)–Al(1)–Br(1) and

C(1)–Al(1)–Br(2) bond angles, 117.46(15) and 120.10(15)°, respectively, are significantly

distorted from classical tetrahedral geometry, while the Br(1)–Al(1)–O(1) bond angle,

97.94(14)°, is much smaller than anticipated. There is one additional structural feature of 3 that

deviates from 1. Specifically, whereas in 1 the Cl–Ga–Cl bond angle (95.05(11)°) was the

smallest bond angle around gallium, the analogous Br(1)–Al(1)–Br(2) bond angle (107.22(6)°) in

3 is consistent with the anticipated value. This may be due to the larger atomic radius of

bromine, which would have greater electronic repulsion than chlorine. It is generally accepted

that with increasing steric crowding about a group 13 element the EC bonds lengthen due to

steric repulsion. Indeed, there is very little difference between the Al(1)C(1) bond distance

(1.979(5) Å) in 3 and that of the only other m-terphenylaluminum dibromide etherate,

Ph3PhAlBr2(OEt2) (AlC 1.983(5) Å), which are in terms of sterics are very similar. This trend is

also consistent when comparing the shorter Al(1)C(1) bond distance in 3 with that of the more

118 sterically encumbered 2,6-Mes2C6H3AlCl2(OEt2) (AlC 1.992(3)Å). However a break in this

concept is revealed when comparing the AlC bond distance in 3 with that of most sterically

encumbered m-terphenylaluminum halide isolated to date, RAlCl2(OEt2) (R = 2,6-(2,4,6-i-

118 Pr3C6H2)2C6H3-), which has a significantly shorter AlC bond distance (1.954(11) Å) than

that in 3. The authors suggested that this short bond distance is the result of a higher degree of

ionic character inherent to the AlC bond, thereby strengthening, and thus shortening, the bond.

Another subtle feature of 3 is that the phenyl ring plane is bent by 15.54° from coplanarity with

the AlC bond. This distortion may be due to packing forces in the crystal lattice, a factor that

allows for flexibility in the ionic Al-C bond.118 In general, the bond distances in 3 are as

expected, however the Al(1)–Br(1) and Al(1)–Br(2) bond distances (2.3175(17) Å and

2.3010(16) Å, respectively) differ slightly but both are similar to those in RAlBr2·OEt2 (R =

118 2,4,6-Ph3C6H2) (2.297(3) and 2.302(3) Å). These bond distances in 3 are also comparable

119 with the terminal AlBr bond distance (2.285(6) Å) in [RAlBr3Li]2, (R = 2,6-Mes2C6H3), but are substantially shorter than those with lithium interactions (2.359(5) and 2.398(5) Å). The anionic nature of [RAlBr3Li]2 may also be partially attributed to the longer AlBr distances.

Figure 2.4. Molecular structure of RAlBr2(OEt2) (3)

Table 2.3 Selected bond distances [Å] and angles [°] for RAlBr2(OEt2) (3) Atoms Distance Atoms Angle Al(1)O(1) 1.877(4) O(1)Al(1)C(1) 106.64(19) Al(1)C(1) 1.979(5) C(1)Al(1)Br(2) 120.08(15) Al(1)Br(2) 2.3013(16) C(1)Al(1)Br(1) 117.46(15) Al(1)Br(1) 2.3173(17) Br(2)Al(1)Br(1) 107.22(6)

The crystal structure of O[AlClR(OEt2)]2 (4) (Fig. 2.5) is as interesting as its peculiar formation. The structure displays two four-coordinate aluminum atoms connected by an oxygen bridge and each is covalently bound to an m-terphenyl and chloride ligand. The tetrahedral aluminum coordination spheres are completed with diethyl ether coordination. It is interesting to note that compound 4 has no counterpart in the literature, however there is one closely related

119 compound, [RAlCl(μ-OH)]2 (R =2,6-(2,4,6-i-Pr3C6H2)2C6H3-), which contains two bridging

hydroxide and terminal chloride ligands on each aluminum atom.

An unusual structural feature of 4 may be viewed along the Al(1)O(1)Al(2) vector,

which shows a “gauche-type” configuration of the m-terphenyl ligands with a torsion angle of

58.66°, while the chloride ligands are assume almost an “anti” conformation (ClAlAlCl

torsional angle, 154.57°), and the diethyl ether molecules are coordinated to the aluminum atoms

in more of a “gauche-like” conformation (torsion angle = 62.56°). A schematic depiction of these phenomena is better illustrated by the Newman projection shown Figure 2.6. Considering the steric bulk of the ligands, it is surprising that this conformation observed for 4 is preferred, as

one might expect the ligands to be arranged on opposite sides of the molecule to lessen steric

interactions. In fact, upon closer examination of the molecular structure of 4 shows that there are

several close intramolecular CH···HC contacts between the two ligands (2.74 Å shortest).

These contacts are well within range of van der Waal forces of attraction (3.44 Å), however it

doubtful that these weak forces (5-7 kJ/mol) are responsible for these unexpected structural

features.

Figure 2.5. Molecular structure of [RAlCl(OEt2)]2O (4)

Table 2.4 Selected bond distances [Å] and angles [°] for [RAlCl(OEt2)]2O (4) Atoms Distance Atoms Angle Al(1)O(1) 1.696(4) Al(2)O(1)Al(1) 160.0(2) Al(1)C(1) 2.001(5) O(1)Al(1)Cl(1) 108.85(15) Al(1)Cl(1) 2.354(2) C(1)Al(1)Cl(1) 117.90(17) Al(2)O(1) 1.691(4) O(1)Al(2)Cl(2) 110.77(14) Al(2)C(31) 2.013(5) C(31)Al(2)Cl(2) 114.45(15) Al(2)Cl(2) 2.3939(19) O(1)Al(2)C(31) 120.68(19)

Atoms assimilated R OEt2 for torsion angle Torsion angle (deg) Al R-Al…Al-R 58.66 Cl-Al…Al-Cl 154.57 R OEt2 Et2O-Al…Al-OEt2 62.56 Cl

Figure 2.6. Table for torsion angles (deg) and Newman projection of 4: “looking down the AlOAl vector”

Further inspection of 4 also shows unusually long Al(1)Cl(1) and Al(2)Cl(2) bond

distances, 2.354(2) and 2.3939(19) Å, respectively, which are substantially longer than average

AlCl bond lengths (2.15 Å av.) previously reported for other m-terphenylaluminum chloride

compounds.120,121 These bond distances are surprisingly more comparable to the AlBr bond

119 distances in [RAlBr3Li]2 (R = 2,6-Mes2C6H3) (2.285(6), 2.359(5), and 2.398(5) Å) and even

118 longer than those in either RAlBr2·OEt2 (R = 2,4,6-Ph3C6H2-) (2.297(3) and 2.302(3) Å) or 3

(2.3175(17) Å and 2.3010(16) Å). For comparison purposes, the Al(1)O(1) and Al(2)O(1)

bond distances (1.696(4) and 1.691(4) Å) are substantially shorter than the bridging AlOHAl

bond distances (1.817(2) Å) in [RAlCl(μ-OH)]2 (R =2,6-(2,4,6-i-Pr3C6H2)2C6H3-), yet the two

aluminum atoms are well separated (AlAl = 3.335Å).

These odd structural anomalies of 4 may be partially attributed to the anomeric effect.

Evidence for this proposal may be supported with previous studies in carbohydrate chemistry, where the anomeric effect has long been used to describe why -substituents to the oxygen atom in pyranose rings prefer the axial position, regardless of 1,3 diaxial steric congestion.122

Furthermore, in acyclic systems such as -halomethyl ethers, MeOCH2X, the anomeric effect

has been used to explain why the gauche conformation is more stable than trans, their CX bond

distances are elongated, and the CO bond distance is shortened.123 All of these features are

found in 4. Although the exact cause of the anomeric effect is debatable, it is generally accepted

that a stabilizing interaction occurs by hyperconjugation in which the lone pair of electrons of the

less electronegative element donates into the *-orbital of the CX bond. The “no bond/double

bond” resonance model (Figure 2.7) paints a clearer picture. In effect, this theory results in two

+ resonance forms at equilibrium the base molecule and hypothetical H2C=OMe intermediate, with release of a halide ion.

MeO CH2 X MeO CH2 X

Figure 2.7. “Double bond-no bond” resonance model for -halomethyl ethers

With the longer than expected AlCl bond lengths, short AlO bond lengths, and the

“gauche-type” orientation of the m-terphenyl ligands in compound 4, it is, indeed, compelling to suggest that the anomeric effect is influencing these structural manifestations. Furthermore, as shown in Figure 2.8, the “double-bond/no-bond” resonance model can be applied to 4. Since the two resonance forms are averaged in the solid state, this may account for the long AlCl and short AlO bonds distances in 4. The gauche-like configuration of the m-terphenyl ligands may also be attributed to the anomeric effect, wherein the molecule assumes a conformation that is optimal for the lone pair of electrons on oxygen to align with a chloride ligand, even at the expense of steric interactions between the ligands. Another notable feature of 4 is the almost linear Al(1)-O(1)-Al(2) bond angle (160.0(2)°), which is over 55° larger than the corresponding

124 HOH bond angle (104.5°) calculated for H2O. Clearly, the bulky ligands in 4 have some

responsibility for this structural observation, yet one could question if the anomeric effect is

influencing this bond angle as well.

R R O O Al Al Cl Cl

Figure 2.8 The “double bond-no bond” resonance model for 4.

Consideration of the X-ray structure of 5, R3In, (Fig. 2.9), which crystallizes as a monomer with one molecule of diethyl ether per asymmetric unit, reveals the first tris-m- terphenylindium and provides an interesting contrast from the organogroup 13 halides discussed above. The three ligands in 5 are arranged about the indium atom in a propeller like fashion and are not crystallographically equivalent due to differing dihedral angles. The dihedral planes were found to be 39.84°, 31.95°, and 65.37° for the C(1), C(27) and C(53) with respect to the central phenyl ring planes, respectively. Indeed, it is remarkable that three sterically imposing ligand are able to arrange in an orientation that is conducive for formation of 5. It is clear that the lack of substituents at the ortho-positions of outer phenyl rings affords conformational freedom that would otherwise be hindered with substitution. The indium atom in 5 resides in a distorted trigonal planar coordination environment, demonstrated by its differing C–In–C angles: C(1)–

In(1)–C(27) 114.77(13)°, C(1)–In(1)–C(53) 120.34(12)°, C(27)–In(1)–C(53), 124.83(13)°.

125 Indeed, these bond angles are comparable with those trimesitylindium, Mes3In, and

36,38 triphenylindium, Ph3In. However, when these angles are compared with the CInC bond angle (157.3(8)°) in the more bulky and somewhat related bis(m-terphenyl)indium bromide, 2,6-

126 Mes2C6H3InBr, they are clearly smaller. The In–C bonds in 5 (In(1)–C(1) 2.200(3) Å, In(1)–

C(27) 2.199(3) Å, In(1)–C(53) 2.193(3) Å) are longer to those in Mes3In (2.170(5) Å; 2.170(5)

Å; 2.163(5) Å) and 2,6-Mes2C6H3InBr (2.171(25) and 2.166(26) Å), and more so for those in

Ph3In (2.111(14) Å and 2.155(14) Å).

Figure 2.9. Molecular structure of R3In (5)

Table 2.5 Selected bond distances [Å] and angles [°] for R3In (5) Atoms Distance Atoms Angle In(1)C(53) 2.192(3) C(53)In(1)C(1) 120.29(13) In(1)C(1) 2.199(3) C(53)In(1)C(27) 124.86(13) In(1)C(27) 2.200(3) C(1)In(1)C(27) 114.79(13)

2.1.4 Synthesis and Structures of 2,6-Di(4-methylpheny)phenylGroup 13 Complexes

As to augment our studies of less sterically demanding m-terphenyl ligands on group 13 metals, we selected 2,6-(4-Me-C6H4)2C6H3- (R) to ascertain if differences in para-substituents, methyl as opposed to tert-butyl, on the outer phenyl rings play a significant role in the stability and structural properties of the respective ligand–metal complexes. Reactions of RLi were conducted with GaCl3 and InCl3 (Eq. 2.3). In general, crystallizing the corresponding ligand– group 13 complexes proved more difficult than complexes 1-5 due to a persistent oily residue

that leached from solution. However, after considerable effort, X-ray quality crystals were

isolated for three new compounds: [RGaCl3][Li(OEt2)2] (6), [RInCl3][Li(OEt2)(THF)] (7), and

R3In (8). These compounds tended to have lower thermal stabilities when compared to the

analogous compounds 1-5. Moreover, compounds 6 and 7 decomposed on melting and are air-

and moisture-sensitive, while 8 shows no signs of decomposition when exposed to air. These

compounds were characterized by single crystal X-ray crystallography, 1H NMR, elemental

analysis, and melting point determination.

Reaction of RLi with GaCl3 in diethyl ether (Eq. 2.3) proceeds smoothly to afford colorless X-ray quality crystals of 6 [RGaCl3][Li(OEt2)2] from viscous brown oil. However,

allowing RLi to react with InCl3 gave two considerably different products depending on solvent

employed (Eq. 2.3). To much surprise, when the reaction is carried out in neat diethyl ether a

tris-(m-terphenyl)indium, R3In (8), is isolated as colorless crystals, however when performed in

mixed solvent (diethyl ether/THF, 10:1) a monomeric anionic m-terphenylindium trichloride,

[RInCl3][Li(OEt2)(THF)] (7), is produced. The preponderance for the formation of either compound may be traced to the solubility of InCl3. Because InCl3 is only sparingly soluble in

diethyl ether, it is easy to consider that RLi reacts multiply with only solubilized InCl3 resulting

in the isolation of 8. Conversely, InCl3 is readily soluble in THF at room temperature and the

reaction proceeds as stoichiometrically dictated to give 7. This observation lends rationale to the

formation of the tris-(m-terphenyl)indium, R3In (5), which was also generated in diethyl ether.

GaCl , Et O -78°C 3 2 [RGaCl3][Li(OEt2)2] 6

R = InCl3, THF/Et2O, r.t. R Li [R InCl3][Li(Et2O)(THF)] (2.3) 7

InCl3, Et2O -78°C - 3 LiCl R 3In 8

The X-ray structure of [RGaCl3][Li(OEt2)2] (6) (Fig. 2.10) provides an opportunity to compare its structure with compound 1, RGaCl2(OEt2), which has t-butyl functionality at paraposition of the m-terphenyl ligand. The most striking distinction between these two four- coordinate organogallium halides is in which the manner the tetrahedral geometries about the gallium atoms are obtained. While 1 is a neutral m-terphenylgallium halide, 6 is anionic with three chloride ligands surrounding gallium, coupled with a lithium cation. It should be noted that the syntheses of 1 and 6 were performed following identical protocols; therefore the structural deviations may be possibly attributed to the electronic effects of the m-terphenyl ligands. This may be an oversimplification of the exact cause of the different adduct formations, however it is well known that methyl groups are weaker -electron donors than t-butyl groups, due to enhanced hyperconjugation in the latter. This would undoubtedly affect the Lewis acidity of the

gallium atoms and thus the preference for either anionic, RGaCl3Li, or diethyl ether,

RGaCl2(OEt2), adduct formation. The different coordination spheres of the gallium atoms appear

to have only a modest affect on the GaC bond distances in 1 and 6 (1.98(5) Å and 1.970(4) Å,

respectively), as both are quite similar. The Ga(1)C(1) bond distance in 6 also compares well

with those of previously reported four-coordinate m-terphenylgallium halides (1.930(8) to

1.985(1) Å).44,46,117 A review of the literature reveals that m-terphenylgallium dihalides are

commonly reported as dimers [RGaCl2]2 and that anionic species are fairly rare but usually

feature m-terphenyl ligands that are devoid of ortho-substitution on the flanking phenyl rings,

44 2,4,6-Ph3PhGaCl3 and 2,6-Ph2PhGaCl3. This provides further evidence that the steric and

electronic effects of the m-terphenyl ligands has an immense effect on structure and bonding in

group 13 chemistry. Indeed, the structure of 6 is consistent with 2,4,6-Ph3PhGaCl3 and 2,6-

Ph2PhGaCl3, all comprising of three chlorine atoms surrounding the gallium atom. Two of the

chlorine atoms in 6 are coordinated with lithium to form a slightly puckered Ga(μ-Cl2)Li four-

membered ring, which contains bond angles that are all slightly less than 90° except for the

Cl(1)-Ga(1)-Cl(2) bond angle (95.25(5)°). The Ga(1)–Cl(1) and Ga(1)–Cl(2) bond distances

(2.2503(14) and 2.2530(13) Å, respectively), which are incorporated in the Ga(μ-Cl2)Li four- membered ring, are longer than the terminal Ga(1)–Cl(3) bond distance (2.2759(13) Å). This is consistent with the extremely sterically encumbered m-terphenylgallium dichloride dimer,

[RGaCl2]2 (R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-2), which also has longer terminal GaCl bond

distances (2.196-2.201 Å) than bridging ones (2.230Å). On average, the GaCl bonds compare

with those in 2,4,6-Ph3PhGaCl3 and 2,6-Ph2PhGaCl3 (2.239 Å av) but are slightly longer than

those in 1 (2.205(2) and 2.1872(13) Å); however, the LiCl bond distances in 2,4,6-Ph3PhGaCl3

and 2,6-Ph2PhGaCl3 were not reported, thus it is difficult to place those of 6 into perspective.

Figure 2.10. Molecular structure of [RGaCl3][Li(OEt2)2] (6)

Table 2.6 Selected bond distances [Å] and angles [°] for [RGaCl3][Li(OEt2)2] (6) Atoms Distance Atoms Angle Ga(1)C(1) 1.970(4) C(1)Ga(1)Cl(1) 113.22(13) Ga(1)Cl(1) 2.2503(14) C(1)Ga(1)Cl(2) 109.80(13) Ga(1)Cl(2) 2.2530(13) Cl(1)Ga(1)Cl(2) 95.25(5) Ga(1)Cl(3) 2.2759(13) C(1)Ga(1)Cl(3) 122.49(13) Cl(1)Li(1) 2.406(10) Cl(1)Ga(1)Cl(3) 105.56(6) Cl(2)Li(1) 2.397(10) Cl(2)Ga(1)Cl(3) 106.97(6)

Moving on, the single crystal X-ray structure of 7, [RInCl3][Li(OEt2)(THF)]) (Fig. 2.

11), reveals the first m-terphenylindium trihalide lithium adduct. In fact, there has been only

one other account of an m-terphenyl-indium dihalide, [RInCl2]2 (R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-

), in the literature, which was reported by two independent groups.115,117 Compound 7 is

isoelectronic with [RGaCl3][Li(OEt2)2] (6); however, it has coordination of both a molecule of

diethyl ether and THF about the lithium cation. Though both solvents were used in the synthesis

of 7, it is peculiar that the more polar THF molecule did not displace diethyl ether. The indium

atom in 7 resides in a distorted tetrahedral environment surrounded by three chloride ligands and

the m-terphenyl ligand. Similar to that in 6, two of the chloride ligands in 7 have lithium

interactions to form a puckered Li(μ-Cl2)In four-membered ring. The Li(1)Cl(1) and Li(1)-

Cl(2) bond distances (2.34(3) and 2.50(3) Å, respectively), which are incorporated in the ring, differ by almost 0.2 Å. However, it appears that the differences between these bond distances have a modest effect on Li(1)Cl(1)In(1) and Li(1)Cl(2)In(1) bond angles, 89.1(6)° and

85.6(6)°, respectively. The In(1)Cl(1) and In(1)Cl(2) bond distances (2.442(4) Å and 2.438(4)

Å, respectively) in 7 are almost identical, but both bond distances are slightly longer than the terminal In(1)Cl(3) bond distance (2.398(4) Å). This structural feature is contrary to that found for 6, wherein the terminal GaCl bond is longer than those with ClLi interactions.

Furthermore, the differences (0.05 Å av) between the terminal InCl bond distance and the two

engaged with Li interactions are comparably larger that the analogous differences for GaCl

bonds distances of 6 (0.025 Å av). Perhaps the larger atomic radius of indium allows for stronger

interaction of the terminal chloride ligand. The In(1)–C(1) bond distance (2.133(13) Å) in 7 is

relatively smaller than those in the tris-m-terphenylindium compound 5 (R3In, (2.1868(17)-

2.2043(16) Å), which is undoubtedly due to steric repulsion of the three bulky ligands. It is also

prudent to compare some structural features of 7 with the only other m-terphenyl-indium halide

115,117 dimer, [RInCl2]2 (R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-). The In(1)C(1) bond distance

(2.133(13) Å) in 7 is shorter than (2.1485(3) Å) that of [RInCl2]2, while the InCl bond distances

in 7 (2.398(4)term, 2.442(4)bridge, and 2.438(4)bridge Å) are all longer than the terminal InCl bond

distance (2.3341(12) Å) but substantially shorter than the bridging InCl bond distances

(2.5239(7) Å) in [RInCl2]2.

The single crystal X-ray structure of 8 (Fig. 2.12) reveals another tris-m-terphenylindium with the three ligands essentially encapsulating the pseudo-trigonal planar indium atom. This is clearly demonstrated with the space-filling model of 8 (Fig. 2.13). Compound 8 is structurally very similar to R3In (5). Interestingly, although 5 contains m-terphenyl ligands with more bulky

t-butyl groups, the ligands are arranged about the indium atom in a fairly symmetrical fashion

with similar CInC bond angles. This is not the case for 8, as the C(1)–In(1)–C(41) and C(21)–

In(1)–C(41) bond angles, 123.80(6)° and 123.52(6)°, respectively, are significantly larger than

the complementary C(1)–In(1)–C(21) bond angle (112.66(6)°), resulting in a less symmetrical

coordination sphere around indium. The In(1)–C(1) and In(1)–C(21) bonds distances (2.2043(16)

and 2.2019(16) Å, respectively) compare well with those in 5 ((In(1)–C(1) 2.200(3) Å, In(1)–

C(27) 2.199(3) Å, In(1)–C(53) 2.193(3) Å), however the In(1)–C(41) bond (2.1868(17) Å) in 8

is somewhat shorter. The reason for this variation is not clear. A comparison of the In–C bonds

in 8 with other triarylindium complexes indicate that they are slightly longer than those of Ph3In

37 125 (2.111(14)-2.155(14) Å), and trimesitylindium Mes3In, (2.163(5)-2.170(5) Å). This may

reflect the added steric encumbrance of 8.

Figure 2.11. Molecular structure of [RInCl3][Li(OEt2)(THF)] (7)

Table 2.7 Selected bond distances [Å] and angles [°] for [RInCl3] [Li(OEt2)(THF)] (7) Atoms Distance Atoms Angle In(1)C(1) 2.133(13) C(1)In(1)Cl(3) 121.2(4) In(1)Cl(3) 2.398(4) C(1)In(1)Cl(2) 115.3(4) In(1)Cl(2) 2.438(4) Cl(3)In(1)Cl(2) 104.74(16) In(1)Cl(1) 2.442(4) C(1)In(1)Cl(1) 115.7(4) Cl(1)Li(1) 2.34(3) Cl(3)In(1)Cl(1) 104.00(14) Cl(2)Li(1) 2.50(3) Cl(2)In(1)Cl(1) 91.33(14)

Figure 2.12. Molecular Structure of R3In (8)

Table 2.8 Selected bond distances [Å] and angles [°] for R3In (8) Atoms Distance Atoms Angle In(1)C(41) 2.1868(17) C(41)In(1)C(21) 123.52(6) In(1)C(21) 2.2019(16) C(41)In(1)C(1) 123.80(6) In(1)C(1) 2.2043(16) C(21)In(1)C(1) 112.66(6)

Figure 2.13. Space filling model of R3In (8)

In summary, reaction of RLi and RLi with group 13 salts provides a number of structurally interesting organometallic group 13 complexes. Specifically, reaction with RLi with

GaCl3 in a 1:1 ratio led to the formation of an m-terphenylgallium dichloride etherate,

RGaCl3(OET2) (1), while an m-terphenylgallium trichloride lithium adduct

[RGaCl3][Li(OEt2)2] (6) was isolated by reaction of RLi under identical reaction conditions.

Moreover, the isolations of RAlBr2(OEt2) (3) and [RInCl3][Li(OEt2)(THF)] (7) suggest that the

different adduct formations, diethyl coordination or anionic group 13 lithium salts, may be a

trend decidedly influenced by the electron donating effects of para-substituents. Overall, the

structure and bonding of ligands R and R on the group 13 metals were very similar to previously

synthesized m-terphenylgroup 13 halides; however, some notable complexes had novel

structures. In particular, compound 4 with its gauche-type conformation of the m-terphenyl ligands, exceeding long AlCl bond distances, and short AlO bond distances are conspicuous characteristics of the anomeric effect, which is rarely found in group 13 chemistry. Also R3In (5)

and R3In (8) are notable as the first tris-m-terphenylgroup 13 compounds. The lack of ortho-

substituents on the flanking phenyl rings affords conformation freedom so that three of these

relatively bulky ligands are well accommodated about the indium atom.

2.1.5 Synthesis and Molecular Structure of [R3Ga3][Na3 (OEt2)3] (9) (R = 2,6-(4-t-BuC6H4)2C6H3-)

Alkali metal reductions of m-terphenylgroup 13 halides, REX2, have been a fruitful

means to synthesize organometallic group 13 compounds containing metalmetal bonds. Our

previous endeavors have shown that metal contact aggregation increases with decreasing ligand

steric bulk. For example, when 2,6-Mes2C6H3GaCl2 is reduced with sodium or potassium metal

127 25 tri-gallium complexes comprising of a Ga3-cyclic ring, M2[GaR]3 (M = Na, K; R = 2,6-

Mes2C6H3-, Mes = 2,4,6-Me3C6H2-) (cyclotrigallenes), are isolated, while on the other hand,

reduction of the more sterically encumbered 2,6-(2,4,6-i-Pr3C6H2)2C6H3GaCl2 yields a di-gallium

complex Na2[RGaGaR] (R =2,6-(2,4,6-i-Pr3C6H2)2C6H3-) (digallyne) (Fig. 1.13) containing a

GaGa triple bond.21 It was hypothesized that by alkali metal reductions of the less bulky m-

terphenyl group 13 halides, REX2(OEt2) and [REX3][Li(OEt2)2], metallic clusters or cyclic compounds with higher metalmetal bonding aggregation could be stabilized. Unfortunately the

results of these endeavors were less than desirable, usually resulting in the isolations of only

ligand hydrocarbons, RH, as a result of CE bond cleavage (E = Al, Ga, In). In only one experiment was a compound containing EE bonds isolated, wherein sodium metal reduction of

RGaCl2(OEt2) (1) (R = 2,6-(4-t-BuC6H4)2C6H3-) in diethyl ether provides orange-red crystals of

9, [R3Ga][Na3(OEt2)3] (Eq. 2.4). Unfortunately, due to low yield complete characterization proved impossible, however a few crystals were adequate for single crystal X-ray

crystallography.

t-Bu R R R Ga H Na/Et2O Ga RGaCl2(OEt2) Ga [Na3(OEt2)3] (2.4) 1 H

t-Bu t-Bu

R = 4-t-BuC6H4-

Single crystal X-ray analysis of 9 (Fig. 2.14) reveals a complex containing a chain of

three gallium atoms with each forming a GaC4 five-membered ring with the m-terphenyl ligand.

Though catenation is common for the group 14 elements, it is rare for the group 13 elements.

Indeed, there are only two reports of open-chain catenated group 13 species,128,129 and only one

129 gallium species, [I2(PEt3)GaGaI(PEt3)Ga(PEt3)I]. The formation of 9 is not well understood,

however it appears that the ortho-positions of the outer phenyl are activated to form the three

130,131 GaC4 five-membered rings. This unusual phenomenon was also observed for Wehmschulte

and coworkers, whereby reaction of RLi (R = 2,6-(4-t-BuC6H4)2C6H3-) with H2ClB•SMe2 at -

78°C yields unsymmetrical 9-borafluorenes via facile intramolecular C–H bond activation of the flanking phenyl rings. Moreover, the presence of the three sodium atoms suggests that 9 is a trianionic complex, even though only the central four-coordinated gallium warrants a –1 formal charge. The most feasible explanation for this occurrence could be the existence of hydrides residing on the pyramidal three-coordinate Ga(2) and Ga(3) atoms. Although the hydrides were not absolutely located, this would fully account for the trianionic nature of 9.

Figure 2.14. Molecular structure of [R3Ga3][Na3(OEt2)3] (9)

Table 2.9 Selected bond distances [Å] and angles [°] for [R3Ga3][Na3(OEt2)3] (9) Atoms Distance Atoms Angle Ga(1)Ga(2) 2.4863(10) Ga(2)Ga(1)Ga(3) 107.79(3) Ga(1)Ga(3) 2.5251(10) C(8)Ga(1)C(1) 84.9(3)

A number of structural features of 9 merit discussion. Particularly, the GaC bond

distances (2.039 Å av) are significantly longer than that in the starting material RGaCl2•(OEt2)

(1) (1.985(5) Å) and also those in the previously reported gallium five-membered heterocycle

132 - [(PhC=CPh)2GaCl2][Li(OEt2)]2 (1.966(4)Å), and the spirogallane{[(PhC=CPh)2]2Ga} (2.012

Å av).133 The lengthening of the GaC bonds in 9 may likely be the result of angle strain induced by bonding with the outer phenyl rings. To place this hypothesis in further perspective, the two

CCC bond angles (117° av) incorporated in the GaC4 five-membered ring are much more

acute than the analogous bond angle involving the ipso-carbons on the central phenyl ring to

“free” flanking phenyl ring (CCC <120° av). Moreover, angle strain is also exhibited by the

GaC bonds, which are slightly “bent” (166° av) from linearity with respect to the para-carbon

of the central phenyl ring. The ramification of this angle strain is a weakened GaC bond. The

three GaC4 five-membered rings in 9 are essential planar and have an average C–Ga–C bond angle of 85°, which consistent with previously published five-membered gallium carbocycles

(galloles).132,134-137 The GaGa bond distances in 9 are also interesting, as the Ga(1)–Ga(2) bond distance (2.4863(10) Å) is slightly longer than the Ga(2)–Ga(3) bond distance (2.5251(10) Å).

The terminal Ga(2) and Ga(3) atoms in 9 are well separated (4.049Å) as to preclude GaGa bond

formation. A comparison of 9 with the only other catenated gallium species,

129 [I2(PEt3)GaGaI(PEt3)Ga(PEt3)I2] is revealing. The GaGa bond distances in 9 (2.4863(10) and

2.5251(10) Å) are longer and the Ga(1)–Ga(2)–Ga(3) bond angle (107.79(3)°) is smaller than the

respective structural factors in [I2(PEt3)GaGaI(PEt3)Ga(PEt3)I2] (2.451(1) and 2.460(1) Å;

121.9(1)°). The smaller GaGaGa in 9 may be attributed to two factors: a) the less bulky

triethyl phosphine ligands in [I2(PEt3)GaGaI(PEt3)Ga(PEt3)I2], which has a cone angle that

protrudes away from the metal centers, allowing for angular freedom; or b) intramolecular

coordination of the Na atoms with the m-terphenyl ligands in 9 contracts the GaGaGa bond angle. The three sodium atoms of 9 are also interesting as each has an explicitly different coordination environment. The eight-coordinate Na(1) atom is complexed with two phenyl rings of opposing m-terphenyl ligandsone in 6-fashion and the other 2, while the Na(2) atom is three-coordinate, afforded by interactions with the flanking and central phenyl rings of different m-terphenyl ligands and a molecule of diethyl ether. The Na(3) atom is four-coordinate and has only one interaction with the m-terphenyl ligand (CNa(3) = 2.644Å) and a slight interaction with the Ga(2) atoms (Na(3)Ga(2) = 2.978Å). Its coordination sphere is rounded out with two diethyl ether molecules.

To conclude, alkali metal reductions of less bulky m-terphenyl group 13 halides,

REX2(OEt2) and [REX2][Li(OEt2)2] were generally unsuccessful at producing compounds with metalmetal bonds. Perhaps the ligands are too small to adequately shield the metal centers. This process may be further complicated by CH activation of the unsubstituted ortho- position of the outer phenyl rings, which was possibly the case in 9. Thus, substitution at this position appears to have a secondary purpose besides steric protection in low-valent, low-coordinate organometallicgroup 13 chemistry, that is, to avoid hydride formation.

2.2 Organometallic Group 13-Group 4 Complexes

2.2.1 Synthesis and Structures of Cp2Hf(ER)2 Compounds (10 E = Ga; 11 E = In; R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-)

Typically the Robinson group has had limited excursions into the organometallic chemistry of transition metals. However, given the considerable number of homogeneous

Ziegler-Natta olefin polymerization catalytic systems involving the early metallocene dihalide

138 derivatives, Cp2MX2 (Cp = C5H5; M = Ti, Zr, Hf), and organo-group 13 metal moieties, it was

surprising that examples of compounds containing directly bound group 4 group 13 metals

were unknown. Thus, we became interested in synthesizing such organometallic compounds not

only because the nature of the transition metalmain group metal bond is intriguing, but also for

84,139-145 the possibility of catalytic function. In 2004, we reported a series of Cp2M(ER)2

compounds (M = Ti, Zr; E = Ga, In; R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-) containing the first group

4group 13 bonds with interesting “V shaped” EME architectures.146,147 As a natural progression in the development of this burgeoning sector of organometallic chemistry, the

synthesis of compounds possessing group 13–Hf bonds was pursued.

Employing our generalized strategy of stabilizing low-valent, low-coordinate main group

species with sterically demanding ligands, Cp2Hf(GaR)2 (10) and Cp2Hf(InR)2 (11) were

prepared by sodium metal reduction of REX2 (E = Ga, In; R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-) and

Cp2HfCl2 in diethyl ether (Eq. 2.5). Compounds 10 and 11 are isolated as dark-green and dark- purple crystals, respectively. Surprisingly, though both 10 and 11 are extremely sensitive to air and moisture, they exhibit exceptionally high thermal stability, melting or decomposing above

270°C. Moreover, these compounds are noteworthy as the only examples with unsupported

Hfgroup 13 bonds and join the small collection of compounds containing group 4–group 13 bonds.146-149

R Cl 6 Na E 2 RECl2 + Hf Hf (2.5) Cl - 6NaCl E R

E = Ga (10), In (11) R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-

The metamorphosis of the formal oxidation states of the metals from starting materials to

III compounds 10 and 11 is fascinating. The group 13 metals in REX2 are formally reduced from E

1 IV II to E , while the Hf atom in Cp2HfCl2 is converted to Hf , transforming the formerly 16-

electron hafnocene dichloride, Cp2HfCl2, into 18-electron Cp2Hf(ER)2 complexes. The two

linear RE: fragments in 10 and 11 seem to behave as two-electron donors and are reminiscent of

150 :CO in hafnocene dicarbonyl, Cp2Hf(CO)2.

Indeed, group 13 diyls, RE:, have considerable Lewis basic and -donor properties and

are well known for their ability to mimic N-heterocyclic carbenes. Moreover, the group 13 diyls

can effectively stabilize transition metals in low oxidations states by forming donor-acceptor

complexes which has provided a viable means to synthesize an array of new compounds and

complexes containing group 13 metaltransition metal bonds.151-157 More recently compounds containing group 13lanthanide bonds (GaNd,158 AlEu, and AlYb159) have also been

obtained by utilizing this strategy. While group 13 diyls are commonly stabilized by Cp* (Cp* =

160 - 149 C5Me5) or -diketiminate ligands ({(Ar)N(Me)C}CH ), the X-ray structures of m-

47 161 terphenylindium and thallium diyls (2,6-(2,4,6-i-Pr3C6H2)2C6H3E:, E = In , Tl ) have been

isolated and confirms the ability m-terphenyl ligands to stabilize group 13 diyls. Furthermore,

although X-ray crystallographic analysis does not exist, spectroscopic and chemical evidence

162 supports the existence an m-terphenylgallium diyl, RGa: (R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-).

Thus, it is not far fetched to consider that the “RE” fragments in 10 and 11 are indeed acting as two electron donors to the Hf center.

Single crystal X-ray analysis was performed to provide further insight into the structure

and bonding of 10 and 11. Although crystals of 10 and 11 differ dramatically in color, dark green and purple, respectively, their crystal structures are both isostructural and isomorphous. Both crystallize in the orthorhombic (Pbcn) space group with a single molecule of diethyl ether in the asymmetric unit.

The crystal structures of 10 (Fig. 2.15) and 11 (Fig. 2.16) reveal trimetallic Cp2Hf(ER2)

(10, E = Ga, 11, E = In) complexes with the two RE: fragments coordinated to a central

tetrahedral hafnocene moiety “HfCp2” in a “V-shape” E–Hf–E bonding motif. The E–Hf–E bond

angles in 10 and 11 of 100.76(6)° and 95.26(4)°, respectively, compare well with the corresponding E–M–E bond angles (97° av.) in the isoelectronic Cp2M(ER)2 (M = Ti, Zr; E =

Ga, In) complexes. The two-coordinate group 13 metals form an essentially linear HfEC bond

angle (Hf(1)-Ga(1)C(1) = 171.7(3)°; Hf(1)-In(1)C(1) = 171°) with the ligand and hafnium

metal. The slight deviation from linearity is undoubtedly due to steric repulsion between the

bulky ligands. The most dominant structural feature of 10 and 11 is the m-terphenyl ligands. The

Hf–E bonds, however, are the most notable feature of these compounds. It is difficult to assess

the Hf–E bond distances in 10 and 11 (Hf(1)–Ga(1) = 2.6198(13) Å; Hf(1)–In(1) = 2.7667(10)

Å) due to the absence of examples with which compare, though they are substantially shorter

than the sum of their respective covalent radii (Hf–Ga = 2.76 Å; Hf(1)–In(1) = 2.94 Å). The

possibility for EE bonding in 10 and 11 is eliminated due to exceedingly long GaGa and

InIn contacts (4.036 Å and 4.088 Å, respectively), which are well out of range for metalmetal

bonding (sum of covalent radii, Ga = 2.52; In = 2.88 ).

Figure 2.15. Molecular structure of Cp2Hf(GaR)2 (10)

Table 2.10 Selected bond distances [Å] and angles [°] for Cp2Hf(GaR)2 (10) Atoms Distance Atoms Angle Hf(1)Ga(1) 2.6198(13) Ga(1)Hf(1)Ga(1A) 100.76(6) Ga(1)C(1) 2.021(10) C(1)Ga(1)Hf(1) 171.7(3)

Figure 2.16. Molecular structure of Cp2Hf(InR)2 (11)

Table 2.11 Selected bond distances [Å] and angles [°] for Cp2Hf(GaR)2 (11) Atoms Distance Atoms Angle Hf(1)In(1) 2.7667(10) In(1)Hf(1)In(1A) 95.26(4) In(1)C(1) 2.194(13) C(1)In(1)Hf(1) 171.3(3)

For more detailed discussion of the bonding of 10 and 11, our previous DFT calculations

on Cp2M(EPh)2 (M = Zr, E= Ga) provide evidence to suggest that the relatively short M–E bonds

are a result of a donor–acceptor ME -bond that is augmented by ME -back-bonding.147

Furthermore, these computations revealed detailed molecular orbital descriptions (Fig. 2.17) that

show the ME bonds are a culmination of the antisymmetric HOMO-1 and symmetric HOMO-2

orbitals, wherein the sp-orbitals of the main group metals donate electrons into the empty d-

orbitals of the group 4 metal, and the HOMO is indicative of -back-bonding from the Cp2M

fragment into the essentially linear RE: fragment. A similar conclusion was discerned

140 163 computationally for two similar compounds, RInMnCp(CO)2 and RGaFe(CO)4, which also suggested the short EM bonds were the result of substantial ME -back-bonding.164

Figure 2. 17. DFT calculated HOMO, HOMO-1 and HOM-2 orbital for Cp2M(ER)2 compounds

2.2.2 Synthesis and Structure of (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12)

It is well known that ligand steric properties can influence metal aggregation in

compounds containing homonuclear main group metalmetal bonds. In this same regard, we

pondered how does this factor affect the structure and bonding of organometallic species

containing group 13group 4 bonds. We have previously shown that when RBiCl2 (R = 2,6-

Mes2C6H3-) and Cp2ZrCl2 are reduced with sodium metal, a Cp2Zr(BiR)2 complex containing a

165 ZrBi2 trimetallic ring is formed. This is contrary to the “V shaped” EME metallic cores

observed in the Cp2Hf(ER)2 compounds 10 and 11. Indeed, this inspired us to gain further insight

into the effect of utilizing even smaller ligands to stabilize group 13group 4 bonds. Fortunately,

our studies of m-terphenyl ligands, 2,6-(4-t-BuC6H4)2C6H3- (R) and 2,6-(4-Me-C6H4)2C6H3- (R), on group 13 metal halides provided adequate precursors to examine in these endeavors.

Though several experiments were performed with various group 13 metals, group 4 metallocenes, ligands, and solvents, only one of these reactions gave crystals adequate for single crystal X-ray analysis. In particular, the sodium metal reduction of RGaCl2·OEt2 (1) in the

presence of Cp2ZrCl2 was performed, wherein the initial colorless solution transforms from

green to almost black over several days (Eq. 2.6). After “hot” filtration of the mother solution

and placing the solution at room temperature for several days, rectangular dark purple crystals

were isolated (12 %).

Na/ Et2O RGaCl2(Et2O) + Cp2ZrCl2 (C10H8)(ZrCp)2(μH)(μCl)(μ-GaR) 1 12 (2.6)

Upon single crystal X-ray structural analysis a trimetallic fulvalene-bridged

dizirconocene-gallium complex containing GaZr bonds was revealed, 12 (Fig. 2.18).

Compound 12 is notable as the first example of gallium bonded with two zirconium atoms. The

literature reveals only two somewhat related aluminum-based compounds containing bridging

166 167 hydride ligands: (C10H8)[CpTi]2(μ-H)(H2AlEt2), and [Cp2Zr(μ-H)]2(μ-H)AlCl2. In

accordance with standard electron counting of the structure 12, the zirconium atoms would be of

mixed oxidation states (+3 and +4). This would provide a compound with paramagnetic

properties, however 12 is ESR silent. Furthermore, radicals commonly distort 1H NMR spectra

by paramagnetic line broadening, but the spectrum of 12 correlates well with its X-ray structure

except for a singlet signal at -4.316 ppm. Initially, this signal was attributed to signal noise or

contaminates; however, after rigorous purification and varying the deuterated solvents, the signal remained. Moreover, this 1H NMR signal (-4.316 ppm) in 12 compares well with the analogous

bridging dizirconium hydride, ZrHZr, signal (-4.67ppm) in the cationic dizirconium complex

[(C10H8)Zr2(μ-Cl)(μ-H)(CH2CCSiMe3)][BMe(C6F5)3], and there are no signals in the spectrum

to suggest a terminal ZrH hydride (3.03 to 7.25 ppm).168-171 It was anticipated that a hydrogen

atom that was undetected by X-ray crystallography techniques might be present in the structure

of 12.

The literature provides two reports that are related to 12 for possible clues to hydride

sources. Indeed, it has been reported that the sodium amalgam reduction of Cp2ZrCl2 forms a fulvalene bridged dizirconocene complex, (C10H8)[CpZr(μ-Cl)]2, by means of cyclopentadienyl

ligand C–H activation172 and that unsymmetrical 9-borafluorenes are formed by a facile

intramolecular C–H activation of the identical m-terphenyl ligand used in 12.130,131 Both of these processes generate putative hydride formation.

Figure 2.18. Molecular structure of (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12)

Table 2.12 Selected bond distances [Å] and angles [°] for (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) Atoms Distance Atoms Angle Ga(1)C(1) 2.019(5) Zr(1)Ga(1)Zr(2) 77.33(2) Ga(1)Zr(1) 2.7457(9) Cl(1)Zr(2)Ga(1) 92.76(4) Ga(1)Zr(2) 2.8796(10) Zr(1)Cl(1)Zr(2) 84.73(4) Zr(1)Cl(1) 2.6033(13) Cl(1)Zr(1)Ga(1) 96.17(4) Zr(2)Cl(1) 2.6141(13) Cl(1)Zr(2)Ga(1) 92.76(4)

To ascertain where a possible ZrHZr hydride signal in 12 should appear in its 1H NMR

spectrum, a theoretical spectrum of a model compound, 12a (C10H8)[CpZr]2(μ-H)(μ-Cl)(μ-GaR)

(R = 2,6-Me2C6H3-) (Fig. 2.19), was computed at the GIAO-PW91PW91/LANL2DZ/-

/PW91/LANL2DZ level. The theoretical chemical shift of the bridging hydride signal (-5.00

ppm) in 12a is comparable to that observed for the experimental value in 12 (-4.316 ppm). The

deviation in chemical shifts may be attributed to the differing chemical environments, primarily

due to the anisotropic effects of the bulky m-terphenyl ligand. In an effort to better understand

the nature of the hydride, density functional theory (DFT) computations were performed on 12a.

Two different methods, B3LYP and PW91PW91, were used in conjunction with the LANL2DZ

basis set for the optimization of 12a (Fig. 2.19). The hydride ligand was arbitrarily positioned in

12a but was ultimately optimized as a ZrHZr bridging hydride.

Figure 2.19. PW91PW91/LANL2DZ optimized structure of (C10H8)[CpZr]2(μ-H)(μ-Cl)(μ-GaR) (R = 2,6-Me2C6H3-) (12a)

In accordance with the molecular structure and computations, the structure of 12 can be

described as a trimetallic fulvalene-bridged dizirconocene-gallium complex with bridging

hydride and chloride ligands with a formula of (C10H8)(ZrCp)2(μH)(μCl)(μGaR). The two

zirconium atoms have formal oxidation +4 states. This can be easily discerned by localizing the

hydride and chloride ligand on separate zirconium atoms (Fig. 2.21). The possibility of the

hydride atom residing on the Ga in 12 is highly unlikely due to two factors: 1) the trigonal planar

environment about the gallium atom; 2) the absence of a GaH bond IR stretch (1800-200 cm-1).

Zr Cl Zr Zr Cl Zr H H Ga Ga

R R

Figure 2.20. ChemDraw representation of 12 depicting with bridging and localized chloride and hydride ligands

A closer inspection of the structure 12 shows that the Zr atoms are coordinated to Cp

ligands, as well as bridging RGa and Cl ligands, which affords a (μ-Ga)Zr2(μ-Cl) four- membered butterfly (bent) core. The two zirconium atoms are also coordinated in a 5-fashion to

the fulvalene ligand and are held in close proximity (ZrZr separation of 3.516 Å). This distance

is only slightly longer than the sum of zirconium covalent radii, 3.4 Å, suggesting minimal ZrZr

contact. Computational studies, however, have suggested that through-space Zr···Zr interactions may occur up to 4.25 Å.173

The structure of 12 also has several additional interesting features of note. Perhaps most significant are the varying GaZr bond distances (Ga(1)Zr(1) 2.7457(9) Å and Ga(1)Zr(2)

2.8796(10) Å), which may be in large part due to steric crowding about the trimetallic centers.

As demonstrated in the space filling view of 12 (Figure 2.19), the m-terphenyl ligand extends

beyond the fulvalene ligand, causing considerable steric interactions. As a consequence, there are

close intramolecular CH···HC interactions between the fulvalene ligand and the flanking phenyl rings (H(33A)···H(12A), 2.583 Å; H(33A)···H(11A), 2.785 Å). To lessen steric congestion, it appears that the central phenyl ring of the m-terphenyl ligand assumes a skewed

conformation (63.41°) relative to the GaZr2 plane, instead of an orthogonal orientation. This

structural manifestation is not only apparent in the solid state but also in solution, as the low- symmetry disposition of 12 is evident in its 1H NMR spectrum which displays two singlet signals

for the Cp ligands and eight well-resolved multiplets corresponding to the fulvalene ligand (two

ABCD spin systems).

Figure 2.21. Space filling model of (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12)

The GaZr bond distances in 12 are comparable to those bonds found in

149 [Li(THF)4][Cp2Zr{Ga[N(Aryl)C(H)]2}2] (Aryl = 2,6-i-Pr2C6H3-) (2.7417(7) and 2.7349(8) Å),

however they are significantly longer than those in Cp2Zr(GaR)2 (R = 2,6-(2,4,6-i-

146 Pr3C6H2)2C6H3-) (2.6350(8) Å), which possesses ZrGa -back-bonding. The Zr(1)Cl(1) and Zr(2)Cl(1) bond distances in 12, 2.6033(13) and 2.6141(13) Å, respectively, are

174 unremarkable and compare with those in (C10H8)[(Cp)Zr(μ-Cl)]2 (2.568(2) and 2.591(2) Å).

Perhaps expected, these bonds in 12 are longer than the terminal ZrCl bonds in

172 (C10H8)[CpZrCl]2(μ-O) (2.471(1) Å). The Zr(1)Cl(1)Zr(2) bond angle (84.73(4)°) in 12 is

smaller than either of the GaZrCl bond angles (92.76(4)° and 96.17(4)°) but slightly larger

than the analogous angles in (C10H8)[CpZr(μ-Cl)]2 (77.35° mean avg.)°. The Zr(1)Ga(1)Zr(2)

bond angle in 12 is 77.33(2)° and has no example to compare.

Returning to the DFT optimized structure of 12a reveals that it agrees well with the

experimental structure of the 12. There are some discrepancies, however, which is observed

when comparing the overall geometry. As previously suggested, the m-terphenyl ligand in 12 is

skewed with respect to the GaZr2 plane due to steric interaction. The structure of the 12a, which

contains a substantially less bulky 2,6-Me2Ph ligand, supports this proposal as the mesityl plane

is nearly perfectly orthogonal to the GaZr2 plane. Additionally, the GaZr bond distances

(2.7457(9) and 2.8796(10) Å) in 12 spans a greater range than those computed for the more

symmetrical and idealized 12a (2.842 and 2.839 Å). Certainly, the steric bulk of the m-terphenyl ligand in 12 contributes to this manifestation.

2.3 m-Terphenyl Group 4 Metallocenes

2.3.1 Synthesis and Structure of Cp2TiR (R = 2,6-(4-Me-C6H4)2C6H3-) (13)

Sodium metal reduction of R3In (R = 2,6-(4-Me-C6H4)2C6H3-)(7) in the presence of

Cp2TiCl2 gave the unexpected formation of a trivalent m-terphenyl stabilized titanocene

complex, Cp2TiR (13) (Eq. 2.7). Though the formation of 13 is not well understood, it is known

174 - 175,176 that triorganoindium, R3In, and indates, R4In , are commonly utilized as nucleophilic

organometallic substrates in catalyzed and non-catalyzed cross coupling reactions of aryl halides.

The formation of 13 may follow a similar pathway, wherein ligand-halide exchange occurs

between R3In and a Cp2TiCl intermediate. Unfortunately, the results of this experiment could

177 not be reproduced, usually giving only the titanocene monochloride dimer [Cp2TiCl]2.

Na R3In + Cp2TiCl2 Ti (2.7) (7)

Monomeric trivalent cyclopentadienyl titanium(III) derivatives are very rare and only a

few unambiguously structurally characterized species have been reported.178-181 Furthermore,

only one of these structurally characterized compounds incorporates unsubstituted Cp ligands,

178 Cp2TiR (Cp = C5H5, R = Mes). Pursuing this compound was of interest due its novelty, however a different synthetic approach would be required. We proposed that 13 could be

synthesized by direct reaction of RLi with [Cp2TiCl]2. Acquiring [Cp2TiCl]2 in adequate

182 177 quantities was approached by several literature techniques including aluminum and zinc

metal reduction of Cp2TiCl2, however yields were low and purification/isolation protocols were

laborious. Lithium nitride (NLi3) reduction of Cp2TiCl2 with in THF was the most practical

183 means to synthesize [Cp2TiCl]2 in acceptable yields (50%) (Eq. 2.8). As predicted, RLi reacts

smoothly with [Cp2TiCl]2 to give green-brown crystals of 13 in good yield (50%) (Eq. 2.9).

Cl 1/ Li N, THF Cl Ti 3 3 Ti Ti -1/ N , -3 LiCl Cl 6 2 Cl (2.8)

[Cp2TiCl]2

Cl THF, -78°C Ti Ti + 2 Li 2 Ti (2.9) Cl -2 LiCl

The single X-ray crystal structure of 13 (Fig. 2.22) displays a trivalent titanocene in a

distorted trigonal planar titanium atom with respect to the Cp centroids, which is demonstrated

by summation of the exceptionally large Cp(centroid)Ti(1)Cp(centroid) bond angle (134.93°) and the two equivalent C(1)Ti(1)Cp(centroid) bond angles (112.54°) to account for 360° around the

Ti atom. The sterically imposing m-terphenyl ligand adequately protects the labile metal center

and dwarfs the Cp ligands. The central phenyl ring of the ligand is aligned nearly orthogonal to

the Cp(centroid)TiCp(centroid) plane in an orientation that imposes a two-fold axis that passes

through the central phenyl ring and the titanium atom. The outer phenyl rings of the m-terphenyl

ligands are C2 symmetry related and have several close CHHC interactions with the CP

ligands (2.274 Å).

The Ti(1)-C(1) bond length in 13 of 2.242(2) Å is comparable to other trivalent

179 titanocenes such as Cp*2TiCH2CMe3 (Cp* = C5Me5) (2.231(5) Å) and Cp2TiR (R = 2,6-

178 Me2C6H3) (2.178(7) Å), and surprisingly similar to the tetravalent 17-electron complex,

180 1 Cp2Ti[2-((CH3)2NCH2)C6H4], (2.22(3) Å), but slightly shorter than those (2.332(2) Å) in -

5 181 C5H5)2( -C5H5)2Ti.

The trivalent nature of 13 and the of lack an observable counter ion are characteristic

features of 15-electron trivalent titanium species, Cp2*TiR (Cp* = Me5C5, R = aryl, alkyl,

halide). Hence, it is compelling to assign a d1 electron configuration to the titanium atom. The 1H

NMR spectrum of 13 shows a series of broad and ill-defined signals that were insufficient for

integration and characterization. The presence of a radical would undeniably cause such a

distortion. An ESR spectrum was recorded to rule out the possibility of an undetected hydride

and also to confirm the paramagnetic properties of 13. Two signals were observed in the ESR

spectrum of 13. The characteristic high-field singlet signal at g = 1.959 (line width 12 G) is

similar to those for other 15-electron titanium(III) species and confirms the paramagnetic nature

of 13, while the smaller low-field signal at g = 1.979 (line width of 6 G) is evidence of THF

coordination to the titanium center. The two signals may represent an equilibrium process

184 between the two species. A similar occurrence was observed for (C5HPh4)2TiCl. Though sterically encumbered electron-deficient, 15-electron, monomeric Cp2*TiR compounds are

reluctant to dimerization or form adducts with solvents or salts, the titanium atom in 13, seems to

be accessible to donor solvents. This is a promising phenomenon for the possible utility of 13 to

185 serve as a one-electron reducing reagent or as a substitute for Cp2TiCl in pinacol and

McMurray186 coupling reaction protocols.

Figure 2.22. Molecular structure of Cp2TiR (13)

Table 2.13 Selected bond distances [Å] and angles [°] for Cp2TiR (13)

Ti(1)C(1) 2.242(2) Cp(centroid)Ti(1)Cp(centroid) 134.93

Ti(1)Cp(centroid) 2.059 C(1)Ti(1)Cp(centroid) 112.54

2.3.2 Synthesis and Structure of Cp2Zr(R)(Cl) (R = 2,6-(4-t-BuC6H4)2C6H3-) (14)

As demonstrated with 13, adequate steric protection about titanium may afford stable

monomeric trivalent Ti(III) radicals; however, this characteristic has thus far eluded zirconium.

+ Typically, trivalent zirconocene compounds are cationic complexes, [Cp2ZrR] , which commonly accept donor molecules,187,188 while zirconocene(III) halides tend to dimerize as

174 demonstrated in the dizirconocene complex [(C10H8)(ZrCp)2(μ-Cl)2]. We hypothesized that a

Zr(III) radical could be synthesized by alkali metal reduction of a sterically crowded

Cp2Zr(R)(Cl) precursor. Our initial attempts to synthesize Cp2Zr(R)(Cl) (R = 2,6-(2,4,6-i-

Pr3C6H2)2C6H3-) were unsuccessful, perhaps due to excessive steric interactions between the Cp

rings and m-terphenyl ligand. Specifically, we postulated that substitution at the ortho-positions

of flanking phenyl rings did not allow the ligand to approach the Zr center, thus we selected a

ligand without such substitution. Indeed, reaction of RLi (R = 2,6-(4-t-BuC6H4)2C6H3-) with

Cp2ZrCl2 affords Cp2Zr(R)(Cl) (14) as colorless crystals (Eq. 2.10). We also proposed that the

corresponding titanium precursor, Cp2Ti(R)(Cl), was an interesting undertaking, as it would

provide an alternative route to 13 through alkali metal reduction. However reaction of RLi with

Cp2TiCl2 only gives the green [Cp2TiCl]2 species (Eq. 2.11). A similar occurrence was observed

189 when Cp2TiCl2 is allowed to react with i-PrMgBr. Thus, it appears that the nucleophilic properties of RLi is dominated by its basicity.

Na Cp2ZrCl2 + RLi Cp2Zr(R)(Cl) RH 14 (2.10)

Cp2TiCl2 + R Li [Cp2TiCl]2 (2.11)

To complete the final step to synthesize the elusive Zr(III) radical species, 14 was reduced with sodium metal in toluene over three days to give a green solution (Eq. 2.10).

Unfortunately, only ligand hydrocarbon (R-H) could be isolated and no further attempts were pursued. although the target molecule, Cp2ZrR, was not successfully synthesized, the single

crystal X-ray structure of its precursor 14 (Fig. 2.23) is interesting in its own right, as it is the first m-terphenyl zirconium complex.

The structure of 14 provides a glimpse into the steric effects of the bulky m-terphenyl ligand on zirconocene. As evidence of the wide C(1)Zr(1)Cl(1) and

Cp(centroid)Zr(1)Cp(centroid) bond angles, 118.79 and 130.73°, respectively, the four coordinate

zirconium atom adopts a trigonal pyramidal environment (Cp(centroid)Zr(1)Cl(1), 101.54 and

101.90°; Cp(centroid)Zr(1)C(1) 100.54 and 105.00°). The structure shows that the outer phenyl

rings on the m-terphenyl ligands are twisted (torsion angle = 80° av) from the central phenyl

rings, and the plane of central phenyl ring is slightly tilted (14°) out of co-planarity with

C(1)Zr(1) to lessen steric interactions with Cp ligands. Nevertheless, the ligands are separated

by less than 2.4 Å. This may also have an affect on the Zr(1)C(1) bond distance (2.380(4) Å), which is significantly longer than the analogous bond distances in Cp2Zr(Cl)(CH2PMe2) and

190 Cp2Zr(Cl)(CH2PPh2), 2.272(6) and 2.317(5) Å, respectively. The ZrCp(centroid) and

Zr(1)Cl(1) bond distances in 14 are 2.200 and 2.461(12) Å, respectively, and are generally

unremarkable.

In conclusion, although we could not successfully synthesize a stable monomeric

Zr(III)species, its precursor 14 joins a exceedingly small collection of zirconocene complexes

with a both halide and aryl substitution191 and the only m-terphenyl zirconocene.

Figure 2.23. Molecular structure of Cp2Zr(R)(Cl) (14)

Table 2.14 Selected bond distances [Å] and angles [°] for Cp2Zr(R)(Cl) (14)

Atoms Distance Atoms Angle Zr(1)C(1) 2.380(4) Cp(centroid)Zr(1)Cp(centroid) 130.73 Zr(1)Cl(1) 2.4612(12) C(1)Zr(1)Cl(1) 118.79(9)

2.4 Gallepins

Our research group has long had a fascination with the concept of aromaticity. Indeed,

24 25 our pioneering discoveries of the cyclotrigallenes, M2[Mes2C6H3Ga]3 (M = Na or K ; Mes =

2,4,6-Me3C6H2), were the first experimentally realized compounds to possess all metallic rings that display traditional aromatic properties and transformed the initial concept of metalloaromaticity. Aromatic species, wherein a metal moiety, MR, replaces a CH fragment of

an arene, have also been the subject of a number of studies.192-199 The exceptional work

conducted by Ashe demonstrated that a BR moiety can readily replace a CH fragment of an

aryl six-membered ring to give anionic six-membered aromatic BC5-boron-carbocycles known as

boratabenzenes.172,200-204 This strategy can also be extended to give borepinsneutral seven-

205-209 membered BC6-boron-carbocycles that are isoelectronic with the tropylium ion. Besides being structurally interesting, the boratabenzenes can serve as alternatives to cyclopentadienyl substitutes for preparing novel transition metal “sandwich” complexes, which have been shown to have surprising catalytic function in olefin polymerization reactions.210,211 On the other hand,

borepins may serve as 7-coordinating ligands for constructing interesting half-sandwiched

Cr209,212 and Mo207,208,213 complexes, however no catalytic activity has been documented utilizing

these complexes.

While the chemistry of aromatic borocarbocycles is quite developed, the analogous

chemistry of gallium is not. Perhaps the distinct electronegativity differences between gallium

and boron constitute this disparity. Though five-membered GaC4-heterocycles are fairly well

132,134-137,214 known, the gallatabenzene, RGaC5H5 (R = Mes), and its precursor, RGaC5H6, are the only examples of six-membered gallium-carbocycles.215 A seven-membered gallium-carbocycle

remained unknown, hence synthesizing this elusive species seemed liked a worthy endeavor, as a

wealth of experimental, spectroscopic, computational, and chemical knowledge would be obtained and would also provide an opportunity to evaluate the aromatic properties of the tropylium ion when a CH fragment is replaced with a gallium moiety, GaR. The borepins have already proven to be aromatic, but how does gallium affect -electron delocalization? Its larger atomic radius (1.30 Å) and metallic properties are central to this question. These seven- membered gallium carbocycles would be isoelectronic with borepins and the tropylium ion

+ 216,217 (cycloheptatrienyl cation, C7H7 ), thus following established nomenclature, they will be referred to as gallepins. The corresponding structures for the tropylium ion, borepin and gallepin are shown in Figure 2.24.

X X

B Ga

Tropylium ion Borepin Gallepin

Figure 2.24. Tropylium ion localized cation and delocalized cation, borepin, and gallepin

Though borepins are readily prepared by boron-tin exchange reactions of the respective stannepin (R2SnC6R6) and organoboron dihalide derivative, RBX2 (Eq. 2.12), this has not been effective strategy to synthesize gallepins; thus, a different approach would have to be embraced to accomplish this undertaking.

(2.12) + RBX2 - R2SnX2 Sn B

R R R

This group’s previous syntheses of five-membered GaC4-heterometallacycles by employing dilithium precursors in ring closure metathesis of gallium halides presented a practical means to prepare gallepin derivatives.132,133Conceptually, ring closure of 1,6-dilithio-

hexa-Z,Z,Z-1,3,5-triene about GaCl3 should easily afford a gallepin (Eq. 2.13). Unfortunately,

there is no convenient synthetic report of the all Z-isomer. We speculated that a Z,Z,Z-trienyl

type system may be better stabilized by replacing the 1,2 and 5,6-olefin segments with phenyl

rings, providing in essence stilbene. Installing bromide atoms at the 2 and 2 positions of Z-

stilbene would allow for selective lithiation at these positions with n-BuLi to give access to the

dilithium derivative.

(2.13) + GaCl3 X Li Li Ga

Auspiciously, Gilheany and coworkers have demonstrated that Z-stilbenes are the major

+ products of Wittig reactions when both the benzyltriphenylphosphonium salt, [PhCH2PR3] , and benzaldehyde, possess ortho-halogen groups.218 In accordance with Vedejs219-221 early mechanism studies, they concluded that a phosphorous-bromide interaction occurs in the transition state to create a “cooperative effect” that makes the Z-isomer preferential.

Indeed, 2,2-dibromo-Z-stilbene (15) is conveniently prepared in good yield as large

colorless crystals by a two-step process (Eq. 2.14). The first step is an Arbuzov reaction of

triphenylphosphine and 2-bromobenzylbromide in refluxing toluene to give 2-

bromobenzyltriphenylphosphomium bromide, which is followed by addition of 2-

bromobenzaldehyde and sodium hydroxide. Surprisingly, the single crystal X-ray structure of 15

has not been reported and is shown in Figure 2.25. The structure of 15 is fairly direct and the

bond distances are as expected. The most interesting feature may be that the molecule is C2

symmetric.

Br Br Br 2-bromobenzaldehyde Br Toluene, PPh 3M NaOH + PPh3 reflux, 4h 3 - OPPh3 (2.14) Br Br 15

Figure 2.25. Molecular structure of 2,2-dibromo-Z-stilbene (15)

With significant quantities of 2,2-dibromo-Z-stilbene (15) in hand, the task became one of obtaining the dilithio precursor. Initially, this step seemed routine and was pursued by reaction with two equivalence of n-BuLi with 15. When the reaction is conducted in diethyl ether the initial colorless solution of 15 turns orange upon addition of n-BuLi. Removal of all solvent

provides orange oily residues consisting of a mixture of products (determined by 1H NMR

spectroscopy) (Eq. 2.15). Alternatively, when the reaction is performed in hexane an orange precipitate forms, which removal of solvent gives a pyrophoric orange powder that spontaneously ignites in air (Eq. 2.15). Given that several single X-ray structures of dilithio organometallic compounds incorporate TMEDA,222,223 it was thought that TMEDA may also be useful at stabilizing the dilithio precursor. It was found that addition of TMEDA to the pyrophoric orange powders in hexane/diethyl ether (10:1) gives orange-red crystals of the dilithio precursor, 2,2-dilithio-Z-stilbene(TMEDA)2 (16) (Eq. 2.15). Alternatively, 16 may also be isolated by extraction of the orange oily residue with hexanes, followed by addition of

TMEDA (Eq. 2.18). If TMEDA is added to the diethyl ether parent solution, copious amounts of

[(TMEDA)LiBr]2 are formed and only minute quantities of 16 are secured (Eq. 2.15).

Et O 2 Orange Oil

Hexane 2 n-BuLi Orange Powder 15 (2.15) -78°C 1) Et2O, 2) TMEDA 16 + [(TMEDA)LiBr]2 (major product) 1) Et O, 2) hexanes 2 16 3) TMEDA

Compound 16 (Fig. 2.26) was examined by single crystal X-ray crystallography to evaluate its structure and bonding, which revealed a Z-stilbenyl moiety bridged by two lithium atoms at the C(1) and C(1A) positions to form a four-membered Li2-μ-C2 butterfly ring. Indeed,

Li2-μ-C2 butterfly cores have been a common structural manifestation for an array of TMEDA stabilized ortho-dilithium biphenyl compounds.224-226 Computations suggest that this bonding model is energetically favored as a consequence of electrostatic interactions.222,223,227 For

comparison purposes, the bonding arrangement in E-stilbenyl bis(lithium TMEDA)228 is distinctly different from that in 16, as to be expected, because the anionic sites are at completely different locales. Whereas in 16 intramolecular dilithium dimerization is stabilized because the ortho-positions are anionic, the lithium atoms in E-stilbenyl bis(lithium TMEDA) are - coordinated above and below the central ethylene segment of the E-stilbene moiety because the two hydrogens on the olefin segment have been deprotonated.

There are several interesting structural features of 16 that merit discussion. Particularly, the central C6 fragment in is nearly planar. To accommodate this configuration the

C(6)C(7)C(7A) bond angles (139.70°) are bent well past ideal trigonal planar geometry

(120°) and the phenyl rings are slightly puckered. A mirror plane bisects through the C(7) and

C(7A) atoms of stilbenyl olefin segment and the lithium atoms, however there are no rotation axes. The coordination spheres about the lithium atoms assume tetrahedral geometry, afforded by bridging the C(1) and C(1A) atoms of the stilbene ligand and chelation of the TMEDA molecules. The Li(2)C(1) and Li(2)C(2) bond lengths are essentially equivalent (2.157(8) and

2.158(4) Å, respectively) and compare well with those of other ortho-dilithium biphenyl compounds (2.147-2.166 Å).224-226 The anionic carbons are in a seriously distorted tetrahedral environment, and they are well separated at a distance of 3.326 Å.

Figure 2.26. Molecular structure of 2,2-dilithio-Z-stilbene(TMEDA)2 (16)

Table 2.15 Selected bond distances [Å] and angles [°] for 2,2-dilithio-Z-stilbene(TMEDA)2 (16) Atoms Distance Atoms Angle Li(1)C(1)#1 2.158(4) C(1)#1Li(1)C(1) 100.8(3) C(1)C(2) 1.405(3) C(1)#1Li(2)C(1) 100.9(3) Li(1)N(2) 2.155(6) C(1)Li(1)Li(2) 54.13(14) Li(1)N(1) 2.194(7) N(2)Li(1)N(1) 84.0(2) Li(1)Li(2) 2.527(8) N(3)Li(2)N(4) 83.9(2) Li(2)N(3) 2.187(7) C(1)C(6)C(7) 124.9(2) Li(2)N(4) 2.247(6) C(7)#1C(7)C(6) 139.70(12)

The isolation of 16 proved that 2,2-dibromo-Z-stilbene could be selectively lithiated by

salt metathesis reactions, and that although a mixture of products, the orange oils and pyrophoric

powder contained the “TMEDA-free” dilithium species. The reactivity of the “TMEDA-free”

orange oil and pyrophoric powder with GaCl3 was evaluated to determine if TMEDA

stabilization was necessary to isolate the gallepin. Perhaps as expected, these reactions generally

gave viscous impure yellow oils. The 1H NMR spectra of these oils were too complex to be adequately useful for characterization, as a multitude of peaks were observed in the aromatic region (6.5-8.0 ppm). Purification by distillation was not attempted due to concerns of destroying the thermolabile GaC bonds. After considerable synthetic effort, however, poor quality colorless crystals covered with yellow oil were isolated from reaction of the orange oil with

GaCl3 (Eq. 2.16). The crystals were suitable for single crystal X-ray analysis and were ultimately

determined to be a spirogallate, (spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17). The single

crystal X-ray structure of 17 (Fig. 2.27) has two very similar molecules in one asymmetric unit

thus only one will be discussed.

Br Br

2 n-BuLi GaCl Ga (2.16) Orange Oil 3 -78°C Hexane,-78C° Li

15 Et2O 17

Figure 2.27. Molecular structure of [spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17)

Table 2.16 Selected bond distances [Å] and angles [°] for [spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17) Atoms Distance Atoms Angle Ga(1)C(1) 1.972(4) C(33)Ga(2)C(42) 108.64(19) Ga(1)C(15) 1.987(4) C(47)Ga(2)C(56) 106.96(16) Ga(1)C(10) 2.022(4) C(56)Ga(2)C(42) 109.33(15) Ga(1)C(24) 2.030(4) C(47)Ga(2)C(33) 117.54(19) Ga(1)Li(1) 2.722(9) C(56)Li(2)C(42) 91.1(3)

The structure of 17 reveals a spirogallate anion with a central four-coordinate gallium

atom engaged in bonding with two puckered Z-stilbenyl moieties. Compound 17 is notable as

only the second spirogallate and the only report of a “spirogallepin”. A distortion to ideal

tetrahedral geometry about the gallium is apparent by the C(47)-Ga(2)-C(33) (117.54(19)°) bond

angle. The remaining bond angles about gallium are close to expected. The anionic nature of the

gallate ion is countered by a lithium cation that is coordinated to the C(42) and C(56) atoms of

opposing stilbenyl fragments (CLi bonds distances, 2.305(9) Å) to form a “diamondlike” four-

membered GaC2Li ring. Indeed, the heteroatomic ring is quite distorted due to variance in bond

angles. While both of the GaCLi bond angles are close to 80°, the C(42)Ga(2)C(56) and

C(42)Li(2)C(56) (109.33(15)° and 91.1(3), respectively), vary significantly, by more than 20°.

The Li atom assumes trigonal planar geometry by coordinating to the opposing stilbenyl ligands and a molecule of diethyl ether. The GaC bond distances in 17 range from 1.972(4) to 2.030(4)

Å and compares well with those in the first spirogallate, [{(PhC=CPh)2}2Ga][Li(THF)12-

crown-4] (2.001(5)-2.023(5) Å)133 and the five-membered gallate heterocycle

132 [{(PhC=CPh)2}GaCl2][Li2(OEt2)4] (1.966(4) Å). Due to the flexibility of the Z-stilbenyl

ligands in 17 the interannular CGaC bond angle (C(47)Ga(2)C(56) and

C(33)Ga(2)C(42), 108.64(19)° and 106.96(16)°, respectively) of the GaC6-seven-membered

rings are considerably larger than the corresponding CGaC bond angles reported for five-

membered GaC4 heterocycles (87.4 - 91.4°). Interestingly, when 17 is recrystallized in diethyl ether the Li coordination to the stilbenyl ligands is disrupted to give a slightly different species,

[spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)3], (17a). (Eq. 2.17). The molecule maintains the

essential elements of 17, but the lithium cation is far removed and surrounded by three diethyl ether molecules.

Recrystallize, Et2O Ga Ga Li(OEt2)3 (2.17)

Et2O

17 17a

Though the isolation of 17 is a significant result, its formation denotes the importance of correct stoichiometric ratios of the dilithio precursor and GaCl3. Not only is it integral to ensure a

single ring closure about the gallium atom, but also it would also likely reduce the probability of

side products formed in the reaction. Thus, obtaining a pure sample of the dilithium reagent is of

utmost importance. Utilizing 2,2’-dilithio-Z-stilbene(TMEDA)2, 16, for the ring closure about

GaCl3 seemed promising because it is a pure, solid, crystalline material, and easily handled (not

pyrophoric). Indeed, allowing 16 to react with GaCl3 in diethyl ether gave large colorless crystals

of bis(gallepin)2·TMEDA (18) (Eq. 2.18) in good yield (60%).

1) 2 n-BuLi 16 GaCl3, Et2O 18 (2.18) 2) TMEDA -78°C Br Br

The crystal structure of 18 (Fig. 2.28) provides a compelling view of the first gallepin.

The structure shows two gallepins bridged on opposite ends of a “stretched-out” TMEDA

molecule. Although not easily discerned, 18 is C2 symmetric about the center of the TMEDA

molecule. The gallepin moieties adopt a “boat-like” conformation instead of planar, with the

phenyl rings pointed in one direction, while the gallium atom and olefin segment in the other. A

detailed evaluation of the pseudo-tetrahedral four coordinate gallium atoms show that they reside

0.58 Å above the central C(1)C(6)C(9)C(10) plane at an angle of 35°. Similar to that in 17, the GaC6-seven-memebered rings show significant signs of angle strain, as the C(6)C(7)C(8)

and the C(7)C(8)C(9) bond angles (137.45(17)° and 137.93(18)°, respectively) of the olefin segment are substantially larger than expected for sp2-hybridized carbons. The Ga(1)C(1) and

Ga(1)C(10) bond distances, 1.9476(17) Å and 1.9477(18) Å, respectively, are as expected and comparable to those bond distances for other gallium heterocycles (1.934-2.164 Å).

Figure 2.28. Molecular structure of bis(gallepin)2·TMEDA (18)

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Table 2.17 Selected bond distances [Å] and angles [°] for bis(gallepin)2·TMEDA (18) Atoms Distance Atoms Angle Ga(1)C(1) 1.9476(17) C(1)Ga(1)C(10) 117.94(7) Ga(1)C(10) 1.9477(18) C(1)Ga(1)N(1) 104.64(6) Ga(1)N(1) 2.1158(15) C(10)Ga(1)N(1) 108.99(7) Ga(1)Cl(1) 2.2258(5) C(10)Ga(1)Cl(1) 112.29(5)

Several structural features of the gallepin moieties in 18 are counterintuitive to elicit

aromatic properties, i.e., 1) the puckered boat-like conformation of the gallepin moieties, 2) the

alternating CC bond distances (1.41, 1.46, 1.35 Å av.), and 3) the coordinating amine. In an effort to better assess aromaticity and compare structures, computations were performed on two simpler models: 18Cl(NMe3) and 18Cl (Fig. 2.29). In the 18Cl(NMe3) model compound the

TMEDA molecule in 18 is replaced with trimethylamine (NMe3), whereas 18Cl is free of amine

coordination. The B3LYP/LANL2DZ optimized bond lengths and angles of the models are in

reasonable agreement with 18. There are, however, a few discrepancies worthy of discussion.

Most significant is that the conformations of the two structures differ dramatically. While

18Cl(NMe3) adopts a boat-like conformation, 18Cl is essentially planar, which suggest the

puckered conformation found in 18 is a result of the NGa interaction. Furthermore, the

computed GaC bonds lengths (1.920 Å) in 18Cl are slightly shorter than those in 18

(1.9476(17) Å), while those in 18Cl(NMe3) are comparably longer (1.958 Å). Though the shorter GaC bond lengths in 18Cl may be expected due to lack of amine coordination, the variance of these bond distances between 18 and 18Cl(NMe3) was unexpected because they are

essentially identical. Perhaps, the greater Lewis basic properties of NMe3 attributes to this

structural feature. More surprising, the computed GaCl bond distance (2.230 Å) for 18Cl is

essentially identical to that in 18 (2.2258(5) Å), whereas that computed for 18Cl(NMe3) (2.121

Å) is significantly shorter by 0.1 Å.

101

18Cl(NMe3) 18Cl

Figure 2.29. B3LYP/LANL2DZ optimized geometries of 18Cl(NMe3) and 18Cl.

Nucleus-independent chemical shifts (NICS)106 were computed at the IGLO-

PW91/IGLOIII level to assess aromatic character in 18Cl(NMe3) and 18Cl. In addition, as only

the perpendicular (zz) tensor -MO contributions are utilized, the NICSzz index was employed

to better assess ring current. Full details of these NICS calculation are shown in Table 2. 18. The

positive NICS values for the GaC6-seven-membered rings in 18, 18Cl(NMe3), and 18Cl (2.6,

1.9, and 1, respectively) are indicative of non-aromatic character, however, the NICSzz values substantiate the presence of ring current (18Cl(NMe3) = -9.9, 18Cl = -9). The minute difference

in NICSzz values between 18Cl(NMe3) and 18Cl suggest that amine coordination has minimal effect on the degree of -electron delocalization.

For purposes of comparison, NICS calculations on an unsubstituted base-gallepin without phenyl rings, HGaC6H6, (NICS(0) = -2.3, NICSpzz = -15.3) shows that its values are much more

negative than those in 18Cl(NMe3) and 18Cl and suggest substitution significantly lowers the

aromatic properties. As illustrated in Table 2.19, the NICS values for the phenyl rings in these

species (-5.5, -7.2, and -8, respectively) are considerably more negative than the central GaC6-

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seven-membered rings and thus more aromatic. This is a well-known effect of benzannulation, wherein the more aromatic phenyl rings siphons more -electrons from the lesser aromatic fragment. Moreover, comparison of the NICSpzz values for the base gallepin (HGaC6H6) and borepin (HBC6H6), -15.3 and –27.7, respectively, imply that gallepins are innately less aromatic than borepins.

To conclude, the first spirogallepin (17) and gallepin (18) were synthesized via a

benzannulation approach. NICS(0) and NICSzz calculations on models of 18, 18Cl and

18Cl(NMe3), suggest that these compounds are somewhat aromatic and that amine coordination has minimal effect on ring current. Moreover, the more negative NICS values calculated for

HGaC6H6 implies that the phenyl rings attached the GaC6 ring in 18Cl and 18Cl(NMe3) greatly diminishes their aromatic properties. It was also concluded by NICS calculations that gallepins as a whole are substantially less aromatic than either the borepin or tropylium ion. This is most likely due to the due to large atomic radius of gallium and thus poor orbital overlap of the GaC bond, which impedes electron delocalization.

Table 2.18. NICS, NICS, and NICSzz for seven-membered rings of 18, 18Cl(NMe3), 18Cl, Gallepin, and Borepin

Compound NICS NICS NICSzz 18 2.6 N/A N/A 18Cl(NMe3) 1.9 -5.3 -9 18Cl 1 -6.6 -9.9 Gallepin -2.3 -10.5 -15.3 Borepin -4.4 -15.1 -27.7

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Table 2.19. NICS, NICS, and NICSzz for phenyl rings in 18, 18Cl(NMe3), and 18Cl

Compound NICS NICS NICSzz 18 -5.5 N/A N/A 18Cl -7.2 -19 -32.7 18Cl(NMe3) -8 -19.5 -34.1

2.5 Examinations of Carbenes in Group 13 Chemistry

2.5.1 Introduction

2 Carbenes, R2C:, are neutral compounds containing a sp -hybridized divalent carbon with

a sextet of electrons (Fig 2. 30). Fischer229,230 and Schrock230,231 type carbenes have been thoroughly studied and are usually encountered in transition metal complexes, while in organic chemistry carbenes can be traced back as far as the 1950’s, where they were hypothesized as intermediates in certain mechanisms for reactions such as Simmons-Smith reactions.232 It was

not until Arduengo’s pioneering synthesis and molecular structure determination of 1-3-di-1-

adamantylimidazol-2-ylidene (Arduengo’s carbene) (Fig 2.30) in 1991, that a stable,

independent, and “bottle-able” carbene was experimentally realized.233

Ad Ad C N N Ad =

general carbene Arduengo’s carbene singlet state

Figure 2.30. General carbene shown as singlet state and Arduengo’s carbenethe first structurally characterized carbene.

The key to Arduengo’s carbenes stability lies in attractive steric effects of the adamantyl ligands and the beneficial electronic effects the two -nitrogen atoms. Specifically, the authors noted that the bulky adamantyl ligand provides adequate steric protection for the nucleophilic

104

center to deter dimerization, while from an electronic perspective, a “push-pull” mechanism

balances the dual disposition of the carbene center. To elaborate, a stabilizing effect occurs

wherein the -donor substituents (nitrogen) donate electrons into the “out-of-plane” empty p-

orbital, while simultaneously withdrawing electron density from the singlet pair of “in-plane”

electrons through -electronegativity effects (Fig. 2.31). Though these carbenes contain an

empty p-orbital, computational studies have shown that they are poor -back bonding acceptors

and the -donor properties dominates.234

-donation

N R

R N

electronegativity -effect

Figure 2.31. General N-heterocyclic carbene depicting electron withdrawing effects of the - nitrogen and -donation into the empty p-orbital of carbenic carbon

Arduengo-type carbenes are formally known as imidazol-2-ylidenes, but they have taken on the common name of N-heterocyclic carbenes (NHCs). They have been thoroughly studied and a wide variety of substituents may be placed at the nitrogen atoms and on the imidazole backbone.235-237 The primary use of these carbenes has been to stabilize low-valent transition

metal complexes in place of phosphine ligands, which has proven to enhance catalytic activity in

olefin polymerizations and ring opening and closing metathesis reactions.234 More recently they

have also been employed as potent organocatalysts for a number of transformations.238 Although

carbenes are important components in catalytic systems, in regards to group 13 chemistry, they

105

present a convenient means to stabilize highly reactive trivalent compounds, and several

carbenegroup 13 complexes have been prepared.239-244 We wished to further explore carbenes

on group 13 elements to understand its effect on structure and bonding, and also its viability to

stabilize group 13 metalmetal bonds.

It was predicted that by employing carbenes with substantial steric bulk on group 13

elements, neutral group 13 triple bonds could be synthesized. Since all three valence electrons of

the metal would be available for bonding, upon alkali metal reductions of organometallicgroup

13 trihalide adducts, (L:)EX3 (L: = carbene, E = group 13 element, E = halide), there would be no

need for electron donation from alkali metals to stabilize group 13 EE triple bonds. This project

was motivated by the objections to the galliumgallium triple bond formulation for the digallyne,

21 Na2[RGaGaR] (R =2,6-(2,4,6-i-Pr3C6H2)2C6H3-) (Fig. 1.13), and specifically, the role of the

sodium atoms.84-86 The opposing authors have suggested that sodium is critical to the stability of

the digallyne, as reduction of RGaCl2 with potassium provides a structurally different complex containing a Ga4 ring, K2[Ga4R2] (R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3) (Fig. 1.18), as opposed to a

22 potassium stabilized digallyne “K2[RGaGaR]”. If a neutral galliumgallium triple bond

could be stabilized without alkali metal electron donation, it would provide an opportunity to

compare and contrast its structure with the digallyne, Na2[RGaGaR].

Our preliminary efforts in this regard were aimed at boron, however when (L:)BBr3 (L: =

i :C{N(2,6-Pr C6H3)CH}2) is reduced with potassium graphite in diethyl ether a boronboron

triple bond is not obtained, but instead the first neutral compound containing boronboron

double bond (diborene), R(H)B=B(H)R, is produced.245 This compound contained the shortest

B=B double bond (1.561(18) Å) on record with an essentially planar CB=BC core.245 The

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unexpected formation of the diborene, as oppose to triple bond formation, was attributed to

hydrogen abstraction from the ethereal solvent. Similarly, potassium graphite reduction of

(L:)BBr3 (L: = :C{N(2,6-Mes)CH}2), utilizing a less bulky carbene, also gave a neutral diborene, L:(H)B=B(H):L, however this compound showed exceptional conformational flexibility, as three different polymorphic structures in the solid state were determined by single crystal X-ray analysis with twisted, planar, and trans-bent geometries.246 Though the

boronboron triple bond was obtained from these reactions, it showed that the carbene

interaction with the boron atom is strong enough to persist through relative harsh reductive conditions.

Extending this chemistry to the heavier group 13 elements, however, was met with disappointing results, as alkali metal reductions of (L:)EX3 (E = Al, Ga, In) gave only free carbene and group 13 metal. The carbene ligand appears to have less affinity for the metallic

heavier group 13 members, which may be attributed to the large atomic radius of these elements

that impedes good orbital overlap with the smaller carbenic carbon. We hypothesized that by

augmenting the carbene-group 13 complexes with a CE -bond, cleavage of the L:E bond would be deterred during reductions, due to a higher oxidation state and enhanced steric protection. Mesityl was selected as a viable candidate to utilize in these studies due its attractive steric qualities and the commercial availability of mesitylmagnesium bromide (MesMgBr). An

i initial attempt to synthesize MesGaCl2(:L) (L: = :C{N(2,6-Pr C6H3)CH}2) was performed by

reaction of the (L:)GaCl3 adduct with MesMgBr, however this method proved unsuccessful as only starting material, (L:)GaCl3, was isolated (Eq. 2.19). Alternatively, we attempted to prepare

i MesGaCl2(:L) by reaction of the carbene (L:) (L: = :C{N(2,6-Pr C6H3)CH}2) with MesGaCl2,

however this reaction also lead to the formation of (L:)GaCl3 (Eq. 2.19). Evidently the steric

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pressure around the gallium atom is too severe to accommodate both the mesityl ligand and the large carbene ligand. Moreover, it appears that carbenegallium trichloride adduct formation is

preferred over maintaining or forming new GaC -bonds, as (L:)GaCl3 is the lone product

isolated from either of the described reactions. This is probably not surprising since the dative

nature of the carbene ligand is a favorable interaction for GaCl3 as it provides a full octet of electrons about the gallium atom, whereas it is well known that GaC -bonds are highly labile and sensitive to protolysis. This was also demonstrated by Nolan and coworkers, who have shown that several carbenegallium trichloride complexes (L:)GaCl3 (L: = :C{N(2,6-

i Pr 2C6H3)CH}2, :C{N(2,4,6-Me3C6H3)CH}2, :C{N(i-Pr)C(Me)}2) can be store in air without

decomposition over a period of months in high humidity.244

GaCl3 N

N N

GaCl3 + MgBr GaCl2 + (2.19) N X X N

X N Ga X N

We then considered utilizing smaller carbenes for this study. Specifically, using a carbene

with only isopropyl functionality (L: = :C{(i-Pr)NC(Me)}2), in place of the 2,6-(di-i-

propyl)phenyl ligands,237 would lessen steric hindrance between the carbene and mesityl ligands

in the MesGaCl2(:L) complex. The condensation of 1,3-diisopropyl-2-thiourea with 3-hydroxy-

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2-butanone to give the 1,3-diisopropyl-4,5-dimethylthioimidazole, followed by reduction with

potassium metal provides this ligand in good yield (Eq. 2.20). Indeed, reaction of this smaller

125,247 carbene (:L) with MesEX2 (Eq. 2.21) gives Lewis base adducts of the general formula

MesEX2(:L), 19-21 (19, E = Ga, X = Cl; 20, E = Al, X = Br; 21, E = In, X = Br).

S O hexanol, NN K, THF NN + (2.20) N N H H OH

NN N (2.21) EX2 + E X X

19; E = Ga, X =Cl 20; E = Al, X = Br 21; E = In, X = Br

Although we synthesized the first organo-group 13 metal carbene complexes,(L:)ER3,

(M=Al, Ga, R = Me) more than a decade ago,239 compounds 19-21 are notable as the first carbene stabilized organo-group 13 dihalides. In all cases complexes 19-21 are remarkably more stable than the ‘free” mesitylgroup 13 dihalides, MesEX2, or carbene and can be exposed to air

without apparent signs of decomposition. Compounds 19 and 20 are insoluble in most organic

solvents, whereas 21 is highly soluble in toluene. However, all of these compounds are readily

dissolved in dichloromethane.

Colorless crystals of 19-21 are grown in a mixture of CH2Cl2 and THF. When neat

solvents are used for crystallization only amorphous materials are obtained. Although the crystal structures of 19-21 are isostructural, they are not isomorphous. Both 19 and 20 are monomeric

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carbene-organogroup 13 adducts, whereas compound 21 co-crystallizes with a molecule of

(L:)InBr3. There are two molecules of 19 in its asymmetric unit (triclinic P-1), whereas in 20

only one molecule is unique for the asymmetric unit (monoclinic C2/c).

The single crystal X-ray structures of 19-20 are depicted in Figures 2.32-2.34, respectively, and they share several interesting features. All have four-coordinate group 13 metal centers with distorted tetrahedral environments. The mesitylgroup 13 CE bond distances

(Ga(1)C(1) 1.978(2) Å, Al(1)C(1) 1.989(3) Å, In(1)C(12) 2.170(13) Å) are comparatively

shorter than the carbenegroup 13 E:L bond distances (Ga(1)C(10) 2.048(2) Å, Al(1)C(10)

2.050(3) Å, In(1)C(1) 2.224(10) Å). The average bond length difference between the two types

of EC bonds is 0.06 Å and denotes the weaker dative nature of the carbenegroup 13 metal

interactions.

Another notable feature of these compounds is the orientation of the two ligands, as the

carbene ligand is situated roughly orthogonal to the mesityl plane. This is obviously a preferable

arrangement to lessen steric interactions. Nevertheless, steric repulsion is still detected in the

CEC bond angles in 19 and 21 (19, C(1)Ga(1)C(10) = 119.14(9)°; 21, C(1)In(1)C(12) =

119.1(4)°), which is severely distorted from the expected value (109.5°) for tetrahedral

geometry. In contrast, the C(1)Al(1)C(10) bond angle (111.10(13)°) in 20 precludes this

structural feature, however the C(1)Al(1)Br(2) bond angle (119.11(13)°) is exceedingly large.

The X-ray structure (Fig. 2.32) of 19, MesGaCl2(:L), shows that the GaC(carbene) bond

length (Ga(1)C(10), 2.048(2) Å) is much longer than those reported for other carbene-gallium

244 trichloride complexes, (L:)GaX3 (L = carbene, X = halide) (1.954-2.016 Å). This is most

likely due to the bulky mesityl ligand incorporated into 19, which impedes a closer interaction of

the carbene to the metal. This may also lend some validity to why the Ga(1)C(10) bond in 19 is

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239 shorter to than (2.13 Å) that in (L:)GaMe3 (L: = :C{(i-Pr)NC(Me)}2 , which has three bulky

methyl groups surrounding the gallium.

The Ga(1)C(10) bond length in 19 is also slightly shorter than the GaC bond length

(2.070(7 )Å) in the unsymmetrical carbene stabilized digallane, (L:)GaI2GaI2 (L: = :C{N(2,6-

i 248 Pr C6H3)CH}2), which may be attributed to a number of reasons such as the lower oxidation

state of the gallium atom, and/or the large size and electronegativity of iodine in the latter.

Though the GaCl bond distances (2.246 Å av) of 19 are comparable to the associative bond

distances (2.19 Å av) in (L:)GaCl3 (L: = :C{(i-Pr)NC(Me)}2), which utilizes the identical carbene, they are almost 0.5 Å longer that those of other reported carbene-gallium trichloride

i complexes containing more bulky carbenes: ((L:)GaCl3, L: = :C{N(2,6-Pr C6H3)CH}2, GaCl

244 2.173 Å); (L:)GaCl3, L: = :C{N(2,4,6-Me3C6H3)CH}2, GaCl 2.175 Å).

Only a few carbene-stabilized aluminum compounds exist, thus it is prudent to discuss

similarities and differences between these complexes and 20, MesAlBr2(:L) (Fig. 2.33). All of

these complexes contain the expected tetrahedral four-coordinate aluminum atoms, however

there are slight differences in the AlC bond lengths. For example, the carbene-aluminum bond

length of (Al(1)C(10) = 2.050(3) Å) in 20 is substantially longer than that (2.0009(5) Å) in

243 (L*:)AlCl3 (L*: = :C{(Me)NC(Me)}2), perhaps due the smaller methyl groups at the nitrogen

sites on the carbene in (L*:)AlCl3, which allows a closer approach to aluminum. The AlC bond

distance (2.0034 Å) in carbene-stabilized alane, (L:)AlH3 (L: = :C{N(2,4,6-Me3C6H3)CH}2) is

also shorter than that in 19, however, in the more crowded (L:)AlMe3 (L: = :C{(i-Pr)NC(Me)}2), the AlC bond distance (2.062(7) Å) is longer.239 A lengthening of the GaC bond was also

observed when comparing 19 with the analogous carbene-stabilized trimethyl gallium complex,

(L:)GaMe3. There are no carbene aluminum tribromide adducts to compare with 20, however the

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Al(1)Br(1) and Al(1)Br(2) bond distances, 2.3364(10) and 2.3373(10) Å, respectively, are

longer than those (2.297(3) and 2.302(3) Å) found in the m-terphenylaluminum dibromide

etherate 3, RAlBr2(OEt2) (R = 2,6-(4-t-BuC6H4)2C6H3-), but are more comparable to those in the

lithium bridged m-terphenylaluminum bromide dimer [RAlBr3Li]2, (R = 2,6-Mes2C6H3), (2.347

Å av).119

Figure 2.32. Molecular structure of MesGaCl2(:L) (19)

Table 2.20 Selected bond distances [Å] and angles [°] for MesGaCl2(:L) (19) Atoms Distance Atoms Angle Ga(1)C(1) 1.978(2) C(1)Ga(1)C(10) 119.14(9) Ga(1)C(10) 2.048(2) C(1)Ga(1)Cl(2) 114.96(7) Ga(1)Cl(2) 2.2444(6) C(10)Ga(1)Cl(2) 98.86(6) Ga(1)Cl(1) 2.2468(6) C(1)Ga(1)Cl(1) 109.34(7) Cl(2)Ga(1)Cl(1) 101.71(3)

112

Figure 2.33. Molecular structure of MesAlBr2(:L) (20)

Table 2.21 Selected bond distances [Å] and angles [°] for MesAlBr2(:L) (20) Atoms Distance Atoms Angle Al(1)C(1) 1.989(3) C(1)Al(1)C(10) 111.10(13) Al(1)C(10) 2.050(3) C(10)Al(1)Br(1) 114.61(9) Al(1)Br(1) 2.3364(10) C(1)Al(1)Br(2) 119.11(10) Al(1)Br(2) 2.3373(10) C(10)Al(1)Br(2) 97.78(9) Br(1)Al(1)Br(2) 104.53(4)

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A closer inspection of the unit cell of 21, MesInBr2(:L), (Fig. 2.35) shows that there are two Br3In(:L) molecules residing in between two MesInBr2(:L) complexes, and there are no

intermolecular contacts between the molecules. Only one of the sets represents the asymmetric

unit. An explanation for the formation of (L:)InBr3 is that unreacted InBr3, which is difficult to

remove from MesInBr2, reacts with the carbene. Nevertheless, it is still quite interesting that the

two molecules crystallized together. Since the crystal structure of Br3In(:L) has been previously

reported, it will not be discussed.249

An interesting feature can be observed along the In(1)C(12) bond in 21, wherein the

mesityl phenyl plane is slightly bent at an angle of 14°. The crystal structure of RAlBr2(OEt2) (3)

showed a similar distortion and was ascribed to packing forces; perhaps these forces are at play

in 21. The In(1)C(1) bond distance (2.224(10) Å) in 21 is somewhat longer than that (2.199(5)

249 Å) in the “mesityl-free” carbeneindium tribromide adduct in (L:)InBr3, but compares well

with those of the dicarbeneindium trihalide congeners, (L:)2InX3 (X = Cl, InC = 2.220(10) and

2.236(9) Å, X = Br, InC = 2.230(10) and 2.231(10) Å). Clearly the steric crowding about the In

atom in 21 causes the lengthening in the InC bond. The InBr bond distances (2.55 Å av) in 21

lie in between the range of those reported for (L:)InBr3 (2.50 Å av) and (L:)2InBr3 (2.69 Å av).

114

Figure 2.34. Molecular structure of MesInBr2(:L) (21)

Table 2.22 Selected bond distances [Å] and angles [°] for MesInBr2(:L) (21) Atoms Distance Atoms Angle In(1)C(12) 2.170(13) C(1) In(1)C(12) 119.1(4) In(1)C(1) 2.224(10) C(12)In(1)Br(2) 119.0(3) In(1)Br(2) 2.5365(16) C(1)In(1)Br(2) 102.0(3) In(1)Br(1) 2.5630(17) C(1)In(1)Br(1) 102.8(3) Br(1)In(1)Br(2) 101.66(6)

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Figure 2.35. A view of the unit cell of [MesInBr2(:L)][InBr3(:L)] (21) showing that there are no intramolecular contacts between the four molecules.

2.7.2 Alkali Metal Reductions of MesEX2(:L)

245,246 The isolations of neutral diborenes by alkali metal reduction of (L:)BBr3, prompted an examination of reductions of 19-21 with the intent to synthesize analogous neutral compounds possessing double bonds of the heavier group 13 elements. Sodium metal reductions of 20 and

21 generally gave yellow viscous oils that could not be adequately characterized. In contrast,

potassium reductions of MesGaCl2(:L) (19) gave solutions that varied in color depending on reducing agent and solvent. Specifically, potassium graphite (KC8) reduction of 19 in hexane gave a pale yellow-orange solution (Eq. 2.22), which after work-up and removal of almost all solvent, a yellow sticky oil was retained. Placing the oil at room temperature over several days

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afforded pale yellow crystals of [MesGaCl(:L)]2 (22) in low yield. The low yield prevented

complete characterization (EA). Fortunately, the crystals of 22 were suitable for single crystal X-

ray crystallographic analysis.

2 KC8, hexane 2 MesGaCl (:L) [MesGaCl(:L)]2 2 -2 KCl 19 22 (2.22)

The crystal structure of 22 (Fig. 2.36) displays two four-coordinate gallium atoms, which

assume distorted tetrahedral geometry, held together by a GaGa bond. Several other structural aspects of 22 merit comment. Perhaps most compelling is the GaGa bond distance (2.4474(11)

Å). For comparison purposes, this bond distance is similar to the corresponding GaGa distances in the gallium(II)-amidinate complexes [GaI(MeC(NAr)]2 and {GaI(HC(NAr)]2 (Ar = 2,6-

i Pr 2C6H3-) (2.4304(10) and 2.4527(15) Å, respectively), which also contain four-coordinate

gallium atoms.250 Contrary, the GaGa bond distance (2.4739(12) Å) of the only other carbene

i stabilized digallane, (L:)GaI2GaI2 (L: = :C{N(2,6-Pr C6H3)CH}2) is significantly longer than that

in 22. Another notable feature of 22 is the CGaC bond angles, (C(1)Ga(1)C(12), 106.7(3)°,

C(21)Ga(2)C(32), 103.0(3)°, which are substantially smaller than the corresponding bond

angle in MesGaCl2(:L) (19) (C(1)Ga(1)C(10), 119.14(9)°). One may consider that steric

repulsion between the ligands on the adjacent gallium atom in 22 causes contraction of geminal

ligands and limits conformational freedom. Evidence for this proposition may be supported by

the larger than expected C(12)Ga(1)Ga(2) and C(21)Ga(2)Ga(1) bond angles (132.2(2) and

122.57(19)°, respectively) and the Ga(1)C(1) and Ga(2)C(21) bonds distances, 2.101(7) and

2.084(7) Å, respectively, which are 0.045Å longer than that in 19 (2.045(2) Å)

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A particularly intriguing aspect of 22 is the four different substituents about the gallium

atoms, which should allow for the possibility of diastereomers. However, a closer inspection of

22 shows that there is an center of inversion. Nevertheless, to our knowledge there are no

diastereomeric digallanes and 22 is the first meso-digallane.

Figure 2.36. Molecular structure of [MesGaCl(:L)]2 (22)

Table 2.23 Selected bond distances [Å] and angles [°] for [MesGaCl(:L)]2 (22) Atoms Angle Atoms Angle Ga(1)C(12) 2.028(7) C(12)Ga(1)Ga(2) 132.2(2) Ga(1)C(1) 2.101(7) C(1)Ga(1)-Ga(2) 101.59(19) Ga(1)Cl(1) 2.300(2) Cl(1)Ga(1)Ga(2) 104.64(6) Ga(1)Ga(2) 2.4474(11) C(32)Ga(2)Ga(1) 117.1(2) Ga(2)C(32) 2.014(7) C(21)Ga(2)Ga(1) 122.57(19) Ga(2)C(21) 2.084(7) Cl(2)Ga(2)Ga(1) 108.12(7) Ga(2)Cl(2) 2.324(2) C(12)Ga(1)C(1) 106.7(3) C(32)Ga(2)C(21) 103.0(3)

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Although compound 22 was not our ultimate goal, it proved that the strategy of

employing a -bonded ligand in conjunction with a carbene ancillary ligand on gallium

adequately stabilizes GaGa bonding. In essence, removal of the remaining chloride ligands of

22 should afford a species with a Ga=Ga double bond.

In light of the difficulties of sodium reduction, 19 was reduced with potassium metal in toluene, which generally gave dark red to red-brown solutions in toluene. Attempts to isolate colorful crystals, which are usually indicative of a multiply bonded species due to the low energy gap of the * or n* transition, were inhibited by crystallization of copious amounts of colorless carbene ligand. After a series of successive extractions with hexane/toluene (10:1),

colorless crystal formation ceased, leaving behind red oil. Placing the oil at -25 °C for several

days afforded purple-red crystals in low yield along with pale-yellow amorphous material. Single

crystal X-ray analysis of these crystals revealed a compound with a Ga6-octahedral core,

Mes4Ga6(:L)2 (23) (Fig. 2.37), containing eight triangular faces and six vertices. The balanced

chemical equation for 23 is formulated in equation 2.23.

12 K, toluene 6 MesGaCl (:L) Mes Ga (:L) + 4 :L + 2 Mes (2.23) 2 -12 KCl 4 6 2 19 23

Examination of the literature reveals that there are only a few gallium clusters containing

251-253 Ga6 deltahedra subunits. It is remarkable to note that 23 is the first neutral Ga6-octahedron.

There are, however, two neutral Ga6 species worth mentioning. One of these, Cp*Ga6 (Cp* =

254 Me5C5), contains a octahedron but no metalmetal bonds, thus cannot be considered a gallium

253 cluster, while R6Ga6 (R = -SiMe(SiMe3)2), which appears to have structural similarities of an

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octahedron, was described by the authors as an extremely folded Ga6-chair. Further proof of its

non-octahedral Ga6 metallic core is revealed by its electron count, which only 12 skeletal electrons are dedicated to the skeletal structure. Conversely, the 14-electron Ga6clososkeleton

112,113 of 23 is consistent with WadeMingos rules, supplied by eight electrons from the [MesGa]4

square planar equatorial core, while the two carbene stabilized gallium caps (Ga(:L)) can be

considered “naked” and dedicate six-electrons collectively. The only “true” Ga6-octahedron

-2 cluster reported in the literature is the isoelectronic dianionic gallium analogue, [R6Ga6] (R =

253 -2 255-259 Si(CMe3)3), of the thoroughly studied aromatic hexaborate dianion, [B6H6] .

Several structural aspects of 23 are worthy of discussion. Perhaps most relevant is the

heteroleptic nature of 23, which causes subtle, yet notable, distortions within the Ga6 skeletal

framework. The slightly varied transannular Ga(1)Ga(1a), Ga(2)Ga(2a), and Ga(3)Ga(3a)

separation distances (3.65 6Å, 3.671 Å, and 3.443 Å respectively) are illustrative of this

manifestation, which ultimately affects the three fused planar quadrangle surfaces. For example,

the [MesGa]4 fragment is essentially square planar, while the two [{MesGa}2{Ga(:L)}2] planes

can best be described as Ga4-rhomboids. These slight variations cause perturbations to ideal

octahedral geometry resulting in three two-fold axes that pass through the Ga(1)Ga(1a),

Ga(2)Ga(2a), and Ga(3)Ga(3a) vectors. The GaGa bond distances in 23 are also interesting.

The Ga(1)Ga(2) bond distances (2.5905(11) Å), wherein a mesityl ligand is bonded to both

galliums, are longer than the Ga(1)Ga(3) and Ga(2)Ga(3), 2.5109(12) and 2.5165(12) Å,

respectively, which have carbene coordination to the Ga(3) atoms. This is contrary to the

expected trend, as the polar GaC -bond usually results in a more + gallium atom and a net

decrease in its effective radius, and thus a shorter GaGa bond should be experienced.23 The

effect of carbenes on group 13 metalmetal bonds is clearly not well understood.

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There are only two structurally characterized digallanes that incorporates carbenes as a

i stabilizing ligands, (L:)GaI2GaI2 (L: = :C{N(2,6-Pr C6H3)CH}2) and 22, both have GaGa bond

distances (2.4739(12) Å and 2.4474(11) Å) that are significant shorter than that found in 23. This

GaGa bond lengthening in 23 may be ascribed to putative 3c-2e bonding mode which has been

used to describe the bonding arrangement in boron polyhedras.259

Some additional features of 23 are also worth mentioning. In particular, the carbene

ligands are almost parallel to one another with a small torsion angle of 11.5°, while the mesityl

ligands on the two Ga(1) atoms are C2 symmetric with a much larger torsional angle (65.23°)

with respect to one another. The mesityl ligands located on the Ga(2) atoms are highly

disordered, thus it is difficult determined their torsion angle. The GaC bond distances in 23 are

also worthy of discussion. The Ga(1)C(1) bond distance (1.966(11) Å) is slightly longer than

the Ga(2)C(7) bond distance (1.955(11) Å), however they are comparable to that (1.957(16) Å)

260 in the MesGaCl2 inorganic polymer. As expected, the Ga(3)C(carbene) bond distance (1.982(11)

Å) is significantly longer the Ga(1)C(1) and Ga(2)C(7) distances with mesityl ligation.

Moreover, this bond distance is significantly shorter than the analogous GaC(carbene) bond

distances of 19 (2.048(2)Å) and 22 (2.028(7) and 2.084(7) Å), which suggest that the

environment around the carbene in 23 is less crowded.

121

Figure 2.37. Molecular structure of Mes4Ga6(:L)2 (23)

Table 2.24 Selected bond distances [Å] and angles [°] for Mes4Ga6(:L)2 (23) Atoms Distance Atoms Angle Ga(1)Ga(2A) 2.5905(11) Ga(1A)Ga(2)Ga(1) 89.76(5) Ga(1)Ga(3) 2.5109(12) Ga(1A)Ga(3)-Ga(1) 93.44(5) Ga(2)Ga(3A) 2.5165(12) Ga(1A)Ga(3)Ga(2) 62.03(3) Ga(1)C(1) 1.966(11) Ga(2)Ga(3)Ga(2A) 93.68(5) Ga(2)C(7) 1.955(11) Ga(2A)Ga(1)Ga(2) 90.24(5) Ga(3)C(15) 1.982(11) Ga(3)Ga(1)Ga(3A) 86.56(5) N(1)C(15) 1.355(9) Ga(3)Ga(2)Ga(3A) 86.32(5) N(1)C(16) 1.399(9) Ga(3)Ga(1)Ga(2A) 59.09(3) Ga(1A)Ga(2)Ga(3) 58.88(3)

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To provide better insight into the nature of 23, computational studies at the B3LYP/6-

311+G** level were conducted on a simpler model, Ga6Ph4(:L)2 (:L =:C(HNCH)2 (23a) (Fig.

2.38), wherein the mesityl ligands are replaced with phenyl groups and the isopropyl ligands on

the carbenes are substituted with only hydrogen. The experimental and theoretical are in

reasonable agreement. However, the Ga(phenyl)Ga(phenyl) bond distances in 23a (2.643 Å) are

about 0.05 Å longer than the analogous bond distances in the experimental (2.5905 Å), while

Ga(phenyl/mes)Ga(carbene) bond distances are more comparable (23, 2.514 Å av., 23a, 2.538 Å).

Several factors may be attributed to these slight deviations such as crystal packing forces and deviations to the ligands steric and electronic effects between the experimental and model.

Consistent with 23, however, the opposing GaGa bond lengths in the theoretical structure are

equivalent, thus rendering three-fold symmetry, and the Ga(phenyl)Ga(phenyl) (2.643 Å) bond distances are longer that the Ga(phenyl)Ga(carbene) bond distances (2.537 Å av). Another interesting

feature of the model 23a is that the carbene ligands are coplanar with an effective 0° torsional angle, perhaps the isopropyl ligands on the carbene in the experimental add steric encumbrance

and are responsible for the slight torsion observed in 23.

Natural atomic orbital (NAO) and Wiberg index (WBI) bond order analysis was also

performed on 23a as to provide better understanding of the bonding in 23. The GaGa bond

orders utilizing the WBI are overall smaller than those calculated using NAO bond order

analysis, while the GaC bond orders are larger. The bond orders calculated for both methods

are shown in Table 2. 25. The Ga(carbene)Ga(phenyl) bond orders (NAO = 0.729 , 0.747; WBI =

0.606, 0.647) are larger than the Ga(phenyl)Ga(phenyl) bond orders (NAO = 0.679; WBI = 0.548).

The larger Ga(carbene)Ga(phenyl) bond order may be the result of the more electron rich Ga(:L)

fragment, which can contribute more electron density for bonding. However, all of the GaGa

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bond orders are less than 1.0 and can be rationalized by three-centered two-electron bonding as is

commonly accepted for main group clusters. In accordance with Wade-Mingos interpretation of

main group polyhedra, the GaC bonds should be 2c-2e -bonds, however the GaC bond

orders are significantly less than 1.0 (WBI 0.736; NAO 0.650). Surprisingly, the GaC(carbene)

bond orders (WBI 0.745; NAO 0.726) are larger than the GaC(phenyl) bond orders (WBI 0.736;

NAO 0.650), since the GaC(carbene) is a true -bond. It is informative to note that bond orders are

commonly under estimated by these methods.

In an effort to assess aromaticity, Nucleus-Independent Chemical Shifts were computed

for 23a at the PW91PW91/6-311+G** level, and for comparison purposes, they were also

2- computed for the hexagallate dianion, [Ga6H6] . The negative NICS value (-10.2) for 23a clearly

2- 2- supports aromaticity, but this value is significantly less than that of [Ga6H6] and [B6H6] (NICS

= -27.3 and -27.521,257 respectively). This suggests that the neutrality of 23a lessens its

2- 2 aromaticity. The charge on 23a, [Ga6H6] , and [B6H6] (1.24, -0.69, and -1.78, respectively) was calculated to compare with the respective calculated NICS values. Indeed, a correlation was

2 2- identified wherein the highly charged [B6H6] and [Ga6H6] species are considerably more

2 aromatic than neutral 23a. Interestingly, although [B6H6] contains two and a half times the

2- charge of [Ga6H6] , its NICS value is only a marginally more negative.

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Figure 2.38 B3LYP/6-311+G** optimized geometry of Ga6Ph4(:L)2 (L: = :C(HNCH)2 (23a)

Table 2.25. Bond order for various bonds are calculated at the PW91PW91/6-31G*//B3LYP/6- 311+G** for Ga6Ph4(:L)2 (:L =:C(HNCH)2 (23a) Bond Wiberg Bond Index NAO Gaaxial-Gacarbene 0.606 0.729 Gaaxial-Gabenzene 0.548 0.679 Gabenzene-Gacarbene 0.647 0.747 Ga-Ccarbene 0.745 0.726 Gaaxial-Cbenzene 0.736 0.648 Gaequatorial-Cbenzene 0.736 0.651

In conclusion, in the course of this study three new carbene adducts of mesitylgroup 13

dihalides, MesEX2(:L) (19, E = Ga X = Cl; 20 E = Al X = Br; 21 E = In X = Br),were isolated.

While alkali metal reduction of 20 and 21 did not provide a compound with metalmetal bonds,

reductions of 19 provided a meso-digallium complex containing a GaGa bond, [MesGaCl(:L)]2

(22), and the unexpected formation of the first carbene stabilized Ga6 octahedron, Mes4Ga6(:L)2

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(23). NICS calculations on the 23b signify substantial aromaticity, although somewhat less than that of the dianionic hexagallates or hexaborates. The neutrality of 23 may reduce its aromaticity.

2.6 A New Synthetic Procedure for Arduengo’s Carbene

Arduengo’s synthesis of 1,3-di-1-adamantylimidazol-2-ylidene (Arduengo’s carbene;

AdL:), by deprotonation of 1,3-di-1-adamantylimidazolium chloride ((Ad)ImidCl) with potassium tert-butoxide in THF, was the first report of a structurally characterized carbene.233

The report, however, provided no detailed protocol on the synthesis of starting material,

(Ad)ImidCl, nor was any single crystal X-ray data supplied for the carbene, AdL:, except for minor structural information. Although AdL: is well known and even commercially available, there remains no detailed protocol for its synthesis in the literature. Though a few groups have prepared transition metal complexes stabilized by Arduengo’s carbene,261 they have cited

Arduengo’s 1999 report for the general synthesis of aryl substituted carbenes,236 which has no specific mentioning of AdL:. This generalized protocol follows a three-step process, in which an

N-arylamine is condensed with glyoxal to give a glyoxal diimine intermediate, followed by cyclization with chloromethyl ethyl ether to give the imidazolium salts (ImidCl). The free carbene is generated by deprotonation of the imidazolium salts with potassium tert-butoxide.

We were interested in examining AdL: on the group 13 elements to evaluate the structure and bonding of the carbenegroup 13 adducts, (AdL:)EX3, and its viability to stabilize group 13 metalmetal bonds. This interest was spawned from the considerable three-dimensional steric bulk bestowed by the adamantyl ligands and the fact that Arduengo’s carbene has been noted as a slightly better -donor as compared to aryl carbenes.262

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Since there was no detailed protocol of AdL: in the literature, its synthesis was pursued

by utilizing the generalized protocol cited in the Arduengo’s 1999 report. We attempted its synthesis by reaction 1-adamantylamine (AdNH3) in n-propanol with aqueous glyoxal to give the

expected glyoxal-bis-(1-adamantyl)imine, however only a white insoluble material was isolated.

A more thorough examination of the literature revealed that a similar phenomenon was encountered by Mol and coworkers, wherein an “white intractable precipitate formed” that could not be adequately characterized.262

After manipulating solvents, it was found that addition of AdNH2 in toluene to aqueous

glyoxal provided glyoxal-bis-(1-adamantyl)imine (24) as a white powder in near quantitative yields (Eq. 2.24). It is worthwhile to note that the isolation of 24 is distinctly different from the method described by the literature report for aryldiimines. Whereas aryldiimines crash out of the solution, only after removal of all solvent is 24 obtained as a white powder. It is reasonable that the more aliphatic characteristics of the adamantyl ligands enhance the solubility of 24. Although this reaction provides 24 in good yield (70-80%), adamantylamine is cost $104.00/ 25 g, thus it was worthy to develop an alternate method to prepare 24 using 1-adamantylammonium hydrochloride, AdNH3Cl, which is one-third the cost of adamantylamine ($145.00/100 g).

The obvious disadvantage of using AdNH3Cl is that HCl must be removed to permit the condensation of the free amine and glyoxal, thereby lengthening the synthetic procedure by an

additional step. However, the cost advantage adequately compensated for this extra step. It was

believed that LiOH could not only neutralize HCl, but also fortuitously generate a Lewis acid,

LiCl, that would promote the condensation of the free amine with glyoxal. Thus, this reaction

was performed by reaction of AdNH3Cl in H2O with aqueous LiOH, which gave a thick white precipitant. Addition of toluene or CHCl3 quickly dissolves the white precipitant. Glyoxal is then

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added to this solution to give 24 as an off-white powder with yields comparable with that of the free amine synthesis (Eq. 2.24). When using CHCl3 as solvent, however, unreacted AdNH3Cl is also isolated with the desired diimine, however separation is easily accomplished by extraction with toluene. Crystals of 24 were acquired by slow evaporation of CHCl3/toluene. The single crystal X-ray structure of 24 has not been reported and is shown in Figure 2.40.

ClH N H2N 3 N H 1) glyoxal, toluene 1) LiOH/ H2O 2) glyoxal (2.24) H N

Figure 2.39. Molecular structure of glyoxal-bis-(1-adamantyl)imine (24)

Consistent with Arduengo’s generalized procedure, reaction of 24 with chloromethyl ethyl ether in THF gave the cyclized precursor, 1,3-bis-(1-adamantyl)imidazolium chloride (25), in almost quantitative yield (Eq. 2.26). Crystals of 25 can be grown by slow evaporation of acetone and CHCl3; however, when removed from solvent the crystals rapidly transformed into a white amorphous material. All efforts to obtain adequate crystals for single crystal X-ray

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structural analysis proved impossible. The chemical composition of 25 was confirmed by

comparing 1H NMR spectra with commercially available reference and melting point determination.

With the imidazolium chloride precursor (25) in hand, deprotonation with potassium tert-

butoxide provided Arduengo’s carbene (26), albeit in low yield (40%) (Eq. 2.26). Crystals of 26

can be readily grown from slow evaporation of diethyl ether.

H -Cl 24 ClCH2OCH2CH3 THF, 2d N N

25 (2.25)

t-BuOK, THF

N N

Arduengo's carbene (40%) 26

The single crystal structure of 26 (Fig. 2.40) confirms the anticipated structure, revealing

a central planar imidazolylidene ring with adamantyl ligands situated at the nitrogen atoms.

There are a few structural features of 26 worthy of discussion. The carbenic nature of the C(1) atom is reflected in the C(1)N(1) and C(1)N(2) bond distances (1.3624(16) and 1.3661(16) Å,

respectively), which are more than 0.1 Å shorter than the C(4)N(2) and C(14)N(1) bond

distances (1.4814(16) and 1.4841(15) Å, respectively) involving nitrogen bonding with the

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adamantyl ligands. The N(1)C(1)N(2) bond angle of 102.62(10)° in 26 is smaller than

expected for five membered rings (108°) and significantly smaller than the expected value for a

trigonal planar carbon. The nitrogen atoms assume a distorted trigonal planar geometry with an

average internal ring CNC bond angle of 112°.

Since the 1991 report of Arduengo’s carbene revealed little structural data on unit cell dimensions besides its Kanvas structure, it is prudent to give some discussion in this regard.

Compound 26 crystallizes in monoclinic, space group P2(1)/c (No. 14) with the following unit cell dimensions: a = 7.5954(5) Å, b = 19.7470(12) Å, c = 12.8016(8) Å; b = 106.5400(10)° V =

1840.6(2) Å3. A single molecule is unique to one asymmetric unit, however the unit cell contains

four molecules without any short intramolecular contacts (Fig. 2.41).

Figure 2.40. Molecular structure of Arduengo’s carbene (AdL:) (26)

Table 2.26 Selected bond distances [Å] and angles [°] for Arduengo’s carbene (AdL:) (26)

Atoms Distance Atoms Angle C(1)N(1) 1.3624(16) N(1)-C(1)-N(2) 102.62(10) C(1)N(2) 1.3661(16) C(1)-N(2)-C(4) 122.29(10) N(1)-C(14) 1.4814(16) C(1)-N(2)-C(3) 112.19(11) N(2)-C(4) 1.4841(15) C(2)-C(3)-N(2) 106.38(11)

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Figure 2.41. A view of the unit cell of Arduengo’s carbene (AdL:) (26) showing arrangements of individual molecules

To evaluate Arduengo’s carbene on group 13 metals, reaction of AdL: with GaCl3 in

diethyl ether was performed; however, instead of the anticipated 1:1 adduct, (AdL:)GaCl3, an imidazolium gallate, [ADL:H][GaCl4] was produced (Eq. 2.27). The same conclusion was drawn

when solvent or temperature was varied. It appears that the exceptional steric bulk afforded by

the adamantyl ligands impedes the interaction of the carbenic nucleophilic center with the metal.

Indeed, studies of ligand substitution enthalpies of reactions of various carbenes on [Cp*RuCl]

showed that AdL: had the lowest reaction enthalpy and bond dissociation energies.234 The

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authors suggested that the adamantyl groups “hinder carbene lone pair overlap with metal

orbitals”. Indeed, the adamantyl groups are quite bulky, but it has been demonstrated that

Arduengo’s carbene readily coordinates to monovalent Au(I)Cl to give adducts of (AdL:)AuCl

with a linear CAuCl bonds angle.261 A similar phenomenon was observed when AdL: is

introduced to iodo-pentaflurobenzene, wherein a 1:1 adduct, AdLIC6HF5, is formed with a

263 linear C(carbene)IC(phenyl) bond angle. With this in mind, AdL: may be able to coordinate to low-valent group 13 elements such as monovalent “EX” species, whereas in trivalent group 13 species the interaction between the adamantyl groups and the halides is excessively congestive for adduct formation.

N N

+ GaCl3 H GaCl4 (2.26) N N

In conclusion, a detailed protocol to prepare Arduengo’s carbene was established using

adamantylamine, as well as, a new, less expensive method using adamantylammonium chloride.

In these studies the crystal structure of glyoxal-bis-(1-adamantyl)imine (24) was reported, as

well as, a detailed structural report of Arduengo’s carbene. It was found that Arduengo’s carbene

may be limited to coordination to monovalent elements and may not be a choice ligand for 1:1

adduct formations with the group 13 elements.

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CHAPTER 3

CONCLUSION

3.1 Concluding remarks

The ultimate goal of my doctoral research was to evaluate new and established ligands to access novel and interesting compounds containing metalmetal bonds. The initial strategy of using less bulky m-terphenyl ligands, 2,6-(4-t-BuC6H4)2C6H3- (R) and 2,6-(4-Me-C6H4)2C6H3-

(R´), with the intent to stabilize metallic rings or clusters did not produce flattering results as

only one tri-gallium catenated complex, [R3Ga3][Na3OEt3] (9), was isolated in very low yield.

These endeavors, however, were not in vain, as several new m-terphenyl-group 13 complexes

were isolated having interesting structures. Specifically, the first tris-m-terphenyl-group 13

complexes, R3In (5) and R3In (8), were realized in these studies, as well as an m-terphenyl-oxo-

bridged dialuminum chloride complex, [RAlCl(OEt2)]2O (4) that contained exceptionally long

AlCl bonds and a peculiar “gauche-like” arrangement of m-terphenyl ligands. These structural

features may be influenced by the anomeric effect. Computational studies may better verify this

hypothesis. Moreover, these studies of less bulky m-terphenyl ligands on group 13 metals

demonstrated that 2,6-di(4-t-butylpheny)phenyl-group 13 dihalides prefer donor solvent

coordination to give the compounds of general formula REX2(OEt2), while those of 2,6-di(4-

methylpheny)phenyl (R’) form lithium salt adducts, R’EX3Li. These differences in structure may

be the consequence of enhanced inductive effects of the tert-butyl functionality, which may

lessen the Lewis acidic behavior of the group 13 metal.

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This study also investigated the organometallic chemistry at the group 4group 13

interface. The first compounds (10 and 11) containing Hfgroup 13 bonds, Cp2Hf(ER) (E = Ga,

In; R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-), which possessed “V-shaped” EHfE metallic cores, were

prepared. Additionally, an intriguing trimetallic fulvalene-bridged dizirconocene-gallium

complex, (C10H8)(ZrCp)2(μH)(μCl)(μGaR), 12, containing rare GaZr bonds was

synthesized. This compound is notable as the only known complex to demonstrate gallium

engaged in bonding to two zirconium atoms. The unexpected existence of a hydride in 12

residing between the two Zr atoms was detected by 1H NMR and further supported by

computational methods.

We extended our study of less bulky m-terphenyl ligands on the group 4 metallocenes,

which yielded a trivalent titanium radical Cp2TiR (R = 2,6-(4-Me-C6H4)2C6H3-) (13) and a four-

coordinate m-terphenyl-zirconocene chloride, Cp2Zr(R)(Cl) (R = 2,6-(4-t-BuC6H4)2C6H3-) (14).

Attempts to isolate a trivalent zirconium radical, Cp2ZrR, or an m-terphenyl-titanocene chloride

Cp2Ti(R)(Cl) was inconclusive. These endeavors demonstrate that though the chemistry of group

4 metallocenes may parallel to some degree, there are distinct differences between the members

of this group.

The multidisciplinary nature of this research project extended our efforts to synthesize a

gallepin derivative. This was accomplished by a benzannulation approach, wherein 2,2-dilithio-

Z-stilbene(TMEDA)2 (16) was allowed to react with GaCl3 to give the first gallepin,

bis(gallepin)2·TMEDA, 18. The single crystal X-ray structure of 18 revealed a complex with two

gallepin moieties bridged by a TMEDA molecule. The gallepin moieties aromatic characteristics

were confirmed by NICS calculations and suggest gallepins are less aromatic than borepins or

the tropylium ion. Furthermore, it was concluded that the phenyl substituents in 18 lessen its

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aromatic characteristic but amine coordination has a minimal effect. Perhaps future studies will

unveil an unsupported gallepin that can provide further insight into its aromatic nature.

We also envisioned that N-heterocyclic carbenes (NHCs) could be convenient ligands to

stabilize main group metalmetal bonds. Indeed, we had previously demonstrated that NHCs can

adequately stabilize neutral compounds possessing boronboron double bonds. We extended

these studies to the heavier group 13 metals by synthesizing several mesityl-group 13carbene

adducts, (MesGaCl2(:L) (19), MesAlBr2(:L) (20), MesInBr2(:L) (21) (:L = :C{(i-Pr)NC(Me)}2), that served as precursors to study their alkali metal reductions. While alkali metal reduction of 20 and 21 failed to give a species containing metalmetal bonds, potassium graphite reduction of 19 yielded a compound with two four-coordinate gallium atoms bound through a GaGa bond,

[MesGaCl(:L)]2 (22). The implications of four different substituents about the gallium atoms in

22 presented a rare meso-digallane. Switching to potassium metal reduction of 19 gave the

unexpected formation of a rare Ga6 octahedron, Mes4Ga6(:L)2 (23), which is also notable as the

only neutral gallium octahedron.

Finally, a new detailed synthetic protocol to prepare Arduengo’s carbene (26) from

adamantlyammonium chloride was produced and full single crystal X-ray structural analysis was

performed. Though it was found that the adamantly ligands impedes carbene coordination to

trivalent group 13 elements, this ligand has demonstrated to readily coordinate monovalent

elements.

To conclude, the passages of this manuscript have revealed the eclectic nature of my

research project. As ideas evolved, I was encouraged to examine the chemistry and the old adage

of CHEM-IS-TRY was thoroughly practiced in the course of this project. Of course, some ideas

worked better than others; however, by having several projects the chance for success greatly

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improved. This research group will undoubtedly be prosperous in the years to come, as the exploration of carbenes as viable ligands to stabilize metalmetal bonds has only recently emerged.

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CHAPTER 4

EXPERIMENTAL

4.1 General Background

4.1.1 Techniques and Reagents

Unless otherwise noted, all manipulations were conducted under anaerobic conditions with strict exclusion of air and moisture. Standard Schlenk techniques in conjunction with an inert atmosphere drybox (VAC He-493) were employed. Diethyl ether, hexane, and tetrahydrofuran were distilled over sodium metal and benzophenone under a nitrogen atmosphere, while toluene was refluxed over sodium metal. All solvents were freshly distilled and degassed prior to use.

Argon was passed through copper-based purification and molecular sieve drying columns to ensure purity. Melting points were measured on a Haake Buchler MFB 595 802 C melting point apparatus and are uncorrected.

1-Adamantylamine, aluminum(III) bromide, aluminum(III) chloride, bis(cyclopentadienyl)hafnium dichloride, 2-bromobenzaldhyde, 2-bromobenzylbromide, 4- bromotoluene, n-butyllithium, 4-tert-butylphenylbromide, 1,3-dichlorobenzene, 1,3-diisopropyl-

2-thiourea, gallium(III) chloride, glyoxal, 3-hydroxy-2-butanone, indium(III) bromide, indium(III) chloride, iodine, lithium hydroxide, lithium nitride, magnesium fillings, 2-mesitylmagnesium bromide, TMEDA, and triphenylphosphine were purchased from Aldrich Chemical Company

(Milwaukee, WI). Bis(cyclopentadienyl)titanium dichloride, bis(cyclopentadienyl)zirconium

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dichloride, potassium metal, and sodium metal were purchased from Strem, Inc (Newburyport,

MA). 1-Adamantylammonium hydrochloride and 2,4,6-triisopropylbromobenzene and were

purchased from Lancaster Synthesis (Windham, NH). Chloromethyl ethyl ether was purchased

from Tokyo Chemical Industry Company, Ltd, (Tokyo, Japan). All reagents were used as

received without further purification.

4.1.2 Instrumental Measurements

1 13 H and C NMR spectra were recorded on a Varian Mercury Plus 400 MHz

spectrometer. Chemical shifts are reported in parts per million (ppm). Deuterated tetrahydrofuran

(THF-d8), benzene (C6D6), and chloroform (CDCl3) were used as the lock solvents in NMR experiments. ESR spectra were recorded with a Bruker 300E EPR spectrometer. IR spectra were

recorded on a Nicolet-Avatar 360 FT-IR spectrometer.

X-ray Diffraction Methods

X-ray quality crystals were mounted and sealed in a glass capillary under argon. The X-

ray intensity data were measured at room temperature on a Bruker SMART APEX II X-ray

diffractometer system with graphite-monochromated Mo Ka radiation (l = 0.71073 Å) w-scan

technique. Subsequent solution and refinement was performed using the SHELXTL 6.1 solution

package operating on a Pentium computer. Data were corrected for Lorentz and polarization

effects and integrated with the manufacturer's SAINT software. Absorption corrections were

applied with the SADABS. Structures were solved by direct methods using the SHELXTL 6.1

Software Package. Non-hydrogen atomic scattering factors were taken from the literature

tabulations. Non-hydrogen atoms were located from successive difference Fourier map

calculations. In the final cycles of each refinement, the non-hydrogen atoms were refined

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anisotropically. Hydrogen atom positions were calculated and allowed to ride on the carbon to which they are bonded assuming a C–H bond length of 0.95 Å. Hydrogen atom temperature factors were fixed at 1.10 times the isotropic temperature factor of the C-atom to which they are bonded.

4.2 Preparations and Characterization of Starting Materials

4.2.1 General Syntheses of m-Terphenyl Ligands

Syntheses of m-terphenyl ligands were performed according to literature protocol.264 In general, excess magnesium shavings were placed in a three–neck round bottom flask equipped with stirbar, dripping funnel and condenser. The magnesium shavings were activated and covered with a generous portion of THF. To the flask was added drop wise the arylhalide, ArX, in THF.

After complete addition, the reaction was stirred overnight and subsequently refluxed for one hour. In another flask equipped with stirbar and dripping funnel, 1,3-dichlorobenzene covered with a generous portion of THF was placed at -78°C. n-Butyllithium (1.6 M in hexane) was added dropwise to this solution over a period of 1 hour. The temperature was maintained, ensuring not to rise above -50°C. After complete addition, the reaction was stirred for an additional hour, followed by drop wise addition of aryl Grignard reagent. This solution was stirred overnight followed by reflux for 1 hour. The flask was cooled and iodine was added in small portions until iodine color persisted for 30 minutes. The reaction was then quenched with an aqueous solution of sodium sulfite until iodine color disappeared. The mother solution was extracted with diethyl ether (3X) and water (2X). The organic portions were collected and dried

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on rotary evaporator. The residue was crystallized in ethanol/toluene or petroleum ether. Yields

of m-terphenyliodides were generally 60-80%.

4.2.2 Lithiation of m-Terphenyl Ligands

2,6-(4-t-BuC6H4)2C6H3Li (RLi) and 2,6-(4-Me-C6H4)2C6H3Li (RLi) were prepared by

modified literature procedure.265 As a general protocol, RI of RI were dissolved in hexane and

placed at -78°C then treated with n-butyllithium and stirred overnight. The supernatant was

filtered from precipitate and all solvent removed to give air- and moisture-sensitive white to off-

white powders. General yields were 90-95%. The powders were used without further

purification. 2,6-(4-t-BuC6H4)2C6H3Li (RLi) and 2,6-(4-Me-C6H4)2C6H3Li (RLi) were confirmed by melting point determination and 1H NMR data.

266 2,6-(2,4,6-i-Pr3C6H2)2C6H3Li(OEt2) was prepared by a modified literature protocol.

2,6-(2,4,6-i-Pr3C6H2)2C6H3I was dissolved in hexane/diethyl ether (6:1) and placed at -78°C,

followed by addition of n-butyllithium (1.5 eq.) and stirred for two days. All solvent was

removed and the residue was extracted with hexane and then filtered from precipitant. The

solvent was removed in vacuo to give white powder (85%) and used without further purification.

1 2,6-(2,4,6-i-Pr3C6H2)2C6H3Li(OEt2) was confirmed by melting point determination and H NMR

data.

4.2.3 Synthesis of 2,2-Dibromo-Z-stilbene

2,2-Dibromo-Z-stilbene was prepared by literature protocol.218 2-Bromobenzylbromide

(100 g, 400 mmol) and triphenylphosphine (104.8 g, 400mmol) was dissolved in toluene and

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refluxed for 4 hrs. 2-bromobenzyltriphenylphosphonium bromide precipitated out of solution.

The white precipitant was filtered from solution and washed with toluene. The powder was dried

in air for 2 hrs and used in the subsequent reaction (172 g, 84%). 2-

bromobenzyltriphenylphosphonium bromide (20.11 g, 39 mmol) was dissolved in CHCl3 and placed at 0°C. 2-Bromobenzaldhyde (7.3 g, 39 mmol) and a 50% w/v solution of sodium hydroxide (15.6 ml, 195 mmol) was rapidly transferred to this solution and stirred vigorously for

3 hrs. The solution was extracted with water (2X) and diethyl ether (2X). The organic layers were combined and all solvent was removed by rotary evaporation to give an oily pasty white residue. The residue was extracted with petroleum ether and filtered from white precipitant. The solvent was removed by rotary evaporation. This procedure was conducted two more successive times until only and amber to yellow oil remained. 2,2-dibromo-Z-stilbene crystallized as large colorless crystals from the oil (9 g, 69%). Purity was determined by melting point determination and 1H NMR data.

4.2.4 Synthesis of Bis(cyclopentadienyl)titanium(III) Chloride, [Cp2TiCl]2

Bis(cyclopentadienyl)titanium(III) chloride, [Cp2TiCl]2, was prepared from literature

183 protocol. Bis(cyclopentadienyl)titanium(IV) dichloride, Cp2TiCl2, (5 g, 20 mmol) and lithium

nitride (0.24 g, 6.6mmol) were placed in a flask and charged with THF and stirred for 16 hrs to

give a green solution. The solution was filtered from precipitant and then removed in vacuo. The

green residue was extracted with toluene and filtered from precipitant. All solvent was reduced

to give green crystalline material (2.2 g, 50%). Mp determination and 1H NMR confirmed purity.

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4.2.5 Synthesis of Mesityl-Group 13 Halides (MesEX3)

267 247 MesGaCl2, MesAlBr2, and MesInBr2 were prepared from modified literature

268 269 125 procedures by reaction of Mes3E (Al , Ga , In ) and EX3. MesMgBr (1 M solution, 50 mL,

50 mmol) in diethyl ether was added to EX3 (16.7 mmol) and stirred overnight, a thick precipitant formed in this duration. The supernatant was filtered from precipitant and discarded.

The off-white precipitant was washed with hexane and dried in vacuo to give Mes3E as white

residues (80-85%). Mes3E was dissolved in toluene and added to EX3 in toluene and stirred

overnight, which formed a thick precipitant The reaction was refluxed for 2 hrs and allowed to

cool. The supernatant was removed and the residue washed with hexane. The powders were

dried in vacuo (60-80%) and used without further purification. Purity was confirmed by mp

determination and 1H NMR.

4.2.6 Synthesis of 1,3-Diisopropyl-4,5-dimethylimidazol-2-ylidene (:L)

1,3-Diisopropyl-4,5-dimethylimidazol-2-ylidene (:L) was synthesized from literature

protocol by potassium reduction of 1,3-diisopropyl-4,5-dimethylimidazole-2(3H)-thione. 237 1,3-

diisopropyl-2-thiourea (15.8 g, 100 mmol) and 3-hydroxy-2-butanone (8.81 g, 100 mmol) was

dissolved in 1-hexanol and refluxed for 12 h. The solvent was boil off in hood to give a thick

brown slurry. The slurry was recrystallized from hexane/hexanol. Colorless crystals of 1,3-

diisopropyl-4,5-dimethylimidazole-2(3H)-thione were washed with hexane and dried in vacuo

(12.75 g, 60%).

1,3-diisopropyl-4,5-dimethylimidazole-2(3H)-thione (12 g, 56.5 mmol) and potassium

metal (5 g, 128 mmol) was covered with THF and refluxed for 4 h. The solution was filtered

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through celite and all solvent removed to give a off-white powder of (:L) (8.86 g, 87%). Purity

was confirmed by melting point determination and 1H NMR.

4.3 Syntheses of Less Sterically Demanding m-Terphenylgroup 13 Complexes

4.3.1 Synthesis of RGaCl2(OEt2), (1) (R = 2,6-(4-t-BuC6H4)2C6H3-)

GaCl3 (1.76 g, 10 mmol) in diethyl ether (25 mL) was rapidly transferred to a yellow

slurry of (2,6-(4-t-BuC6H4)2C6H3)Li (3.47 g, 10 mmol) in diethyl ether (40 mL) at ca. -78°C and

allowed to slowly warm to r.t. After stirring for 48 hrs, a clear pale yellow solution was filtered

from white precipitant. All solvent was removed in vacuo and then the residue was extracted in

hexane/diethyl ether (1:1, 20 mL) and placed at r.t. for 2 days, which afforded colorless, cubic

crystals of 1 (2.13 g, 38% mp: 212-214°C), Elemental anal. Calc. (found) for C30H39Cl2GaO

1 (556.26): C, 64.78 (64.67); H, 7.07 (6.94); H NMR (THF-D8, 400 MHz) 1.116 (q, 6H, -

OCH2CH3); 1.360 (s, 18H, C(CH3)3); 3.385 (t, 4H, -OCH2CH3); 7.377-7.493 (m, 11H, Ar-H).

4.3.2 Synthesis of R2GaCl,(2) (R = 2,6-(4-t-BuC6H4)2C6H3-)

GaCl3 (1.22 g, 6.95 mmol) in diethyl ether (25 mL), was rapidly transferred to a yellow

slurry of (2,6-(4-t-BuC6H4)2C6H3)Li (4.85 g, 13.9 mmol) in diethyl ether (40 mL) at ca. -78°C and allowed to slowly warm to r.t. After stirring for 12 hrs, a clear yellow solution with white precipitant was observed. The solution was filtered from the precipitant and solvent reduced by half. After 3 days at r.t. colorless, cubic crystals of 2 formed (2.35 g, 43%; mp: 202-204°C),

1 Elemental anal. Calc. (found) for C52H58GaCl (788.19): C 79.24 (79.06); H, 7.42 (7.61); H

NMR (THF-D8, 400 MHz) 1.31 (s, 18H, C(CH3)3); 6.987-7.267 (m, 11H, Ar-H).

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4.3.3 Synthesis of RAlBr2(OEt2), (3) (R = 2,6-(4-t-BuC6H4)2C6H3-).

AlBr3 (1.29 g, 4.8 mmol) in diethyl ether (30 mL), was rapidly transferred by cannula to a

yellow slurry of (2,6-(4-t-BuC6H4)2C6H3)Li (1.69 g, 4.8 mmol) in diethyl ether (40 mL) at ca. -

78°C and allowed to warm slowly to r.t. After stirring for 72 hrs, a colorless solution with white

precipitant was observed. The solution was filtered from precipitant and solvent reduced by a

third and then placed in freezer at -20°C. After 3 days a yellow viscous, oily residue formed. The

colorless solution was filtered from the oil and then reduced by a third and placed at r.t. for 3

days to give colorless, rectangular crystals of 3 (2.25 g, 78%; mp: 196-198°C)). Elemental anal.

1 Calc. (found) for C30H39AlBr2O (604.42): C 59.81 (59.64); H 6.53 (6.50); H NMR (D6-benzene,

400 MHz) 0.451 (t, 6H, -OCH2CH3), 1.236 (s, 18H, C(CH3)3), 3.219 (q, 4H, -OCH2CH3),

7.347-7.410 (m, 7H, Ar-H), 7.866-7.887 (m, 4H, Ar-H).

4.3.4 Synthesis of [RAlCl(OEt2)]2O (4) (R = 2,6-(4-t-BuC6H4)2C6H3-)

AlCl3 (1.34 g, 5 mmol) in diethyl ether (30 mL), was rapidly transferred by cannula to a

yellow slurry of 2,6-(4-t-BuC6H4)2C6H3)Li (3.52 g, 10 mmol) in diethyl ether (40 mL) at ca. -

78°C and allowed to warm slowly to r.t. The reaction was stirred for 48 hrs. The solution was

filtered from precipitant followed by reduction volume to ~ 20 mL then placed at r.t for 3 days.

1 Colorless needles of 4 formed. (1.24g, 31%, mp: 180-182 °C) H NMR (D6-benzene, 400 MHz)

0.52-0.55 (m, 12H, -OCH2CH3), 1.22 (s, 18H, C(CH3)3), 1.27 (s, 18H, C(CH3)3) 3.12-3.64 (m,

8H, -OCH2CH3) 7.160 (dd, 2H, Ar-H) 6.98-7.21 (m, 10H, Ar-H), 7.32-7.56 (m, 4H, Ar-H), 7.97-

8.05 (m, 6H, Ar-H).

144

4.3.5. Synthesis of R3In (5) (R = 2,6-(4-t-BuC6H4)2C6H3-)

A slurry of (2,6-(4-t-BuC6H4)2C6H3)Li (1.69 g, 4.8 mmol) in diethyl ether (40 mL) was

transferred by cannula to a slurry of InCl3 (1.07 g, 4.8 mmol) in diethyl ether (30 mL) at ca. -

78°C. The reaction was slowly allowed warm to r.t. After 3 days of stirring, a clear, colorless

solution with an appreciable amount of white precipitant was observed. The solution was filtered

from precipitant and solvent reduced and placed in freezer at -20°C. After 10 days, colorless,

flat, rectangular crystals of 5 formed (0.21 g, 11.5%; mp: 288-290°C), Elemental anal. Calc.

1 (found) for C78H87In (1139.34): C 82.23 (82.51); H 7.70 (7.76); H NMR (D6-benzene, 400

MHz) 1.218 (s, 18H, C(CH3)3), 6.972-7.227 (m,11H, Ar-H).

4.3.6 Synthesis of [R´GaCl3][Li(OEt2)2] (6) (R´=2,6-(4-Me-C6H4)2C6H3-)

To a solution of GaCl3 (0.811 g, 5 mmol) in diethyl ether was added RLi (1.38g, 5

mmol) in diethyl ether (50 mL) at 0°C. The reaction was stirred overnight. All solvent was

removed in vacuo and extracted with hexane (10 mL) and filtered from precipitate. Diethyl ether

(15 mL) was added to the solution followed by removal of solvent (5mL). Upon placing the

solution at r.t., a gray oily substance formed. After several days small colorless needle shaped

crystals of 6 formed from oily residue. (1.52 g, 52%; mp: wets 98°C, 103-108°C (decomp.).)

1 Elemental anal. Calc. (found) for C28H37Cl3GaLiO2 (588.61): C 57.13 (54.50); H 6.34; (5.36); H

NMR (D6-benzene, 400 MHz) 0.58 (t, 6H, -OCH2CH3), 2.10(s, 3H, -CH3), 3.62 (t, 8H, -

OCH2CH3), 6.972-7.227 (m,11H, Ar-H).

145

4.3.7 Synthesis of [R´InCl3][Li(OEt2)(THF)] (7) (R´=2,6-(4-Me-C6H4)2C6H3-)

A slurry of 2,6-(4-Me-C6H4)2C6H3Li (10 mmol, 1.89 g) in diethyl ether (30 mL) was

transferred slowly via cannula to a solution of InCl3 (2.21g, 10mmol) in THF (25 mL) at 0°C and

stirred for 24hrs. All solvent was removed and extracted with diethyl ether (25 mL) and hexanes

(20 mL). Colorless crystals of 7 formed over several days (2.52 g, 40%; mp: wets 135-137 °C)

1 H NMR (D6- Benzene, 400 MHz) 0.58 (t, 6H, -OCH2CH3), 2.10(s, 3H, CH3), 3.62 (t, 8H, -

OCH2CH3), 6.972-7.227 (m,11H, Ar-H).

4.3.8 Synthesis of R´3In (8) (R´= 2,6-(4-Me-C6H4)2C6H3-)

A slurry of 2,6-(4-Me-C6H4)2C6H3Li (10 mmol, 1.89 g) in diethyl ether (50mL) and toluene (10 ml) was transferred slowly via cannula to a solution of InCl3 (2.21g, 10 mmol) in

toluene (25 mL) at -78°C. The reaction was allowed to warm to room temperature and stirred

overnight for ~18 hr. The solution was filtered from the white precipitant then all solvent was

removed. The creamy residue was extracted in diethyl ether (15 mL) and hexane (20 mL),

wherein an oily residue formed at the bottom of the flask. The solution was filtered from the oily

residue and placed at room temperature overnight, resulting in large, cubic, colorless crystals of

8. (1.03 g, 68%); mp 239-240°C., Anal.: Calc. (Found) for C60H51In (886.86): C 81.25 (81.07); H

1 5.80 (5.79). H NMR (D6-Benzene, 400 MHz) 2.10(s, 6H, CH3), 6.82-6.85(m, 8H, Ar´-H), 7.00

(dd, 1H, p-C6H3) 7.78 (d, 2H, m-C6H3).

146

4.4 Syntheses of Organometallic Group 13Group 4 Complexes

4.4.1 Synthesis of Cp2Hf(GaR)2, (10) (R = 2,6-(2,4,6-i-Pr3C6H2)2C6H3-)

RGaCl2 (2.00 g, 4.00 mmol) and Cp2HfCl2 (1.52 g, 4.00 mmol) and finely divided sodium

metal (0.500 g, 22.0 mmol) were placed in a flask and charged with diethyl ether (80 mL). The

resultant slurry was stirred for three days. The solution was filtered from the precipitant and

reduced in volume by 50%. Upon standing at -25°C for 3 days, small green-black crystals of 10

were obtained. (1.83 g, 33%. m.p. 274 °C. Anal. Calc. for C86H118OGa2Hf: C, 69.05; H, 7.82%.

1 Found: C, 69.48; H 8.17%. H NMR (D6-benzene C6D6): ppm 1.29 (d, 24H, o-CH(CH3)2), 1.35

(d, 24H, o-CH(CH3)2), 1.51 (d, 24H, p-CH(CH3)2), 2.98 (sept, 4H, p-CH(CH3)2), 3.26 (sept, 8H,

o-CH(CH3)2), 3.87 (s, 10H, C5H5), 7.21 (s, 6H, -C6H3), 7.26 (s, 8H, -C6H2).

4.4.2 Synthesis of Cp2Hf(GaR)2, (11) (R =2,6-(2,4,6-i-Pr3C6H2)2C6H3-)

RInCl2 (2.40 g, 3.75mmol) and Cp2HfCl2 (1.42 g, 3.75 mmol) and finely divided sodium

metal (0.500 g, 22.0 mmol) were placed in a flask and charged with diethyl ether (80 mL). The

resultant slurry was stirred for three days. The solution was filtered from the precipitant and

reduced in volume by 50%. Upon standing at -25°C for 3 days, dark purple crystals of 11

formed. (1.24 g, 21%. m.p. 174°C (wets) 284°C (decomp.) Anal. Calc. for C86H118OIn2Hf: C,

1 64.99; H, 7.36%. Found: C, 65.53; H, 7.72 %. H NMR (C6D6): ppm 1.29 (d, 24H, o-

CH(CH3)2), 1.35 (d, 24H, o-CH(CH3)2), 1.51 (d, 24H, p- CH(CH3)2), 2.96 (sept, 4H, p-

CH(CH3)2), 3.26 (sept, 8H, o-CH(CH3)2), 3.96 (s, 10H, C5H5), 7.21 (s, 6H, -C6H3), 7.25 (s, 8H, -

C6H2).

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4.4.3 Synthesis of (C10H8)(ZrCp)2(μH)(μCl)(μGaR), (12) (R = 2,6-(4-t-BuC6H4)2C6H3-)

RGaCl2·(OEt2) (5.54 g, 10 mmol) in diethyl ether (75 mL) was transferred to a flask containing Cp2ZrCl2 (2.92 g, 10 mmol) and finely divided sodium metal (1 g, 43.5 mmol) and

stirred at room temperature. The initial colorless solution turned brown after 24 hours. After 5

days, a reddish brown solution was filtered from precipitant. The filtrate was collected and

solvent removed in vacuo, resulting in a brownish-black residue. The residue was extracted with

toluene (15 mL), and the solution was filtered at ca. -78 °C. The solution was placed at 5°C,

where upon overnight purple-black crystals formed. The crystals were re-crystallized in a

mixture of toluene and diethyl ether (1:1 ratio, 20 mL total). After 2 weeks at room temperature,

purple-black, flat, rectangular X-ray quality crystals of 12 formed (0.615 g, 0.627 mmol, 6.3 %

yield). m.p. 253-255°C, Elemental anal. (Complete Analysis Laboratories, Inc., Parsippany, NJ)

1 Calc.(found) for C53H56ClGaZr2 (980.64): C, 64.91(64.75); H, 5.76 (5.33).; H NMR (400 MHz,

[D8]THF): = 7.46 - 7.56 (m, 11H, Ar-H), 7.14 - 7.26 (m, 5H, C6H5CH3), 5.26 (s, 5H, C5H5),

5.12 (s, 5H, C5H5); 5.91, 5.62, 4.26, 4.20, 3.85, 3.79, 3.70, 3.53 (m, 1H x 8, two ABCD spin systems, C10H8), 2.30 (s, 3H, C6H5CH3), 1.29 (s, 18H, C(CH3)3), 4.316 (s, 1H, Zr-H-Zr); IR

(KBr): = 3114.83 (w), 3044.64 (w), 2960.68 (s), 2902.51 (w), 2864.98 (w), 1529.43 (m),

1507.98 (m), 1461.08 (m), 1438.41 (m), 1393.85 (m), 1362.21 (m), 1289.88 (m), 1115.86 (m),

1042.00 (s), 1014.85 (s), 797.20 (vs), 729.69 (s), 693.98 (m), 574.88 (w).

4.5 Syntheses of m-Terphenyl Group 4 Metallocenes

4.5.1 Synthesis of Cp2TiR´ (R´ = 2,6-(4-Me-C6H4)2C6H3) (13)

R´Li (1.25 g, 4.7 mmol) in THF (25 mL) was slowly added to [Cp2TiCl]2 (1.0 g, 4.7

mmol) in THF (25 mL) at ca. -78°C. The reaction was allowed to warm to room temperature and

148

stirred overnight. All solvent was removed in vacuo, and the residue was extracted with toluene

(25 mL). The toluene solution was removed in vacuo, and the residue was extracted with diethyl

ether (25 mL). The solution was filtered and reduced by half then placed in a -25°C freezer.

Overnight green-brown needles of 13 were isolated (1.03 g, 50%), mp. 180-182°C. Anal.: Calc.

(Found) for C30H27Ti (435.40): C, 82.76 (82.93); H, 6.25 (6.27).

4.5.2 Synthesis of Cp2ZrR(Cl) (R = 2,6-(4-t-Bu-C6H4)2C6H3) (14)

RLi (0.265 g, 1 mmol) in toluene (10 mL) was added to a toluene (5 mL) solution of

Cp2ZrCl2 (0.292g, 1 mmol) at -78°C. Upon addition, the pale creamy solution of Cp2ZrCl2 turned

pale yellow. The solution was allowed to warm to room temperature and stirred overnight. The

yellow solution was reduced in vacuo to ~ 5mL and placed at room temperature. Colorless,

needle-like crystals of 14 formed overnight. (0.52 g, 87%) mp. 221-222°C. Anal.: Calc. (Found)

1 for C43H47ClZr (690.51): C, 74.79 (73.72); H, 6.86 (6.70). H NMR (D6-Benzene, 400 MHz)

1.06 (s, 9H, -C(CH3)3) 1.15 (s, 9H, -C(CH3)3), 1.99 (s, 3H, Toluene -CH3), 5.65, (s, 10H, -C5H5),

6.85-6.90 (m, 5H, toluene ArH), 6.95-7.21 (m, 10H, ArH).

4.6 Synthesis of Gallepins and Dilithium Precursor

4.6.1 Synthesis of 2,2-Dilithio-Z-stilbene(TMEDA)2 (16)

2,2-Dibromo-Z-stilbene(13) (1.69g, 5 mmol) was dissolved in diethyl ether (50 mL) and

treated with of n-butyllithium (6.25 mL, 1.6 M, 10 mmol) at -78°C. The solution was stirred

overnight resulting in a yellow solution. All solvent was removed in vacuo, and the residue was extracted with hexane (30 mL). Upon addition of hexane a white precipitant crashed out of

149

solution (LiBr) and a brown-orange solution formed. The solution was filtered from the precipitant and treated with 1.1 mL TMEDA. The solution was reduced by half and placed at -

25°C. Orange-red crystals formed overnight. Procedure B: 2,2-Dibromo-Z-stilbene(13) (1.69g, 5 mmol) was dissolved in hexane (50 mL) and treated with of n-butyllithium (6.25 mL, 1.6 M, 10 mmol) at -78°C. The solution was stirred overnight resulting in a yellow solution and a thick orange precipitant. All solvent was removed by filter cannula to give a orange powder. Diethyl ether (10 mL) and hexane (50 mL) was added followed by addition of TMEDA. The solution was reduced by half and placed at -25°C. Orange-red crystals of 16 formed overnight (0.72 g, 34

%) m.p. 45-46°C, Found (calc.) for C26H42Li2N4 C: 73.38 (73.56) H: 10.01 (9.97) N: 13.22

1 (13.20) H NMR 1.281 (broad s, 8H, CH2N), 1.625 (broad s, 24H, N(CH3)2) 6.748 (d, 2H,=CH)

7.207- 7.227 (m, 2H, ArH) 7.326-7.367 (m, 2H, ArH) 7.423-7.441(m, 2H, ArH) 8.244-8.264 (m,

2H, ArH).

4.6.2 Synthesis of [spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)], (17)

2,2- dibromo-Z-stilbene (1.69g, 5 mmol) (16) was dissolved in diethyl ether (50 mL )and treated with of n-butyllithium (6.25 mL,1.6 M, 10 mmol) at -78°C. The solution was stirred overnight resulting in a yellow solution. All of the solvent was removed in vacuo, and the residue was extracted with hexane (30 mL) and filtered from precipitant. The resulting orange solution was placed at 0°C and transferred to GaCl3 (0.88g, 5 mmol) in 20 mL of diethyl ether.

The reaction was allowed to proceed overnight (~16 hrs). The mother solution was removed and the residue extracted with 25 mL of toluene. The solvent was reduced to ~10 mL and placed at -

25 °C. Colorless crystals of 17 formed after three days.

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4.6.3 Synthesis of bis(gallepin)TMEDA (18)

16 (0.70 g, 1.65 mmol) was dissolved in diethyl ether (40 mL) and added to GaCl3 (0.29

g, 1.65 mmol) in diethyl ether (25 mL) at ca. -78°C, and stirred for 5 hours. The dry ice bath was

removed and the reaction was allowed continued stirring for 12 hours. An appreciable amount of

precipitant was observed during this time. The supernatant was filtered from precipitant,

followed by reduction of solvent (in vacuo) to ~ 10 mL. Small colorless crystal formed

immediately, which were re-dissolved by light heating. The solution was placed in a -25°C freezer, where overnight large colorless crystals of 18 formed (0.44 g). The remaining precipitant was taken up in toluene (20 mL) and solvent reduced by half to yield additional crystals (0.34g).

Yield: (0.78 g, 69%) mp wets 207 °C, complete decomposition 248°C, (Found: C, 59.76; H,

1 5.28; N, 4.27. Calc. for C34H36Cl2Ga2N2: C, 59.79; H, 5.31; N, 4.10); H NMR H (DMSO-d6,

400 MHz) 2.31 (12H, s, -N(CH3)2), 2.58 (4H, s, NCH2), 6.62-6.73 (4H, m, =CH), 7.19-7.42

(12H, m, ArH), 7.70-7.78 (4H, m, ArH).

4.7 Synthesis CarbeneGroup 13 complexes

4.7.1 Synthesis of MesGaCl2(:L) (19), MesAlBr2(:L) (20), and MesInBr2(:L) (21)

Compounds 19, 20, and 21 were prepared in similar manner by reaction of :L and

MesEX2. In general, :L (3.9 g, 15 mmol) in toluene (50 mL) was transferred to MesEX2 (2.7g 15 mmol) in diethyl ether. For 19 and 20, the clear colorless solution gradually became cloudy and after 18hr a heavy precipitant formed, whereas for 21 a yellow solution formed. Removal of all volatiles in vacuo gives off-white powder, which were dissolved in tetrahydrofuran/methylene dichloride. Removal of solvent until incipient crystallization afforded large colorless crystals

1 overnight (91% av.) 19 (mp 177°C, H NMR (CDCl3) 1.41 (d, 12H, NCH(CH3)2) 2.23 (s, 3H,

151

p-CH3), 2.28 (s, 6H, [imidazoleC(CH3)]2) 2.48 (s, 6H, o-CH3), 5.52 (sept, 2H, NCH(CH3)2), 6.78 (s,

1 2H, ArH); 20 (mp 187°C . H NMR (CDCl3) 1.38 (d, 12H, NCH(CH3)2) 2.21 (s, 3H, p-CH3),

2.27 (s, 6H, [imidazoleC(CH3)]2) 2.51 (s, 6H, o-CH3), 5.58 (sept, 2H, NCH(CH3)2), 6.73 (s, 2H,

1 ArH); 21(mp 149-150, H NMR (C6D6) 1.07, (d, 24H, NCH(CH3)2), 1.50 (s, 6H,

[imidazoleC(CH3)]2), 1.52 (s, 6H, [imidazoleC(CH3)]2), 2.19 (s, 3H, p-CH3), 2.78 (s, 6H, o-CH3), 5.33-

5.52 (m, 4H, NCH(CH3)2), 6.84 (s, 2H, ArH).

4.7.2 Synthesis of [MesGaCl(:L)]2 (22)

Compound 19 (3.78 g, 7.2 mmol) and potassium graphite, KC8, (3.0 g, 22 mmol) in

diethyl ether were stirred for three days at r.t. The solution was filtered and solvent was removed

in vacuo resulting in a yellow residue. The residue was extracted with hexanes and filtered. The

solvent was reduced to ~2 mL giving a yellow oily residue and placed -25°C where small pale-

1 yellow crystals formed over several days. (0.3 g, 9 %, mp (decomp) 94-96°C) H NMR (benzene-

d6) 1.03 (d, 24H, NCH(CH3)2), 1.52 (s, 12H, [C(CH3)im]2), 2.32 (s, 6H, p-CH3), 2.82 (s, 12H, o-CH3) s, 5.79 (m, 4H, NCH(CH3)2), 6.92 (s, 4H, ArH)

4.7.3 Synthesis of Mes4Ga6(:L)2 (23)

Compound 19 (3.00 g, 6.8 mmol) and potassium, (0.54 g, 13.6 mmol) in toluene were heated until potassium melted and stirred for three days at r.t. The mother solution was filtered from precipitant followed by reduction of solvent to ~2 mL and addition of hexane (1mL). The solution was placed at -25°C, wherein pale-yellow amorphous material along with small cubic purple-red crystals formed over a period of weeks. (~0.1 g, 6%, mp. 148°C) 1H NMR (benzene-

d6) 1.05 (d, 24H, NCH(CH3)2), 1.18 (s, 12H, C(CH3)im), 2.32 (s, 24H, p-CH3) 2.82 (s, 24H, o-

CH3), 5.78 (sept, 4H, NCH(CH3)2), 6.92 (s, 8H, ArH)

152

4.8 Synthesis of Arduengo’s Carbene

4.8.1 Synthesis of glyoxal-bis-(1-adamantyl)imine (24)

Adamantylammonium chloride (29.9 g, 159 mmol) dissolved in H2O (250 mL) was

stirred until dissolved and treated with LiOH (3.66 g, 159 mmol) in H2O (100 mL). Upon

addition of LiOH solution a white precipitant formed immediately. Complete addition of LiOH

results in a thick white slurry. The reaction was stirred for 1 hr, where subsequent addition of

toluene results in two layers and disappearance of white slurry. Stirring was continued for an

additional hour. An aqueous 40% glyoxal solution (11.5 mL, 79.5 mmol) was then added and stirred for ~15 hrs. The two layers were separated. The aqueous layer was extracted (2X) with toluene. The organic layers were combined and solvent remove in vacuo. The beige solid was crystallized in toluene, filtered and dried, resulting in 24 as white crystalline material. (18.5 g,

1 72%, m.p. 243.5-244°C) H NMR (CDCl3): 1.64-1.78 (m, 24 H), 2.15 (s, 6H) 7.83, (s, 2H).

13 C NMR (CDCl3) 29.5, 36.6, 42.9, 58.7, 158.0.

4.8.2 Synthesis of 1,3-bis-(1-adamantyl)imidazolium chloride (25)

To 24 (15 g, 46.2 mmol) in THF, chloromethyl ethyl ether (4.5 g, 47.6 mmol) was added

dropwise by syringe. After 1 hour precipitant formed, and the color of the solution changed from

yellow to orange. The reaction was allowed continued stirring for 18hrs then placed at -20°C.

The precipitant was filtered and washed with THF and hexanes and dried. The powder was

1 dissolved in CHCl3, and then precipitated with THF (10 g, 58%, 335°C). H NMR (CDCl3):

1.76 (m, 12H) 2.29 (s, 18 H), 7.54 (s, 2H) 10.39 (s, 1H).

153

4.8.3 Synthesis of 1,3-bis-(1-adamantyl)imidazol-2-ylidene “Arduengo’s carbene” (26)

In drybox, 25 (10 g, 26 mmol) was covered with THF and rapidly stirred. Potassium tert- butoxide (3 g, 26 mmol) was added in small portions and stirred overnight. All solvent was removed and residue extracted with toluene then filtered through a celite column. All solvent was removed and the residue was taken up in diethyl ether. Removal of solvent until incipient precipitation and setting at r.t. for one day gave colorless crystal of 26. (3.5 g, 40%) Melting point (240-241°C) and NMR data (1.58 (s, 12H), 2.01 (s, 6H), 2.29 (s, 12H) 6.91(s,2H) compares well with reference.

154

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171

APPENDIX A

CRYSTALLOGRAPHIC DATA

Structural Data for RGaCl2(OEt2) (1) (R = 2,6-(4-t-BuC6H4)2C6H3-)

Table 1. Crystal data and structural refinement for RGaCl2(OEt2) (1)

Empirical formula C42H39Cl2GaO Formula weight 556.23 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Orthorhombic, Pna2(1) Unit cell dimensions a = 24.640(7) Å b = 11.365(3) Å c = 21.545(6) Å = 90° = 90° = 90° Volume 6033(3) Å3 Z, Calculated density 8, 1.225 Mg/m3 Absorption coefficient 1.108 mm-1 F(000) 2336 Crystal size 0.40 x 0.35 x 0.30 mm Theta range for data collection 1.89 to 25.00 deg. Limiting indices -29<=h<=29, -13<=k<=12, -24<=l<=25 Reflections collected / unique 35166 / 10454 [R(int) = 0.0313] Completeness to theta = 25.00 99.8 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.7322 and 0.6655 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 10454 / 1 / 608 Goodness-of-fit on F^2 1.042 Final R indices [I>2sigma(I)] R1 = 0.0463, wR2 = 0.1124 R indices (all data) R1 = 0.0593, wR2 = 0.1189 Absolute structure parameter 0.286(11) Largest diff. peak and hole 0.416 and -0.213 e.Å-3

172

Table 2. Bond Lengths [Å] for RGaCl2(OEt2) (1) Atoms Distance Atom Distance Ga(1)-C(1) 1.985(5) C(21)-C(22) 1.378(7) Ga(1)-O(1) 2.041(4) C(23)-C(25) 1.526(8) Ga(1)-Cl(1) 2.1872(13) C(23)-C(26) 1.495(11) Ga(1)-Cl(2) 2.2238(14) C(23)-C(24) 1.552(11) Ga(2)-C(31) 1.984(4) C(27)-C(28) 1.306(11) Ga(2)-O(2) 2.032(4) C(29)-C(30) 1.428(14) Ga(2)-Cl(3) 2.1993(15) C(31)-C(32) 1.392(7) Ga(2)-Cl(4) 2.2004(14) C(31)-C(36) 1.417(6) O(1)-C(27) 1.423(9) C(32)-C(33) 1.407(7) O(1)-C(29) 1.448(7) C(32)-C(37) 1.502(6) O(2)-C(57) 1.488(10) C(33)-C(34) 1.386(7) O(2)-C(59) 1.486(11) C(34)-C(35) 1.378(8) C(1)-C(2) 1.402(6) C(35)-C(36) 1.407(7) C(1)-C(6) 1.426(6) C(36)-C(47) 1.492(7) C(2)-C(3) 1.404(6) C(37)-C(42) 1.382(6) C(2)-C(7) 1.510(6) C(37)-C(38) 1.391(6) C(3)-C(4) 1.367(7) C(38)-C(39) 1.400(7) C(4)-C(5) 1.392(7) C(39)-C(40) 1.379(7) C(5)-C(6) 1.379(7) C(40)-C(41) 1.385(6) C(6)-C(17) 1.485(6) C(40)-C(43) 1.548(7) C(7)-C(8) 1.370(6) C(41)-C(42) 1.386(6) C(7)-C(12) 1.393(6) C(43)-C(46) 1.523(8) C(8)-C(9) 1.393(6) C(43)-C(45) 1.531(8) C(9)-C(10) 1.398(6) C(43)-C(44) 1.536(8) C(10)-C(11) 1.372(7) C(47)-C(48) 1.376(6) C(10)-C(13) 1.522(7) C(47)-C(52) 1.406(6) C(11)-C(12) 1.381(7) C(48)-C(49) 1.389(7) C(13)-C(15) 1.443(10) C(49)-C(50) 1.378(7) C(13)-C(14) 1.482(11) C(50)-C(51) 1.403(7) C(13)-C(16) 1.526(9) C(50)-C(53) 1.539(8) C(17)-C(22) 1.384(6) C(51)-C(52) 1.364(7) C(17)-C(18) 1.411(6) C(53)-C(55) 1.492(9 C(18)-C(19) 1.369(7) C(53)-C(56) 1.523(9) C(19)-C(20) 1.385(7) C(53)-C(54) 1.577(9) C(20)-C(21) 1.401(7) C(57)-C(58) 1.311(14) C(20)-C(23) 1.532(8) C(59)-C(60) 1.46(2)

173

Table 3. Bond angles [°] for RGaCl2(OEt2) (1) Atoms Angle Atoms Angle C(1)-Ga(1)-O(1) 105.89(15) C(10)-C(13)-C(14) 108.0(5) C(1)-Ga(1)-Cl(1) 123.49(12) C(15)-C(13)-C(16) 107.5(8) O(1)-Ga(1)-Cl(1) 101.47(11) C(10)-C(13)-C(16) 112.6(5) C(1)-Ga(1)-Cl(2) 118.72(13) C(14)-C(13)-C(16) 103.4(8) O(1)-Ga(1)-Cl(2) 95.05(11) C(22)-C(17)-C(18) 116.5(4) Cl(1)-Ga(1)-Cl(2) 106.70(6) C(22)-C(17)-C(6) 122.7(4) C(31)-Ga(2)-O(2) 104.01(16) C(18)-C(17)-C(6) 120.8(4) C(31)-Ga(2)-Cl(3) 123.84(13) C(19)-C(18)-C(17) 120.9(4) O(2)-Ga(2)-Cl(3) 102.93(14) C(18)-C(19)-C(20) 123.1(5) C(31)-Ga(2)-Cl(4) 118.80(13) C(21)-C(20)-C(19) 115.8(5) O(2)-Ga(2)-Cl(4) 94.99(11) C(21)-C(20)-C(23) 122.6(5) Cl(3)-Ga(2)-Cl(4) 106.67(7) C(19)-C(20)-C(23) 121.6(5) C(27)-O(1)-C(29) 116.2(5) C(22)-C(21)-C(20) 121.9(4) C(27)-O(1)-Ga(1) 124.5(4) C(17)-C(22)-C(21) 121.9(4) C(29)-O(1)-Ga(1) 117.0(4) C(20)-C(23)-C(25) 113.8(5) C(57)-O(2)-C(59) 119.8(7) C(20)-C(23)-C(26) 110.0(6) C(57)-O(2)-Ga(2) 114.4(4) C(25)-C(23)-C(26) 108.9(6) C(59)-O(2)-Ga(2) 122.7(6) C(20)-C(23)-C(24) 108.8(5) C(2)-C(1)-C(6) 118.4(4) C(25)-C(23)-C(24) 107.1(6) C(2)-C(1)-Ga(1) 123.4(3) C(26)-C(23)-C(24) 108.0(8) C(6)-C(1)-Ga(1) 117.6(3) C(28)-C(27)-O(1) 127.2(10) C(1)-C(2)-C(3) 119.5(4) C(30)-C(29)-O(1) 115.1(9) C(1)-C(2)-C(7) 124.0(4) C(32)-C(31)-C(36) 119.3(4) C(3)-C(2)-C(7) 116.5(4) C(32)-C(31)-Ga(2) 117.6(3) C(4)-C(3)-C(2) 121.2(5) C(36)-C(31)-Ga(2) 122.2(3) C(3)-C(4)-C(5) 120.0(5) C(31)-C(32)-C(33) 120.3(4) C(6)-C(5)-C(4) 120.4(5) C(31)-C(32)-C(37) 121.2(4) C(5)-C(6)-C(1) 120.2(4) C(33)-C(32)-C(37) 118.5(4) C(5)-C(6)-C(17) 118.6(4) C(34)-C(33)-C(32) 120.0(5) C(1)-C(6)-C(17) 121.2(4) C(35)-C(34)-C(33) 120.3(5) C(8)-C(7)-C(12) 117.3(4) C(34)-C(35)-C(36) 120.7(5) C(8)-C(7)-C(2) 121.5(4) C(35)-C(36)-C(31) 119.2(4) C(12)-C(7)-C(2) 121.0(4) C(35)-C(36)-C(47) 117.8(4) C(7)-C(8)-C(9) 120.7(4) C(31)-C(36)-C(47) 123.0(4) C(10)-C(9)-C(8) 122.3(4) C(42)-C(37)-C(38) 118.2(4) C(11)-C(10)-C(9) 116.0(4) C(42)-C(37)-C(32) 121.5(4) C(11)-C(10)-C(13) 123.0(5) C(38)-C(37)-C(32) 120.3(4) C(9)-C(10)-C(13) 121.0(5) C(37)-C(38)-C(39) 120.1(4) C(10)-C(11)-C(12) 122.2(4) C(40)-C(39)-C(38) 122.0(4) C(11)-C(12)-C(7) 121.5(4) C(39)-C(40)-C(41) 116.6(4)

174

Table 3 (con’t). Bond angles [°] for RGaCl2(OEt2) (1) Atoms Angle Atoms Angle C(15)-C(13)-C(10) 113.4(5) C(39)-C(40)-C(43) 120.0(4) C(15)-C(13)-C(14) 111.6(10) C(41)-C(40)-C(43) 123.4(4) C(40)-C(41)-C(42) 122.4(4) C(49)-C(50)-C(51) 116.4(5) C(37)-C(42)-C(41) 120.5(4) C(49)-C(50)-C(53) 120.7(5) C(46)-C(43)-C(45) 107.9(6) C(51)-C(50)-C(53) 122.8(5) C(46)-C(43)-C(44) 107.5(6) C(52)-C(51)-C(50) 121.0(4) C(45)-C(43)-C(44) 110.0(6) C(51)-C(52)-C(47) 122.5(4) C(46)-C(43)-C(40) 108.9(5) C(55)-C(53)-C(50) 110.1(5) C(45)-C(43)-C(40) 110.5(5) C(55)-C(53)-C(56) 112.1(6) C(44)-C(43)-C(40) 111.8(4) C(50)-C(53)-C(56) 112.9(5) C(48)-C(47)-C(52) 116.4(4) C(55)-C(53)-C(54) 107.9(6) C(48)-C(47)-C(36) 121.4(4) C(50)-C(53)-C(54) 108.0(5) C(52)-C(47)-C(36) 122.0(4) C(56)-C(53)-C(54) 105.5(6) C(47)-C(48)-C(49) 121.0(4) C(58)-C(57)-O(2) 122.0(11) C(50)-C(49)-C(48) 122.6(5) C(60)-C(59)-O(2) 109.1(13)

175

Structural Data for R2GaCl (2) (R = 2,6-(4-t-BuC6H4)2C6H3-)

Table 4. Crystal data and structural refinement for R2GaCl (2) Empirical formula C52H58ClGa Formula weight 788.15 Temperature 273(2) K Wavelength 0.71073 A Crystal system, space group Monoclinic, P2(1)/n Unit cell dimensions a = 17.587(4) Å b = 13.911(3) Å c = 19.968(4) Å = 90° = 110.010(4)° = 90° Volume 4590.4(16) Å3 Z, Calculated density 4, 1.140 Mg/m3 Absorption coefficient 0.689 mm-1 F(000) 1672 Crystal size 0.35 x 0.25 x 0.15 mm Theta range for data collection 1.82 to 25.00 deg. Limiting indices -20<=h<=20, -14<=k<=16, -23<=l<=23 Reflections collected / unique 27144 / 8018 [R(int) = 0.0281] Completeness to theta = 25.00 99.2 % Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 8018 / 0 / 487 Goodness-of-fit on F^2 1.019 Final R indices [I>2sigma(I)] R1 = 0.0472, wR2 = 0.1284 R indices (all data) R1 = 0.0678, wR2 = 0.1422 Largest diff. peak and hole 0.789 and -0.188 e.Å-3

176

Table 5. Bond Lengths [Å] for R2GaCl (2) Atoms Distances Atoms Distances Ga(1)-C(1) 1.981(3) C(20)-C(23) 1.530(5) Ga(1)-C(27) 1.997(3) C(21)-C(22) 1.384(4) Ga(1)-Cl(1) 2.2537(10) C(23)-C(26) 1.511(7) C(1)-C(6) 1.405(4) C(23)-C(24) 1.512(6) C(1)-C(2) 1.411(4) C(23)-C(25) 1.519(8) C(2)-C(3) 1.402(4) C(27)-C(32) 1.404(4) C(2)-C(7) 1.485(4) C(27)-C(28) 1.421(4) C(3)-C(4) 1.373(4) C(28)-C(29) 1.402(5) C(4)-C(5) 1.378(4) C(28)-C(33) 1.478(5) C(5)-C(6) 1.395(4) C(29)-C(30) 1.383(6) C(6)-C(17) 1.489(4) C(30)-C(31) 1.364(6) C(7)-C(12) 1.389(4) C(31)-C(32) 1.400(5) C(7)-C(8) 1.392(4) C(32)-C(43) 1.492(4) C(8)-C(9) 1.384(4) C(33)-C(34) 1.391(5) C(9)-C(10) 1.392(4) C(39)-C(42) 1.538(6) C(10)-C(11) 1.396(4) C(39)-C(40) 1.547(7) C(10)-C(13) 1.528(4) C(39)-C(41) 1.532(6) C(10)-C(13) 1.528(4) C(43)-C(44) 1.398(4) C(11)-C(12) 1.387(4) C(43)-C(48) 1.392(4) C(13)-C(15) 1.482(6) C(44)-C(45) 1.376(4) C(13)-C(14) 1.510(7) C(45)-C(46) 1.393(4) C(13)-C(16) 1.527(6) C(46)-C(47) 1.401(4) C(17)-C(22) 1.385(4) C(46)-C(49) 1.533(4) C(17)-C(18) 1.397(4) C(47)-C(48) 1.369(4) C(18)-C(19) 1.381(4) C(49)-C(50) 1.520(4) C(19)-C(20) 1.390(5) C(49)-C(51) 1.536(5) C(20)-C(21) 1.396(4) C(49)-C(52) 1.543(5)

177

Table 6. Bond angles [°] for R2GaCl (2) Atoms Angle Atoms Angle C(1)-Ga(1)-C(27) 137.37(12) C(26)-C(23)-C(25) 110.9(6) C(1)-Ga(1)-Cl(1) 106.69(9) C(24)-C(23)-C(25) 107.6(5) C(27)-Ga(1)-Cl(1) 115.76(9) C(32)-C(27)-C(28) 118.9(3) C(6)-C(1)-C(2) 118.5(3) C(32)-C(27)-Ga(1) 120.5(2) C(6)-C(1)-Ga(1) 117.12(19) C(28)-C(27)-Ga(1) 119.9(2) C(2)-C(1)-Ga(1) 124.4(2) C(29)-C(28)-C(27) 119.4(3) C(1)-C(2)-C(3) 119.6(3) C(29)-C(28)-C(33) 119.0(3) C(1)-C(2)-C(7) 121.7(2) C(27)-C(28)-C(33) 121.5(3) C(3)-C(2)-C(7) 118.7(2) C(30)-C(29)-C(28) 120.7(3) C(4)-C(3)-C(2) 120.9(3) C(31)-C(30)-C(29) 119.7(3) C(3)-C(4)-C(5) 120.1(3) C(30)-C(31)-C(32) 121.9(4) C(4)-C(5)-C(6) 120.5(3) C(31)-C(32)-C(27) 119.3(3) C(1)-C(6)-C(5) 120.4(3) C(31)-C(32)-C(43) 118.1(3) C(1)-C(6)-C(17) 120.3(2) C(27)-C(32)-C(43) 122.6(3) C(5)-C(6)-C(17) 119.3(2) C(34)-C(33)-C(38) 116.6(3) C(12)-C(7)-C(8) 117.1(3) C(34)-C(33)-C(28) 122.6(3) C(12)-C(7)-C(2) 123.1(2) C(38)-C(33)-C(28) 120.8(3) C(8)-C(7)-C(2) 119.8(3) C(33)-C(34)-C(35) 121.3(3) C(7)-C(8)-C(9) 121.7(3) C(36)-C(35)-C(34) 121.9(3) C(10)-C(9)-C(8) 121.5(3) C(35)-C(36)-C(37) 115.9(4) C(9)-C(10)-C(11) 116.6(3) C(35)-C(36)-C(39) 123.7(3) C(9)-C(10)-C(13) 120.2(3) C(37)-C(36)-C(39) 120.4(3) C(11)-C(10)-C(13) 123.2(3) C(38)-C(37)-C(36) 122.0(3) C(12)-C(11)-C(10) 121.9(3) C(37)-C(38)-C(33) 121.8(3) C(11)-C(12)-C(7) 121.2(3) C(36)-C(39)-C(42) 112.8(3) C(15)-C(13)-C(14) 112.0(5) C(36)-C(39)-C(40) 109.5(4) C(15)-C(13)-C(10) 113.1(3) C(42)-C(39)-C(40) 108.3(5) C(14)-C(13)-C(10) 109.8(4) C(36)-C(39)-C(41) 110.5(4) C(15)-C(13)-C(16) 106.9(5) C(42)-C(39)-C(41) 108.1(4) C(14)-C(13)-C(16) 105.1(6) C(40)-C(39)-C(41) 107.3(4) C(10)-C(13)-C(16) 109.7(3) C(44)-C(43)-C(48) 116.4(3) C(22)-C(17)-C(18) 117.4(3) C(44)-C(43)-C(32) 121.5(3) C(22)-C(17)-C(6) 120.9(3) C(48)-C(43)-C(32) 122.0(2) C(18)-C(17)-C(6) 121.8(3) C(43)-C(44)-C(45) 121.8(3) C(19)-C(18)-C(17) 121.1(3) C(46)-C(45)-C(44) 121.9(3) C(18)-C(19)-C(20) 121.7(3) C(45)-C(46)-C(47) 115.8(3) C(21)-C(20)-C(19) 117.0(3) C(45)-C(46)-C(49) 124.1(3) C(21)-C(20)-C(23) 122.5(3) C(47)-C(46)-C(49) 120.1(3)

178

Table 6 (con’t). Bond angles [°] for R2GaCl (2) Atoms Angle Atoms Angle C(19)-C(20)-C(23) 120.5(3) C(48)-C(47)-C(46) 122.4(3) C(20)-C(21)-C(22) 121.2(3) C(47)-C(48)-C(43) 121.6(3) C(17)-C(22)-C(21) 121.6(3) C(46)-C(49)-C(50) 110.0(3) C(20)-C(23)-C(26) 108.6(4) C(46)-C(49)-C(51) 109.1(3) C(20)-C(23)-C(24) 110.5(3) C(50)-C(49)-C(51) 109.5(3) C(26)-C(23)-C(24) 108.3(5) C(46)-C(49)-C(52) 111.8(3) C(20)-C(23)-C(25) 110.8(4) C(50)-C(49)-C(52) 108.0(3) C(51)-C(49)-C(52) 108.3(3)

179

Structural Data for RAlBr2(Et2O) (3) (R = 2,6-(4-t-BuC6H4)2C6H3-)

Table 7. Crystal data and structural refinement for (2,6-(4-t-BuC6H4)2C6H3)AlBr2(Et2O) (3) Empirical formula C60H78Al2Br4O2 Formula weight 1204.82 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, P2(1)/n Unit cell dimensions a = 24.1758(17) Å b = 11.5810(8) Å c = 24.6206(16) Å = 90° = 118.4790(10)° = 90° Volume 6059.1(7) Å3 Z, Calculated density 4, 1.321 Mg/m3 Absorption coefficient 2.724 mm-1 F(000) 2480 Crystal size 0.40 x 0.30 x 0.25 mm Theta range for data collection 1.92 to 25.00 deg. Limiting indices -26<=h<=28, -13<=k<=13, -28<=l<=29 Reflections collected / unique 35885 / 10646 [R(int) = 0.0323] Completeness to theta 25.00 99.7 % Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 10646 / 0 / 596 Goodness-of-fit on F^2 1.013 Final R indices [I>2sigma(I)] R1 = 0.0554, wR2 = 0.1523 R indices (all data) R1 = 0.0981, wR2 = 0.1852 Largest diff. peak and hole 0.616 and -0.752 e.Å-3

180

Table 8. Bond Lengths [Å] for RAlBr2(Et2O) (3) Atoms Distance Atoms Distance Al(1)-O(1) 1.877(4) C(23)-C(25') 1.44(2) Al(1)-C(1) 1.979(5) C(23)-C(26') 1.52(2) Al(1)-Br(2) 2.3013(16) C(23)-C(24) 1.592(19) Al(1)-Br(1) 2.3173(17) C(23)-C(25) 1.624(16) Al(2)-O(2) 1.875(4) C(23)-C(24') 1.55(2) Al(2)-C(31) 1.975(5) C(23)-C(26) 1.655(16) Al(2)-Br(4) 2.2999(17) C(24)-C(24') 0.58(3) Al(2)-Br(3) 2.3151(17) C(24)-C(26) 2.17(2) O(1)-C(29) 1.365(16) C(25)-C(25') 1.31(3) O(1)-C(27) 1.496(13) C(25')-C(26') 1.32(3) O(1)-C(29') 1.94(5) C(26)-C(26') 1.28(2) O(1)-C(27') 1.62(2) C(27)-C(28') 1.11(3) O(2)-C(57') 1.34(2) C(27)-C(27') 1.27(2) O(2)-C(59') 1.377(15) C(27)-C(28) 1.58(2) O(2)-C(57) 1.653(15) C(27')-C(28) 1.14(2) O(2)-C(59) 1.67(2) C(27')-C(28') 1.53(3) C(1)-C(6) 1.411(6) C(28)-C(28') 0.93(3) C(1)-C(2) 1.409(6) C(29)-C(30') 1.00(6) C(2)-C(3) 1.386(7) C(29)-C(30) 1.30(3) C(2)-C(7) 1.487(7) C(29')-C(30') 1.08(7) C(3)-C(4) 1.371(7) C(29')-C(30) 1.68(6) C(4)-C(5) 1.364(7) C(30)-C(30') 0.80(6) C(5)-C(6) 1.405(7) C(31)-C(36) 1.417(7) C(6)-C(17) 1.497(7) C(31)-C(32) 1.412(7) C(7)-C(8) 1.382(7) C(32)-C(33) 1.390(7) C(7)-C(12) 1.399(7) C(32)-C(37) 1.496(7) C(8)-C(9) 1.374(7) C(33)-C(34) 1.378(7) C(9)-C(10) 1.382(8) C(34)-C(35) 1.370(7) C(10)-C(11) 1.374(7) C(35)-C(36) 1.386(7) C(10)-C(13) 1.531(8) C(36)-C(47) 1.499(7) C(11)-C(12) 1.383(7) C(37)-C(38) 1.378(7) C(13)-C(15') 1.40(2) C(37)-C(42) 1.380(7) C(13)-C(16) 1.474(18) C(38)-C(39) 1.383(7) C(13)-C(14) 1.528(18) C(39)-C(40) 1.390(8) C(13)-C(16') 1.67(2) C(40)-C(41) 1.377(8) C(13)-C(14') 1.637(17) C(40)-C(43) 1.540(8) C(13)-C(15) 1.723(17) C(41)-C(42) 1.384(7) C(14)-C(14') 0.65(2) C(43)-C(46') 1.518(18) C(15)-C(15') 0.75(2) C(43)-C(44) 1.617(16) C(15')-C(16) 1.86(3) C(43)-C(44') 1.52(2)

181

Table 8 (con’t). Bond Lengths [Å] for RAlBr2(Et2O) (3) Atoms Distance Atoms Distance C(16)-C(16') 0.89(2) C(43)-C(45) 1.59(2) C(17)-C(18) 1.378(7) C(43)-C(46) 1.63(2) C(17)-C(22) 1.395(7) C(43)-C(45') 1.600(18) C(18)-C(19) 1.375(7) C(44)-C(44') 0.76(2) C(19)-C(20) 1.391(7) C(44')-C(45) 2.06(3) C(20)-C(21) 1.383(8) C(45)-C(45') 0.84(2) C(20)-C(23) 1.533(8) C(45')-C(46') 2.09(3) C(21)-C(22) 1.374(8) C(46)-C(46') 0.73(3) C(47)-C(52) 1.395(7) C(57)-C(58') 1.27(3) C(47)-C(48) 1.393(7) C(57)-C(58) 1.54(2) C(48)-C(49) 1.377(7) C(57')-C(58) 1.31(2) C(49)-C(50) 1.398(7) C(57')-C(58') 1.43(3) C(50)-C(51) 1.391(7) C(58)-C(58') 1.69(3) C(50)-C(53) 1.521(7) C(59)-C(59') 0.60(3) C(51)-C(52) 1.378(7) C(59)-C(60) 1.52(3) C(53)-C(56) 1.513(8) C(59)-C(60') 1.82(3) C(53)-C(55) 1.554(9) C(59')-C(60') 1.53(3) C(53)-C(54) 1.551(8) C(59')-C(60) 1.60(3) C(57)-C(57') 0.71(2) C(60)-C(60') 1.10(3)

182

Table 9. Bond angles [°] for RAlBr2(Et2O) (3) Atoms Angles Atoms Angle O(1)-Al(1)-C(1) 106.64(19) C(1)-C(2)-C(7) 120.4(4) O(1)-Al(1)-Br(2) 104.27(14) C(2)-C(3)-C(4) 120.4(5) C(1)-Al(1)-Br(2) 120.08(15) C(3)-C(4)-C(5) 120.1(5) O(1)-Al(1)-Br(1) 97.97(14) C(4)-C(5)-C(6) 120.8(5) C(1)-Al(1)-Br(1) 117.46(15) C(1)-C(6)-C(5) 120.2(5) Br(2)-Al(1)-Br(1) 107.22(6) C(1)-C(6)-C(17) 122.8(4) O(2)-Al(2)-C(31) 103.93(19) C(5)-C(6)-C(17) 116.9(4) O(2)-Al(2)-Br(4) 106.57(15) C(8)-C(7)-C(12) 117.2(5) C(31)-Al(2)-Br(4) 121.72(15) C(8)-C(7)-C(2) 121.0(4) O(2)-Al(2)-Br(3) 97.43(14) C(12)-C(7)-C(2) 121.8(4) C(31)-Al(2)-Br(3) 117.59(16) C(7)-C(8)-C(9) 121.0(5) Br(4)-Al(2)-Br(3) 106.17(6) C(10)-C(9)-C(8) 122.2(5) C(29)-O(1)-C(27) 110.8(8) C(9)-C(10)-C(11) 116.7(5) C(29)-O(1)-C(29') 17.3(19) C(9)-C(10)-C(13) 120.7(5) C(27)-O(1)-C(29') 108.9(16) C(11)-C(10)-C(13) 122.5(5) C(29)-O(1)-C(27') 114.5(11) C(10)-C(11)-C(12) 122.1(5) C(27)-O(1)-C(27') 47.8(9) C(11)-C(12)-C(7) 120.4(5) C(29')-O(1)-C(27') 126.8(18) C(15')-C(13)-C(16) 80.5(12) C(29)-O(1)-Al(1) 118.8(7) C(15')-C(13)-C(14) 121.2(12) C(27)-O(1)-Al(1) 129.4(5) C(16)-C(13)-C(14) 109.4(11) C(29')-O(1)-Al(1) 115.2(15) C(15')-C(13)-C(10) 117.2(10) C(27')-O(1)-Al(1) 113.5(9) C(16)-C(13)-C(10) 110.5(8) C(57')-O(2)-C(59') 98.3(12) C(14)-C(13)-C(10) 112.6(8) C(57')-O(2)-C(57) 24.6(11) C(15')-C(13)-C(16') 110.0(13) C(59')-O(2)-C(57) 114.2(9) C(16)-C(13)-C(16') 32.0(9) C(57')-O(2)-C(59) 116.8(13) C(14)-C(13)-C(16') 83.1(11) C(59')-O(2)-C(59) 19.9(10) C(10)-C(13)-C(16') 106.1(9) C(57)-O(2)-C(59) 134.1(10) C(15')-C(13)-C(14') 107.6(11) C(57')-O(2)-Al(2) 125.5(10) C(16)-C(13)-C(14') 129.0(10) C(59')-O(2)-Al(2) 135.9(7) C(14)-C(13)-C(14') 23.5(7) C(57)-O(2)-Al(2) 108.8(5) C(10)-C(13)-C(14') 109.3(7) C(59)-O(2)-Al(2) 116.5(9) C(16')-C(13)-C(14') 106.2(11) C(6)-C(1)-C(2) 116.9(4) C(15')-C(13)-C(15) 25.2(9) C(6)-C(1)-Al(1) 122.9(3) C(16)-C(13)-C(15) 105.5(10) C(2)-C(1)-Al(1) 119.3(3) C(14)-C(13)-C(15) 114.3(10) C(3)-C(2)-C(1) 121.3(4) C(10)-C(13)-C(15) 104.3(7) C(3)-C(2)-C(7) 118.3(4) C(16')-C(13)-C(15) 135.0(10)

183

Table 9 (con’t). Bond angles [°] for RAlBr2(Et2O) (3) Atoms Angles Atoms Angle C(14')-C(13)-C(15) 94.0(8) C(26')-C(23)-C(26) 47.2(8) C(14')-C(14)-C(13) 88(3) C(20)-C(23)-C(26) 104.8(7) C(14)-C(14')-C(13) 69(2) C(24)-C(23)-C(26) 83.9(9) C(15')-C(15)-C(13) 52(2) C(25)-C(23)-C(26) 143.3(8) C(15)-C(15')-C(13) 102(3) C(24')-C(23)-C(26) 102.9(11) C(15)-C(15')-C(16) 153(3) C(24')-C(24)-C(23) 76(3) C(13)-C(15')-C(16) 51.5(9) C(24')-C(24)-C(26) 120(4) C(16')-C(16)-C(13) 86(2) C(23)-C(24)-C(26) 49.3(7) C(16')-C(16)-C(15') 130(2) C(24)-C(24')-C(23) 83(4) C(13)-C(16)-C(15') 47.9(8) C(25')-C(25)-C(23) 57.7(12) C(16)-C(16')-C(13) 61.6(18) C(26')-C(25')-C(25) 138(2) C(18)-C(17)-C(22) 117.2(5) C(26')-C(25')-C(23) 66.4(15) C(18)-C(17)-C(6) 121.2(4) C(25)-C(25')-C(23) 72.0(15) C(22)-C(17)-C(6) 121.5(5) C(26')-C(26)-C(23) 60.7(11) C(17)-C(18)-C(19) 120.9(5) C(26')-C(26)-C(24) 101.1(14) C(20)-C(19)-C(18) 122.4(5) C(23)-C(26)-C(24) 46.8(7) C(21)-C(20)-C(19) 116.4(5) C(26)-C(26')-C(25') 130(2) C(21)-C(20)-C(23) 122.2(5) C(26)-C(26')-C(23) 72.0(12) C(19)-C(20)-C(23) 121.4(6) C(25')-C(26')-C(23) 60.7(14) C(22)-C(21)-C(20) 121.5(5) C(28')-C(27)-C(27') 80(2) C(21)-C(22)-C(17) 121.6(5) C(28')-C(27)-O(1) 145(2) C(25')-C(23)-C(26') 52.9(11) C(27')-C(27)-O(1) 71.4(13) C(25')-C(23)-C(20) 114.9(10) C(28')-C(27)-C(28) 35.2(16) C(26')-C(23)-C(20) 110.5(8) C(27')-C(27)-C(28) 45.7(12) C(25')-C(23)-C(24) 132.2(12) O(1)-C(27)-C(28) 111.0(11) C(26')-C(23)-C(24) 122.2(11) C(28)-C(27')-C(27) 82(2) C(20)-C(23)-C(24) 110.3(8) C(28)-C(27')-C(28') 37.4(15) C(25')-C(23)-C(25) 50.3(11) C(27)-C(27')-C(28') 45.6(14) C(26')-C(23)-C(25) 102.8(10) C(28)-C(27')-O(1) 132(2) C(20)-C(23)-C(25) 106.2(7) C(27)-C(27')-O(1) 60.8(12) C(24)-C(23)-C(25) 103.0(9) C(28')-C(27')-O(1) 104.1(19) C(25')-C(23)-C(24') 119.3(13) C(28')-C(28)-C(27') 94(3) C(26')-C(23)-C(24') 132.5(12) C(28')-C(28)-C(27) 43(2) C(20)-C(23)-C(24') 113.1(10) C(27')-C(28)-C(27) 52.4(15) C(24)-C(23)-C(24') 21.0(10) C(27)-C(28')-C(28) 101(3) C(25)-C(23)-C(24') 82.3(10) C(27)-C(28')-C(27') 54.7(16) C(25')-C(23)-C(26) 98.5(12) C(28)-C(28')-C(27') 94(3)

184

Table 9 (Continued). Bond angles [°] for RAlBr2•(Et2O) (3) Atoms Angles Atoms Angle C(30')-C(29)-C(30) 38(4) C(46')-C(43)-C(44') 126.9(12) C(30')-C(29)-O(1) 80(2) C(40)-C(43)-C(44') 112.1(9) C(30)-C(29)-O(1) 123.3(17) C(44)-C(43)-C(44') 27.9(8) C(30')-C(29')-C(30) 23(4) C(46')-C(43)-C(45) 112.8(12) C(30')-C(29')-O(1) 94(6) C(40)-C(43)-C(45) 106.5(8) C(30)-C(29')-O(1) 80(2) C(44)-C(43)-C(45) 109.2(10) C(30')-C(30)-C(29) 50(5) C(44')-C(43)-C(45) 82.9(12) C(30')-C(30)-C(29') 32(5) C(46')-C(43)-C(46) 26.6(9) C(29)-C(30)-C(29') 26(2) C(40)-C(43)-C(46) 104.9(9) C(30)-C(30')-C(29) 92(6) C(44)-C(43)-C(46) 85.1(10) C(30)-C(30')-C(29') 126(8) C(44')-C(43)-C(46) 111.1(12) C(29)-C(30')-C(29') 42(3) C(45)-C(43)-C(46) 137.0(12) C(36)-C(31)-C(32) 116.7(4) C(46')-C(43)-C(45') 83.9(11) C(36)-C(31)-Al(2) 122.5(4) C(40)-C(43)-C(45') 110.4(7) C(32)-C(31)-Al(2) 119.4(3) C(44)-C(43)-C(45') 129.4(9) C(33)-C(32)-C(31) 121.0(4) C(44')-C(43)-C(45') 108.3(11) C(33)-C(32)-C(37) 118.5(4) C(45)-C(43)-C(45') 30.4(8) C(31)-C(32)-C(37) 120.4(4) C(46)-C(43)-C(45') 110.0(11) C(32)-C(33)-C(34) 120.5(5) C(44')-C(44)-C(43) 69(2) C(35)-C(34)-C(33) 119.7(5) C(44)-C(44')-C(43) 83(2) C(34)-C(35)-C(36) 121.0(5) C(44)-C(44')-C(45) 130(3) C(31)-C(36)-C(35) 120.7(5) C(43)-C(44')-C(45) 50.0(9) C(31)-C(36)-C(47) 121.9(4) C(45')-C(45)-C(43) 75(2) C(35)-C(36)-C(47) 117.4(4) C(45')-C(45)-C(44') 115(2) C(38)-C(37)-C(42) 117.5(5) C(43)-C(45)-C(44') 47.1(8) C(38)-C(37)-C(32) 120.6(4) C(45)-C(45')-C(43) 74(2) C(42)-C(37)-C(32) 121.9(5) C(45)-C(45')-C(46') 118(2) C(37)-C(38)-C(39) 120.9(5) C(43)-C(45')-C(46') 46.4(7) C(38)-C(39)-C(40) 122.0(5) C(46')-C(46)-C(43) 68(2) C(41)-C(40)-C(39) 116.3(5) C(46)-C(46')-C(43) 85(3) C(41)-C(40)-C(43) 122.7(5) C(46)-C(46')-C(45') 134(3) C(39)-C(40)-C(43) 121.0(5) C(43)-C(46')-C(45') 49.7(8) C(40)-C(41)-C(42) 121.9(5) C(52)-C(47)-C(48) 116.6(5) C(37)-C(42)-C(41) 121.2(5) C(52)-C(47)-C(36) 122.5(5) C(46')-C(43)-C(40) 110.8(8) C(48)-C(47)-C(36) 120.8(4) C(46')-C(43)-C(44) 106.0(10) C(47)-C(48)-C(49) 121.1(5) C(40)-C(43)-C(44) 111.5(7) C(48)-C(49)-C(50) 122.6(5)

185

Table 9 (con’t). Bond angles [°] for RAlBr2•(Et2O) (3) Atoms Angles Atoms Angle C(51)-C(50)-C(49) 115.8(5) C(57')-C(58)-C(57) 27.2(11) C(51)-C(50)-C(53) 124.1(5) C(57')-C(58)-C(58') 55.0(13) C(49)-C(50)-C(53) 120.1(5) C(57)-C(58)-C(58') 45.8(10) C(52)-C(51)-C(50) 121.8(5) C(57)-C(58')-C(57') 63(2) C(51)-C(52)-C(47) 122.0(5) C(57)-C(58')-C(58) 60.8(14) C(50)-C(53)-C(56) 109.9(5) C(57')-C(58')-C(58) 48.6(13) C(50)-C(53)-C(55) 110.0(5) C(59')-C(59)-C(60) 86(3) C(56)-C(53)-C(55) 109.6(6) C(59')-C(59)-C(60') 52(3) C(50)-C(53)-C(54) 111.5(5) C(60)-C(59)-C(60') 37.2(14) C(56)-C(53)-C(54) 107.8(5) C(59')-C(59)-O(2) 51(3) C(55)-C(53)-C(54) 107.9(5) C(60)-C(59)-O(2) 101.4(19) C(57')-C(57)-C(58') 88(3) C(60')-C(59)-O(2) 88.3(13) C(57')-C(57)-C(58) 58(3) C(59)-C(59')-O(2) 109(3) C(58')-C(57)-C(58) 73.4(14) C(59)-C(59')-C(60') 110(3) C(57')-C(57)-O(2) 52(3) O(2)-C(59')-C(60') 114.0(14) C(58')-C(57)-O(2) 103.1(15) C(59)-C(59')-C(60) 72(3) C(58)-C(57)-O(2) 109.4(11) O(2)-C(59')-C(60) 112.5(15) C(57)-C(57')-C(58) 95(3) C(60')-C(59')-C(60) 41.3(13) C(57)-C(57')-O(2) 104(3) C(60')-C(60)-C(59) 86(3) C(58)-C(57')-O(2) 161(2) C(60')-C(60)-C(59') 66(2) C(57)-C(57')-C(58') 63(2) C(59)-C(60)-C(59') 22.2(11) C(58)-C(57')-C(58') 76.4(18) C(60)-C(60')-C(59') 73(2) O(2)-C(57')-C(58') 113(2) C(60)-C(60')-C(59) 56(2) C(59')-C(60')-C(59) 29.7(12)

186

Structural Data for ([RAlCl(OEt2)]2O (4) (R =2,6-(4-t-BuC6H4)2C6H3-)

Table 10. Crystal data and structural refinement for [2,6-(4-t-BuC6H4)2C6H3AlCl(OEt2)]2O (4) Empirical formula C63.50H82Al2Cl2O3 Formula weight 1018.15 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, C2/c Unit cell dimensions a = 66.721(4) Å b = 10.1736(6) Å c = 19.2750(10) Å = 90° = 105.9820(10)° = 90° Volume 12578.1(12) A3 Z, Calculated density 8, 1.075 Mg/m3 Absorption coefficient 0.171 mm-1 F(000) 4376 Crystal size 0.80 x 0.40 x 0.20 mm Theta range for data collection 1.90 to 25.00 deg. Limiting indices -74<=h<=79, -12<=k<=12, -20<=l<=22 Reflections collected / unique 36893 / 10985 [R(int) = 0.0328] Completeness to theta 25.00 99.3 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9665 and 0.8751 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 10985 / 0 / 630 Goodness-of-fit on F^2 1.054 Final R indices [I>2sigma(I)] R1 = 0.1121, wR2 = 0.3410 R indices (all data) R1 = 0.1489, wR2 = 0.4049 Extinction coefficient 0.0026(6) Largest diff. peak and hole 1.917 and -0.570 e.Å-3

187

Table 11. Bond Lengths [Å] for [RAlCl(OEt2)]2O (4) Atoms Distance Atoms Distance Al(1)-O(1) 1.696(4) C(10)-C(11) 1.396(8) Al(1)-O(2) 1.906(4) C(10)-C(13) 1.547(9) Al(1)-C(1) 2.001(5) C(11)-C(12) 1.374(8) Al(1)-Cl(1) 2.354(2) C(13)-C(14) 1.504(12) Al(2)-O(1) 1.691(4) C(13)-C(16) 1.509(16) Al(2)-O(3) 1.906(4) C(13)-C(15) 1.568(13) Al(2)-C(31) 2.013(5) C(17)-C(22) 1.373(9) Al(2)-Cl(2) 2.3939(19) C(17)-C(18) 1.379(9) O(2)-C(29) 1.429(9) C(18)-C(19) 1.406(12) O(2)-C(28) 1.476(10) C(19)-C(20) 1.360(13) O(3)-C(59) 1.447(7) C(20)-C(21) 1.358(11) O(3)-C(58) 1.477(7) C(20)-C(23) 1.512(12) C(1)-C(2) 1.409(7) C(21)-C(22) 1.378(8) C(1)-C(6) 1.418(8) C(23)-C(25) 1.38(3) C(2)-C(3) 1.384(8) C(23)-C(25') 1.47(3) C(2)-C(7) 1.477(8) C(23)-C(26) 1.54(3) C(3)-C(4) 1.405(10) C(23)-C(24') 1.37(4) C(4)-C(5) 1.377(10) C(23)-C(24) 1.61(3) C(5)-C(6) 1.418(8) C(23)-C(26') 1.71(3) C(6)-C(17) 1.484(8) C(24)-C(24') 1.18(4) C(7)-C(8) 1.384(8) C(24)-C(25') 2.09(4) C(7)-C(12) 1.396(8) C(24')-C(26) 1.24(4) C(8)-C(9) 1.390(8) C(25)-C(25') 1.22(4) C(9)-C(10) 1.404(9) C(25)-C(26') 1.35(4)

188

Table 11 (con’t). Bond Lengths [Å] for [RAlCl(OEt2)]2O (4) Atoms Distance Atoms Distance C(26)-C(26') 1.46(4) C(48)-C(49) 1.389(8) C(27)-C(28) 1.219(18) C(49)-C(50) 1.396(8) C(29)-C(30) 1.356(13) C(50)-C(51) 1.391(8) C(31)-C(32) 1.404(7) C(50)-C(53) 1.512(9) C(31)-C(36) 1.438(7) C(51)-C(52) 1.400(8) C(32)-C(33) 1.390(8) C(53)-C(54') 1.39(4) C(32)-C(37) 1.492(8) C(53)-C(56) 1.54(2) C(33)-C(34) 1.378(9) C(53)-C(55') 1.48(2) C(34)-C(35) 1.370(8) C(53)-C(54) 1.57(2) C(35)-C(36) 1.401(7) C(53)-C(56') 1.35(5) C(36)-C(47) 1.477(7) C(53)-C(55) 1.52(3) C(37)-C(38) 1.382(8) C(54)-C(54') 0.86(4) C(37)-C(42) 1.392(8) C(54')-C(56) 1.80(5) C(38)-C(39) 1.379(8) C(55)-C(55') 0.71(3) C(39)-C(40) 1.400(10) C(55)-C(56') 1.45(5) C(40)-C(41) 1.383(10) C(56)-C(56') 0.89(5) C(40)-C(43) 1.549(10) C(57)-C(58) 1.516(11) C(41)-C(42) 1.345(9) C(59)-C(60) 1.437(12) C(43)-C(46) 1.409(15) C(61)-C(63)#1 1.34(2) C(43)-C(45) 1.431(15) C(61)-C(62) 1.26(2) C(43)-C(44) 1.612(17) C(62)-C(63) 1.35(2) C(47)-C(52) 1.383(7) C(63)-C(61)#1 1.34(2) C(47)-C(48) 1.391(7) C(63)-C(64) 1.50(4

189

Table 12. Bond angles [°] for [RAlCl(OEt2)]2O (4) Atoms Angle Atoms Angle O(1)-Al(1)-Cl(1) 108.85(15) C(14)-C(13)-C(16) 108.6(11) O(2)-Al(1)-Cl(1) 95.92(15) C(10)-C(13)-C(16) 107.4(7) C(1)-Al(1)-Cl(1) 117.90(17) C(14)-C(13)-C(15) 106.9(8) O(1)-Al(2)-O(3) 104.80(18) C(10)-C(13)-C(15) 106.3(7) O(1)-Al(2)-C(31) 120.68(19) C(16)-C(13)-C(15) 115.4(11) O(3)-Al(2)-C(31) 105.40(19) C(22)-C(17)-C(18) 115.2(6) O(1)-Al(2)-Cl(2) 110.77(14) C(22)-C(17)-C(6) 121.5(5) O(3)-Al(2)-Cl(2) 97.23(14) C(18)-C(17)-C(6) 123.1(6) C(31)-Al(2)-Cl(2) 114.45(15) C(17)-C(18)-C(19) 122.6(8) Al(2)-O(1)-Al(1) 160.0(2) C(20)-C(19)-C(18) 120.6(7) C(29)-O(2)-C(28) 111.7(7) C(19)-C(20)-C(21) 116.6(7) C(29)-O(2)-Al(1) 127.6(5) C(19)-C(20)-C(23) 119.2(9) C(28)-O(2)-Al(1) 118.2(5) C(21)-C(20)-C(23) 124.2(10) C(59)-O(3)-C(58) 114.7(5) C(22)-C(21)-C(20) 123.0(8) C(59)-O(3)-Al(2) 122.0(4) C(21)-C(22)-C(17) 121.8(6) C(58)-O(3)-Al(2) 118.1(3) C(25)-C(23)-C(25') 50.6(15) C(2)-C(1)-C(6) 117.5(5) C(25)-C(23)-C(26) 101(2) C(2)-C(1)-Al(1) 120.1(4) C(25')-C(23)-C(26) 144.1(19) C(6)-C(1)-Al(1) 122.1(4) C(25)-C(23)-C(24') 129(2) C(3)-C(2)-C(1) 120.9(5) C(25')-C(23)-C(24') 126(2) C(3)-C(2)-C(7) 116.2(5) C(26)-C(23)-C(24') 50.2(18) C(1)-C(2)-C(7) 122.8(5) C(25)-C(23)-C(20) 118.2(16) C(2)-C(3)-C(4) 121.6(6) C(25')-C(23)-C(20) 108.7(15) C(3)-C(4)-C(5) 118.2(6) C(26)-C(23)-C(20) 104.3(14) C(4)-C(5)-C(6) 121.2(6) C(24')-C(23)-C(20) 110.6(18) C(1)-C(6)-C(5) 120.2(6) C(25)-C(23)-C(24) 120.1(18) C(1)-C(6)-C(17) 125.6(5) C(25')-C(23)-C(24) 85.2(17) C(5)-C(6)-C(17) 114.2(5) C(26)-C(23)-C(24) 95.2(16) C(8)-C(7)-C(12) 116.8(5) C(24')-C(23)-C(24) 45.9(18) C(8)-C(7)-C(2) 121.2(5) C(20)-C(23)-C(24) 112.6(14) C(12)-C(7)-C(2) 121.9(5) C(25)-C(23)-C(26') 50.6(17) C(7)-C(8)-C(9) 121.9(5) C(25')-C(23)-C(26') 101.0(18) C(8)-C(9)-C(10) 120.6(6) C(26)-C(23)-C(26') 53.1(16) C(11)-C(10)-C(9) 117.4(6) C(24')-C(23)-C(26') 98(2) C(11)-C(10)-C(13) 121.7(6) C(20)-C(23)-C(26') 110.6(14) C(9)-C(10)-C(13) 120.9(6) C(24)-C(23)-C(26') 131.6(16) C(10)-C(11)-C(12) 120.9(6) C(24')-C(24)-C(23) 56(2) C(7)-C(12)-C(11) 122.3(5) C(24')-C(24)-C(25') 98(3) C(14)-C(13)-C(10) 112.3(6) C(23)-C(24)-C(25') 44.8(12)

190

Table 12 (con’t). Bond angles [°] for [RAlCl(OEt2)]2O (4) Atoms Angle Atoms Angle C(24)-C(24')-C(26) 147(4) C(37)-C(42)-C(41) 123.2(6) C(24)-C(24')-C(23) 78(3) C(46)-C(43)-C(45) 111.9(13) C(26)-C(24')-C(23) 72(3) C(46)-C(43)-C(40) 113.8(8) C(25')-C(25)-C(23) 69(2) C(45)-C(43)-C(40) 109.6(8) C(25')-C(25)-C(26') 145(4) C(46)-C(43)-C(44) 107.2(10) C(23)-C(25)-C(26') 77(2) C(45)-C(43)-C(44) 107.9(11) C(25)-C(25')-C(23) 61(2) C(40)-C(43)-C(44) 106.2(8) C(25)-C(25')-C(24) 100(3) C(52)-C(47)-C(48) 117.3(5) C(23)-C(25')-C(24) 50.1(13) C(52)-C(47)-C(36) 121.2(5) C(24')-C(26)-C(26') 120(3) C(48)-C(47)-C(36) 121.4(4) C(24')-C(26)-C(23) 58(2) C(49)-C(48)-C(47) 121.6(5) C(26')-C(26)-C(23) 69(2) C(48)-C(49)-C(50) 121.6(5) C(26)-C(26')-C(25) 106(3) C(51)-C(50)-C(49) 116.4(5) C(26)-C(26')-C(23) 57.6(18) C(51)-C(50)-C(53) 122.0(5) C(25)-C(26')-C(23) 52.1(18) C(49)-C(50)-C(53) 121.6(6) C(27)-C(28)-O(2) 125.1(16) C(50)-C(51)-C(52) 122.1(5) C(30)-C(29)-O(2) 121.8(8) C(51)-C(52)-C(47) 120.9(5) C(32)-C(31)-C(36) 116.9(4) C(54')-C(53)-C(50) 117.4(19) C(32)-C(31)-Al(2) 123.9(4) C(54')-C(53)-C(56) 76(2) C(36)-C(31)-Al(2) 119.1(4) C(50)-C(53)-C(56) 107.8(9) C(31)-C(32)-C(33) 120.9(5) C(54')-C(53)-C(55') 118(2) C(31)-C(32)-C(37) 123.3(5) C(50)-C(53)-C(55') 113.7(9) C(33)-C(32)-C(37) 115.6(5) C(56)-C(53)-C(55') 118.2(12) C(34)-C(33)-C(32) 121.3(6) C(54')-C(53)-C(54) 33.1(18) C(35)-C(34)-C(33) 119.6(5) C(50)-C(53)-C(54) 109.0(9) C(34)-C(35)-C(36) 120.9(5) C(56)-C(53)-C(54) 108.8(11) C(35)-C(36)-C(31) 120.2(5) C(55')-C(53)-C(54) 98.7(12) C(35)-C(36)-C(47) 116.1(5) C(54')-C(53)-C(56') 101(3) C(31)-C(36)-C(47) 123.5(4) C(50)-C(53)-C(56') 117(2) C(38)-C(37)-C(42) 115.8(5) C(56)-C(53)-C(56') 35(2) C(38)-C(37)-C(32) 122.3(5) C(55')-C(53)-C(56') 85(2) C(42)-C(37)-C(32) 121.7(5) C(54)-C(53)-C(56') 128(2) C(37)-C(38)-C(39) 121.6(6) C(54')-C(53)-C(55) 131(2) C(38)-C(39)-C(40) 121.6(7) C(50)-C(53)-C(55) 111.6(12) C(41)-C(40)-C(39) 116.1(6) C(56)-C(53)-C(55) 95.3(14) C(41)-C(40)-C(43) 122.9(7) C(55')-C(53)-C(55) 27.3(12) C(39)-C(40)-C(43) 120.9(8) C(54)-C(53)-C(55) 122.7(15) C(40)-C(41)-C(42) 121.8(6) C(56')-C(53)-C(55) 60(2)

191

Table 12 (con’t). Bond angles [°] for [RAlCl(OEt2)]2O (4) Atoms Angle Atoms Angle C(54')-C(54)-C(53) 62(3) C(53)-C(56)-C(54') 48.2(15) C(54)-C(54')-C(53) 85(4) C(56)-C(56')-C(53) 84(4) C(54)-C(54')-C(56) 141(5) C(56)-C(56')-C(55) 149(5) C(53)-C(54')-C(56) 55.8(17) C(53)-C(56')-C(55) 65(2) C(55')-C(55)-C(56') 121(4) O(3)-C(58)-C(57) 112.2(6) C(55')-C(55)-C(53) 74(3) O(3)-C(59)-C(60) 115.5(8) C(56')-C(55)-C(53) 54(2) C(63)#1-C(61)-C(62) 118.1(17) C(55)-C(55')-C(53) 79(3) C(61)-C(62)-C(63) 117.1(17) C(56')-C(56)-C(53) 61(4) C(61)#1-C(63)-C(64) 119(2) C(56')-C(56)-C(54') 98(4) C(61)#1-C(63)-C(62) 124.5(19) C(64)-C(63)-C(62) 116(2)

192

Structural Data for R3In (5) (R = 2,6-(4-t-BuC6H4)2C6H3-)

Table 13. Crystal data and structural refinement for R3In (5) Empirical formula C82H97InO Formula weight 1213.42 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Triclinic, P-1 Unit cell dimensions a = 11.6636(13)Å b = 15.0818(16) Å c = 21.278(2) Å = 103.912(2)° = 96.812(2)° = 90.555(2)° Volume 3604.6(7) Å3 Z, Calculated density 2, 1.118 Mg/m3 Absorption coefficient 0.370 mm-1 F(000) 1292 Crystal size 0.45 x 0.35 x 0.25 mm Theta range for data collection 1.76 to 25.00 deg. Limiting indices -13<=h<=13, -17<=k<=17, -25<=l<=22 Reflections collected / unique 21456 / 12638 [R(int) = 0.0204] Completeness to theta = 25.00 99.6 % Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 12638 / 0 / 745 Goodness-of-fit on F^2 1.076 Final R indices [I>2sigma(I)] R1 = 0.0533, wR2 = 0.1457 R indices (all data) R1 = 0.0628, wR2 = 0.1559 Largest diff. peak and hole 0.777 and -0.528 e. Å-3

193

Table 14. Bond Lengths [Å] for R3In (5) Atoms Distance Atoms Distance In(1)-C(53) 2.192(3) C(27)-C(28) 1.401(5) In(1)-C(1) 2.199(3) C(27)-C(32) 1.419(5) In(1)-C(27) 2.200(3) C(28)-C(29) 1.406(6) C(1)-C(2) 1.409(5) C(28)-C(33) 1.494(5) C(1)-C(6) 1.408(5) C(29)-C(30) 1.374(7) C(2)-C(3) 1.410(6) C(30)-C(31) 1.363(7) C(2)-C(7) 1.483(6) C(31)-C(32) 1.410(6) C(3)-C(4) 1.376(7) C(32)-C(43) 1.476(6) C(4)-C(5) 1.374(6) C(33)-C(38) 1.394(6) C(5)-C(6) 1.389(5) C(33)-C(34) 1.391(6) C(6)-C(17) 1.487(5) C(34)-C(35) 1.389(6) C(7)-C(8) 1.374(6) C(35)-C(36) 1.385(6) C(7)-C(12) 1.397(5) C(36)-C(37) 1.392(5) C(8)-C(9) 1.394(6) C(36)-C(39) 1.533(6) C(9)-C(10) 1.380(6) C(37)-C(38) 1.377(5) C(10)-C(11) 1.387(6) C(39)-C(41') 1.46(2) C(10)-C(13) 1.535(6) C(39)-C(40') 1.55(3) C(11)-C(12) 1.376(6) C(39)-C(42) 1.506(13) C(13)-C(16) 1.532(8) C(39)-C(40) 1.592(12) C(13)-C(15) 1.527(8) C(39)-C(41) 1.589(14) C(13)-C(14) 1.537(8) C(39)-C(42') 1.679(19) C(17)-C(18) 1.379(6) C(40)-C(40') 1.63(3) C(17)-C(22) 1.394(5) C(40)-C(41') 2.02(2) C(18)-C(19) 1.381(6) C(40')-C(42) 1.22(3) C(19)-C(20) 1.387(7) C(40')-C(42') 2.22(3) C(20)-C(21) 1.391(6) C(41)-C(41') 0.70(2) C(20)-C(23) 1.531(7) C(42)-C(42') 1.104(19) C(21)-C(22) 1.370(5) C(43)-C(44) 1.388(5) C(23)-C(26) 1.482(16) C(43)-C(48) 1.392(6) C(23)-C(24) 1.540(18) C(44)-C(45) 1.373(6) C(23)-C(25') 1.65(2) C(45)-C(46) 1.391(6) C(23)-C(25) 1.600(19) C(46)-C(47) 1.389(6) C(23)-C(26') 1.622(18) C(46)-C(49) 1.540(7) C(23)-C(24') 1.697(17) C(47)-C(48) 1.376(6) C(24)-C(24') 0.67(2) C(49)-C(52') 1.48(2) C(24)-C(25) 2.03(3) C(49)-C(50') 1.50(3) C(25)-C(25') 0.81(3) C(49)-C(50) 1.554(13) C(25')-C(26) 2.09(3) C(49)-C(51) 1.559(14) C(26)-C(26') 0.879(19) C(49)-C(51') 1.61(2)

194

Table 14 (con’t) Bond Lengths [Å] for R3In (5) Atoms Distance Atoms Distance C(49)-C(52) 1.626(14) C(65)-C(66) 1.533(8) C(50)-C(50') 1.42(3) C(65)-C(67) 1.557(8) C(50)-C(51') 1.83(2) C(69)-C(74) 1.381(5) C(50')-C(52) 1.45(3) C(69)-C(70) 1.390(6) C(51)-C(52') 1.12(2) C(70)-C(71) 1.390(6) C(51)-C(51') 1.39(2) C(71)-C(72) 1.375(6) C(52)-C(52') 1.62(2) C(72)-C(73) 1.387(6) C(53)-C(54) 1.409(5) C(72)-C(75) 1.541(6) C(53)-C(58) 1.403(5) C(73)-C(74) 1.375(5) C(54)-C(55) 1.403(5) C(75)-C(78') 1.49(3) C(54)-C(59) 1.487(5) C(75)-C(76') 1.49(2) C(55)-C(56) 1.353(7) C(75)-C(77) 1.522(14) C(56)-C(57) 1.374(6) C(75)-C(76) 1.562(13) C(57)-C(58) 1.398(5) C(75)-C(78) 1.639(13) C(58)-C(69) 1.487(5) C(75)-C(77') 1.70(3) C(59)-C(60) 1.384(6) C(76)-C(76') 0.74(2) C(59)-C(64) 1.388(6) C(76')-C(77') 1.79(3) C(60)-C(61) 1.374(6) C(77)-C(78') 1.06(3) C(61)-C(62) 1.386(6) C(77)-C(77') 1.55(3) C(62)-C(63) 1.383(6) C(78)-C(78') 1.54(3) C(62)-C(65) 1.540(6) O(1)-C(81) 1.411(16) C(63)-C(64) 1.376(6) O(1)-C(80) 1.465(18) C(65)-C(68) 1.487(9) C(79)-C(80) 1.61(2) C(81)-C(82) 1.399(17)

195

Table 15. Bond angles [°] for R3In (5) Atoms Angle Atoms Angle C(53)-In(1)-C(1) 120.29(13) C(22)-C(21)-C(20) 121.6(4) C(53)-In(1)-C(27) 124.86(13) C(21)-C(22)-C(17) 122.0(4) C(1)-In(1)-C(27) 114.79(13) C(26)-C(23)-C(20) 113.7(8) C(2)-C(1)-C(6) 117.8(3) C(26)-C(23)-C(24) 126.5(10) C(2)-C(1)-In(1) 117.3(3) C(20)-C(23)-C(24) 113.1(7) C(6)-C(1)-In(1) 124.0(3) C(26)-C(23)-C(25') 83.4(11) C(1)-C(2)-C(3) 119.9(4) C(20)-C(23)-C(25') 105.4(9) C(1)-C(2)-C(7) 122.4(3) C(24)-C(23)-C(25') 107.7(12) C(3)-C(2)-C(7) 117.6(3) C(26)-C(23)-C(25) 108.0(10) C(4)-C(3)-C(2) 120.6(4) C(20)-C(23)-C(25) 107.7(8) C(5)-C(4)-C(3) 120.0(4) C(24)-C(23)-C(25) 80.7(11) C(4)-C(5)-C(6) 120.6(4) C(25')-C(23)-C(25) 29.0(9) C(5)-C(6)-C(1) 120.9(4) C(26)-C(23)-C(26') 32.5(7) C(5)-C(6)-C(17) 116.3(4) C(20)-C(23)-C(26') 105.3(7) C(1)-C(6)-C(17) 122.8(3) C(24)-C(23)-C(26') 109.7(10) C(8)-C(7)-C(12) 117.0(4) C(25')-C(23)-C(26') 115.7(11) C(8)-C(7)-C(2) 122.2(3) C(25)-C(23)-C(26') 137.5(10) C(12)-C(7)-C(2) 120.8(4) C(26)-C(23)-C(24') 112.8(9) C(7)-C(8)-C(9) 121.1(4) C(20)-C(23)-C(24') 110.8(7) C(10)-C(9)-C(8) 122.4(4) C(24)-C(23)-C(24') 23.2(7) C(9)-C(10)-C(11) 116.0(4) C(25')-C(23)-C(24') 128.2(11) C(9)-C(10)-C(13) 124.1(4) C(25)-C(23)-C(24') 103.1(10) C(11)-C(10)-C(13) 119.9(4) C(26')-C(23)-C(24') 89.0(9) C(12)-C(11)-C(10) 122.3(4) C(24')-C(24)-C(23) 92(3) C(11)-C(12)-C(7) 121.3(4) C(24')-C(24)-C(25) 140(3) C(16)-C(13)-C(10) 108.8(4) C(23)-C(24)-C(25) 50.9(8) C(16)-C(13)-C(15) 107.8(5) C(24)-C(24')-C(23) 65(2) C(10)-C(13)-C(15) 111.9(4) C(25')-C(25)-C(23) 79(3) C(16)-C(13)-C(14) 110.0(5) C(25')-C(25)-C(24) 124(3) C(10)-C(13)-C(14) 109.6(4) C(23)-C(25)-C(24) 48.4(7) C(15)-C(13)-C(14) 108.7(5) C(25)-C(25')-C(23) 72(2) C(18)-C(17)-C(22) 116.6(4) C(25)-C(25')-C(26) 111(3) C(18)-C(17)-C(6) 122.0(4) C(23)-C(25')-C(26) 44.9(8) C(22)-C(17)-C(6) 121.3(3) C(26')-C(26)-C(23) 82.6(17) C(17)-C(18)-C(19) 121.4(4) C(26')-C(26)-C(25') 134(2) C(20)-C(19)-C(18) 122.2(4) C(23)-C(26)-C(25') 51.7(8) C(19)-C(20)-C(21) 116.2(4) C(26)-C(26')-C(23) 64.9(16) C(19)-C(20)-C(23) 122.2(5) C(28)-C(27)-C(32) 117.6(3) C(21)-C(20)-C(23) 121.5(5) C(28)-C(27)-In(1) 121.4(3)

196

Table 15 (con’t). Bond angles [°] for R3In (5) Atoms Angle Atoms Angle C(32)-C(27)-In(1) 119.7(3) C(40)-C(39)-C(42') 142.9(8) C(27)-C(28)-C(29) 120.9(4) C(41)-C(39)-C(42') 79.4(8) C(27)-C(28)-C(33) 123.6(3) C(39)-C(40)-C(40') 57.4(10) C(29)-C(28)-C(33) 115.5(4) C(39)-C(40)-C(41') 45.8(6) C(30)-C(29)-C(28) 120.3(4) C(40')-C(40)-C(41') 94.1(13) C(31)-C(30)-C(29) 120.2(4) C(42)-C(40')-C(39) 64.8(15) C(30)-C(31)-C(32) 121.1(4) C(42)-C(40')-C(40) 121(2) C(31)-C(32)-C(27) 119.8(4) C(39)-C(40')-C(40) 60.2(11) C(31)-C(32)-C(43) 116.7(3) C(42)-C(40')-C(42') 15.8(10) C(27)-C(32)-C(43) 123.4(3) C(39)-C(40')-C(42') 48.9(9) C(38)-C(33)-C(34) 117.2(4) C(40)-C(40')-C(42') 106.3(15) C(38)-C(33)-C(28) 121.5(3) C(41')-C(41)-C(39) 66(2) C(34)-C(33)-C(28) 121.1(4) C(41)-C(41')-C(39) 87(2) C(33)-C(34)-C(35) 120.6(4) C(41)-C(41')-C(40) 139(3) C(36)-C(35)-C(34) 122.5(4) C(39)-C(41')-C(40) 51.5(7) C(35)-C(36)-C(37) 116.3(4) C(42')-C(42)-C(40') 147(2) C(35)-C(36)-C(39) 123.2(4) C(42')-C(42)-C(39) 78.4(12) C(37)-C(36)-C(39) 120.5(4) C(40')-C(42)-C(39) 68.2(15) C(38)-C(37)-C(36) 122.0(4) C(42)-C(42')-C(39) 61.5(11) C(37)-C(38)-C(33) 121.4(4) C(42)-C(42')-C(40') 17.5(12) C(41')-C(39)-C(40') 126.2(13) C(39)-C(42')-C(40') 44.0(8) C(41')-C(39)-C(42) 122.0(10) C(44)-C(43)-C(48) 116.2(4) C(40')-C(39)-C(42) 47.0(10) C(44)-C(43)-C(32) 121.7(4) C(41')-C(39)-C(36) 116.5(8) C(48)-C(43)-C(32) 121.9(4) C(40')-C(39)-C(36) 112.3(11) C(43)-C(44)-C(45) 121.6(4) C(42)-C(39)-C(36) 114.8(6) C(46)-C(45)-C(44) 122.6(4) C(41')-C(39)-C(40) 82.7(9) C(45)-C(46)-C(47) 115.5(4) C(40')-C(39)-C(40) 62.4(11) C(45)-C(46)-C(49) 122.5(4) C(42)-C(39)-C(40) 106.7(7) C(47)-C(46)-C(49) 122.0(4) C(36)-C(39)-C(40) 106.7(5) C(48)-C(47)-C(46) 122.2(4) C(41')-C(39)-C(41) 26.3(8) C(47)-C(48)-C(43) 121.8(4) C(40')-C(39)-C(41) 138.6(12) C(52')-C(49)-C(50') 114.5(14) C(42)-C(39)-C(41) 110.6(8) C(52')-C(49)-C(46) 113.5(9) C(36)-C(39)-C(41) 108.9(6) C(50')-C(49)-C(46) 106.0(11) C(40)-C(39)-C(41) 108.9(7) C(52')-C(49)-C(50) 132.1(10) C(41')-C(39)-C(42') 101.5(11) C(50')-C(49)-C(50) 55.2(11) C(40')-C(39)-C(42') 87.1(12) C(46)-C(49)-C(50) 114.2(6) C(42)-C(39)-C(42') 40.1(7) C(52')-C(49)-C(51) 43.1(8) C(36)-C(39)-C(42') 104.2(7) C(50')-C(49)-C(51) 143.8(12)

197

Table 15 (con’t). Bond angles [°] for R3In (5) Atoms Angle Atoms Angle C(46)-C(49)-C(51) 109.5(6) C(57)-C(58)-C(53) 120.6(3) C(50)-C(49)-C(51) 113.5(7) C(57)-C(58)-C(69) 116.7(3) C(52')-C(49)-C(51') 93.9(11) C(53)-C(58)-C(69) 122.6(3) C(50')-C(49)-C(51') 125.0(13) C(60)-C(59)-C(64) 116.2(4) C(46)-C(49)-C(51') 103.5(8) C(60)-C(59)-C(54) 123.4(4) C(50)-C(49)-C(51') 70.5(8) C(64)-C(59)-C(54) 120.2(4) C(51)-C(49)-C(51') 52.0(8) C(59)-C(60)-C(61) 121.7(4) C(52')-C(49)-C(52) 62.8(9) C(62)-C(61)-C(60) 122.1(4) C(50')-C(49)-C(52) 55.0(11) C(61)-C(62)-C(63) 116.1(4) C(46)-C(49)-C(52) 111.0(6) C(61)-C(62)-C(65) 120.5(4) C(50)-C(49)-C(52) 103.6(7) C(63)-C(62)-C(65) 123.3(4) C(51)-C(49)-C(52) 104.4(7) C(64)-C(63)-C(62) 121.8(4) C(51')-C(49)-C(52) 143.8(9) C(63)-C(64)-C(59) 121.9(4) C(50')-C(50)-C(49) 60.4(12) C(68)-C(65)-C(62) 110.1(5) C(50')-C(50)-C(51') 116.0(14) C(68)-C(65)-C(66) 111.8(7) C(49)-C(50)-C(51') 56.3(7) C(62)-C(65)-C(66) 108.8(4) C(52)-C(50')-C(49) 67.0(13) C(68)-C(65)-C(67) 108.2(6) C(52)-C(50')-C(50) 122(2) C(62)-C(65)-C(67) 111.9(5) C(49)-C(50')-C(50) 64.4(13) C(66)-C(65)-C(67) 106.0(6) C(52')-C(51)-C(51') 128.1(18) C(74)-C(69)-C(70) 116.2(4) C(52')-C(51)-C(49) 64.5(13) C(74)-C(69)-C(58) 122.7(3) C(51')-C(51)-C(49) 66.1(10) C(70)-C(69)-C(58) 121.0(4) C(51)-C(51')-C(49) 61.9(10) C(69)-C(70)-C(71) 121.8(4) C(51)-C(51')-C(50) 107.0(13) C(72)-C(71)-C(70) 121.5(4) C(49)-C(51')-C(50) 53.2(7) C(71)-C(72)-C(73) 116.5(4) C(50')-C(52)-C(49) 58.0(12) C(71)-C(72)-C(75) 122.6(4) C(50')-C(52)-C(52') 109.1(15) C(73)-C(72)-C(75) 120.9(4) C(49)-C(52)-C(52') 54.1(8) C(74)-C(73)-C(72) 122.1(4) C(51)-C(52')-C(49) 72.4(14) C(73)-C(74)-C(69) 121.9(4) C(51)-C(52')-C(52) 132.8(19) C(78')-C(75)-C(76') 129.4(15) C(49)-C(52')-C(52) 63.1(9) C(78')-C(75)-C(77) 41.3(12) C(54)-C(53)-C(58) 117.9(3) C(76')-C(75)-C(77) 113.9(10) C(54)-C(53)-In(1) 120.3(3) C(78')-C(75)-C(72) 116.8(13) C(58)-C(53)-In(1) 121.8(2) C(76')-C(75)-C(72) 113.5(9) C(53)-C(54)-C(55) 119.6(4) C(77)-C(75)-C(72) 110.6(6) C(53)-C(54)-C(59) 123.0(3) C(78')-C(75)-C(76) 126.1(13) C(55)-C(54)-C(59) 117.3(3) C(76')-C(75)-C(76) 27.9(8) C(56)-C(55)-C(54) 121.3(4) C(77)-C(75)-C(76) 133.3(7) C(55)-C(56)-C(57) 120.3(4) C(72)-C(75)-C(76) 111.6(6) C(56)-C(57)-C(58) 120.1(4) C(78')-C(75)-C(78) 58.6(13)

198

Table 15 (con’t). Bond angles [°] for R3In (5) Atoms Angle Atoms Angle C(76')-C(75)-C(78) 111.9(9) C(75)-C(76')-C(77') 61.8(11) C(77)-C(75)-C(78) 99.8(7) C(78')-C(77)-C(75) 67.5(19) C(72)-C(75)-C(78) 105.9(6) C(78')-C(77)-C(77') 131(2) C(76)-C(75)-C(78) 86.9(7) C(75)-C(77)-C(77') 67.2(11) C(78')-C(75)-C(77') 97.0(15) C(76')-C(77')-C(75) 50.4(10) C(76')-C(75)-C(77') 67.8(11) C(76')-C(77')-C(77) 98.0(15) C(77)-C(75)-C(77') 57.2(9) C(75)-C(77')-C(77) 55.6(10) C(72)-C(75)-C(77') 101.2(9) C(78')-C(78)-C(75) 55.7(12) C(76)-C(75)-C(77') 95.5(10) C(78)-C(78')-C(77) 137(3) C(78)-C(75)-C(77') 149.6(10) C(78)-C(78')-C(75) 65.7(14) C(76')-C(76)-C(75) 70(2) C(77)-C(78')-C(75) 71.2(19) C(76)-C(76')-C(75) 82(2) C(81)-O(1)-C(80) 116.0(13) C(76)-C(76')-C(77') 143(3) O(1)-C(80)-C(79) 106.6(16) O(1)-C(81)-C(82) 111.1(12)

199

Structural Data for [(RGaCl3][Li(OEt2)2] (6) (R = 2,6-(4-Me-C6H4)2C6H3-)

Table 16. Crystal data and structural refinement for [RGaCl3][Li(OEt2)2] (6) Empirical formula C28H37Cl3Ga Li O2 Formula weight 588.59 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Orthorhombic, Pbca Unit cell dimensions a = 10.3332(17) Å b = 17.310(3) Å c = 35.168(6) Å = 90° = 90° = 90° Volume 6290.6(18) Å3 Z, Calculated density 8, 1.243 Mg/m3 Absorption coefficient 1.150 mm-1 F(000) 2448 Crystal size 0.60 x 0.48 x 0.38 mm Theta range for data collection 2.29 to 25.00 deg. Limiting indices -12<=h<=12, -20<=k<=19, -41<=l<=41 Reflections collected / unique 35380 / 5522 [R(int) = 0.0265] Completeness to theta 25.00 99.6 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.6690 and 0.5452 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 5522 / 0 / 292 Goodness-of-fit on F^2 1.06 Final R indices [I>2sigma(I)] R1 = 0.0616, wR2 = 0.1803

200

Table 17. Bond Lengths [Å] for [RGaCl3][Li(OEt2)2] (6) Atoms Distance Atoms Distance Ga(1)-C(1) 1.970(4) C(16)-C(17) 1.354(9) Ga(1)-Cl(1) 2.2503(14) C(17)-C(18) 1.387(11) Ga(1)-Cl(2) 2.2530(13) C(17)-C(20) 1.514(10) Ga(1)-Cl(3) 2.2759(13) C(18)-C(19) 1.397(10) Ga(1)-Li(1) 3.213(9) Li(1)-O(1) 1.928(10) Cl(1)-Li(1) 2.406(10) Li(1)-O(2) 1.926(10) Cl(2)-Li(1) 2.397(10) O(1)-C(23) 1.407(9) C(1)-C(2) 1.406(6) O(1)-C(22) 1.478(18) C(1)-C(6) 1.422(6) O(1)-C(22') 1.52(2) C(2)-C(3) 1.390(6) O(2)-C(25') 1.46(3) C(2)-C(7) 1.487(7) O(2)-C(27) 1.477(10) C(3)-C(4) 1.348(9) O(2)-C(25) 1.80(5) C(4)-C(5) 1.368(9) C(21)-C(22') 1.01(3) C(5)-C(6) 1.397(7) C(21)-C(21') 1.35(3) C(6)-C(14) 1.478(8) C(21)-C(22) 1.72(3) C(7)-C(8) 1.362(7) C(21')-C(22) 0.99(3) C(7)-C(12) 1.404(7) C(21')-C(22') 1.06(3) C(8)-C(9) 1.384(9) C(22)-C(22') 0.81(2) C(9)-C(10) 1.357(10) C(23)-C(24) 1.380(12) C(10)-C(11) 1.388(9) C(25)-C(25') 0.77(5) C(10)-C(13) 1.527(9) C(25)-C(26') 0.89(5) C(11)-C(12) 1.375(7) C(25)-C(26) 1.43(5) C(14)-C(15) 1.395(8) C(25')-C(26) 0.97(4) C(14)-C(19) 1.394(7) C(25')-C(26') 1.27(4) C(15)-C(16) 1.403(8) C(27)-C(28) 1.358(12)

201

Table 18. Bond angles [°] for[RGaCl3][Li(OEt2)2] (6) Atoms Angle Atoms Angle C(1)-Ga(1)-Cl(1) 113.22(13) C(19)-C(14)-C(6) 121.5(5) C(1)-Ga(1)-Cl(2) 109.80(13) C(14)-C(15)-C(16) 121.7(5) Cl(1)-Ga(1)-Cl(2) 95.25(5) C(17)-C(16)-C(15) 121.1(7) C(1)-Ga(1)-Cl(3) 122.49(13) C(16)-C(17)-C(18) 118.2(7) Cl(1)-Ga(1)-Cl(3) 105.56(6) C(16)-C(17)-C(20) 122.1(9) Cl(2)-Ga(1)-Cl(3) 106.97(6) C(18)-C(17)-C(20) 119.7(8) C(1)-Ga(1)-Li(1) 113.8(2) C(17)-C(18)-C(19) 121.4(6) Cl(1)-Ga(1)-Li(1) 48.40(19) C(14)-C(19)-C(18) 120.9(6) Cl(2)-Ga(1)-Li(1) 48.17(19) O(1)-Li(1)-O(2) 113.8(5) Cl(3)-Ga(1)-Li(1) 123.69(17) O(1)-Li(1)-Cl(1) 108.9(5) Ga(1)-Cl(1)-Li(1) 87.2(2) O(2)-Li(1)-Cl(1) 116.9(5) Ga(1)-Cl(2)-Li(1) 87.4(2) O(1)-Li(1)-Cl(2) 109.4(4) C(2)-C(1)-C(6) 118.0(4) O(2)-Li(1)-Cl(2) 117.3(5) C(2)-C(1)-Ga(1) 120.6(3) Cl(1)-Li(1)-Cl(2) 87.7(3) C(6)-C(1)-Ga(1) 120.4(3) O(1)-Li(1)-Ga(1) 109.1(4) C(3)-C(2)-C(1) 120.0(5) O(2)-Li(1)-Ga(1) 137.2(5) C(3)-C(2)-C(7) 117.4(4) Cl(1)-Li(1)-Ga(1) 44.38(15) C(1)-C(2)-C(7) 122.6(4) Cl(2)-Li(1)-Ga(1) 44.46(15) C(4)-C(3)-C(2) 121.7(5) C(23)-O(1)-C(22) 119.7(8) C(3)-C(4)-C(5) 119.5(5) C(23)-O(1)-C(22') 115.1(10) C(4)-C(5)-C(6) 122.0(5) C(22)-O(1)-C(22') 31.3(10) C(5)-C(6)-C(1) 118.6(5) C(23)-O(1)-Li(1) 121.8(6) C(5)-C(6)-C(14) 119.0(5) C(22)-O(1)-Li(1) 117.5(7) C(1)-C(6)-C(14) 122.4(4) C(22')-O(1)-Li(1) 119.0(9) C(8)-C(7)-C(12) 116.7(5) C(25')-O(2)-C(27) 108.9(11) C(8)-C(7)-C(2) 123.1(5) C(25')-O(2)-C(25) 24.5(17) C(12)-C(7)-C(2) 120.2(4) C(27)-O(2)-C(25) 113.3(16) C(7)-C(8)-C(9) 121.7(6) C(25')-O(2)-Li(1) 121.2(11) C(10)-C(9)-C(8) 121.9(6) C(27)-O(2)-Li(1) 124.3(6) C(9)-C(10)-C(11) 117.5(6) C(25)-O(2)-Li(1) 122.4(15) C(9)-C(10)-C(13) 120.6(8) C(22')-C(21)-C(21') 51.3(19) C(11)-C(10)-C(13) 121.9(8) C(22')-C(21)-C(22) 16.5(16) C(12)-C(11)-C(10) 120.9(6) C(21')-C(21)-C(22) 35.0(15) C(11)-C(12)-C(7) 121.2(5) C(22)-C(21')-C(22') 46(2) C(15)-C(14)-C(19) 116.6(5) C(22)-C(21')-C(21) 94(3) C(15)-C(14)-C(6) 121.8(4) C(22')-C(21')-C(21) 48(2)

202

Table 18 (con’t). Bond angles [°] for[RGaCl3][Li(OEt2)2] (6) Atoms Angle Atoms Angle C(21')-C(22)-C(22') 72(2) C(25')-C(25)-C(26) 40(3) C(21')-C(22)-O(1) 146(3) C(26')-C(25)-C(26) 83(4) C(22')-C(22)-O(1) 77(2) C(25')-C(25)-O(2) 52(4) C(21')-C(22)-C(21) 51(2) C(26')-C(25)-O(2) 103(5) C(22')-C(22)-C(21) 21(2) C(26)-C(25)-O(2) 91(3) O(1)-C(22)-C(21) 96.4(13) C(25)-C(25')-C(26) 110(5) C(22)-C(22')-C(21) 143(4) C(25)-C(25')-O(2) 104(5) C(22)-C(22')-C(21') 62(2) C(26)-C(25')-O(2) 144(4) C(21)-C(22')-C(21') 81(3) C(25)-C(25')-C(26') 44(4) C(22)-C(22')-O(1) 72(2) C(26)-C(25')-C(26') 89(3) C(21)-C(22')-O(1) 142(3) O(2)-C(25')-C(26') 106(2) C(21')-C(22')-O(1) 132(3) C(25')-C(26)-C(25) 30(3) O(1)-C(23)-C(24) 115.8(9) C(25)-C(26')-C(25') 37(4) C(25')-C(25)-C(26') 100(7) O(2)-C(27)-C(28) 111.1(8)

203

Structural Data for [RInCl3][Li(OEt2)(THF)] (7) (R = 2,6-(4-Me-C6H4)2C6H3-)

Table 19. Crystal data and structural refinement for [RInCl3][Li(OEt2)(THF)] (7)

Empirical formula C56H68Cl6In2Li2O4 Formula weight 1261.32 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Triclinic, P-1 Unit cell dimensions a = 9.4678(10) Å b = 18.8936(19) Å c = 18.952(2) Å = 91.346(2)° = 91.652(2)° = 94.416(2)° Volume 3377.5(6) Å3 Z, Calculated density 2, 1.240 Mg/m3 Absorption coefficient 0.956 mm-1 F(000) 1284 Crystal size 0.12 x 0.10 x 0.04 mm Theta range for data collection 2.15 to 28.32 deg. Limiting indices -12<=h<=12, -25<=k<=25, -25<=l<=25 Reflections collected / unique 47241 / 16756 [R(int) = 0.2334] Completeness to theta = 28.32 99.50% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9628 and 0.8939 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 16756 / 447 / 792 Goodness-of-fit on F^2 1.005 Final R indices [I>2sigma(I)] R1 = 0.0949, wR2 = 0.2234 R indices (all data) R1 = 0.3550, wR2 = 0.3030 Largest diff. peak and hole 1.275 and -0.546 e.Å-3

204

Table 2.20. Bond Lengths [Å] for [RInCl3][Li(OEt2)(THF)] (7) Atoms Distance Atoms Distance In(1)-C(1) 2.133(13) O(1)-C(22) 1.51(4) In(1)-Cl(3) 2.398(4) C(21)-C(22) 1.53(3) In(1)-Cl(2) 2.438(4) C(23)-C(24) 1.66(4) In(1)-Cl(1) 2.442(4) C(21')-C(22') 1.555(19) In(1)-Li(1) 3.35(2) C(23')-C(24') 1.66(4) Cl(1)-Li(1) 2.34(3) O(2)-C(25') 1.31(3) Cl(2)-Li(1) 2.50(3) O(2)-C(28') 1.37(2) Li(1)-O(1) 1.85(3) O(2)-C(25) 1.486(19) Li(1)-O(2) 1.91(3) O(2)-C(28) 1.490(19) C(1)-C(2) 1.415(18) C(25)-C(26) 1.55(4) C(1)-C(6) 1.387(17) C(26)-C(27) 1.54(4) C(2)-C(3) 1.393(19) C(27)-C(28) 1.36(4) C(2)-C(14) 1.52(2) C(25')-C(26') 1.55(3) C(3)-C(4) 1.30(2) C(26')-C(27') 1.53(4) C(4)-C(5) 1.37(2) C(27')-C(28') 1.36(4) C(5)-C(6) 1.446(18) In(2)-C(29) 2.125(13) C(6)-C(7) 1.500(18) In(2)-Cl(6) 2.402(4) C(7)-C(8) 1.347(17) In(2)-Cl(5) 2.419(4) C(7)-C(12) 1.390(19) In(2)-Cl(4) 2.433(4) C(8)-C(9) 1.34(2) In(2)-Li(2) 3.23(2) C(9)-C(10) 1.37(3) Cl(4)-Li(2) 2.27(3) C(10)-C(11) 1.39(2) Cl(5)-Li(2) 2.43(3) C(10)-C(13) 1.60(3) Li(2)-O(3') 1.924(18) C(11)-C(12) 1.44(2) Li(2)-O(4') 1.957(17) C(14)-C(15) 1.41(2) Li(2)-O(4) 2.001(19) C(14)-C(19) 1.434(19) Li(2)-O(3) 1.91(4) C(15)-C(16) 1.38(2) C(29)-C(30) 1.407(17) C(16)-C(17) 1.34(2) C(29)-C(34) 1.410(17) C(17)-C(18) 1.32(2) C(30)-C(31) 1.380(17) C(17)-C(20) 1.36(2) C(30)-C(42) 1.442(17) C(18)-C(19) 1.41(2) C(31)-C(32) 1.392(19) O(1)-C(23) 1.60(4) C(32)-C(33) 1.38(2) O(1)-C(23') 0.87(3) C(33)-C(34) 1.360(18) O(1)-C(22') 1.528(19) C(34)-C(35) 1.428(18)

205

Table 20 (con’t). Bond Lengths [Å] for [RInCl3][Li(OEt2)(THF)] (7) Atoms Distance Atoms Distance C(35)-C(40) 1.361(18) C(50)-C(51) 1.29(3) C(35)-C(36) 1.414(19) C(51)-C(52) 1.60(3) C(36)-C(37) 1.44(2) O(3')-C(52') 1.26(4) C(37)-C(38) 1.43(2) O(3')-C(49') 1.45(8) C(38)-C(39) 1.38(3) C(49')-C(50') 1.96(3) C(38)-C(41) 1.59(2) C(50')-C(51') 1.29(3) C(39)-C(40) 1.35(2) C(51')-C(52') 1.60(3) C(42)-C(47) 1.361(17) O(4)-C(53) 1.43(3) C(42)-C(43) 1.382(18) O(4)-C(56) 1.45(3) C(43)-C(44) 1.403(19) C(53)-C(54) 1.33(3) C(44)-C(45) 1.39(2) C(54)-C(55) 1.57(4) C(45)-C(46) 1.39(2) C(55)-C(56) 1.41(3) C(45)-C(48) 1.516(19) O(4')-C(53') 1.41(2) C(46)-C(47) 1.374(18) O(4')-C(56') 1.44(2) O(3)-C(52) 1.25(5) C(53')-C(54') 1.33(3) O(3)-C(49) 1.44(8) C(54')-C(55') 1.57(3) C(49)-C(50) 1.95(3) C(55')-C(56') 1.40(3)

206

Table 2.21. Bond angles [°] for [RInCl3][Li(OEt2)(THF)] (7) Atoms Distance Atoms Distance C(1)-In(1)-Cl(3) 121.2(4) C(9)-C(10)-C(11) 122(2) C(1)-In(1)-Cl(2) 115.3(4) C(9)-C(10)-C(13) 131(2) Cl(3)-In(1)-Cl(2) 104.74(16) C(11)-C(10)-C(13) 108(2) C(1)-In(1)-Cl(1) 115.7(4) C(10)-C(11)-C(12) 114.9(18) Cl(3)-In(1)-Cl(1) 104.00(14) C(7)-C(12)-C(11) 122.3(16) Cl(2)-In(1)-Cl(1) 91.33(14) C(15)-C(14)-C(19) 115.5(19) C(1)-In(1)-Li(1) 134.7(6) C(15)-C(14)-C(2) 122.7(16) Cl(3)-In(1)-Li(1) 104.1(4) C(19)-C(14)-C(2) 121.7(17) Cl(2)-In(1)-Li(1) 48.0(5) C(16)-C(15)-C(14) 121.1(17) Cl(1)-In(1)-Li(1) 44.1(5) C(15)-C(16)-C(17) 123.7(19) Li(1)-Cl(1)-In(1) 89.1(6) C(18)-C(17)-C(16) 117(2) In(1)-Cl(2)-Li(1) 85.6(6) C(18)-C(17)-C(20) 117(2) O(1)-Li(1)-O(2) 110.9(14) C(16)-C(17)-C(20) 126(2) O(1)-Li(1)-Cl(1) 112.7(15) C(17)-C(18)-C(19) 125(2) O(2)-Li(1)-Cl(1) 114.9(12) C(14)-C(19)-C(18) 117.6(18) O(1)-Li(1)-Cl(2) 121.4(12) C(23)-O(1)-C(23') 19(4) O(2)-Li(1)-Cl(2) 103.5(13) C(23)-O(1)-C(22') 123(2) Cl(1)-Li(1)-Cl(2) 92.4(8) C(23')-O(1)-C(22') 139(4) O(1)-Li(1)-In(1) 137.7(13) C(23)-O(1)-C(22) 94(3) O(2)-Li(1)-In(1) 111.4(10) C(23')-O(1)-C(22) 101(5) Cl(1)-Li(1)-In(1) 46.7(4) C(22')-O(1)-C(22) 47(3) Cl(2)-Li(1)-In(1) 46.4(4) C(23)-O(1)-Li(1) 133(2) C(2)-C(1)-C(6) 117.0(14) C(23')-O(1)-Li(1) 118(3) C(2)-C(1)-In(1) 121.0(12) C(22')-O(1)-Li(1) 103.2(18) C(6)-C(1)-In(1) 121.7(10) C(22)-O(1)-Li(1) 128(3) C(1)-C(2)-C(3) 121.8(16) O(1)-C(22)-C(21) 93(3) C(1)-C(2)-C(14) 119.0(14) O(1)-C(23)-C(24) 94(4) C(3)-C(2)-C(14) 119.2(16) O(1)-C(22')-C(21') 98.1(16) C(4)-C(3)-C(2) 121.4(18) O(1)-C(23')-C(24') 148(4) C(3)-C(4)-C(5) 119.9(19) C(25')-O(2)-C(28') 113(2) C(4)-C(5)-C(6) 121.5(16) C(25')-O(2)-C(25) 64(3) C(1)-C(6)-C(5) 118.1(14) C(28')-O(2)-C(25) 70(3) C(1)-C(6)-C(7) 119.4(13) C(25')-O(2)-C(28) 88(3) C(5)-C(6)-C(7) 122.4(15) C(28')-O(2)-C(28) 53(3) C(8)-C(7)-C(12) 117.6(15) C(25)-O(2)-C(28) 98(3) C(8)-C(7)-C(6) 123.5(14) C(25')-O(2)-Li(1) 116.1(18) C(12)-C(7)-C(6) 118.6(16) C(28')-O(2)-Li(1) 128.3(18) C(7)-C(8)-C(9) 122.5(17) C(25)-O(2)-Li(1) 148(3) C(10)-C(9)-C(8) 120.9(19) C(28)-O(2)-Li(1) 115(3)

207

Table 2.21 (con’t). Bond angles [°] for [RInCl3][Li(OEt2)(THF)] (7) Atoms Distance Atoms Distance O(2)-C(25)-C(26) 78(3) C(31)-C(30)-C(29) 118.3(14) C(25)-C(26)-C(27) 94(4) C(31)-C(30)-C(42) 119.7(15) C(28)-C(27)-C(26) 104(3) C(29)-C(30)-C(42) 122.0(13) C(27)-C(28)-O(2) 97(2) C(34)-C(33)-C(32) 116.7(16) O(2)-C(25')-C(26') 107(3) C(33)-C(34)-C(35) 115.9(15) C(25')-C(26')-C(27') 94(3) C(33)-C(34)-C(29) 122.5(15) C(28')-C(27')-C(26') 106(3) C(35)-C(34)-C(29) 121.6(14) C(27')-C(28')-O(2) 103(3) C(40)-C(35)-C(36) 118.4(16) C(29)-In(2)-Cl(6) 119.8(3) C(40)-C(35)-C(34) 120.3(15) C(29)-In(2)-Cl(5) 116.3(4) C(36)-C(35)-C(34) 121.2(16) Cl(6)-In(2)-Cl(5) 104.62(15) C(35)-C(36)-C(37) 117.7(16) C(29)-In(2)-Cl(4) 116.2(4) C(36)-C(37)-C(38) 121.8(18) Cl(6)-In(2)-Cl(4) 104.69(15) C(37)-C(38)-C(39) 115(2) Cl(5)-In(2)-Cl(4) 90.85(14) C(37)-C(38)-C(41) 116(2) C(29)-In(2)-Li(2) 139.7(5) C(39)-C(38)-C(41) 128(2) Cl(6)-In(2)-Li(2) 100.5(4) C(40)-C(39)-C(38) 123.1(19) Cl(5)-In(2)-Li(2) 48.3(5) C(39)-C(40)-C(35) 123.6(17) Cl(4)-In(2)-Li(2) 44.5(5) C(47)-C(42)-C(43) 116.8(14) Li(2)-Cl(4)-In(2) 86.8(6) C(47)-C(42)-C(30) 121.4(14) In(2)-Cl(5)-Li(2) 83.7(6) C(43)-C(42)-C(30) 121.7(14) O(3')-Li(2)-O(4') 106.1(16) C(42)-C(43)-C(44) 121.9(14) O(4)-Li(2)-O(3) 114(5) C(45)-C(44)-C(43) 119.1(15) O(3')-Li(2)-Cl(4) 116(3) C(44)-C(45)-C(46) 119.3(15) O(4')-Li(2)-Cl(4) 115.0(12) C(44)-C(45)-C(48) 117.5(18) O(3)-Li(2)-Cl(4) 112(5) C(46)-C(45)-C(48) 123.3(18) O(3')-Li(2)-Cl(5) 115(2) C(45)-C(46)-C(47) 119.4(14) O(4')-Li(2)-Cl(5) 110.2(11) C(42)-C(47)-C(46) 123.5(14) O(4)-Li(2)-Cl(5) 133(2) C(52)-O(3)-C(49) 89(5) O(3)-Li(2)-Cl(5) 110(3) C(52)-O(3)-Li(2) 126(5) Cl(4)-Li(2)-Cl(5) 94.7(8) C(49)-O(3)-Li(2) 121(7) O(3')-Li(2)-In(2) 118.0(15) O(3)-C(49)-C(50) 85(4) O(4')-Li(2)-In(2) 135.8(9) C(51)-C(50)-C(49) 88(3) O(4)-Li(2)-In(2) 100(2) C(50)-C(51)-C(52) 109(3) O(3)-Li(2)-In(2) 111.2(18) O(3)-C(52)-C(51) 102(5) Cl(4)-Li(2)-In(2) 48.7(4) C(52')-O(3')-C(49') 87(5) Cl(5)-Li(2)-In(2) 48.1(4) C(52')-O(3')-Li(2) 137(4) C(30)-C(29)-C(34) 119.3(13) C(49')-O(3')-Li(2) 120(3) C(30)-C(29)-In(2) 119.9(11) O(3')-C(49')-C(50') 84(4) C(34)-C(29)-In(2) 120.6(11) C(51')-C(50')-C(49') 89(2)

208

Table 21 (con’t). Bond angles [°] for [RInCl3][Li(OEt2)(THF)] (7) Atoms Distance Atoms Distance C(50')-C(51')-C(52') 108(2) C(56)-C(55)-C(54) 115(3) O(3')-C(52')-C(51') 99(4) C(55)-C(56)-O(4) 94(3) C(53)-O(4)-C(56) 113(3) C(53')-O(4')-C(56') 116.3(16) C(32)-C(31)-C(30) 119.8(15) C(53')-O(4')-Li(2) 118.4(15) C(31)-C(32)-C(33) 123.1(15) C(56')-O(4')-Li(2) 122.4(14) C(53)-O(4)-Li(2) 102(5) C(54')-C(53')-O(4') 110(2) C(56)-O(4)-Li(2) 127(5) C(53')-C(54')-C(55') 101(2) C(54)-C(53)-O(4) 108(3) C(56')-C(55')-C(54') 116(2) C(53)-C(54)-C(55) 100(3) C(55')-C(56')-O(4') 96(2)

209

Structural Data for R3In (8) (R = 2,6-(4-Me-C6H4)2C6H3-)

Table 22. Crystal data and structural refinement for R3In (8)

Empirical formula C60H51In Formula weight 886.83 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, P2(1)/n Unit cell dimensions a = 11.6715(4) Å b = 19.3972(7) Å c = 21.2111(7) Å = 90° = 103.10° = 90° Volume 4677.1(3) A3 Z, Calculated density 4, 1.259 Mg/m3 Absorption coefficient 0.543 mm-1 F(000) 1840 Crystal size 0.26 x 0.18 x 0.14 mm Theta range for data collection 2.08 to 28.30 deg. Limiting indices -15<=h<=15, -22<=k<=25, -27<=l<=28 Reflections collected / unique 37381 / 11290 [R(int) = 0.0183] Completeness to theta 28.30 97.1 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9278 and 0.8717 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 11290 / 0 / 550 Goodness-of-fit on F^2 1.003 Final R indices [I>2sigma(I)] R1 = 0.0277, wR2 = 0.0741 R indices (all data) R1 = 0.0376, wR2 = 0.0801 Largest diff. peak and hole 0.319 and -0.536 e.Å-3

210

Table 23. Bond Lengths [Å] for R3In (8) Atoms Distance Atoms Distance In(1)-C(41) 2.1868(17) C(27)-C(32) 1.389(2) In(1)-C(21) 2.2019(16) C(28)-C(29) 1.380(3) In(1)-C(1) 2.2043(16) C(29)-C(30) 1.380(3) C(1)-C(6) 1.406(2) C(30)-C(31) 1.382(3) C(1)-C(2) 1.409(2) C(30)-C(33) 1.515(3) C(2)-C(3) 1.399(3) C(31)-C(32) 1.385(3) C(2)-C(14) 1.490(2) C(34)-C(39) 1.400(3) C(3)-C(4) 1.375(3) C(34)-C(35) 1.384(3) C(4)-C(5) 1.382(3) C(35)-C(36) 1.383(3) C(5)-C(6) 1.397(2) C(36)-C(37) 1.376(4) C(6)-C(7) 1.489(2) C(37)-C(38) 1.386(4) C(7)-C(12) 1.388(3) C(37)-C(40) 1.513(3) C(7)-C(8) 1.387(3) C(38)-C(39) 1.387(3) C(8)-C(9) 1.383(3) C(41)-C(46) 1.404(3) C(9)-C(10) 1.374(3) C(41)-C(42) 1.412(3) C(10)-C(11) 1.376(3) C(42)-C(43) 1.394(3) C(10)-C(13) 1.517(3) C(42)-C(54) 1.490(3) C(11)-C(12) 1.386(3) C(43)-C(44) 1.376(4) C(14)-C(15) 1.388(3) C(44)-C(45) 1.365(4) C(14)-C(19) 1.388(3) C(45)-C(46) 1.401(3) C(15)-C(16) 1.384(3) C(46)-C(47) 1.485(3) C(16)-C(17) 1.376(3) C(47)-C(52) 1.385(3) C(17)-C(18) 1.377(3) C(47)-C(48) 1.386(3) C(17)-C(20) 1.512(3) C(48)-C(49) 1.381(4) C(18)-C(19) 1.388(3) C(49)-C(50) 1.381(4) C(21)-C(26) 1.409(2) C(50)-C(51) 1.370(4) C(21)-C(22) 1.409(2) C(50)-C(53) 1.517(4) C(22)-C(23) 1.395(3) C(51)-C(52) 1.378(4) C(22)-C(34) 1.491(3) C(54)-C(59) 1.376(3) C(23)-C(24) 1.376(3) C(54)-C(55) 1.380(3) C(24)-C(25) 1.374(3) C(55)-C(56) 1.396(4) C(25)-C(26) 1.401(2) C(56)-C(57) 1.361(4) C(26)-C(27) 1.480(2) C(57)-C(58) 1.361(4) C(27)-C(28) 1.391(2) C(57)-C(60) 1.525(4) C(58)-C(59) 1.388(3)

211

Table 24. Bond angles [°] for R3In (8) Atoms Angle Atoms Angle C(41)-In(1)-C(21) 123.52(6) C(15)-C(14)-C(19) 117.55(19) C(41)-In(1)-C(1) 123.80(6) C(15)-C(14)-C(2) 122.52(18) C(21)-In(1)-C(1) 112.66(6) C(19)-C(14)-C(2) 119.83(17) C(6)-C(1)-C(2) 117.85(15) C(14)-C(15)-C(16) 120.6(2) C(6)-C(1)-In(1) 118.45(11) C(17)-C(16)-C(15) 121.8(2) C(2)-C(1)-In(1) 122.52(12) C(16)-C(17)-C(18) 117.8(2) C(1)-C(2)-C(3) 119.86(17) C(16)-C(17)-C(20) 121.4(2) C(1)-C(2)-C(14) 122.69(15) C(18)-C(17)-C(20) 120.8(3) C(3)-C(2)-C(14) 117.41(16) C(19)-C(18)-C(17) 121.1(2) C(4)-C(3)-C(2) 121.42(17) C(18)-C(19)-C(14) 121.1(2) C(3)-C(4)-C(5) 119.53(17) C(26)-C(21)-C(22) 117.56(15) C(6)-C(5)-C(4) 120.23(18) C(26)-C(21)-In(1) 118.34(11) C(1)-C(6)-C(5) 121.04(16) C(22)-C(21)-In(1) 123.02(13) C(1)-C(6)-C(7) 121.07(15) C(23)-C(22)-C(21) 120.26(18) C(5)-C(6)-C(7) 117.88(16) C(23)-C(22)-C(34) 117.12(16) C(12)-C(7)-C(8) 117.79(17) C(21)-C(22)-C(34) 122.58(16) C(12)-C(7)-C(6) 120.50(17) C(24)-C(23)-C(22) 121.34(18) C(8)-C(7)-C(6) 121.71(17) C(23)-C(24)-C(25) 119.41(18) C(9)-C(8)-C(7) 120.9(2) C(24)-C(25)-C(26) 120.70(18) C(10)-C(9)-C(8) 121.3(2) C(21)-C(26)-C(25) 120.68(16) C(11)-C(10)-C(9) 117.91(19) C(21)-C(26)-C(27) 121.31(14) C(11)-C(10)-C(13) 121.5(3) C(25)-C(26)-C(27) 118.01(16) C(9)-C(10)-C(13) 120.6(2) C(28)-C(27)-C(32) 117.00(17) C(10)-C(11)-C(12) 121.6(2) C(28)-C(27)-C(26) 121.99(16) C(7)-C(12)-C(11) 120.4(2) C(32)-C(27)-C(26) 121.01(16)

212

Table 24 (con’t). Bond angles [°] for R3In (8) Atoms Angle Atoms Angle C(27)-C(28)-C(29) 121.28(19) C(45)-C(44)-C(43) 119.9(2) C(30)-C(29)-C(28) 121.8(2) C(44)-C(45)-C(46) 121.2(2) C(31)-C(30)-C(29) 116.99(19) C(41)-C(46)-C(45) 119.9(2) C(31)-C(30)-C(33) 121.2(2) C(41)-C(46)-C(47) 122.31(18) C(29)-C(30)-C(33) 121.8(2) C(45)-C(46)-C(47) 117.72(19) C(30)-C(31)-C(32) 121.82(19) C(52)-C(47)-C(48) 117.0(2) C(27)-C(32)-C(31) 120.97(18) C(52)-C(47)-C(46) 122.6(2) C(39)-C(34)-C(35) 117.79(19) C(48)-C(47)-C(46) 120.33(19) C(39)-C(34)-C(22) 121.2(2) C(49)-C(48)-C(47) 120.9(2) C(35)-C(34)-C(22) 120.89(18) C(50)-C(49)-C(48) 121.8(3) C(34)-C(35)-C(36) 121.5(2) C(49)-C(50)-C(51) 117.0(3) C(37)-C(36)-C(35) 121.0(3) C(49)-C(50)-C(53) 121.2(3) C(36)-C(37)-C(38) 118.1(2) C(51)-C(50)-C(53) 121.7(3) C(36)-C(37)-C(40) 121.8(3) C(52)-C(51)-C(50) 121.7(3) C(38)-C(37)-C(40) 120.1(3) C(51)-C(52)-C(47) 121.4(3) C(39)-C(38)-C(37) 121.6(2) C(59)-C(54)-C(55) 116.9(2) C(34)-C(39)-C(38) 120.0(2) C(59)-C(54)-C(42) 121.19(18) C(46)-C(41)-C(42) 118.03(17) C(55)-C(54)-C(42) 121.7(2) C(46)-C(41)-In(1) 120.43(14) C(54)-C(55)-C(56) 120.6(2) C(42)-C(41)-In(1) 121.53(13) C(57)-C(56)-C(55) 122.0(3) C(43)-C(42)-C(41) 120.3(2) C(58)-C(57)-C(56) 117.4(2) C(43)-C(42)-C(54) 116.92(19) C(58)-C(57)-C(60) 121.9(3) C(41)-C(42)-C(54) 122.70(17) C(56)-C(57)-C(60) 120.7(3) C(42)-C(43)-C(44) 120.6(2) C(57)-C(58)-C(59) 121.6(2) C(54)-C(59)-C(58) 121.4(2)

213

Structural Data for [R3Ga3]Na3 (9) (R =2,6-(4-t-BuC6H4)2C6H3-)

Table 25. Crystal data and structural refinement for [R3Ga3]Na3 (9) Empirical formula C90H114Ga3Na3O3 Formula weight 1521.94 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, P2(1)/c Unit cell dimensions a = 16.760(3) Å b = 17.875(4) Å c = 29.598(6) Å = 90° = 103.970(5)° = 90° Volume 8605(3) Å3 Z, Calculated density 4, 1.175 Mg/m3 Absorption coefficient 0.993 mm-1 F(000) 3216 Crystal size 0.50 x 0.40 x 0.30 mm Theta range for data collection 1.25 to 25.00 deg. Limiting indices -19<=h<=18, -9<=k<=19, -35<=l<=35 Reflections collected / unique 29576 / 13108 [R(int) = 0.0674] Completeness to theta = 25.00 86.6 % Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 13108 / 0 / 854 Goodness-of-fit on F^2 1 Final R indices [I>2sigma(I)] R1 = 0.0694, wR2 = 0.1355 R indices (all data) R1 = 0.1446, wR2 = 0.1645 Largest diff. peak and hole 0.516 and -0.321 e.Å-3

214

Table 26. Bond Lengths [Å] for [R3Ga3]Na3 (9) Atoms Distance Atoms Distance Ga(1)-C(8) 2.040(6) Na(2)-C(1) 3.107(8) Ga(1)-C(1) 2.034(6) Na(3)-O(3) 2.245(9) Ga(1)-Ga(2) 2.4863(10) Na(3)-O(2) 2.332(9) Ga(1)-Ga(3) 2.5251(10) Na(3)-C(27) 2.644(5) Ga(1)-Na(2) 2.964(4) Na(3)-C(86') 3.10(3) Ga(1)-Na(1) 3.057(3) Na(3)-C(32) 3.086(7) Ga(2)-C(33) 2.024(7) Na(3)-C(83) 3.08(3) Ga(2)-C(27) 2.064(6) C(1)-C(6) 1.414(8) Ga(2)-Na(3) 2.978(3) C(1)-C(2) 1.409(9) Ga(2)-Na(1) 3.201(3) C(2)-C(3) 1.400(9) Ga(3)-C(64) 2.027(6) C(2)-C(7) 1.513(9) Ga(3)-C(53) 2.044(6) C(3)-C(4) 1.346(10) Ga(3)-Na(1) 3.019(3) C(4)-C(5) 1.386(10) Ga(3)-Na(2) 3.145(4) C(5)-C(6) 1.386(9) Na(1)-C(33) 2.647(6) C(6)-C(17) 1.493(9) Na(1)-C(34) 2.807(7) C(7)-C(8) 1.391(8) Na(1)-C(19) 2.846(7) C(7)-C(12) 1.397(9) Na(1)-C(18) 2.916(7) C(8)-C(9) 1.384(8) Na(1)-C(20) 2.921(7) C(9)-C(10) 1.383(9) Na(1)-C(21) 2.945(8) C(10)-C(11) 1.384(10) Na(1)-C(17) 3.023(7) C(10)-C(13) 1.572(11) Na(1)-C(22) 3.007(8) C(11)-C(12) 1.370(10) Na(2)-O(1) 2.250(8) C(13)-C(14) 1.455(12) Na(2)-C(8) 2.701(7) C(13)-C(15) 1.470(13) Na(2)-C(53) 2.741(7) C(13)-C(16) 1.561(15) Na(2)-C(58) 2.887(7) C(17)-C(22) 1.359(9) Na(2)-C(7) 2.920(7) C(17)-C(18) 1.382(10)

215

Table 26 (con’t). Bond Lengths [Å] for [R3Ga3]Na3 (9) Atoms Distance Atoms Distance C(18)-C(19) 1.394(10) C(36)-C(37) 1.379(10) C(19)-C(20) 1.374(10) C(37)-C(38) 1.422(9) C(20)-C(21) 1.375(11) C(39)-C(42) 1.438(12) C(20)-C(23) 1.534(11) C(39)-C(40) 1.515(11) C(21)-C(22) 1.387(10) C(39)-C(41) 1.540(15) C(23)-C(25) 1.46(2) C(43)-C(44) 1.350(9) C(23)-C(24') 1.52(2) C(43)-C(48) 1.397(9) C(23)-C(26') 1.60(3) C(44)-C(45) 1.379(9) C(23)-C(24) 1.56(2) C(45)-C(46) 1.388(9) C(23)-C(25') 1.64(3) C(46)-C(47) 1.354(10) C(23)-C(26) 1.76(3) C(46)-C(49) 1.537(10) C(24)-C(24') 1.02(2) C(47)-C(48) 1.368(10) C(24')-C(26) 1.90(3) C(49)-C(52) 1.524(11) C(25)-C(25') 1.13(3) C(49)-C(51) 1.492(13) C(25)-C(26') 1.47(3) C(49)-C(50) 1.505(13) C(26)-C(26') 1.29(3) C(53)-C(58) 1.392(8) C(27)-C(28) 1.424(8) C(53)-C(54) 1.432(8) C(27)-C(32) 1.429(8) C(54)-C(55) 1.393(9) C(28)-C(29) 1.370(9) C(54)-C(59) 1.489(9) C(28)-C(38) 1.484(9) C(55)-C(56) 1.371(10) C(29)-C(30) 1.378(11) C(56)-C(57) 1.389(10) C(30)-C(31) 1.365(10) C(57)-C(58) 1.418(9) C(31)-C(32) 1.415(9) C(58)-C(69) 1.467(9) C(32)-C(43) 1.516(9) C(59)-C(64) 1.391(9) C(33)-C(38) 1.407(8) C(59)-C(60) 1.385(9) C(33)-C(34) 1.401(9) C(60)-C(61) 1.365(10) C(34)-C(35) 1.412(9) C(61)-C(62) 1.394(10) C(35)-C(36) 1.361(10) C(62)-C(63) 1.405(8) C(35)-C(39) 1.525(10) C(62)-C(65) 1.513(10)

216

Table 26 (con’t). Bond Lengths [Å] for [R3Ga3]Na3 (9) Atoms Distance Atoms Distance C(63)-C(64) 1.389(8) C(79)-C(79') 0.99(5) C(65)-C(67) 1.500(10) C(79)-C(80) 1.31(4) C(65)-C(68) 1.493(11) C(79')-C(80) 0.82(5) C(65)-C(66) 1.536(10) C(81)-C(82) 1.37(2) C(69)-C(70) 1.411(10) O(2)-C(85) 1.66(2) C(69)-C(74) 1.406(10) O(2)-C(84) 1.483(16) C(70)-C(71) 1.361(12) C(83)-C(84) 1.58(3) C(71)-C(72) 1.364(12) C(83')-C(84) 1.48(4) C(72)-C(73) 1.415(12) C(85)-C(86') 1.33(3) C(72)-C(75) 1.553(12) C(85)-C(86) 1.33(4) C(73)-C(74) 1.366(10) C(86')-C(86) 0.79(4) C(75)-C(76') 1.48(3) O(3)-C(88') 1.44(5) C(75)-C(78') 1.56(4) O(3)-C(89') 1.38(4) C(75)-C(77') 1.61(4) O(3)-C(89) 1.67(6) C(75)-C(76) 1.53(3) O(3)-C(88) 1.73(4) C(75)-C(77) 1.61(2) C(87)-C(88') 1.18(5) C(75)-C(78) 1.69(2) C(87)-C(88) 1.38(4) C(76)-C(76') 1.30(3) C(87')-C(88') 1.69(9) C(76)-C(77') 1.60(4) C(87')-C(88) 1.75(8) C(76')-C(78) 2.01(3) C(88)-C(88') 1.18(5) C(77)-C(78') 1.16(4) C(89)-C(90') 1.11(6) C(77)-C(77') 1.42(4) C(89)-C(89') 1.40(6) C(78)-C(78') 1.54(4) C(89)-C(90) 1.79(6) O(1)-C(80) 1.42(3) C(89')-C(90') 1.33(5) O(1)-C(81) 1.34(2) C(89')-C(90) 1.21(4) C(90)-C(90') 0.99(4)

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Table 27. Bond angles [°] for [R3Ga3]Na3 (9) Atoms Angle Atoms Angle C(8)-Ga(1)-C(1) 84.9(3) C(33)-Na(1)-C(20) 118.9(3) C(8)-Ga(1)-Ga(2) 112.12(17) C(34)-Na(1)-C(20) 125.0(2) C(1)-Ga(1)-Ga(2) 113.37(17) C(19)-Na(1)-C(20) 27.5(2) C(8)-Ga(1)-Ga(3) 109.78(19) C(18)-Na(1)-C(20) 48.9(2) C(1)-Ga(1)-Ga(3) 126.47(17) C(33)-Na(1)-C(21) 98.3(2) Ga(2)-Ga(1)-Ga(3) 107.79(3) C(34)-Na(1)-C(21) 115.8(2) C(8)-Ga(1)-Na(2) 62.13(19) C(19)-Na(1)-C(21) 47.5(2) C(1)-Ga(1)-Na(2) 74.3(2) C(18)-Na(1)-C(21) 55.2(2) Ga(2)-Ga(1)-Na(2) 170.70(11) C(20)-Na(1)-C(21) 27.1(2) Ga(3)-Ga(1)-Na(2) 69.37(7) C(33)-Na(1)-Ga(3) 101.86(15) C(8)-Ga(1)-Na(1) 174.3(2) C(34)-Na(1)-Ga(3) 92.45(16) C(1)-Ga(1)-Na(1) 99.4(2) C(19)-Na(1)-Ga(3) 111.6(2) Ga(2)-Ga(1)-Na(1) 69.67(5) C(18)-Na(1)-Ga(3) 95.81(19) Ga(3)-Ga(1)-Na(1) 64.66(6) C(20)-Na(1)-Ga(3) 139.0(2) Na(2)-Ga(1)-Na(1) 115.32(10) C(21)-Na(1)-Ga(3) 149.51(19) C(33)-Ga(2)-C(27) 85.4(3) C(33)-Na(1)-C(17) 116.2(2) C(33)-Ga(2)-Ga(1) 116.66(17) C(34)-Na(1)-C(17) 145.6(2) C(27)-Ga(2)-Ga(1) 124.93(15) C(19)-Na(1)-C(17) 48.5(2) C(33)-Ga(2)-Na(3) 91.54(18) C(18)-Na(1)-C(17) 26.83(19) C(27)-Ga(2)-Na(3) 60.03(15) C(20)-Na(1)-C(17) 56.8(2) Ga(1)-Ga(2)-Na(3) 151.04(9) C(21)-Na(1)-C(17) 47.3(2) C(33)-Ga(2)-Na(1) 55.51(16) Ga(3)-Na(1)-C(17) 102.75(16) C(27)-Ga(2)-Na(1) 102.55(16) C(33)-Na(1)-C(22) 97.5(2) Ga(1)-Ga(2)-Na(1) 63.59(5) C(34)-Na(1)-C(22) 124.2(2) Na(3)-Ga(2)-Na(1) 145.32(9) C(19)-Na(1)-C(22) 55.4(2) C(64)-Ga(3)-C(53) 86.9(3) C(18)-Na(1)-C(22) 46.5(2) C(64)-Ga(3)-Ga(1) 102.76(19) C(20)-Na(1)-C(22) 48.1(2) C(53)-Ga(3)-Ga(1) 120.65(17) C(21)-Na(1)-C(22) 26.9(2) C(64)-Ga(3)-Na(1) 125.9(2) Ga(3)-Na(1)-C(22) 126.46(19) C(53)-Ga(3)-Na(1) 145.78(18) C(17)-Na(1)-C(22) 26.05(18) Ga(1)-Ga(3)-Na(1) 66.24(6) C(33)-Na(1)-Ga(1) 84.47(15) C(64)-Ga(3)-Na(2) 107.3(2) C(34)-Na(1)-Ga(1) 99.24(15) C(53)-Ga(3)-Na(2) 59.36(18) C(19)-Na(1)-Ga(1) 110.5(2) Ga(1)-Ga(3)-Na(2) 61.91(7) C(18)-Na(1)-Ga(1) 82.72(19) Na(1)-Ga(3)-Na(2) 111.25(11) C(20)-Na(1)-Ga(1) 126.85(19) C(33)-Na(1)-C(34) 29.57(18) C(21)-Na(1)-Ga(1) 111.3(2) C(33)-Na(1)-C(19) 145.4(3) Ga(3)-Na(1)-Ga(1) 49.10(4) C(34)-Na(1)-C(19) 149.6(3) C(17)-Na(1)-Ga(1) 70.08(14) C(33)-Na(1)-C(18) 142.7(3) C(22)-Na(1)-Ga(1) 84.42(18) C(34)-Na(1)-C(18) 170.5(3) C(33)-Na(1)-Ga(2) 39.06(14) C(19)-Na(1)-C(18) 28.0(2) C(34)-Na(1)-Ga(2) 62.45(15)

218

Table 27 (con’t). Bond angles [°] for [R3Ga3]Na3 (9) Atoms Angle Atoms Angle C(19)-Na(1)-Ga(2) 137.2(2) C(27)-Na(3)-Ga(2) 42.57(14) C(18)-Na(1)-Ga(2) 114.2(2) O(3)-Na(3)-C(86') 101.3(6) C(20)-Na(1)-Ga(2) 128.2(2) O(2)-Na(3)-C(86') 44.9(6) C(21)-Na(1)-Ga(2) 101.1(2) C(27)-Na(3)-C(86') 116.6(6) Ga(3)-Na(1)-Ga(2) 81.16(6) Ga(2)-Na(3)-C(86') 92.8(5) C(17)-Na(1)-Ga(2) 89.36(15) O(3)-Na(3)-C(32) 116.0(3) C(22)-Na(1)-Ga(2) 83.69(16) O(2)-Na(3)-C(32) 117.7(2) Ga(1)-Na(1)-Ga(2) 46.74(4) C(27)-Na(3)-C(32) 27.52(17) O(1)-Na(2)-C(8) 115.8(3) Ga(2)-Na(3)-C(32) 63.94(14) O(1)-Na(2)-C(53) 125.4(3) C(86')-Na(3)-C(32) 142.7(6) C(8)-Na(2)-C(53) 109.2(2) O(3)-Na(3)-C(83) 99.7(7) O(1)-Na(2)-C(58) 101.1(3) O(2)-Na(3)-C(83) 49.3(6) C(8)-Na(2)-C(58) 137.7(2) C(27)-Na(3)-C(83) 87.9(6) C(53)-Na(2)-C(58) 28.49(17) Ga(2)-Na(3)-C(83) 126.3(5) O(1)-Na(2)-C(7) 91.8(3) C(86')-Na(3)-C(83) 94.2(8) C(8)-Na(2)-C(7) 28.31(17) C(32)-Na(3)-C(83) 79.4(6) C(53)-Na(2)-C(7) 137.4(2) C(6)-C(1)-C(2) 116.9(6) C(58)-Na(2)-C(7) 165.9(2) C(6)-C(1)-Ga(1) 130.9(5) O(1)-Na(2)-Ga(1) 146.3(3) C(2)-C(1)-Ga(1) 111.2(4) C(8)-Na(2)-Ga(1) 41.89(14) C(6)-C(1)-Na(2) 129.5(4) C(53)-Na(2)-Ga(1) 88.28(17) C(2)-C(1)-Na(2) 80.7(4) C(58)-Na(2)-Ga(1) 110.86(18) Ga(1)-C(1)-Na(2) 66.68(18) C(7)-Na(2)-Ga(1) 57.95(15) C(3)-C(2)-C(1) 120.4(7) O(1)-Na(2)-C(1) 110.5(3) C(3)-C(2)-C(7) 124.1(7) C(8)-Na(2)-C(1) 56.00(19) C(1)-C(2)-C(7) 115.4(6) C(53)-Na(2)-C(1) 119.8(2) C(4)-C(3)-C(2) 121.0(8) C(58)-Na(2)-C(1) 129.7(2) C(5)-C(4)-C(3) 120.7(8) C(7)-Na(2)-C(1) 48.25(19) C(6)-C(5)-C(4) 119.5(7) Ga(1)-Na(2)-C(1) 39.05(12) C(5)-C(6)-C(1) 121.5(7) O(1)-Na(2)-Ga(3) 164.2(2) C(5)-C(6)-C(17) 119.4(6) C(8)-Na(2)-Ga(3) 79.28(15) C(1)-C(6)-C(17) 119.0(6) C(53)-Na(2)-Ga(3) 39.90(14) C(8)-C(7)-C(12) 119.4(6) C(58)-Na(2)-Ga(3) 63.13(15) C(8)-C(7)-C(2) 117.0(6) C(7)-Na(2)-Ga(3) 104.01(17) C(12)-C(7)-C(2) 123.6(6) Ga(1)-Na(2)-Ga(3) 48.72(6) C(8)-C(7)-Na(2) 67.0(3) C(1)-Na(2)-Ga(3) 81.38(15) C(12)-C(7)-Na(2) 114.5(5) O(3)-Na(3)-O(2) 106.5(3) C(2)-C(7)-Na(2) 86.1(4) O(3)-Na(3)-C(27) 140.7(3) C(7)-C(8)-C(9) 118.7(6) O(2)-Na(3)-C(27) 107.5(3) C(7)-C(8)-Ga(1) 111.0(4) O(3)-Na(3)-Ga(2) 130.7(3) C(9)-C(8)-Ga(1) 130.3(5) O(2)-Na(3)-Ga(2) 116.3(2) C(7)-C(8)-Na(2) 84.6(4)

219

Table 27 (con’t). Bond angles [°] for [R3Ga3]Na3 (9) Atoms Angle Atoms Angle C(9)-C(8)-Na(2) 109.3(5) C(25)-C(23)-C(24) 122.4(14) Ga(1)-C(8)-Na(2) 76.0(2) C(24')-C(23)-C(24) 38.6(9) C(10)-C(9)-C(8) 123.1(6) C(26')-C(23)-C(24) 140.2(16) C(9)-C(10)-C(11) 116.4(7) C(25)-C(23)-C(25') 42.2(11) C(9)-C(10)-C(13) 122.7(7) C(24')-C(23)-C(25') 115.6(14) C(11)-C(10)-C(13) 120.8(7) C(26')-C(23)-C(25') 97.5(15) C(12)-C(11)-C(10) 122.8(7) C(24)-C(23)-C(25') 84.2(14) C(11)-C(12)-C(7) 119.5(7) C(25)-C(23)-C(20) 111.1(10) C(14)-C(13)-C(15) 116.5(10) C(24')-C(23)-C(20) 111.5(9) C(14)-C(13)-C(10) 113.5(7) C(26')-C(23)-C(20) 110.8(13) C(15)-C(13)-C(10) 109.1(9) C(24)-C(23)-C(20) 105.6(9) C(14)-C(13)-C(16) 105.5(11) C(25')-C(23)-C(20) 110.3(12) C(15)-C(13)-C(16) 101.8(10) C(25)-C(23)-C(26) 100.4(13) C(10)-C(13)-C(16) 109.5(8) C(24')-C(23)-C(26) 70.3(12) C(22)-C(17)-C(18) 117.2(8) C(26')-C(23)-C(26) 44.9(12) C(22)-C(17)-C(6) 121.9(7) C(24)-C(23)-C(26) 108.3(12) C(18)-C(17)-C(6) 120.8(7) C(25')-C(23)-C(26) 134.0(14) C(22)-C(17)-Na(1) 76.3(4) C(20)-C(23)-C(26) 108.4(11) C(18)-C(17)-Na(1) 72.3(4) C(24')-C(24)-C(23) 68.4(18) C(6)-C(17)-Na(1) 119.8(4) C(24)-C(24')-C(23) 73.0(18) C(17)-C(18)-C(19) 121.1(8) C(24)-C(24')-C(26) 133(2) C(17)-C(18)-Na(1) 80.9(4) C(23)-C(24')-C(26) 60.7(11) C(19)-C(18)-Na(1) 73.2(4) C(25')-C(25)-C(26') 139(3) C(20)-C(19)-C(18) 121.6(8) C(25')-C(25)-C(23) 77.2(19) C(20)-C(19)-Na(1) 79.3(4) C(26')-C(25)-C(23) 66.3(16) C(18)-C(19)-Na(1) 78.8(4) C(25)-C(25')-C(23) 60.5(18) C(21)-C(20)-C(19) 116.3(8) C(26')-C(26)-C(23) 61.2(19) C(21)-C(20)-C(23) 122.3(9) C(26')-C(26)-C(24') 105(2) C(19)-C(20)-C(23) 121.2(9) C(23)-C(26)-C(24') 48.9(10) C(21)-C(20)-Na(1) 77.4(4) C(25)-C(26')-C(26) 128(3) C(19)-C(20)-Na(1) 73.2(4) C(25)-C(26')-C(23) 56.6(15) C(23)-C(20)-Na(1) 115.0(5) C(26)-C(26')-C(23) 74(2) C(20)-C(21)-C(22) 122.2(8) C(28)-C(27)-C(32) 117.4(6) C(20)-C(21)-Na(1) 75.5(4) C(28)-C(27)-Ga(2) 109.6(4) C(22)-C(21)-Na(1) 79.0(4) C(32)-C(27)-Ga(2) 132.9(5) C(17)-C(22)-C(21) 121.4(8) C(28)-C(27)-Na(3) 104.7(4) C(17)-C(22)-Na(1) 77.6(4) C(32)-C(27)-Na(3) 93.7(3) C(21)-C(22)-Na(1) 74.0(4) Ga(2)-C(27)-Na(3) 77.40(18) C(25)-C(23)-C(24') 137.1(13) C(29)-C(28)-C(27) 121.1(7) C(25)-C(23)-C(26') 57.1(13) C(29)-C(28)-C(38) 123.1(7) C(24')-C(23)-C(26') 110.3(16) C(27)-C(28)-C(38) 115.8(6)

220

Table 27 (con’t). Bond angles [°] for [R3Ga3]Na3 (9) Atoms Angle Atoms Angle C(67)-C(65)-C(66) 107.0(7) C(77')-C(77)-C(75) 63.9(19) C(68)-C(65)-C(66) 107.6(7) C(77)-C(77')-C(76) 116(3) C(70)-C(69)-C(74) 115.0(7) C(77)-C(77')-C(75) 64(2) C(70)-C(69)-C(58) 122.9(8) C(76)-C(77')-C(75) 57.2(18) C(74)-C(69)-C(58) 122.1(6) C(78')-C(78)-C(75) 57.5(18) C(69)-C(70)-C(71) 122.0(9) C(78')-C(78)-C(76') 90(2) C(72)-C(71)-C(70) 122.9(9) C(75)-C(78)-C(76') 46.2(10) C(71)-C(72)-C(73) 116.5(8) C(77)-C(78')-C(75) 71(2) C(71)-C(72)-C(75) 122.6(10) C(77)-C(78')-C(78) 134(4) C(73)-C(72)-C(75) 120.9(10) C(75)-C(78')-C(78) 66.1(19) C(72)-C(73)-C(74) 121.1(9) C(80)-O(1)-C(81) 108.6(16) C(69)-C(74)-C(73) 122.4(8) C(80)-O(1)-Na(2) 122.0(14) C(76')-C(75)-C(78') 113(2) C(81)-O(1)-Na(2) 122.1(11) C(76')-C(75)-C(72) 115.6(11) C(79')-C(79)-C(80) 39(3) C(78')-C(75)-C(72) 120.1(18) C(80)-C(79')-C(79) 92(6) C(76')-C(75)-C(77') 109(2) C(79')-C(80)-O(1) 111(5) C(78')-C(75)-C(77') 90(2) C(79')-C(80)-C(79) 49(4) C(72)-C(75)-C(77') 104.7(15) O(1)-C(80)-C(79) 113(3) C(76')-C(75)-C(76) 50.8(12) C(82)-C(81)-O(1) 115.7(19) C(78')-C(75)-C(76) 125.1(18) C(85)-O(2)-C(84) 112.5(12) C(72)-C(75)-C(76) 112.3(12) C(85)-O(2)-Na(3) 119.5(8) C(77')-C(75)-C(76) 61.1(17) C(84)-O(2)-Na(3) 119.8(9) C(76')-C(75)-C(77) 138.7(13) C(84)-C(83)-Na(3) 84.8(15) C(78')-C(75)-C(77) 42.9(15) C(83')-C(84)-C(83) 123(2) C(72)-C(75)-C(77) 105.3(10) C(83')-C(84)-O(2) 113.4(19) C(77')-C(75)-C(77) 52.4(15) C(83)-C(84)-O(2) 100.4(16) C(76)-C(75)-C(77) 109.2(14) O(2)-C(85)-C(86') 93.6(19) C(76')-C(75)-C(78) 78.3(14) O(2)-C(85)-C(86) 124(2) C(78')-C(75)-C(78) 56.4(17) C(86')-C(85)-C(86) 34.4(19) C(72)-C(75)-C(78) 102.7(11) C(86)-C(86')-C(85) 73(4) C(77')-C(75)-C(78) 144.2(17) C(86)-C(86')-Na(3) 134(4) C(76)-C(75)-C(78) 126.6(15) C(85)-C(86')-Na(3) 94.2(18) C(77)-C(75)-C(78) 98.2(13) C(86')-C(86)-C(85) 73(4) C(76')-C(76)-C(77') 121(3) C(88')-O(3)-C(89') 90(3) C(76')-C(76)-C(75) 62.6(16) C(88')-O(3)-C(89) 107(3) C(77')-C(76)-C(75) 61.7(18) C(89')-O(3)-C(89) 54(2) C(75)-C(76')-C(76) 66.6(18) C(88')-O(3)-C(88) 42(2) C(75)-C(76')-C(78) 55.5(12) C(89')-O(3)-C(88) 118(2) C(76)-C(76')-C(78) 120(2) C(89)-O(3)-C(88) 98(2) C(78')-C(77)-C(77') 120(3) C(88')-O(3)-Na(3) 124(2) C(78')-C(77)-C(75) 66(2) C(89')-O(3)-Na(3) 122.3(15)

221

Table 27 (con’t). Bond angles [°] for [R3Ga3]Na3 (9) Atoms Atoms Atoms Atoms C(28)-C(29)-C(30) 120.5(8) C(47)-C(48)-C(43) 121.2(7) C(29)-C(30)-C(31) 121.3(8) C(52)-C(49)-C(51) 110.4(10) C(30)-C(31)-C(32) 120.0(8) C(52)-C(49)-C(46) 111.7(6) C(31)-C(32)-C(27) 119.7(7) C(51)-C(49)-C(46) 108.8(7) C(31)-C(32)-C(43) 118.9(7) C(52)-C(49)-C(50) 103.2(8) C(27)-C(32)-C(43) 121.2(6) C(51)-C(49)-C(50) 111.3(10) C(31)-C(32)-Na(3) 121.0(4) C(46)-C(49)-C(50) 111.4(8) C(27)-C(32)-Na(3) 58.8(3) C(58)-C(53)-C(54) 118.9(6) C(43)-C(32)-Na(3) 87.5(3) C(58)-C(53)-Ga(3) 133.3(5) C(38)-C(33)-C(34) 118.2(6) C(54)-C(53)-Ga(3) 107.5(4) C(38)-C(33)-Ga(2) 110.3(5) C(58)-C(53)-Na(2) 81.6(4) C(34)-C(33)-Ga(2) 131.5(5) C(54)-C(53)-Na(2) 106.9(4) C(38)-C(33)-Na(1) 105.2(4) Ga(3)-C(53)-Na(2) 80.7(2) C(34)-C(33)-Na(1) 81.6(4) C(55)-C(54)-C(53) 118.9(6) Ga(2)-C(33)-Na(1) 85.4(2) C(55)-C(54)-C(59) 123.4(6) C(35)-C(34)-C(33) 123.8(7) C(53)-C(54)-C(59) 117.7(6) C(35)-C(34)-Na(1) 112.4(4) C(54)-C(55)-C(56) 121.2(7) C(33)-C(34)-Na(1) 68.8(3) C(55)-C(56)-C(57) 121.5(8) C(34)-C(35)-C(36) 115.3(7) C(56)-C(57)-C(58) 118.3(7) C(34)-C(35)-C(39) 120.4(7) C(53)-C(58)-C(57) 121.1(6) C(36)-C(35)-C(39) 124.3(7) C(53)-C(58)-C(69) 123.0(6) C(37)-C(36)-C(35) 124.6(7) C(57)-C(58)-C(69) 115.7(6) C(36)-C(37)-C(38) 119.4(7) C(53)-C(58)-Na(2) 69.9(4) C(33)-C(38)-C(37) 118.7(7) C(57)-C(58)-Na(2) 111.5(5) C(33)-C(38)-C(28) 118.3(6) C(69)-C(58)-Na(2) 94.0(4) C(37)-C(38)-C(28) 123.0(6) C(64)-C(59)-C(60) 118.9(7) C(42)-C(39)-C(40) 115.0(9) C(64)-C(59)-C(54) 117.6(5) C(42)-C(39)-C(35) 111.4(8) C(60)-C(59)-C(54) 123.5(7) C(40)-C(39)-C(35) 112.5(7) C(61)-C(60)-C(59) 121.3(7) C(42)-C(39)-C(41) 102.2(11) C(62)-C(61)-C(60) 122.4(7) C(40)-C(39)-C(41) 101.9(9) C(61)-C(62)-C(63) 115.1(7) C(35)-C(39)-C(41) 113.0(7) C(61)-C(62)-C(65) 124.5(7) C(44)-C(43)-C(48) 116.3(7) C(63)-C(62)-C(65) 120.3(7) C(44)-C(43)-C(32) 123.4(6) C(64)-C(63)-C(62) 123.7(7) C(48)-C(43)-C(32) 120.3(7) C(59)-C(64)-C(63) 118.5(6) C(45)-C(44)-C(43) 121.9(7) C(59)-C(64)-Ga(3) 109.6(4) C(46)-C(45)-C(44) 122.0(7) C(63)-C(64)-Ga(3) 131.2(5) C(47)-C(46)-C(45) 115.7(7) C(62)-C(65)-C(67) 108.7(6) C(47)-C(46)-C(49) 125.1(7) C(62)-C(65)-C(68) 111.1(6) C(45)-C(46)-C(49) 119.2(7) C(67)-C(65)-C(68) 109.5(8) C(48)-C(47)-C(46) 122.9(7) C(62)-C(65)-C(66) 112.9(7)

222

Table 27 (con’t). Bond angles [°] for [R3Ga3]Na3 (9) Atoms Angle Atoms Angle C(89)-O(3)-Na(3) 128.9(19) C(90')-C(89)-O(3) 111(5) C(88)-O(3)-Na(3) 117.4(12) C(89')-C(89)-O(3) 53(3) C(88')-C(87)-C(88) 54(3) C(90')-C(89)-C(90) 30(3) C(88')-C(87')-C(88) 40(2) C(89')-C(89)-C(90) 42(2) C(88')-C(88)-C(87') 67(4) O(3)-C(89)-C(90) 82(3) C(88')-C(88)-C(87) 54(3) C(90')-C(89')-C(90) 46(2) C(87')-C(88)-C(87) 18(4) C(90')-C(89')-O(3) 117(3) C(88')-C(88)-O(3) 56(3) C(90)-C(89')-O(3) 123(3) C(87')-C(88)-O(3) 96(3) C(90')-C(89')-C(89) 48(3) C(87)-C(88)-O(3) 95(2) C(90)-C(89')-C(89) 86(4) C(88)-C(88')-C(87') 73(5) O(3)-C(89')-C(89) 74(3) C(88)-C(88')-C(87) 71(4) C(90')-C(90)-C(89') 74(3) C(87')-C(88')-C(87) 13(4) C(90')-C(90)-C(89) 34(3) C(88)-C(88')-O(3) 82(4) C(89')-C(90)-C(89) 51(2) C(87')-C(88')-O(3) 111(4) C(90)-C(90')-C(89) 116(6) C(87)-C(88')-O(3) 123(5) C(90)-C(90')-C(89') 61(3) C(90')-C(89)-C(89') 63(4) C(89)-C(90')-C(89') 69(4)

223

Structural Data for Cp2Hf(GaR)2 (10) (R = 2,6-(2,4,6-i-PrC6H2)2C6H3-)

Table 28. Crystal data and structural refinement for Cp2Hf(GaR)2 (10) Empirical formula C86H118Ga2HfO Formula weight 1485.74 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Orthorhombic, Pbcn Unit cell dimensions a = 15.879(4) Å b = 17.556(4) Å c = 29.381(6) Å = 90° = 90° = 90° Volume 8191(3) Å3 Z, Calculated density 4, 1.205 Mg/m3 Absorption coefficient 1.958 mm-1 F(000) 3104 Crystal size 0.20 x 0.10 x 0.05 mm Theta range for data collection 2.22 to 25.00 deg. Limiting indices -18<=h<=14, -20<=k<=20, -34<=l<=34 Reflections collected / unique 41723 / 7217 [R(int) = 0.1355] Completeness to theta = 25.00 99.90% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9084 and 0.6955 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 7217 / 141 / 431 Goodness-of-fit on F^2 1.01 Final R indices [I>2sigma(I)] R1 = 0.0613, wR2 = 0.1555 R indices (all data) R1 = 0.1600, wR2 = 0.2302 Largest diff. peak and hole 0.981 and -2.308 e.Å-3

224

Table 29. Bond Lengths [Å] for Cp2Hf(GaR)2 (10) Atoms Distance Atoms Distance Hf(1)-C(41')#1 2.40(5) C(16)-C(17) 1.40(2) Hf(1)-C(37)#1 2.44(4) C(19)-C(21) 1.53(2) Hf(1)-C(37')#1 2.48(4) C(19)-C(20) 1.515(19) Hf(1)-C(40)#1 2.49(5) C(22)-C(27) 1.379(15) Hf(1)-C(38)#1 2.48(3) C(22)-C(23) 1.393(17) Hf(1)-C(38')#1 2.50(4) C(23)-C(24) 1.381(18) Hf(1)-C(40')#1 2.48(6) C(23)-C(34) 1.53(2) Hf(1)-C(39)#1 2.49(5) C(24)-C(25) 1.357(19) Hf(1)-C(41)#1 2.48(5) C(25)-C(26) 1.338(19) Hf(1)-C(39')#1 2.51(5) C(25)-C(31) 1.577(19) Hf(1)-Ga(1) 2.6198(13) C(26)-C(27) 1.388(16) Hf(1)-Ga(1)#1 2.6198(13) C(27)-C(28) 1.513(18) Ga(1)-C(1) 2.021(10) C(28)-C(30) 1.51(2) C(1)-C(2) 1.396(14) C(28)-C(29) 1.53(2) C(1)-C(6) 1.409(14) C(31)-C(33) 1.43(3) C(2)-C(3) 1.357(15) C(31)-C(32) 1.51(3) C(2)-C(22) 1.526(15) C(34)-C(36) 1.50(2) C(3)-C(4) 1.427(16) C(34)-C(35) 1.54(2) C(4)-C(5) 1.372(15) C(37)-C(41) 1.40(5) C(5)-C(6) 1.400(14) C(37)-C(38) 1.42(3) C(6)-C(7) 1.501(15) C(38)-C(39) 1.43(5) C(7)-C(12) 1.374(16) C(39)-C(40) 1.36(5) C(7)-C(8) 1.395(16) C(40)-C(41) 1.37(6) C(8)-C(9) 1.417(17) C(37')-C(41') 1.41(4) C(8)-C(19) 1.505(18) C(37')-C(38') 1.48(6) C(9)-C(10) 1.336(18) C(38')-C(39') 1.40(5) C(10)-C(11) 1.364(18) C(39')-C(40') 1.36(5) C(10)-C(16) 1.554(18) C(40')-C(41') 1.42(6) C(11)-C(12) 1.399(16) O(1)-C(42')#2 1.36788(18) C(12)-C(13) 1.489(17) O(1)-C(42') 1.36789(17) C(13)-C(14) 1.529(17) O(1)-C(42)#2 1.3869(2) C(13)-C(15) 1.527(17) O(1)-C(42) 1.3869(2) C(16)-C(18) 1.37(2) C(42)-C(43) 1.3313(2) C(42')-C(43') 1.3691(2)

225

Table 30. Bond angles [°] for Cp2Hf(GaR)2 (10) Atoms Angle Atoms Angle C(41')#1-Hf(1)-C(37)#1 20.2(12) C(37')#1-Hf(1)-C(39')#1 55.5(16) C(41')#1-Hf(1)-C(37')#1 33.6(10) C(40)#1-Hf(1)-C(39')#1 19.3(11) C(37)#1-Hf(1)-C(37')#1 15.8(10) C(38)#1-Hf(1)-C(39')#1 47.0(12) C(41')#1-Hf(1)-C(40)#1 41.7(15) C(38')#1-Hf(1)-C(39')#1 32.3(11) C(37)#1-Hf(1)-C(40)#1 53.8(17) C(40')#1-Hf(1)-C(39')#1 31.6(11) C(37')#1-Hf(1)-C(40)#1 56.0(17) C(39)#1-Hf(1)-C(39')#1 15.5(10) C(41')#1-Hf(1)-C(38)#1 47.8(14) C(41)#1-Hf(1)-C(39')#1 48.1(14) C(37)#1-Hf(1)-C(38)#1 33.5(8) C(41')#1-Hf(1)-Ga(1) 130.8(12) C(37')#1-Hf(1)-C(38)#1 18.5(10) C(37)#1-Hf(1)-Ga(1) 122.2(12) C(40)#1-Hf(1)-C(38)#1 54.8(15) C(37')#1-Hf(1)-Ga(1) 107.1(15) C(41')#1-Hf(1)-C(38')#1 55.4(15) C(40)#1-Hf(1)-Ga(1) 98.1(12) C(37)#1-Hf(1)-C(38')#1 47.2(13) C(38)#1-Hf(1)-Ga(1) 88.8(13) C(37')#1-Hf(1)-C(38')#1 34.7(14) C(38')#1-Hf(1)-Ga(1) 76.4(13) C(40)#1-Hf(1)-C(38')#1 45.7(15) C(40')#1-Hf(1)-Ga(1) 110.3(14) C(38)#1-Hf(1)-C(38')#1 18.4(11) C(39)#1-Hf(1)-Ga(1) 76.2(11) C(41')#1-Hf(1)-C(40')#1 33.8(14) C(41)#1-Hf(1)-Ga(1) 128.3(13) C(37)#1-Hf(1)-C(40')#1 49.9(15) C(39')#1-Hf(1)-Ga(1) 80.4(13) C(37')#1-Hf(1)-C(40')#1 56.1(18) C(41')#1-Hf(1)-Ga(1)#1 96.8(14) C(40)#1-Hf(1)-C(40')#1 12.4(12) C(37)#1-Hf(1)-Ga(1)#1 117.0(13) C(38)#1-Hf(1)-C(40')#1 59.5(17) C(37')#1-Hf(1)-Ga(1)#1 128.9(13) C(38')#1-Hf(1)-C(40')#1 54.2(16) C(40)#1-Hf(1)-Ga(1)#1 78.5(13) C(41')#1-Hf(1)-C(39)#1 54.9(17) C(38)#1-Hf(1)-Ga(1)#1 133.2(10) C(37)#1-Hf(1)-C(39)#1 53.8(15) C(38')#1-Hf(1)-Ga(1)#1 121.6(15) C(37')#1-Hf(1)-C(39)#1 45.6(14) C(40')#1-Hf(1)-Ga(1)#1 74.4(14) C(40)#1-Hf(1)-C(39)#1 31.6(11) C(39)#1-Hf(1)-Ga(1)#1 104.7(14) C(38)#1-Hf(1)-C(39)#1 33.4(11) C(41)#1-Hf(1)-Ga(1)#1 84.7(12) C(38')#1-Hf(1)-C(39)#1 17.0(11) C(39')#1-Hf(1)-Ga(1)#1 89.2(14) C(40')#1-Hf(1)-C(39)#1 42.3(14) Ga(1)-Hf(1)-Ga(1)#1 100.76(6) C(41')#1-Hf(1)-C(41)#1 13.4(12) C(1)-Ga(1)-Hf(1) 171.7(3) C(37)#1-Hf(1)-C(41)#1 33.0(11) C(2)-C(1)-C(6) 117.9(9) C(37')#1-Hf(1)-C(41)#1 44.4(14) C(2)-C(1)-Ga(1) 120.5(8) C(40)#1-Hf(1)-C(41)#1 32.1(13) C(6)-C(1)-Ga(1) 121.4(8) C(38)#1-Hf(1)-C(41)#1 55.3(13) C(3)-C(2)-C(1) 122.5(10) C(38')#1-Hf(1)-C(41)#1 58.3(17) C(3)-C(2)-C(22) 117.9(10) C(40')#1-Hf(1)-C(41)#1 22.0(14) C(1)-C(2)-C(22) 119.4(10) C(39)#1-Hf(1)-C(41)#1 53.1(15) C(2)-C(3)-C(4) 119.7(11) C(41')#1-Hf(1)-C(39')#1 54.2(17) C(5)-C(4)-C(3) 118.8(11) C(37)#1-Hf(1)-C(39')#1 59.6(15) C(6)-C(5)-C(4) 121.3(11)

226

Table 30 (con’t). Bond angles [°] for Cp2Hf(GaR)2 (10) Atoms Angle Atoms Angle C(5)-C(6)-C(1) 119.8(10) C(26)-C(25)-C(24) 117.5(13) C(5)-C(6)-C(7) 117.0(10) C(26)-C(25)-C(31) 118.6(16) C(1)-C(6)-C(7) 123.1(10) C(24)-C(25)-C(31) 123.9(16) C(12)-C(7)-C(8) 120.9(11) C(25)-C(26)-C(27) 124.3(14) C(12)-C(7)-C(6) 120.9(11) C(22)-C(27)-C(26) 116.8(12) C(8)-C(7)-C(6) 118.2(11) C(22)-C(27)-C(28) 121.5(11) C(7)-C(8)-C(9) 117.0(13) C(26)-C(27)-C(28) 121.6(13) C(7)-C(8)-C(19) 122.5(12) C(27)-C(28)-C(30) 112.9(14) C(9)-C(8)-C(19) 120.2(13) C(27)-C(28)-C(29) 107.4(14) C(10)-C(9)-C(8) 123.7(13) C(30)-C(28)-C(29) 110.7(16) C(9)-C(10)-C(11) 116.9(12) C(33)-C(31)-C(32) 124(2) C(9)-C(10)-C(16) 120.4(16) C(33)-C(31)-C(25) 111.7(18) C(11)-C(10)-C(16) 122.7(15) C(32)-C(31)-C(25) 108.5(17) C(10)-C(11)-C(12) 123.8(13) C(36)-C(34)-C(23) 112.0(14) C(7)-C(12)-C(11) 117.6(12) C(36)-C(34)-C(35) 111.3(15) C(7)-C(12)-C(13) 123.1(12) C(23)-C(34)-C(35) 114.2(15) C(11)-C(12)-C(13) 119.3(13) C(41)-C(37)-C(38) 110(4) C(12)-C(13)-C(14) 113.1(12) C(37)-C(38)-C(39) 103(4) C(12)-C(13)-C(15) 115.2(12) C(40)-C(39)-C(38) 111(4) C(14)-C(13)-C(15) 105.8(12) C(39)-C(40)-C(41) 109(5) C(18)-C(16)-C(17) 125.5(18) C(40)-C(41)-C(37) 108(4) C(18)-C(16)-C(10) 114.5(15) C(41')-C(37')-C(38') 104(4) C(17)-C(16)-C(10) 112.9(14) C(39')-C(38')-C(37') 108(4) C(8)-C(19)-C(21) 111.3(14) C(40')-C(39')-C(38') 111(4) C(8)-C(19)-C(20) 112.1(13) C(39')-C(40')-C(41') 107(4) C(21)-C(19)-C(20) 110.7(14) C(37')-C(41')-C(40') 111(5) C(27)-C(22)-C(23) 120.9(12) C(42')#2-O(1)-C(42') 180 C(27)-C(22)-C(2) 120.5(10) C(42')#2-O(1)-C(42)#2 53.099(10) C(23)-C(22)-C(2) 118.5(11) C(42')-O(1)-C(42)#2 126.901(10) C(24)-C(23)-C(22) 117.8(14) C(42')#2-O(1)-C(42) 126.901(10) C(24)-C(23)-C(34) 118.9(14) C(42')-O(1)-C(42) 53.099(10) C(22)-C(23)-C(34) 123.0(13) C(42)#2-O(1)-C(42) 180 C(23)-C(24)-C(25) 122.7(14) C(43)-C(42)-O(1) 157.623(4) O(1)-C(42')-C(43') 117.031(11)

227

Structural Data for Cp2Hf(InR)2 (11) (R = 2,6-(2,4,6-i-PrC6H2)2C6H3-)

Table 31. Crystal data and structural refinement for Cp2Hf(InR)2 (11) Empirical formula C86H118HfIn2O Formula weight 1575.94 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Orthorhombic, Pbcn Unit cell dimensions a = 15.748(4) Å b = 17.855(5) Å c = 29.708(8) Å = 90° = 90° = 90° Volume 8354(4) Å3 Z, Calculated density 4, 1.253 Mg/m3 Absorption coefficient 1.827 mm-1 F(000) 3248 Crystal size 0.07 x 0.07 x 0.06 mm Theta range for data collection 2.20 to 25.00 deg. Limiting indices -18<=h<=18, -21<=k<=21, -35<=l<=35 Reflections collected / unique 64198 / 7353 [R(int) = 0.2256] Completeness to theta = 25.00 99.90% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.8983 and 0.8828 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 7353 / 75 / 413 Goodness-of-fit on F^2 1.008 Final R indices [I>2sigma(I)] R1 = 0.0653, wR2 = 0.1453 R indices (all data) R1 = 0.1888, wR2 = 0.2080 Largest diff. peak and hole 0.789 and -2.675 e.Å-3

228

Table 32. Bond Lengths [Å] for Cp2Hf(InR)2 (11) Atoms Distance Atoms Distance Hf(1)-C(37) 2.399(17) C(16)-C(17) 1.47(3) Hf(1)-C(37)#1 2.399(17) C(16)-C(18) 1.53(3) Hf(1)-C(38) 2.43(2) C(19)-C(21) 1.46(2) Hf(1)-C(38)#1 2.43(2) C(19)-C(20) 1.52(2) Hf(1)-C(41) 2.43(2) C(22)-C(23) 1.40(2) Hf(1)-C(41)#1 2.43(2) C(22)-C(27) 1.41(2) Hf(1)-C(39) 2.48(2) C(23)-C(24) 1.40(2) Hf(1)-C(39)#1 2.48(2) C(23)-C(34) 1.50(2) Hf(1)-C(40) 2.52(2) C(24)-C(25) 1.36(2) Hf(1)-C(40)#1 2.52(2) C(25)-C(26) 1.34(2) Hf(1)-In(1) 2.7667(10) C(25)-C(31) 1.58(2) Hf(1)-In(1)#1 2.7667(10) C(25)-C(31') 1.60(4) In(1)-C(1) 2.194(13) C(26)-C(27) 1.40(2) C(1)-C(6) 1.403(17) C(27)-C(28) 1.49(2) C(1)-C(2) 1.429(17) C(28)-C(29) 1.50(2) C(2)-C(3) 1.374(17) C(28)-C(30) 1.52(2) C(2)-C(22) 1.522(19) C(31)-C(33) 1.34(3) C(3)-C(4) 1.357(17) C(31)-C(32) 1.39(3) C(4)-C(5) 1.401(17) C(31')-C(33') 1.33(3) C(5)-C(6) 1.338(18) C(31')-C(32') 1.38(3) C(6)-C(7) 1.539(17) C(34)-C(35) 1.50(2) C(7)-C(12) 1.364(18) C(34)-C(36) 1.51(2) C(7)-C(8) 1.41(2) C(37)-C(41) 1.34(3) C(8)-C(9) 1.38(2) C(37)-C(38) 1.38(3) C(8)-C(19) 1.52(2) C(38)-C(39) 1.33(3) C(9)-C(10) 1.40(2) C(39)-C(40) 1.34(3) C(10)-C(11) 1.32(2) C(40)-C(41) 1.38(3) C(10)-C(16) 1.52(2) O(1)-C(42')#2 1.3306(3) C(11)-C(12) 1.39(2) O(1)-C(42') 1.3306(3) C(12)-C(13) 1.52(2) O(1)-C(42)#2 1.5381(3) C(13)-C(15) 1.53(2) O(1)-C(42) 1.5381(3) C(13)-C(14) 1.56(2) C(42)-C(43) 1.5359(3) C(42')-C(43') 1.2695(3)

229

Table 33. Bond angles [°] for Cp2Hf(InR)2 (11). Atoms Angle Atoms Angle C(37)-Hf(1)-C(37)#1 82.1(15) C(38)-Hf(1)-C(40)#1 132.6(11) C(37)-Hf(1)-C(38) 33.3(7) C(38)#1-Hf(1)-C(40)#1 52.7(9) C(37)#1-Hf(1)-C(38) 94.3(12) C(41)-Hf(1)-C(40)#1 154.1(10) C(37)-Hf(1)-C(38)#1 94.3(11) C(41)#1-Hf(1)-C(40)#1 32.3(8) C(37)#1-Hf(1)-C(38)#1 33.3(7) C(39)-Hf(1)-C(40)#1 149.1(8) C(38)-Hf(1)-C(38)#1 119(2) C(39)#1-Hf(1)-C(40)#1 31.0(7) C(37)-Hf(1)-C(41) 32.2(8) C(40)-Hf(1)-C(40)#1 172.0(14) C(37)#1-Hf(1)-C(41) 105.2(17) C(37)-Hf(1)-In(1) 125.8(7) C(38)-Hf(1)-C(41) 53.9(7) C(37)#1-Hf(1)-In(1) 115.6(9) C(38)#1-Hf(1)-C(41) 101.5(10) C(38)-Hf(1)-In(1) 92.6(8) C(37)-Hf(1)-C(41)#1 105.2(17) C(38)#1-Hf(1)-In(1) 129.3(7) C(37)#1-Hf(1)-C(41)#1 32.2(8) C(41)-Hf(1)-In(1) 129.1(9) C(38)-Hf(1)-C(41)#1 101.5(10) C(41)#1-Hf(1)-In(1) 83.7(10) C(38)#1-Hf(1)-C(41)#1 53.9(7) C(39)-Hf(1)-In(1) 78.5(7) C(41)-Hf(1)-C(41)#1 134(2) C(39)#1-Hf(1)-In(1) 102.4(9) C(37)-Hf(1)-C(39) 53.0(9) C(40)-Hf(1)-In(1) 97.8(11) C(37)#1-Hf(1)-C(39) 125.8(11) C(40)#1-Hf(1)-In(1) 76.7(7) C(38)-Hf(1)-C(39) 31.5(7) C(37)-Hf(1)-In(1)#1 115.6(9) C(38)#1-Hf(1)-C(39) 147.3(14) C(37)#1-Hf(1)-In(1)#1 125.8(7) C(41)-Hf(1)-C(39) 52.6(10) C(38)-Hf(1)-In(1)#1 129.3(7) C(41)#1-Hf(1)-C(39) 126.7(10) C(38)#1-Hf(1)-In(1)#1 92.6(8) C(37)-Hf(1)-C(39)#1 125.8(11) C(41)-Hf(1)-In(1)#1 83.7(10) C(37)#1-Hf(1)-C(39)#1 53.0(9) C(41)#1-Hf(1)-In(1)#1 129.1(9) C(38)-Hf(1)-C(39)#1 147.3(14) C(39)-Hf(1)-In(1)#1 102.4(9) C(38)#1-Hf(1)-C(39)#1 31.5(7) C(39)#1-Hf(1)-In(1)#1 78.5(7) C(41)-Hf(1)-C(39)#1 126.7(10) C(40)-Hf(1)-In(1)#1 76.7(7) C(41)#1-Hf(1)-C(39)#1 52.6(10) C(40)#1-Hf(1)-In(1)#1 97.8(11) C(39)-Hf(1)-C(39)#1 178.8(15) In(1)-Hf(1)-In(1)#1 95.26(4) C(37)-Hf(1)-C(40) 53.1(10) C(1)-In(1)-Hf(1) 171.3(3) C(37)#1-Hf(1)-C(40) 134.8(12) C(6)-C(1)-C(2) 117.1(12) C(38)-Hf(1)-C(40) 52.7(9) C(6)-C(1)-In(1) 121.0(10) C(38)#1-Hf(1)-C(40) 132.6(11) C(2)-C(1)-In(1) 121.9(10) C(41)-Hf(1)-C(40) 32.3(8) C(3)-C(2)-C(1) 121.1(14) C(41)#1-Hf(1)-C(40) 154.1(10) C(3)-C(2)-C(22) 118.8(12) C(39)-Hf(1)-C(40) 31.0(7) C(1)-C(2)-C(22) 120.1(12) C(39)#1-Hf(1)-C(40) 149.1(8) C(4)-C(3)-C(2) 118.6(13) C(37)-Hf(1)-C(40)#1 134.8(12) C(3)-C(4)-C(5) 122.0(13) C(37)#1-Hf(1)-C(40)#1 53.1(10) C(6)-C(5)-C(4) 119.6(13)

230

Table 33 (con’t). Bond angles [°] for Cp2Hf(InR)2 (11). Atoms Angle Atoms Angle C(5)-C(6)-C(1) 121.5(13) C(25)-C(26)-C(27) 123.1(17) C(5)-C(6)-C(7) 120.8(13) C(26)-C(27)-C(22) 116.5(17) C(1)-C(6)-C(7) 117.6(12) C(26)-C(27)-C(28) 121.2(16) C(12)-C(7)-C(8) 121.8(14) C(22)-C(27)-C(28) 122.0(16) C(12)-C(7)-C(6) 119.7(14) C(29)-C(28)-C(27) 113.7(15) C(8)-C(7)-C(6) 118.5(13) C(29)-C(28)-C(30) 108.8(15) C(9)-C(8)-C(7) 116.5(16) C(27)-C(28)-C(30) 112.7(15) C(9)-C(8)-C(19) 120.9(17) C(33)-C(31)-C(32) 127(4) C(7)-C(8)-C(19) 122.2(16) C(33)-C(31)-C(25) 121(4) C(8)-C(9)-C(10) 122.4(17) C(32)-C(31)-C(25) 111(4) C(11)-C(10)-C(9) 117.8(16) C(33')-C(31')-C(32') 129(3) C(11)-C(10)-C(16) 120.6(19) C(33')-C(31')-C(25) 115(3) C(9)-C(10)-C(16) 121.5(19) C(32')-C(31')-C(25) 115(3) C(10)-C(11)-C(12) 123.7(18) C(23)-C(34)-C(35) 114.3(15) C(7)-C(12)-C(11) 117.7(16) C(23)-C(34)-C(36) 108.4(15) C(7)-C(12)-C(13) 122.6(14) C(35)-C(34)-C(36) 111.0(15) C(11)-C(12)-C(13) 119.7(15) C(41)-C(37)-C(38) 108(3) C(12)-C(13)-C(15) 114.8(15) C(41)-C(37)-Hf(1) 75.2(14) C(12)-C(13)-C(14) 109.3(14) C(38)-C(37)-Hf(1) 74.5(12) C(15)-C(13)-C(14) 108.8(16) C(39)-C(38)-C(37) 107(3) C(17)-C(16)-C(10) 112(2) C(39)-C(38)-Hf(1) 76.3(15) C(17)-C(16)-C(18) 120(2) C(37)-C(38)-Hf(1) 72.2(12) C(10)-C(16)-C(18) 111(2) C(38)-C(39)-C(40) 111(3) C(21)-C(19)-C(8) 111.7(17) C(38)-C(39)-Hf(1) 72.2(15) C(21)-C(19)-C(20) 112.7(17) C(40)-C(39)-Hf(1) 76.0(17) C(8)-C(19)-C(20) 111.4(17) C(39)-C(40)-C(41) 107(3) C(23)-C(22)-C(27) 121.6(16) C(39)-C(40)-Hf(1) 72.9(17) C(23)-C(22)-C(2) 117.6(15) C(41)-C(40)-Hf(1) 70.5(15) C(27)-C(22)-C(2) 120.8(15) C(40)-C(41)-C(37) 108(3) C(22)-C(23)-C(24) 116.9(16) C(40)-C(41)-Hf(1) 77.2(16) C(22)-C(23)-C(34) 123.2(14) C(37)-C(41)-Hf(1) 72.6(13) C(24)-C(23)-C(34) 119.8(16) C(42')#2-O(1)-C(42') 180 C(25)-C(24)-C(23) 122.0(17) C(42')#2-O(1)-C(42)#2 47.487(9) C(26)-C(25)-C(24) 119.8(16) C(42')-O(1)-C(42)#2 132.513(9) C(26)-C(25)-C(31) 129(4) C(42')#2-O(1)-C(42) 132.513(9) C(24)-C(25)-C(31) 110(4) C(42')-O(1)-C(42) 47.487(9) C(26)-C(25)-C(31') 115(3) C(42)#2-O(1)-C(42) 180 C(24)-C(25)-C(31') 125(3) C(43)-C(42)-O(1) 131.438(10) C(31)-C(25)-C(31') 19(6) C(43')-C(42')-O(1) 137.392(3)

231

Structural Data for (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) (R = 2,6-(4-t-BuC6H4)2C6H3-)

Table 34. Crystal data and structural refinement for (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12)

Empirical formula C53H55ClGaZr2 Formula weight 979.58 Temperature 100(2) K Wavelength 1.54178 Å Crystal system, space group Monoclinic, P2(1)/c Unit cell dimensions a = 17.9545(3) Å b = 13.3890(3) Å c = 18.1881(5) Å = 90° = 99.2920(10)° = 90° Volume 4314.92(17) Å3 Z, Calculated density 4, 1.508 Mg/m3 Absorption coefficient 5.454 mm^-1 F(000) 2004 Crystal size 0.40 x 0.18 x 0.08 mm Theta range for data collection 2.49 to 65.14 deg. Limiting indices -21<=h<=21, -15<=k<=15, -20<=l<=19 Reflections collected / unique 33367 / 7213 [R(int) = 0.0567] Completeness to theta = 65.14 97.8 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.6695 and 0.2190 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 7213 / 0 / 514 Goodness-of-fit on F^2 1.011 Final R indices [I>2sigma(I)] R1 = 0.0478, wR2 = 0.1117 R indices (all data) R1 = 0.0589, wR2 = 0.1193 Largest diff. peak and hole 2.417 and -3.703 e.Å-3

232

Table 35. Bond Lengths [Å] for (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) Atoms Distance Atoms Distance Ga(1)-C(1) 2.019(5) C(13)-C(14) 1.524(8) Ga(1)-Zr(1) 2.7457(9) C(13)-C(16) 1.540(8) Ga(1)-Zr(2) 2.8796(10) C(13)-C(15) 1.535(8) Zr(1)-C(32) 2.467(5) C(17)-C(18) 1.373(7) Zr(1)-C(36) 2.476(5) C(17)-C(22) 1.390(8) Zr(1)-C(33) 2.481(5) C(18)-C(19) 1.396(7) Zr(1)-C(34) 2.481(6) C(19)-C(20) 1.393(7) Zr(1)-C(29) 2.493(6) C(20)-C(21) 1.405(7) Zr(1)-C(28) 2.486(6) C(20)-C(23) 1.527(7) Zr(1)-C(35) 2.495(5) C(21)-C(22) 1.386(7) Zr(1)-C(30) 2.493(5) C(23)-C(25) 1.521(8) Zr(1)-C(31) 2.506(6) C(23)-C(26) 1.537(7) Zr(1)-C(27) 2.512(6) C(23)-C(24) 1.534(7) Zr(1)-Cl(1) 2.6033(13) C(27)-C(28) 1.401(12) Zr(2)-C(37) 2.476(5) C(27)-C(31) 1.397(10) Zr(2)-C(42) 2.480(5) C(28)-C(29) 1.412(10) Zr(2)-C(38) 2.477(5) C(29)-C(30) 1.391(9) Zr(2)-C(46) 2.494(5) C(30)-C(31) 1.403(9) Zr(2)-C(43) 2.493(5) C(32)-C(33) 1.426(8) Zr(2)-C(41) 2.490(5) C(32)-C(36) 1.430(8) Zr(2)-C(44) 2.498(5) C(32)-C(37) 1.458(8) Zr(2)-C(40) 2.500(6) C(33)-C(34) 1.417(8) Zr(2)-C(39) 2.502(5) C(34)-C(35) 1.402(8) Zr(2)-C(45) 2.520(5) C(35)-C(36) 1.410(9) Zr(2)-Cl(1) 2.6141(13) C(37)-C(38) 1.432(8) C(1)-C(6) 1.410(7) C(37)-C(41) 1.440(8) C(1)-C(2) 1.407(7) C(38)-C(39) 1.402(8) C(2)-C(3) 1.395(7) C(39)-C(40) 1.403(9) C(2)-C(7) 1.500(7) C(40)-C(41) 1.410(8) C(3)-C(4) 1.383(7) C(42)-C(43) 1.410(8) C(4)-C(5) 1.382(7) C(42)-C(46) 1.421(9) C(5)-C(6) 1.401(7) C(43)-C(44) 1.410(8) C(6)-C(17) 1.496(7) C(44)-C(45) 1.418(8) C(7)-C(12) 1.385(7) C(45)-C(46) 1.401(8) C(7)-C(8) 1.406(7) C(47)-C(48) 1.374(9) C(8)-C(9) 1.377(7) C(47)-C(52) 1.414(9) C(9)-C(10) 1.402(7) C(47)-C(53) 1.466(10) C(10)-C(11) 1.389(7) C(48)-C(49) 1.424(10) C(10)-C(13) 1.538(7) C(49)-C(50) 1.361(10) C(11)-C(12) 1.391(7) C(50)-C(51) 1.396(9) C(51)-C(52) 1.370(10)

233

Table 36. Bond angles [°] for (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) Atoms Angle Atoms Angle C(1)-Ga(1)-Zr(1) 147.58(15) C(30)-Zr(1)-C(31) 32.6(2) C(1)-Ga(1)-Zr(2) 134.53(15) C(32)-Zr(1)-C(27) 155.5(2) Zr(1)-Ga(1)-Zr(2) 77.33(2) C(36)-Zr(1)-C(27) 155.7(2) C(32)-Zr(1)-C(36) 33.63(18) C(33)-Zr(1)-C(27) 122.9(3) C(32)-Zr(1)-C(33) 33.49(19) C(34)-Zr(1)-C(27) 108.9(3) C(36)-Zr(1)-C(33) 54.96(18) C(29)-Zr(1)-C(27) 54.0(2) C(32)-Zr(1)-C(34) 55.4(2) C(28)-Zr(1)-C(27) 32.5(3) C(36)-Zr(1)-C(34) 54.6(2) C(35)-Zr(1)-C(27) 123.3(2) C(33)-Zr(1)-C(34) 33.18(19) C(30)-Zr(1)-C(27) 53.7(2) C(32)-Zr(1)-C(29) 149.2(2) C(31)-Zr(1)-C(27) 32.3(2) C(36)-Zr(1)-C(29) 117.1(2) C(32)-Zr(1)-Cl(1) 82.67(13) C(33)-Zr(1)-C(29) 157.3(2) C(36)-Zr(1)-Cl(1) 76.60(15) C(34)-Zr(1)-C(29) 124.1(2) C(33)-Zr(1)-Cl(1) 115.64(14) C(32)-Zr(1)-C(28) 166.6(2) C(34)-Zr(1)-Cl(1) 131.03(16) C(36)-Zr(1)-C(28) 149.1(2) C(29)-Zr(1)-Cl(1) 78.72(16) C(33)-Zr(1)-C(28) 154.4(3) C(28)-Zr(1)-Cl(1) 86.3(2) C(34)-Zr(1)-C(28) 137.8(2) C(35)-Zr(1)-Cl(1) 104.43(14) C(29)-Zr(1)-C(28) 33.0(2) C(30)-Zr(1)-Cl(1) 105.26(16) C(32)-Zr(1)-C(35) 55.51(19) C(31)-Zr(1)-Cl(1) 132.74(17) C(36)-Zr(1)-C(35) 33.0(2) C(27)-Zr(1)-Cl(1) 118.4(2) C(33)-Zr(1)-C(35) 54.82(18) C(32)-Zr(1)-Ga(1) 88.06(12) C(34)-Zr(1)-C(35) 32.73(19) C(36)-Zr(1)-Ga(1) 121.44(14) C(29)-Zr(1)-C(35) 106.0(2) C(33)-Zr(1)-Ga(1) 79.40(12) C(28)-Zr(1)-C(35) 135.5(2) C(34)-Zr(1)-Ga(1) 105.52(14) C(32)-Zr(1)-C(30) 136.73(18) C(29)-Zr(1)-Ga(1) 118.06(15) C(36)-Zr(1)-C(30) 105.67(19) C(28)-Zr(1)-Ga(1) 85.51(17) C(33)-Zr(1)-C(30) 125.2(2) C(35)-Zr(1)-Ga(1) 134.18(13) C(34)-Zr(1)-C(30) 92.3(2) C(30)-Zr(1)-Ga(1) 131.63(14) C(29)-Zr(1)-C(30) 32.4(2) C(31)-Zr(1)-Ga(1) 104.15(16) C(28)-Zr(1)-C(30) 54.1(2) C(27)-Zr(1)-Ga(1) 77.97(15) C(35)-Zr(1)-C(30) 81.59(19) Cl(1)-Zr(1)-Ga(1) 96.17(4) C(32)-Zr(1)-C(31) 139.2(2) C(37)-Zr(2)-C(42) 137.03(19) C(36)-Zr(1)-C(31) 123.4(2) C(37)-Zr(2)-C(38) 33.60(18) C(33)-Zr(1)-C(31) 109.9(2) C(42)-Zr(2)-C(38) 105.55(19) C(34)-Zr(1)-C(31) 83.8(2) C(37)-Zr(2)-C(46) 140.24(19) C(29)-Zr(1)-C(31) 54.0(2) C(42)-Zr(2)-C(46) 33.2(2) C(28)-Zr(1)-C(31) 54.1(3) C(38)-Zr(2)-C(46) 123.8(2) C(35)-Zr(1)-C(31) 91.2(2) C(37)-Zr(2)-C(43) 148.82(18)

234

Table 36 (con’t). Bond angles [°] for (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) Atoms Angle Atoms Angle C(42)-Zr(2)-C(43) 32.94(19) C(37)-Zr(2)-Cl(1) 103.90(15) C(38)-Zr(2)-C(43) 117.31(18) C(38)-Zr(2)-Cl(1) 76.39(14) C(46)-Zr(2)-C(43) 54.7(2) C(46)-Zr(2)-Cl(1) 131.96(15) C(37)-Zr(2)-C(41) 33.71(18) C(43)-Zr(2)-Cl(1) 77.31(14) C(42)-Zr(2)-C(41) 126.6(2) C(41)-Zr(2)-Cl(1) 115.44(14) C(38)-Zr(2)-C(41) 55.15(19) C(44)-Zr(2)-Cl(1) 85.67(14) C(46)-Zr(2)-C(41) 110.9(2) C(40)-Zr(2)-Cl(1) 130.75(15) C(43)-Zr(2)-C(41) 159.21(19) C(39)-Zr(2)-Cl(1) 104.39(14) C(37)-Zr(2)-C(44) 165.33(18) C(45)-Zr(2)-Cl(1) 118.15(14) C(42)-Zr(2)-C(44) 54.47(19) C(37)-Zr(2)-Ga(1) 86.31(13) C(38)-Zr(2)-C(44) 149.15(18) C(42)-Zr(2)-Ga(1) 134.65(14) C(46)-Zr(2)-C(44) 54.3(2) C(38)-Zr(2)-Ga(1) 119.38(14) C(43)-Zr(2)-C(44) 32.83(18) C(46)-Zr(2)-Ga(1) 107.72(14) C(41)-Zr(2)-C(44) 154.61(19) C(43)-Zr(2)-Ga(1) 117.75(13) C(37)-Zr(2)-C(40) 55.21(19) C(41)-Zr(2)-Ga(1) 79.42(14) C(42)-Zr(2)-C(40) 94.0(2) C(44)-Zr(2)-Ga(1) 85.93(13) C(38)-Zr(2)-C(40) 54.6(2) C(40)-Zr(2)-Ga(1) 106.50(14) C(46)-Zr(2)-C(40) 85.0(2) C(39)-Zr(2)-Ga(1) 133.74(14) C(43)-Zr(2)-C(40) 126.4(2) C(45)-Zr(2)-Ga(1) 80.45(12) C(41)-Zr(2)-C(40) 32.81(19) Cl(1)-Zr(2)-Ga(1) 92.76(4) C(44)-Zr(2)-C(40) 139.2(2) Zr(1)-Cl(1)-Zr(2) 84.73(4) C(37)-Zr(2)-C(39) 54.97(19) C(6)-C(1)-C(2) 117.4(4) C(42)-Zr(2)-C(39) 82.71(19) C(6)-C(1)-Ga(1) 124.3(4) C(38)-Zr(2)-C(39) 32.70(19) C(2)-C(1)-Ga(1) 118.3(4) C(46)-Zr(2)-C(39) 92.1(2) C(3)-C(2)-C(1) 121.0(5) C(43)-Zr(2)-C(39) 107.90(19) C(3)-C(2)-C(7) 117.1(4) C(41)-Zr(2)-C(39) 54.37(19) C(1)-C(2)-C(7) 121.9(4) C(44)-Zr(2)-C(39) 137.11(19) C(4)-C(3)-C(2) 120.7(5) C(40)-Zr(2)-C(39) 32.6(2) C(3)-C(4)-C(5) 119.5(5) C(37)-Zr(2)-C(45) 155.93(18) C(4)-C(5)-C(6) 120.5(5) C(42)-Zr(2)-C(45) 54.42(18) C(1)-C(6)-C(5) 120.9(5) C(38)-Zr(2)-C(45) 156.22(19) C(1)-C(6)-C(17) 122.5(4) C(46)-Zr(2)-C(45) 32.46(19) C(5)-C(6)-C(17) 116.6(4) C(43)-Zr(2)-C(45) 54.43(19) C(12)-C(7)-C(8) 117.1(5) C(41)-Zr(2)-C(45) 123.15(19) C(12)-C(7)-C(2) 122.1(5) C(44)-Zr(2)-C(45) 32.84(19) C(8)-C(7)-C(2) 120.6(4) C(40)-Zr(2)-C(45) 109.7(2) C(9)-C(8)-C(7) 120.9(5) C(39)-Zr(2)-C(45) 124.21(19) C(8)-C(9)-C(10) 121.9(5)

235

Table 36 (con’t). Bond angles [°] for (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) Atoms Angle Atoms Angle C(11)-C(10)-C(9) 117.2(5) C(31)-C(30)-Zr(1) 74.2(3) C(11)-C(10)-C(13) 122.8(5) C(27)-C(31)-C(30) 107.5(7) C(9)-C(10)-C(13) 119.9(5) C(27)-C(31)-Zr(1) 74.1(4) C(10)-C(11)-C(12) 120.8(5) C(30)-C(31)-Zr(1) 73.2(3) C(7)-C(12)-C(11) 122.1(5) C(33)-C(32)-C(36) 106.4(5) C(14)-C(13)-C(16) 108.4(5) C(33)-C(32)-C(37) 126.9(5) C(14)-C(13)-C(15) 108.4(5) C(36)-C(32)-C(37) 126.6(5) C(16)-C(13)-C(15) 109.7(5) C(33)-C(32)-Zr(1) 73.8(3) C(14)-C(13)-C(10) 112.2(5) C(36)-C(32)-Zr(1) 73.5(3) C(16)-C(13)-C(10) 109.6(4) C(37)-C(32)-Zr(1) 114.6(3) C(15)-C(13)-C(10) 108.6(4) C(32)-C(33)-C(34) 108.2(5) C(18)-C(17)-C(22) 117.8(5) C(32)-C(33)-Zr(1) 72.7(3) C(18)-C(17)-C(6) 120.8(5) C(34)-C(33)-Zr(1) 73.4(3) C(22)-C(17)-C(6) 121.4(5) C(35)-C(34)-C(33) 108.7(5) C(17)-C(18)-C(19) 122.1(5) C(35)-C(34)-Zr(1) 74.2(3) C(20)-C(19)-C(18) 120.8(5) C(33)-C(34)-Zr(1) 73.4(3) C(19)-C(20)-C(21) 116.7(5) C(36)-C(35)-C(34) 107.8(5) C(19)-C(20)-C(23) 122.6(5) C(36)-C(35)-Zr(1) 72.8(3) C(21)-C(20)-C(23) 120.7(5) C(34)-C(35)-Zr(1) 73.1(3) C(22)-C(21)-C(20) 121.8(5) C(35)-C(36)-C(32) 108.9(5) C(17)-C(22)-C(21) 120.8(5) C(35)-C(36)-Zr(1) 74.3(3) C(25)-C(23)-C(20) 112.2(4) C(32)-C(36)-Zr(1) 72.9(3) C(25)-C(23)-C(26) 108.5(4) C(38)-C(37)-C(41) 106.4(5) C(20)-C(23)-C(26) 108.2(4) C(38)-C(37)-C(32) 127.1(5) C(25)-C(23)-C(24) 108.0(4) C(41)-C(37)-C(32) 126.3(5) C(20)-C(23)-C(24) 110.5(4) C(38)-C(37)-Zr(2) 73.2(3) C(26)-C(23)-C(24) 109.4(4) C(41)-C(37)-Zr(2) 73.7(3) C(28)-C(27)-C(31) 108.4(6) C(32)-C(37)-Zr(2) 114.6(3) C(28)-C(27)-Zr(1) 72.7(4) C(39)-C(38)-C(37) 108.4(5) C(31)-C(27)-Zr(1) 73.6(4) C(39)-C(38)-Zr(2) 74.6(3) C(27)-C(28)-C(29) 107.7(6) C(37)-C(38)-Zr(2) 73.2(3) C(27)-C(28)-Zr(1) 74.7(4) C(40)-C(39)-C(38) 108.8(5) C(29)-C(28)-Zr(1) 73.8(3) C(40)-C(39)-Zr(2) 73.6(3) C(30)-C(29)-C(28) 107.6(6) C(38)-C(39)-Zr(2) 72.7(3) C(30)-C(29)-Zr(1) 73.8(3) C(39)-C(40)-C(41) 108.3(5) C(28)-C(29)-Zr(1) 73.3(4) C(39)-C(40)-Zr(2) 73.8(3) C(29)-C(30)-C(31) 108.7(6) C(41)-C(40)-Zr(2) 73.2(3) C(29)-C(30)-Zr(1) 73.8(3) C(40)-C(41)-C(37) 108.0(5)

236

Table 36 (con’t). Bond angles [°] for (C10H8)(ZrCp)2(μH)(μCl)(μGaR) (12) Atoms Angle Atoms Angle C(40)-C(41)-Zr(2) 74.0(3) C(46)-C(45)-Zr(2) 72.8(3) C(37)-C(41)-Zr(2) 72.6(3) C(44)-C(45)-Zr(2) 72.7(3) C(43)-C(42)-C(46) 107.9(5) C(45)-C(46)-C(42) 108.2(5) C(43)-C(42)-Zr(2) 74.1(3) C(45)-C(46)-Zr(2) 74.8(3) C(46)-C(42)-Zr(2) 73.9(3) C(42)-C(46)-Zr(2) 72.8(3) C(42)-C(43)-C(44) 107.8(5) C(48)-C(47)-C(52) 119.0(6) C(42)-C(43)-Zr(2) 73.0(3) C(48)-C(47)-C(53) 120.8(6) C(44)-C(43)-Zr(2) 73.8(3) C(52)-C(47)-C(53) 120.1(6) C(43)-C(44)-C(45) 108.3(5) C(47)-C(48)-C(49) 121.1(6) C(43)-C(44)-Zr(2) 73.4(3) C(50)-C(49)-C(48) 119.8(6) C(45)-C(44)-Zr(2) 74.4(3) C(49)-C(50)-C(51) 118.3(7) C(46)-C(45)-C(44) 107.8(5) C(52)-C(51)-C(50) 123.5(7) C(51)-C(52)-C(47) 118.3(7)

237

Structural Data for RTiCp2 (R = 2,6-(4-Me-C6H4)2C6H3-) Table 37. Crystal data and structural refinement for RTiCp2 (13)

Empirical formula C15H13.50Ti 0.50 Formula weight 217.71 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, C2/c Unit cell dimensions a = 11.1466(7) Å b = 16.4429(11)Å c = 13.0786(8) Å alpha = 90° beta =106.2040(10)° gamma = 90° Volume 2301.9(3) Å3 Z, Calculated density 8, 1.256 Mg/m3 Absorption coefficient 0.386 mm-1 F(000) 916 Crystal size 0.40 x 0.38 x 0.20 mm Theta range for data collection 2.27 to 25.00 deg. Limiting indices -12<=h<=13, -19<=k<=19, -13<=l<=15 Reflections collected / unique 6879 / 2025 [R(int) = 0.0167] Completeness to theta = 25.00 100.00% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9268 and 0.8609 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 2025 / 0 / 142 Goodness-of-fit on F^2 1.029 Final R indices [I>2sigma(I)] R1 = 0.0373, wR2 = 0.1058 R indices (all data) R1 = 0.0477, wR2 = 0.1157 Largest diff. peak and hole 0.188 and -0.306 e.Å-3

238

Table 38. Bond Lengths [Å] for RTiCp2 (13) Atoms Distance Atoms Distance Ti(1)-C(1) 2.242(2) C(2)-C(5) 1.485(3) Ti(1)-C(13)#1 2.358(2) C(3)-C(4) 1.373(3) Ti(1)-C(13) 2.358(2) C(4)-C(3)#1 1.373(3) Ti(1)-C(16)#1 2.365(2) C(5)-C(6) 1.389(3) Ti(1)-C(16) 2.365(2) C(5)-C(10) 1.392(3) Ti(1)-C(15) 2.373(2) C(6)-C(7) 1.384(3) Ti(1)-C(15)#1 2.373(2) C(7)-C(8) 1.377(3) Ti(1)-C(14)#1 2.370(2) C(8)-C(9) 1.380(4) Ti(1)-C(14) 2.370(2) C(8)-C(11) 1.521(4) Ti(1)-C(12)#1 2.369(2) C(9)-C(10) 1.373(3) Ti(1)-C(12) 2.369(2) C(12)-C(16) 1.362(4) C(1)-C(2)#1 1.421(2) C(12)-C(13) 1.338(4) C(1)-C(2) 1.421(2) C(13)-C(14) 1.370(4) C(2)-C(3) 1.402(3) C(14)-C(15) 1.401(4) C(15)-C(16) 1.390(4)

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Table 39. Bond angles [°] for RTiCp2 (13) Atoms Distance Atoms Distance C(1)-Ti(1)-C(13)#1 111.31(8) C(13)-Ti(1)-C(12)#1 106.40(12) C(1)-Ti(1)-C(13) 111.31(8) C(16)#1-Ti(1)-C(12)#1 33.45(9) C(13)#1-Ti(1)-C(13) 137.38(16) C(16)-Ti(1)-C(12)#1 86.30(11) C(1)-Ti(1)-C(16)#1 125.87(8) C(15)-Ti(1)-C(12)#1 119.67(11) C(13)#1-Ti(1)-C(16)#1 55.75(9) C(15)#1-Ti(1)-C(12)#1 55.76(9) C(13)-Ti(1)-C(16)#1 97.87(11) C(14)#1-Ti(1)-C(12)#1 55.38(10) C(1)-Ti(1)-C(16) 125.87(8) C(14)-Ti(1)-C(12)#1 135.19(10) C(13)#1-Ti(1)-C(16) 97.87(11) C(1)-Ti(1)-C(12) 140.09(7) C(13)-Ti(1)-C(16) 55.75(9) C(13)#1-Ti(1)-C(12) 106.40(12) C(16)#1-Ti(1)-C(16) 108.26(17) C(13)-Ti(1)-C(12) 32.87(10) C(1)-Ti(1)-C(15) 92.53(8) C(16)#1-Ti(1)-C(12) 86.30(11) C(13)#1-Ti(1)-C(15) 121.57(12) C(16)-Ti(1)-C(12) 33.45(9) C(13)-Ti(1)-C(15) 56.24(10) C(15)-Ti(1)-C(12) 55.76(9) C(16)#1-Ti(1)-C(15) 140.91(12) C(15)#1-Ti(1)-C(12) 119.67(11) C(16)-Ti(1)-C(15) 34.12(10) C(14)#1-Ti(1)-C(12) 135.19(10) C(1)-Ti(1)-C(15)#1 92.53(8) C(14)-Ti(1)-C(12) 55.38(10) C(13)#1-Ti(1)-C(15)#1 56.25(10) C(12)#1-Ti(1)-C(12) 79.82(15) C(13)-Ti(1)-C(15)#1 121.57(12) C(2)#1-C(1)-C(2) 114.8(2) C(16)#1-Ti(1)-C(15)#1 34.12(10) C(2)#1-C(1)-Ti(1) 122.59(11) C(16)-Ti(1)-C(15)#1 140.91(12) C(2)-C(1)-Ti(1) 122.59(11) C(15)-Ti(1)-C(15)#1 174.94(16) C(3)-C(2)-C(1) 122.09(19) C(1)-Ti(1)-C(14)#1 84.71(7) C(3)-C(2)-C(5) 116.74(17) C(13)#1-Ti(1)-C(14)#1 33.68(10) C(1)-C(2)-C(5) 121.16(17) C(13)-Ti(1)-C(14)#1 154.04(11) C(4)-C(3)-C(2) 120.8(2) C(16)#1-Ti(1)-C(14)#1 56.50(9) C(3)-C(4)-C(3)#1 119.3(3) C(16)-Ti(1)-C(14)#1 131.30(11) C(6)-C(5)-C(10) 116.36(19) C(15)-Ti(1)-C(14)#1 146.47(10) C(6)-C(5)-C(2) 121.59(17) C(15)#1-Ti(1)-C(14)#1 34.36(11) C(10)-C(5)-C(2) 122.05(17) C(1)-Ti(1)-C(14) 84.71(7) C(7)-C(6)-C(5) 121.74(19) C(13)#1-Ti(1)-C(14) 154.04(11) C(8)-C(7)-C(6) 121.3(2) C(13)-Ti(1)-C(14) 33.68(10) C(7)-C(8)-C(9) 117.1(2) C(16)#1-Ti(1)-C(14) 131.30(11) C(7)-C(8)-C(11) 120.8(2) C(16)-Ti(1)-C(14) 56.50(9) C(9)-C(8)-C(11) 122.1(2) C(15)-Ti(1)-C(14) 34.36(11) C(10)-C(9)-C(8) 122.0(2) C(15)#1-Ti(1)-C(14) 146.47(10) C(9)-C(10)-C(5) 121.4(2) C(14)#1-Ti(1)-C(14) 169.43(14) C(16)-C(12)-C(13) 109.8(3) C(1)-Ti(1)-C(12)#1 140.09(7) C(16)-C(12)-Ti(1) 73.11(14) C(13)#1-Ti(1)-C(12)#1 32.87(10) C(13)-C(12)-Ti(1) 73.12(14)

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Table 39 (con’t). Bond angles [°] for RTiCp2 (13) Atoms Distance Atoms Distance C(14)-C(13)-C(12) 108.9(3) C(16)-C(15)-C(14) 106.8(2) C(14)-C(13)-Ti(1) 73.64(15) C(16)-C(15)-Ti(1) 72.64(15) C(12)-C(13)-Ti(1) 74.01(15) C(14)-C(15)-Ti(1) 72.73(14) C(13)-C(14)-C(15) 107.2(2) C(12)-C(16)-C(15) 107.3(2) C(13)-C(14)-Ti(1) 72.68(15) C(12)-C(16)-Ti(1) 73.44(14) C(15)-C(14)-Ti(1) 72.91(15) C(15)-C(16)-Ti(1) 73.25(14)

241

Structural Data for (R)(Cl)ZrCp2 (14) (R = 2,6-(4-t-BuC6H4)2C6H3-) Table 40. Crystal data and structural refinement for (R)(Cl)ZrCp2 (14)

Empirical formula C79H86Cl2Zr2 Formula weight 1288.82 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, P2(1)/n Unit cell dimensions a = 18.9577(10) Å b = 9.2362(5) Å c = 19.2877(10) Å = 90° = 96.9220(10)° . = 90° Volume 3352.6(3) Å3 Z, Calculated density 2, 1.277 Mg/m3 Absorption coefficient 0.433 mm-1 F(000) 1348 Crystal size 0.33 x 0.23 x 0.09 mm Theta range for data collection 2.45 to 25.00 deg. Limiting indices -22<=h<=22, -10<=k<=10, -22<=l<=22 Reflections collected / unique 21486 / 5880 [R(int) = 0.0478] Completeness to theta = 25.00 99.60% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9621 and 0.8703 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 5880 / 13 / 380 Goodness-of-fit on F^2 1.054 Final R indices [I>2sigma(I)] R1 = 0.0431, wR2 = 0.0999 R indices (all data) R1 = 0.0807, wR2 = 0.1190 Largest diff. peak and hole 0.561 and -0.434 e.Å-3

242

Table 41. Bond Lengths [Å] for (R)(Cl)ZrCp2 (14) Atoms Distance Atoms Distance Zr(1)-C(1) 2.380(4) C(13)-C(14) 1.534(6) Zr(1)-Cl(1) 2.4612(12) C(13)-C(16) 1.529(6) Zr(1)-C(33) 2.488(4) C(13)-C(15) 1.529(6) Zr(1)-C(27) 2.491(4) C(17)-C(18) 1.379(5) Zr(1)-C(28) 2.497(4) C(17)-C(22) 1.385(6) Zr(1)-C(34) 2.505(4) C(18)-C(19) 1.394(6) Zr(1)-C(32) 2.500(4) C(19)-C(20) 1.382(6) Zr(1)-C(36) 2.506(4) C(20)-C(21) 1.383(5) Zr(1)-C(35) 2.513(4) C(20)-C(23) 1.526(5) Zr(1)-C(31) 2.515(4) C(21)-C(22) 1.382(5) Zr(1)-C(30) 2.523(4) C(23)-C(25) 1.498(7) Zr(1)-C(29) 2.534(4) C(23)-C(26) 1.520(7) C(1)-C(2) 1.411(5) C(23)-C(24) 1.533(7) C(1)-C(6) 1.426(5) C(27)-C(28) 1.386(6) C(2)-C(3) 1.390(5) C(27)-C(31) 1.397(6) C(2)-C(7) 1.486(5) C(28)-C(29) 1.364(6) C(3)-C(4) 1.368(6) C(29)-C(30) 1.406(6) C(4)-C(5) 1.372(6) C(30)-C(31) 1.399(6) C(5)-C(6) 1.391(5) C(32)-C(36) 1.391(7) C(6)-C(17) 1.508(5) C(32)-C(33) 1.411(6) C(7)-C(12) 1.388(5) C(33)-C(34) 1.402(6) C(7)-C(8) 1.390(5) C(34)-C(35) 1.380(6) C(8)-C(9) 1.370(5) C(35)-C(36) 1.399(7) C(9)-C(10) 1.392(5) C(37)-C(38) 1.136(14) C(10)-C(11) 1.394(5) C(38)-C(40)#1 1.480(16) C(10)-C(13) 1.519(6) C(38)-C(39) 1.395(12) C(11)-C(12) 1.370(5) C(39)-C(40) 1.329(17) C(40)-C(38)#1 1.480(16)

243

Table 42. Bond Angles [°] for (R)(Cl)ZrCp2 (14) Atoms Angle Atoms Angle C(1)-Zr(1)-Cl(1) 118.79(9) C(27)-Zr(1)-C(31) 32.39(13) C(1)-Zr(1)-C(33) 91.79(14) C(28)-Zr(1)-C(31) 53.26(15) Cl(1)-Zr(1)-C(33) 129.82(12) C(34)-Zr(1)-C(31) 116.91(16) C(1)-Zr(1)-C(27) 94.23(15) C(32)-Zr(1)-C(31) 128.19(18) Cl(1)-Zr(1)-C(27) 127.78(12) C(36)-Zr(1)-C(31) 160.22(19) C(33)-Zr(1)-C(27) 83.57(16) C(35)-Zr(1)-C(31) 146.77(17) C(1)-Zr(1)-C(28) 124.49(15) C(1)-Zr(1)-C(30) 88.04(14) Cl(1)-Zr(1)-C(28) 98.60(13) Cl(1)-Zr(1)-C(30) 86.33(13) C(33)-Zr(1)-C(28) 93.74(16) C(33)-Zr(1)-C(30) 136.85(16) C(27)-Zr(1)-C(28) 32.28(15) C(27)-Zr(1)-C(30) 53.46(15) C(1)-Zr(1)-C(34) 124.28(15) C(28)-Zr(1)-C(30) 53.00(15) Cl(1)-Zr(1)-C(34) 104.15(13) C(34)-Zr(1)-C(30) 130.57(15) C(33)-Zr(1)-C(34) 32.61(15) C(32)-Zr(1)-C(30) 159.78(19) C(27)-Zr(1)-C(34) 84.90(16) C(36)-Zr(1)-C(30) 167.55(19) C(28)-Zr(1)-C(34) 77.60(16) C(35)-Zr(1)-C(30) 143.13(18) C(1)-Zr(1)-C(32) 76.93(15) C(31)-Zr(1)-C(30) 32.23(14) Cl(1)-Zr(1)-C(32) 112.67(14) C(1)-Zr(1)-C(29) 120.09(14) C(33)-Zr(1)-C(32) 32.87(15) Cl(1)-Zr(1)-C(29) 75.03(12) C(27)-Zr(1)-C(32) 113.57(18) C(33)-Zr(1)-C(29) 124.90(16) C(28)-Zr(1)-C(32) 126.32(16) C(27)-Zr(1)-C(29) 53.03(15) C(34)-Zr(1)-C(32) 53.65(16) C(28)-Zr(1)-C(29) 31.45(14) C(1)-Zr(1)-C(36) 98.11(17) C(34)-Zr(1)-C(29) 103.33(16) Cl(1)-Zr(1)-C(36) 81.22(15) C(32)-Zr(1)-C(29) 156.44(16) C(33)-Zr(1)-C(36) 54.17(17) C(36)-Zr(1)-C(29) 141.23(19) C(27)-Zr(1)-C(36) 136.07(16) C(35)-Zr(1)-C(29) 110.95(18) C(28)-Zr(1)-C(36) 128.72(16) C(31)-Zr(1)-C(29) 53.21(15) C(34)-Zr(1)-C(36) 53.56(16) C(30)-Zr(1)-C(29) 32.28(14) C(32)-Zr(1)-C(36) 32.27(16) C(2)-C(1)-C(6) 114.7(3) C(1)-Zr(1)-C(35) 128.83(16) C(2)-C(1)-Zr(1) 114.9(3) Cl(1)-Zr(1)-C(35) 76.51(13) C(6)-C(1)-Zr(1) 129.4(2) C(33)-Zr(1)-C(35) 53.69(17) C(3)-C(2)-C(1) 122.8(4) C(27)-Zr(1)-C(35) 114.48(17) C(3)-C(2)-C(7) 115.9(3) C(28)-Zr(1)-C(35) 97.21(17) C(1)-C(2)-C(7) 121.3(3) C(34)-Zr(1)-C(35) 31.92(15) C(4)-C(3)-C(2) 120.7(4) C(32)-Zr(1)-C(35) 53.33(17) C(3)-C(4)-C(5) 118.4(4) C(36)-Zr(1)-C(35) 32.37(16) C(4)-C(5)-C(6) 122.3(4) C(1)-Zr(1)-C(31) 72.53(13) C(5)-C(6)-C(1) 120.9(4) Cl(1)-Zr(1)-C(31) 118.55(12) C(5)-C(6)-C(17) 113.8(4) C(33)-Zr(1)-C(31) 107.75(17) C(1)-C(6)-C(17) 125.3(3)

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Table 42 (con’t.). Bond Angles [°] for (R)(Cl)ZrCp2 (14) Atoms Angle Atoms Angle C(12)-C(7)-C(8) 116.6(4) C(28)-C(27)-Zr(1) 74.1(3) C(12)-C(7)-C(2) 123.4(3) C(31)-C(27)-Zr(1) 74.8(2) C(8)-C(7)-C(2) 119.8(3) C(29)-C(28)-C(27) 109.3(4) C(9)-C(8)-C(7) 121.4(4) C(29)-C(28)-Zr(1) 75.8(2) C(8)-C(9)-C(10) 122.1(4) C(27)-C(28)-Zr(1) 73.6(2) C(11)-C(10)-C(9) 116.3(4) C(28)-C(29)-C(30) 107.9(4) C(11)-C(10)-C(13) 123.6(4) C(28)-C(29)-Zr(1) 72.8(2) C(9)-C(10)-C(13) 120.0(4) C(30)-C(29)-Zr(1) 73.5(2) C(12)-C(11)-C(10) 121.5(4) C(31)-C(30)-C(29) 107.5(4) C(11)-C(12)-C(7) 122.1(4) C(31)-C(30)-Zr(1) 73.6(2) C(10)-C(13)-C(14) 112.7(4) C(29)-C(30)-Zr(1) 74.3(2) C(10)-C(13)-C(16) 108.9(3) C(27)-C(31)-C(30) 107.6(4) C(14)-C(13)-C(16) 106.8(4) C(27)-C(31)-Zr(1) 72.8(2) C(10)-C(13)-C(15) 109.9(4) C(30)-C(31)-Zr(1) 74.2(2) C(14)-C(13)-C(15) 108.2(4) C(36)-C(32)-C(33) 108.5(5) C(16)-C(13)-C(15) 110.2(4) C(36)-C(32)-Zr(1) 74.1(3) C(18)-C(17)-C(22) 116.8(4) C(33)-C(32)-Zr(1) 73.1(2) C(18)-C(17)-C(6) 120.8(4) C(34)-C(33)-C(32) 106.8(5) C(22)-C(17)-C(6) 121.8(3) C(34)-C(33)-Zr(1) 74.4(2) C(17)-C(18)-C(19) 121.2(4) C(32)-C(33)-Zr(1) 74.0(2) C(20)-C(19)-C(18) 122.3(4) C(35)-C(34)-C(33) 108.6(5) C(19)-C(20)-C(21) 115.6(4) C(35)-C(34)-Zr(1) 74.4(2) C(19)-C(20)-C(23) 123.2(4) C(33)-C(34)-Zr(1) 73.0(2) C(21)-C(20)-C(23) 121.2(4) C(34)-C(35)-C(36) 108.7(5) C(20)-C(21)-C(22) 122.7(4) C(34)-C(35)-Zr(1) 73.7(3) C(17)-C(22)-C(21) 121.2(4) C(36)-C(35)-Zr(1) 73.6(2) C(25)-C(23)-C(26) 111.2(5) C(32)-C(36)-C(35) 107.5(5) C(25)-C(23)-C(20) 109.4(4) C(32)-C(36)-Zr(1) 73.6(2) C(26)-C(23)-C(20) 109.7(4) C(35)-C(36)-Zr(1) 74.1(3) C(25)-C(23)-C(24) 107.4(5) C(40)#1-C(38)-C(37) 97.6(13) C(26)-C(23)-C(24) 107.7(5) C(40)#1-C(38)-C(39) 113.0(9) C(20)-C(23)-C(24) 111.4(4) C(37)-C(38)-C(39) 149.4(16) C(28)-C(27)-C(31) 107.7(4) C(38)-C(39)-C(40) 137.1(15) C(38)#1-C(40)-C(39) 109.8(17)

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Structural Data for 2,2’-Z-dibromostilbene (15) Table 43. Crystal data and structural refinement for 2,2’-Z-dibromostilbene (15)

Empirical formula C14H10Br2 Formula weight 338.04 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, C2/c Unit cell dimensions a = 16.133(4) Å b = 14.983(4) Å c = 11.328(3) Å = 90° = 113.031(4)° = 90° Volume 2519.9(11) Å3 Z, Calculated density 8, 1.782 Mg/m3 Absorption coefficient 6.402 mm-1 F(000) 1312 Crystal size 0.50 x 0.28 x 0.10 mm Theta range for data collection 1.93 to 25.00 deg. Limiting indices -19<=h<=18, -17<=k<=17, -13<=l<=13 Reflections collected / unique 8088 / 2220 [R(int) = 0.0231] Completeness to theta = 25.00 100.00% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.5669 and 0.1420 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 2220 / 0 / 145 Goodness-of-fit on F^2 1.047 Final R indices [I>2sigma(I)] R1 = 0.0427, wR2 = 0.0917 R indices (all data) 0.752 and -0.768 e.Å-3

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Table 44. Bond Lengths [Å] for 2,2’-Z-dibromostilbene (15) Atoms Distance Atoms Distance Br(1)-C(1) 1.903(4) C(6)-C(7) 1.464(6) Br(2)-C(14) 1.898(5) C(7)-C(8) 1.328(6) C(1)-C(2) 1.382(7) C(8)-C(9) 1.479(6) C(1)-C(6) 1.390(6) C(9)-C(14) 1.379(6) C(2)-C(3) 1.373(7) C(9)-C(10) 1.388(7) C(3)-C(4) 1.373(7) C(10)-C(11) 1.379(7) C(4)-C(5) 1.371(7) C(11)-C(12) 1.361(8) C(5)-C(6) 1.396(6) C(12)-C(13) 1.364(8) C(13)-C(14) 1.374(7)

Table 45. Bond angles [°] for 2,2’-Z-dibromostilbene (15) Atoms Angle Atoms Angle C(2)-C(1)-C(6) 122.6(4) C(7)-C(8)-C(9) 126.8(5) C(2)-C(1)-Br(1) 117.9(4) C(14)-C(9)-C(10) 116.7(4) C(6)-C(1)-Br(1) 119.6(4) C(14)-C(9)-C(8) 121.9(4) C(3)-C(2)-C(1) 119.4(5) C(10)-C(9)-C(8) 121.3(4) C(4)-C(3)-C(2) 119.8(5) C(11)-C(10)-C(9) 120.9(5) C(3)-C(4)-C(5) 120.3(5) C(12)-C(11)-C(10) 120.7(5) C(4)-C(5)-C(6) 121.9(4) C(13)-C(12)-C(11) 119.7(5) C(1)-C(6)-C(5) 116.0(4) C(12)-C(13)-C(14) 119.5(5) C(1)-C(6)-C(7) 122.2(4) C(9)-C(14)-C(13) 122.5(5) C(5)-C(6)-C(7) 121.6(4) C(9)-C(14)-Br(2) 118.8(4) C(8)-C(7)-C(6) 128.3(4) C(13)-C(14)-Br(2) 118.7(4)

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Structural Data for 2,2’-dilithio-Z-stilbene(TMEDA)2 (16) Table 46. Crystal data and structural refinement for 2,2’-dilithio-Z-stilbene(TMEDA)2 (16) Empirical formula C26H42Li2N4 Formula weight 424.52 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, P2(1)/m Unit cell dimensions a = 9.628(3) Å b = 12.277(3) Å c = 12.009(3) Å = 90° = 92.147(4)° = 90° Volume 1418.5(7) Å3 Z, Calculated density 2, 0.994 Mg/m3 Absorption coefficient 0.058 mm-1 F(000) 464 Crystal size 0.22 x 0.22 x 0.07 mm Theta range for data collection 2.12 to 25.00 deg. Limiting indices -11<=h<=11, -13<=k<=14, -14<=l<=14 Reflections collected / unique 9491 / 2634 [R(int) = 0.0317] Completeness to theta = 25.00 100.00% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9960 and 0.9875 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 2634 / 84 / 198 Goodness-of-fit on F^2 1.011 Final R indices [I>2sigma(I)] R1 = 0.0561, wR2 = 0.1581 R indices (all data) R1 = 0.1280, wR2 = 0.2043 Largest diff. peak and hole 0.107 and -0.107 e.Å-3

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Table 47. Bond Lengths [Å] for 2,2’-dilithio-Z-stilbene(TMEDA)2 (16) Atoms Distance Atoms Distance Li(1)-C(1)#1 2.158(4) N(3)-C(12')#1 1.507(19) Li(1)-C(1) 2.158(4) N(3)-C(12') 1.507(19) Li(1)-N(2) 2.155(6) N(3)-C(15)#1 1.456(4) Li(1)-N(1) 2.194(7) N(3)-C(15) 1.456(4) Li(1)-Li(2) 2.527(8) N(3)-C(12) 1.473(13) Li(2)-C(1)#1 2.157(4) N(3)-C(12)#1 1.473(13) Li(2)-C(1) 2.157(4) N(4)-C(14)#1 1.428(4) Li(2)-N(3) 2.187(7) N(4)-C(14) 1.428(5) Li(2)-N(4) 2.247(6) N(4)-C(13)#1 1.47(2) Li(2)-C(12')#1 2.84(3) N(4)-C(13) 1.47(2) Li(2)-C(12') 2.84(3) N(4)-C(13')#1 1.527(19) N(1)-C(10)#1 1.452(4) N(4)-C(13') 1.527(19) N(1)-C(10) 1.452(4) C(1)-C(2) 1.405(3) N(1)-C(8) 1.52(2) C(1)-C(6) 1.420(3) N(1)-C(8)#1 1.52(2) C(2)-C(3) 1.379(4) N(1)-C(8')#1 1.519(18) C(3)-C(4) 1.362(5) N(1)-C(8') 1.519(18) C(4)-C(5) 1.345(4) N(2)-C(11)#1 1.453(4) C(5)-C(6) 1.394(3) N(2)-C(11) 1.453(4) C(6)-C(7) 1.463(3) N(2)-C(9)#1 1.507(18) C(7)-C(7)#1 1.340(5) N(2)-C(9) 1.507(18) C(8)-C(9) 1.443(16) N(2)-C(9') 1.518(19) C(8')-C(9') 1.468(18) N(2)-C(9')#1 1.518(19) C(12)-C(13) 1.480(16) C(12')-C(13') 1.479(19)

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Table 48. Bond angles [°] for 2,2’-dilithio-Z-stilbene(TMEDA)2 (16) Atoms Angle Atoms Angle C(1)#1-Li(1)-C(1) 100.8(3) C(10)-N(1)-C(8')#1 108.4(6) C(1)#1-Li(1)-N(2) 119.93(17) C(8)-N(1)-C(8')#1 26.8(14) C(1)-Li(1)-N(2) 119.93(17) C(8)#1-N(1)-C(8')#1 26.8(14) C(1)#1-Li(1)-N(1) 116.51(18) C(10)#1-N(1)-C(8') 108.4(6) C(1)-Li(1)-N(1) 116.51(18) C(10)-N(1)-C(8') 108.4(6) N(2)-Li(1)-N(1) 84.0(2) C(8)-N(1)-C(8') 26.8(14) C(1)#1-Li(1)-Li(2) 54.13(14) C(8)#1-N(1)-C(8') 26.8(14) C(1)-Li(1)-Li(2) 54.13(14) C(8')#1-N(1)-C(8') 0.0(2) N(2)-Li(1)-Li(2) 118.3(3) C(10)#1-N(1)-Li(1) 112.5(2) N(1)-Li(1)-Li(2) 157.7(3) C(10)-N(1)-Li(1) 112.5(2) C(1)#1-Li(2)-C(1) 100.9(3) C(8)-N(1)-Li(1) 97.5(10) C(1)#1-Li(2)-N(3) 112.98(19) C(8)#1-N(1)-Li(1) 97.5(10) C(1)-Li(2)-N(3) 112.98(19) C(8')#1-N(1)-Li(1) 105.2(10) C(1)#1-Li(2)-N(4) 122.81(17) C(8')-N(1)-Li(1) 105.2(10) C(1)-Li(2)-N(4) 122.81(17) C(11)#1-N(2)-C(11) 109.2(4) N(3)-Li(2)-N(4) 83.9(2) C(11)#1-N(2)-C(9)#1 109.3(4) C(1)#1-Li(2)-Li(1) 54.17(14) C(11)-N(2)-C(9)#1 109.3(4) C(1)-Li(2)-Li(1) 54.17(14) C(11)#1-N(2)-C(9) 109.3(4) N(3)-Li(2)-Li(1) 151.0(3) C(11)-N(2)-C(9) 109.3(4) N(4)-Li(2)-Li(1) 125.0(3) C(9)#1-N(2)-C(9) 0.0(14) C(1)#1-Li(2)-C(12')#1 112.0(10) C(11)#1-N(2)-C(9') 135.1(14) C(1)-Li(2)-C(12')#1 139.1(10) C(11)-N(2)-C(9') 88.1(12) N(3)-Li(2)-C(12')#1 31.7(6) C(9)#1-N(2)-C(9') 27.6(14) N(4)-Li(2)-C(12')#1 56.6(5) C(9)-N(2)-C(9') 27.6(14) Li(1)-Li(2)-C(12')#1 165.7(10) C(11)#1-N(2)-C(9')#1 88.1(12) C(1)#1-Li(2)-C(12') 139.1(10) C(11)-N(2)-C(9')#1 135.1(15) C(1)-Li(2)-C(12') 112.0(10) C(9)#1-N(2)-C(9')#1 27.6(14) N(3)-Li(2)-C(12') 31.7(6) C(9)-N(2)-C(9')#1 27.6(14) N(4)-Li(2)-C(12') 56.6(5) C(9')-N(2)-C(9')#1 54(3) Li(1)-Li(2)-C(12') 165.7(10) C(11)#1-N(2)-Li(1) 110.9(2) C(12')#1-Li(2)-C(12') 29(2) C(11)-N(2)-Li(1) 110.9(2) C(10)#1-N(1)-C(10) 109.6(4) C(9)#1-N(2)-Li(1) 107.0(7) C(11)#1-N(2)-C(9) 133.7(14) C(9)-N(2)-Li(1) 107.0(7) C(10)-N(1)-C(8) 88.6(11) C(9')-N(2)-Li(1) 99.8(12) C(10)#1-N(1)-C(8)#1 88.6(11) C(9')#1-N(2)-Li(1) 99.8(12) C(10)-N(1)-C(8)#1 133.7(14) C(12')#1-N(3)-C(12') 56(4) C(8)-N(1)-C(8)#1 52(3) C(12')#1-N(3)-C(15)#1 87.3(14) C(10)#1-N(1)-C(8')#1 108.4(6) C(12')-N(3)-C(15)#1 136(2)

250

Table 48 (con’t.). Bond angles [°] for 2,2’-dilithio-Z-stilbene(TMEDA)2 (16) Atoms Angle Atoms Angle C(12')#1-N(3)-C(15) 136(2) C(13)-N(4)-C(13') 25.2(17) C(12')-N(3)-C(15) 87.3(14) C(13')#1-N(4)-C(13') 0.0(17) C(15)#1-N(3)-C(15) 109.6(5) C(14)#1-N(4)-Li(2) 113.1(3) C(12')#1-N(3)-C(12) 28(2) C(14)-N(4)-Li(2) 113.1(3) C(12')-N(3)-C(12) 28(2) C(13)#1-N(4)-Li(2) 97.5(10) C(15)#1-N(3)-C(12) 109.0(4) C(13)-N(4)-Li(2) 97.5(10) C(15)-N(3)-C(12) 109.0(4) C(13')#1-N(4)-Li(2) 103.7(13) C(12')#1-N(3)-C(12)#1 28(2) C(13')-N(4)-Li(2) 103.7(13) C(12')-N(3)-C(12)#1 28(2) C(2)-C(1)-C(6) 113.5(2) C(15)#1-N(3)-C(12)#1 109.0(4) C(2)-C(1)-Li(2) 119.0(2) C(15)-N(3)-C(12)#1 109.0(4) C(6)-C(1)-Li(2) 110.9(2) C(12)-N(3)-C(12)#1 0.0(13) C(2)-C(1)-Li(1) 128.8(2) C(12')#1-N(3)-Li(2) 98.6(16) C(6)-C(1)-Li(1) 106.0(2) C(12')-N(3)-Li(2) 98.6(16) Li(2)-C(1)-Li(1) 71.69(18) C(15)#1-N(3)-Li(2) 111.4(2) C(3)-C(2)-C(1) 124.5(3) C(15)-N(3)-Li(2) 111.4(2) C(4)-C(3)-C(2) 119.3(3) C(12)-N(3)-Li(2) 106.3(7) C(5)-C(4)-C(3) 119.5(3) C(12)#1-N(3)-Li(2) 106.3(7) C(4)-C(5)-C(6) 122.2(3) C(14)#1-N(4)-C(14) 110.4(6) C(5)-C(6)-C(1) 120.9(2) C(14)#1-N(4)-C(13)#1 88.8(12) C(5)-C(6)-C(7) 114.2(2) C(14)-N(4)-C(13)#1 131.6(16) C(1)-C(6)-C(7) 124.9(2) C(14)#1-N(4)-C(13) 131.6(16) C(7)#1-C(7)-C(6) 139.70(12) C(14)-N(4)-C(13) 88.8(12) C(9)-C(8)-N(1) 114(2) C(13)#1-N(4)-C(13) 49(3) C(8)-C(9)-N(2) 109.1(16) C(14)#1-N(4)-C(13')#1 108.0(8) C(9')-C(8')-N(1) 110(2) C(14)-N(4)-C(13')#1 108.0(7) C(8')-C(9')-N(2) 111(2) C(13)#1-N(4)-C(13')#1 25.2(17) C(13)-C(12)-N(3) 111.7(15) C(13)-N(4)-C(13')#1 25.2(17) C(12)-C(13)-N(4) 115.9(19) C(14)#1-N(4)-C(13') 108.0(8) N(3)-C(12')-C(13') 112(3) C(14)-N(4)-C(13') 108.0(7) N(3)-C(12')-Li(2) 49.7(10) C(13)#1-N(4)-C(13') 25.2(17) C(13')-C(12')-Li(2) 81.6(18) C(12')-C(13')-N(4) 110(2)

251

Structural Data for [(spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17).

Table 49. Crystal data and structural refinement for [(spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17).

Empirical formula C32H30GaLiO Formula weight 507.22 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, P2(1)/n Unit cell dimensions a = 11.141(2) Å b = 29.107(5) Å c = 16.640(3) Å = 90° = 90.551(3)° = 90° Volume 5396.0(17) Å3 Z, Calculated density 8, 1.249 Mg/m3 Absorption coefficient 1.041 mm-1 F(000) 2112 Crystal size 0.20 x 0.16 x 0.08 mm Theta range for data collection 1.86 to 25.00 deg. Limiting indices -13<=h<=13, -34<=k<=34, -19<=l<=19 Reflections collected / unique 57574 / 9498 [R(int) = 0.1282] Completeness to theta = 25.00 100.00% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9213 and 0.8188 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 9498 / 160 / 705 Goodness-of-fit on F^2 1.037 Final R indices [I>2sigma(I)] R1 = 0.0461, wR2 = 0.0693 R indices (all data) R1 = 0.1216, wR2 = 0.0893 Largest diff. peak and hole 0.222 and -0.219 eÅ-3

252

Table 50. Bond Lengths [Å] for [(spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17). Atoms Distance Atoms Distance Ga(1)-C(1) 1.972(4) C(16)-C(17) 1.388(5) Ga(1)-C(15) 1.987(4) C(17)-C(18) 1.370(6) Ga(1)-C(10) 2.022(4) C(18)-C(19) 1.350(6) Ga(1)-C(24) 2.030(4) C(19)-C(20) 1.410(6) Ga(1)-Li(1) 2.722(9) C(20)-C(21) 1.472(6) Ga(2)-C(47) 1.968(4) C(21)-C(22) 1.351(6) Ga(2)-C(33) 1.968(4) C(22)-C(23) 1.464(6) Ga(2)-C(56) 2.013(4) C(23)-C(24) 1.405(5) Ga(2)-C(42) 2.020(4) C(23)-C(28) 1.411(6) Ga(2)-Li(2) 2.775(8) C(24)-C(25) 1.395(5) Li(1)-O(1) 1.849(10) C(25)-C(26) 1.388(6) Li(1)-C(24) 2.294(9) C(26)-C(27) 1.375(6) Li(1)-C(10) 2.368(10) C(27)-C(28) 1.360(6) Li(1)-C(9) 2.488(9) O(1)-C(30') 1.305(17) Li(1)-C(8) 2.586(11) O(1)-C(31') 1.41(2) Li(1)-C(23) 2.638(10) O(1)-C(31) 1.588(18) Li(2)-O(2) 1.815(9) O(1)-C(30) 1.590(17) Li(2)-C(56) 2.305(9) C(29)-C(30) 1.30(3) Li(2)-C(42) 2.305(9) C(31)-C(32) 1.58(2) Li(2)-C(55) 2.568(9) C(29')-C(30') 1.47(3) Li(2)-C(41) 2.543(9) C(31')-C(32') 1.38(4) C(1)-C(6) 1.412(5) C(33)-C(38) 1.400(6) C(1)-C(2) 1.400(5) C(33)-C(34) 1.400(6) C(2)-C(3) 1.382(5) C(34)-C(35) 1.395(7) C(3)-C(4) 1.367(5) C(35)-C(36) 1.367(8) C(4)-C(5) 1.364(5) C(36)-C(37) 1.347(8) C(5)-C(6) 1.401(5) C(37)-C(38) 1.415(7) C(6)-C(7) 1.469(5) C(38)-C(39) 1.470(7) C(7)-C(8) 1.339(5) C(39)-C(40) 1.351(7) C(8)-C(9) 1.467(5) C(40)-C(41) 1.446(7) C(9)-C(10) 1.405(5) C(41)-C(42) 1.392(6) C(9)-C(14) 1.414(5) C(41)-C(46) 1.422(7) C(10)-C(11) 1.401(5) C(42)-C(43) 1.395(5) C(11)-C(12) 1.379(5) C(43)-C(44) 1.374(6) C(12)-C(13) 1.374(6) C(44)-C(45) 1.363(8) C(13)-C(14) 1.357(6) C(45)-C(46) 1.352(8) C(15)-C(20) 1.403(5) C(47)-C(48) 1.387(5) C(15)-C(16) 1.392(5) C(47)-C(52) 1.409(5)

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Table 50 (Cont.). Bond Lengths [Å] for [(spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17). Atoms Distance Atoms Distance C(48)-C(49) 1.386(6) C(57)-C(58) 1.383(5) C(49)-C(50) 1.374(7) C(58)-C(59) 1.373(6) C(50)-C(51) 1.373(6) C(59)-C(60) 1.365(6) C(51)-C(52) 1.404(5) O(2)-C(62') 1.31(2) C(52)-C(53) 1.466(5) O(2)-C(63) 1.594(17) C(53)-C(54) 1.341(5) O(2)-C(63') 1.35(3) C(54)-C(55) 1.469(5) O(2)-C(62) 1.581(17) C(55)-C(56) 1.408(5) C(61)-C(62) 1.404(19) C(55)-C(60) 1.404(5) C(63)-C(64) 1.44(8) C(56)-C(57) 1.390(5) C(61')-C(62') 1.50(2) C(63')-C(64') 1.50(8)

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Table 51. Bond angles [°] for [(spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17). Atoms Angle Atoms Angle C(1)-Ga(1)-C(15) 120.79(17) C(9)-Li(1)-Ga(1) 71.1(2) C(1)-Ga(1)-C(10) 105.97(15) C(8)-Li(1)-Ga(1) 79.0(3) C(15)-Ga(1)-C(10) 106.37(16) C(23)-Li(1)-Ga(1) 68.6(2) C(1)-Ga(1)-C(24) 105.06(16) O(2)-Li(2)-C(56) 133.1(5) C(15)-Ga(1)-C(24) 106.20(16) O(2)-Li(2)-C(42) 135.7(5) C(10)-Ga(1)-C(24) 112.63(16) C(56)-Li(2)-C(42) 91.1(3) C(1)-Ga(1)-Li(1) 112.3(3) O(2)-Li(2)-C(55) 110.1(4) C(15)-Ga(1)-Li(1) 126.9(3) C(56)-Li(2)-C(55) 33.05(17) C(10)-Ga(1)-Li(1) 57.7(2) C(42)-Li(2)-C(55) 107.7(4) C(24)-Ga(1)-Li(1) 55.5(2) O(2)-Li(2)-C(41) 111.6(4) C(47)-Ga(2)-C(33) 117.54(19) C(56)-Li(2)-C(41) 112.0(4) C(47)-Ga(2)-C(56) 106.96(16) C(42)-Li(2)-C(41) 32.92(18) C(33)-Ga(2)-C(56) 108.15(16) C(55)-Li(2)-C(41) 137.9(4) C(47)-Ga(2)-C(42) 106.01(18) O(2)-Li(2)-Ga(2) 178.4(6) C(33)-Ga(2)-C(42) 108.64(19) C(56)-Li(2)-Ga(2) 45.54(18) C(56)-Ga(2)-C(42) 109.33(15) C(42)-Li(2)-Ga(2) 45.70(18) C(47)-Ga(2)-Li(2) 123.7(3) C(55)-Li(2)-Ga(2) 69.1(2) C(33)-Ga(2)-Li(2) 118.8(3) C(41)-Li(2)-Ga(2) 69.4(2) C(56)-Ga(2)-Li(2) 54.8(2) C(6)-C(1)-C(2) 115.7(4) C(42)-Ga(2)-Li(2) 54.8(2) C(6)-C(1)-Ga(1) 120.6(3) O(1)-Li(1)-C(24) 131.5(5) C(2)-C(1)-Ga(1) 123.3(3) O(1)-Li(1)-C(10) 127.4(5) C(3)-C(2)-C(1) 123.5(4) C(24)-Li(1)-C(10) 92.6(3) C(4)-C(3)-C(2) 119.4(4) O(1)-Li(1)-C(9) 112.6(4) C(5)-C(4)-C(3) 119.8(4) C(24)-Li(1)-C(9) 115.7(4) C(4)-C(5)-C(6) 121.5(4) C(10)-Li(1)-C(9) 33.52(16) C(1)-C(6)-C(5) 120.1(4) O(1)-Li(1)-C(8) 114.6(5) C(1)-C(6)-C(7) 125.8(4) C(24)-Li(1)-C(8) 108.1(4) C(5)-C(6)-C(7) 114.1(4) C(10)-Li(1)-C(8) 61.3(2) C(8)-C(7)-C(6) 135.7(4) C(9)-Li(1)-C(8) 33.54(17) C(7)-C(8)-C(9) 132.5(4) O(1)-Li(1)-C(23) 102.7(4) C(7)-C(8)-Li(1) 105.5(4) C(24)-Li(1)-C(23) 32.16(17) C(9)-C(8)-Li(1) 69.6(3) C(10)-Li(1)-C(23) 106.5(4) C(10)-C(9)-C(14) 119.9(4) C(9)-Li(1)-C(23) 138.5(4) C(10)-C(9)-C(8) 123.7(4) C(8)-Li(1)-C(23) 140.2(4) C(14)-C(9)-C(8) 116.3(4) O(1)-Li(1)-Ga(1) 161.3(6) C(10)-C(9)-Li(1) 68.5(3) C(24)-Li(1)-Ga(1) 46.79(19) C(14)-C(9)-Li(1) 125.8(4) C(10)-Li(1)-Ga(1) 46.16(18) C(8)-C(9)-Li(1) 76.9(4)

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Table 51 (con’t.). Bond angles [°] for [(spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17). Atoms Angle Atoms Angle C(9)-C(10)-C(11) 116.1(4) C(30')-O(1)-C(31') 106.1(18) C(9)-C(10)-Ga(1) 123.6(3) C(30')-O(1)-C(31) 85.3(15) C(11)-C(10)-Ga(1) 119.9(3) C(31')-O(1)-C(31) 42.4(11) C(9)-C(10)-Li(1) 77.9(3) C(30')-O(1)-C(30) 23.8(18) C(11)-C(10)-Li(1) 124.1(4) C(31')-O(1)-C(30) 130.0(16) Ga(1)-C(10)-Li(1) 76.2(2) C(31)-O(1)-C(30) 103.7(13) C(12)-C(11)-C(10) 123.3(4) C(30')-O(1)-Li(1) 136.4(14) C(11)-C(12)-C(13) 119.3(4) C(31')-O(1)-Li(1) 116.7(13) C(14)-C(13)-C(12) 120.0(5) C(31)-O(1)-Li(1) 132.1(12) C(13)-C(14)-C(9) 121.4(4) C(30)-O(1)-Li(1) 113.0(10) C(20)-C(15)-C(16) 116.5(4) C(29)-C(30)-O(1) 115(3) C(20)-C(15)-Ga(1) 121.1(3) C(32)-C(31)-O(1) 99.0(18) C(16)-C(15)-Ga(1) 122.1(3) O(1)-C(30')-C(29') 104(2) C(17)-C(16)-C(15) 122.6(4) O(1)-C(31')-C(32') 111(3) C(18)-C(17)-C(16) 119.8(5) C(38)-C(33)-C(34) 116.4(5) C(19)-C(18)-C(17) 119.5(5) C(38)-C(33)-Ga(2) 122.7(4) C(18)-C(19)-C(20) 121.8(5) C(34)-C(33)-Ga(2) 120.8(4) C(19)-C(20)-C(15) 119.8(5) C(33)-C(34)-C(35) 123.2(6) C(19)-C(20)-C(21) 115.0(4) C(36)-C(35)-C(34) 118.7(7) C(15)-C(20)-C(21) 125.1(4) C(37)-C(36)-C(35) 120.2(7) C(22)-C(21)-C(20) 135.6(4) C(36)-C(37)-C(38) 122.0(7) C(21)-C(22)-C(23) 132.5(5) C(33)-C(38)-C(37) 119.4(6) C(24)-C(23)-C(28) 119.7(4) C(33)-C(38)-C(39) 125.6(5) C(24)-C(23)-C(22) 124.3(4) C(37)-C(38)-C(39) 114.9(6) C(28)-C(23)-C(22) 115.9(4) C(40)-C(39)-C(38) 135.8(6) C(24)-C(23)-Li(1) 60.3(3) C(39)-C(40)-C(41) 135.7(6) C(28)-C(23)-Li(1) 119.7(4) C(42)-C(41)-C(46) 119.8(5) C(22)-C(23)-Li(1) 91.9(4) C(42)-C(41)-C(40) 124.3(5) C(25)-C(24)-C(23) 117.0(4) C(46)-C(41)-C(40) 115.9(6) C(25)-C(24)-Ga(1) 120.5(3) C(42)-C(41)-Li(2) 64.1(3) C(23)-C(24)-Ga(1) 122.2(3) C(46)-C(41)-Li(2) 116.7(4) C(25)-C(24)-Li(1) 111.1(4) C(40)-C(41)-Li(2) 89.9(4) C(23)-C(24)-Li(1) 87.5(4) C(41)-C(42)-C(43) 115.8(4) Ga(1)-C(24)-Li(1) 77.7(3) C(41)-C(42)-Ga(2) 124.3(4) C(24)-C(25)-C(26) 122.0(4) C(43)-C(42)-Ga(2) 119.8(3) C(27)-C(26)-C(25) 120.4(5) C(41)-C(42)-Li(2) 83.0(4) C(28)-C(27)-C(26) 119.2(5) C(43)-C(42)-Li(2) 110.2(4) C(27)-C(28)-C(23) 121.6(5) Ga(2)-C(42)-Li(2) 79.5(2)

256

Table 51 (cont.). Bond angles [°] for [(spiro-[6,6]-bis-stilbenylgallium][Li(OEt2)] (17). Atoms Angle Atoms Angle C(44)-C(43)-C(42) 124.3(5) C(57)-C(56)-Ga(2) 120.1(3) C(43)-C(44)-C(45) 118.4(6) C(55)-C(56)-Ga(2) 123.9(3) C(46)-C(45)-C(44) 120.8(7) C(57)-C(56)-Li(2) 109.8(4) C(45)-C(46)-C(41) 120.8(7) C(55)-C(56)-Li(2) 83.8(4) C(48)-C(47)-C(52) 116.8(4) Ga(2)-C(56)-Li(2) 79.7(2) C(48)-C(47)-Ga(2) 121.4(3) C(58)-C(57)-C(56) 123.5(4) C(52)-C(47)-Ga(2) 121.4(3) C(57)-C(58)-C(59) 119.3(4) C(47)-C(48)-C(49) 123.1(5) C(60)-C(59)-C(58) 119.9(5) C(50)-C(49)-C(48) 119.6(5) C(59)-C(60)-C(55) 120.9(4) C(49)-C(50)-C(51) 119.0(5) C(62')-O(2)-C(63) 104.0(14) C(50)-C(51)-C(52) 121.9(5) C(62')-O(2)-C(63') 110.4(18) C(47)-C(52)-C(51) 119.4(4) C(63)-O(2)-C(63') 40.2(13) C(47)-C(52)-C(53) 126.4(4) C(62')-O(2)-C(62) 44.7(11) C(51)-C(52)-C(53) 114.2(4) C(63)-O(2)-C(62) 124.3(15) C(54)-C(53)-C(52) 136.4(4) C(63')-O(2)-C(62) 99.9(13) C(53)-C(54)-C(55) 134.6(4) C(62')-O(2)-Li(2) 122.8(13) C(56)-C(55)-C(60) 120.4(4) C(63)-O(2)-Li(2) 117.6(12) C(56)-C(55)-C(54) 124.0(4) C(63')-O(2)-Li(2) 126.8(16) C(60)-C(55)-C(54) 115.6(4) C(62)-O(2)-Li(2) 118.1(11) C(56)-C(55)-Li(2) 63.2(3) C(61)-C(62)-O(2) 109(2) C(60)-C(55)-Li(2) 115.2(3) C(64)-C(63)-O(2) 108(3) C(54)-C(55)-Li(2) 93.2(4) O(2)-C(62')-C(61') 107(3) C(57)-C(56)-C(55) 115.9(4) C(64')-C(63')-O(2) 99(3)

257

Structural Data for bis(gallepin)2.TMEDA (18)

Table 52. Crystal data and structural refinement for bis(gallepin)2.TMEDA (18) Empirical formula C34 H36 Cl2 Ga2 N2 Formula weight 682.98 Temperature 273(2) K Wavelength 0.71073 A Crystal system, space group Monoclinic, C2/c Unit cell dimensions a = 26.8548(10) A b = 7.6807(3) A c = 16.9633(6) A alpha = 90 deg. beta = 113.4040(10) deg. gamma = 90 deg. Volume 3211.0(2) A^3 Z, Calculated density 4, 1.413 Mg/m^3 Absorption coefficient 1.870 mm^-1 F(000) 1400 Crystal size 0.25 x 0.14 x 0.09 mm Theta range for data collection 2.48 to 28.34 deg. -35<=h<=35, -10<=k<=10, - Limiting indices 22<=l<=22 Reflections collected / unique 21591 / 4018 [R(int) = 0.0301] Completeness to theta = 28.34 99.90% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.8498 and 0.6522 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 4018 / 18 / 209 Goodness-of-fit on F^2 1.012 Final R indices [I>2sigma(I)] R1 = 0.0261, wR2 = 0.0642 R indices (all data) R1 = 0.0371, wR2 = 0.0693 Largest diff. peak and hole 0.377 and -0.251 e.A^-3

258

Table 53. Bond Lengths [Å] for bis(gallepin)2.TMEDA (18) Atoms Distance Atoms Distance Ga(1)-C(1) 1.9476(17) C(9)-C(10) 1.410(3) Ga(1)-C(10) 1.9477(18) C(9)-C(14) 1.404(3) Ga(1)-N(1) 2.1158(15) C(10)-C(11) 1.394(2) Ga(1)-Cl(1) 2.2258(5) C(11)-C(12) 1.383(3) C(1)-C(6) 1.408(3) C(12)-C(13) 1.377(3) C(1)-C(2) 1.392(3) C(13)-C(14) 1.378(3) C(2)-C(3) 1.387(3) N(1)-C(16') 1.432(15) C(3)-C(4) 1.377(3) N(1)-C(17) 1.466(6) C(4)-C(5) 1.369(3) N(1)-C(15) 1.506(4) C(5)-C(6) 1.409(2) N(1)-C(15') 1.520(7) C(6)-C(7) 1.465(3) N(1)-C(16) 1.526(6) C(7)-C(8) 1.346(3) N(1)-C(17') 1.533(11) C(8)-C(9) 1.475(3) C(15)-C(15)#1 1.499(9) C(15')-C(15')#1 1.509(15)

259

Table 54. Bond angles [°] for bis(gallepin)2.TMEDA (18) Atoms Angle Atoms Angle C(1)-Ga(1)-C(10) 117.94(7) C(13)-C(12)-C(11) 119.28(19) C(1)-Ga(1)-N(1) 104.64(6) C(14)-C(13)-C(12) 119.7(2) C(10)-Ga(1)-N(1) 108.99(7) C(13)-C(14)-C(9) 121.9(2) C(1)-Ga(1)-Cl(1) 110.47(6) C(16')-N(1)-C(17) 125.4(6) C(10)-Ga(1)-Cl(1) 112.29(5) C(16')-N(1)-C(15) 80.5(4) N(1)-Ga(1)-Cl(1) 100.79(5) C(17)-N(1)-C(15) 112.7(3) C(6)-C(1)-C(2) 118.62(16) C(16')-N(1)-C(15') 112.5(5) C(6)-C(1)-Ga(1) 121.03(13) C(17)-N(1)-C(15') 81.1(3) C(2)-C(1)-Ga(1) 120.36(14) C(15)-N(1)-C(15') 35.6(3) C(3)-C(2)-C(1) 121.8(2) C(16')-N(1)-C(16) 24.8(5) C(2)-C(3)-C(4) 119.6(2) C(17)-N(1)-C(16) 108.5(4) C(5)-C(4)-C(3) 119.89(18) C(15)-N(1)-C(16) 104.2(3) C(4)-C(5)-C(6) 121.82(19) C(15')-N(1)-C(16) 132.3(4) C(1)-C(6)-C(5) 118.28(17) C(16')-N(1)-C(17') 110.8(8) C(1)-C(6)-C(7) 126.15(16) C(17)-N(1)-C(17') 23.9(4) C(5)-C(6)-C(7) 115.53(17) C(15)-N(1)-C(17') 133.2(4) C(8)-C(7)-C(6) 137.45(17) C(15')-N(1)-C(17') 104.6(5) C(7)-C(8)-C(9) 137.93(18) C(16)-N(1)-C(17') 89.2(6) C(10)-C(9)-C(14) 118.25(18) C(16')-N(1)-Ga(1) 109.1(5) C(10)-C(9)-C(8) 126.41(17) C(17)-N(1)-Ga(1) 111.7(3) C(14)-C(9)-C(8) 115.34(18) C(15)-N(1)-Ga(1) 114.03(18) C(11)-C(10)-C(9) 118.31(17) C(15')-N(1)-Ga(1) 114.5(3) C(11)-C(10)-Ga(1) 121.60(14) C(16)-N(1)-Ga(1) 104.9(2) C(9)-C(10)-Ga(1) 120.09(13) C(17')-N(1)-Ga(1) 104.9(4) C(12)-C(11)-C(10) 122.33(19) N(1)-C(15)-C(15)#1 112.9(5)

260

Structural Data for MesGaCl2(:L) (19)

Table 55. Crystal data and structural refinement for MesGaCl2(:L) (19)

Empirical formula C20H31Cl2GaN2 Formula weight 440.09 Temperature 273(2) K Wavelength 0.71073 A Crystal system, space group Triclinic, P-1 Unit cell dimensions a = 8.9728(6) Å b = 9.1409(7) Å c = 31.088(2) Å = 87.0230(10)° = 85.2090(10)° = 61.5030(10)° Volume 2232.9(3) Å3 Z, Calculated density 4, 1.309 Mg/m3 Absorption coefficient 1.477 mm-1 F(000) 920 Crystal size 0.45 x 0.42 x 0.15 mm Theta range for data collection 2.54 to 28.40 deg. Limiting indices -11<=h<=11, -12<=k<=12, -41<=l<=41 Reflections collected / unique 29671 / 11117 [R(int) = 0.0228] Completeness to theta = 28.40 99.30% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.8089 and 0.5562 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 11117 / 0 / 451 Goodness-of-fit on F^2 1.064 Final R indices [I>2sigma(I)] R1 = 0.0373, wR2 = 0.0992 R indices (all data) R1 = 0.0449, wR2 = 0.1031 Largest diff. peak and hole 0.468 and -0.777 e.A-3

261

Table 56. Bond Lengths [Å] for MesGaCl2(:L) (19) Atoms Distance Atoms Distance Ga(1)-C(1) 1.978(2) C(4)-C(8) 1.512(4) Ga(1)-C(10) 2.048(2) C(5)-C(6) 1.395(3) Ga(1)-Cl(2) 2.2444(6) C(6)-C(7) 1.509(4) Ga(1)-Cl(1) 2.2468(6) C(11)-C(12) 1.350(3) Ga(2)-C(21) 1.981(2) C(11)-C(17) 1.495(3) Ga(2)-C(30) 2.043(2) C(12)-C(16) 1.496(3) Ga(2)-Cl(4) 2.2478(6) C(13)-C(14) 1.520(4) Ga(2)-Cl(3) 2.2449(6) C(13)-C(15) 1.523(4) N(1)-C(10) 1.350(3) C(18)-C(19) 1.519(4) N(1)-C(11) 1.393(3) C(18)-C(20) 1.532(4) N(1)-C(18) 1.484(3) C(21)-C(26) 1.402(3) N(2)-C(10) 1.350(3) C(21)-C(22) 1.415(3) N(2)-C(12) 1.390(3) C(22)-C(23) 1.399(3) N(2)-C(13) 1.484(3) C(22)-C(29) 1.510(3) N(3)-C(30) 1.350(3) C(23)-C(24) 1.377(4) N(3)-C(31) 1.392(3) C(24)-C(25) 1.377(4) N(3)-C(38) 1.482(3) C(24)-C(28) 1.507(4) N(4)-C(30) 1.355(3) C(25)-C(26) 1.402(3) N(4)-C(32) 1.389(3) C(26)-C(27) 1.515(4) N(4)-C(33) 1.491(3) C(31)-C(32) 1.350(4) C(1)-C(2) 1.411(3) C(31)-C(37) 1.500(3) C(1)-C(6) 1.411(3) C(32)-C(36) 1.494(4) C(2)-C(3) 1.393(3) C(33)-C(34) 1.521(4) C(2)-C(9) 1.514(3) C(33)-C(35) 1.530(4) C(3)-C(4) 1.389(4) C(38)-C(40) 1.529(4) C(4)-C(5) 1.375(4) C(38)-C(39) 1.521(4)

262

Table 57. Bond Angles [°] for MesGaCl2(:L) (19) Atoms Angle Atoms Angle C(1)-Ga(1)-C(10) 119.14(9) C(12)-C(11)-N(1) 106.67(19) C(1)-Ga(1)-Cl(2) 114.96(7) C(12)-C(11)-C(17) 127.8(2) C(10)-Ga(1)-Cl(2) 98.86(6) N(1)-C(11)-C(17) 125.4(2) C(1)-Ga(1)-Cl(1) 109.34(7) C(11)-C(12)-N(2) 106.84(19) C(10)-Ga(1)-Cl(1) 111.20(6) C(11)-C(12)-C(16) 127.5(2) Cl(2)-Ga(1)-Cl(1) 101.71(3) N(2)-C(12)-C(16) 125.6(2) C(21)-Ga(2)-C(30) 119.36(9) N(2)-C(13)-C(14) 111.8(2) C(21)-Ga(2)-Cl(4) 108.49(7) N(2)-C(13)-C(15) 111.0(2) C(30)-Ga(2)-Cl(4) 111.46(6) C(14)-C(13)-C(15) 113.7(2) C(21)-Ga(2)-Cl(3) 115.93(7) N(1)-C(18)-C(19) 112.0(2) C(30)-Ga(2)-Cl(3) 97.85(6) N(1)-C(18)-C(20) 111.1(2) Cl(4)-Ga(2)-Cl(3) 102.26(3) C(19)-C(18)-C(20) 113.5(3) C(10)-N(1)-C(11) 110.34(18) C(26)-C(21)-C(22) 117.9(2) C(10)-N(1)-C(18) 122.96(18) C(26)-C(21)-Ga(2) 121.76(17) C(11)-N(1)-C(18) 126.55(19) C(22)-C(21)-Ga(2) 120.27(17) C(10)-N(2)-C(12) 110.37(18) C(23)-C(22)-C(21) 119.4(2) C(10)-N(2)-C(13) 122.68(18) C(23)-C(22)-C(29) 118.3(2) C(12)-N(2)-C(13) 126.82(18) C(21)-C(22)-C(29) 122.2(2) C(30)-N(3)-C(31) 110.20(19) C(24)-C(23)-C(22) 122.5(2) C(30)-N(3)-C(38) 122.65(19) C(25)-C(24)-C(23) 118.1(2) C(31)-N(3)-C(38) 126.93(19) C(25)-C(24)-C(28) 120.3(3) C(30)-N(4)-C(32) 110.06(19) C(23)-C(24)-C(28) 121.6(3) C(30)-N(4)-C(33) 123.0(2) C(24)-C(25)-C(26) 121.5(2) C(32)-N(4)-C(33) 126.8(2) C(21)-C(26)-C(25) 120.5(2) C(2)-C(1)-C(6) 117.5(2) C(21)-C(26)-C(27) 122.5(2) C(2)-C(1)-Ga(1) 120.59(16) C(25)-C(26)-C(27) 116.9(2) C(6)-C(1)-Ga(1) 121.86(17) N(3)-C(30)-N(4) 105.90(18) C(3)-C(2)-C(1) 120.3(2) N(3)-C(30)-Ga(2) 129.53(16) C(3)-C(2)-C(9) 117.1(2) N(4)-C(30)-Ga(2) 123.81(15) C(1)-C(2)-C(9) 122.5(2) C(32)-C(31)-N(3) 106.81(19) C(2)-C(3)-C(4) 121.8(2) C(32)-C(31)-C(37) 127.9(2) C(3)-C(4)-C(5) 117.9(2) N(3)-C(31)-C(37) 125.1(2) C(3)-C(4)-C(8) 121.0(2) C(31)-C(32)-N(4) 107.0(2) C(5)-C(4)-C(8) 121.0(2) C(31)-C(32)-C(36) 127.9(2) C(4)-C(5)-C(6) 122.0(2) N(4)-C(32)-C(36) 125.0(2) C(5)-C(6)-C(1) 120.4(2) N(4)-C(33)-C(34) 112.0(2) C(5)-C(6)-C(7) 117.3(2) N(4)-C(33)-C(35) 110.7(2)

263

Table 57 (con’t). Bond Angles [°] for MesGaCl2(:L) (19) Atoms Angle Atoms Angle C(1)-C(6)-C(7) 122.3(2) C(34)-C(33)-C(35) 113.5(3) N(2)-C(10)-N(1) 105.76(18) N(3)-C(38)-C(40) 111.4(2) N(2)-C(10)-Ga(1) 129.87(15) N(3)-C(38)-C(39) 112.1(2) N(1)-C(10)-Ga(1) 123.91(14) C(40)-C(38)-C(39) 113.6(2)

264

Structural Data for MesAlBr2(:L) (20)

Table 58. Crystal data and structural refinement for MesAlBr2(:L) (20) Empirical formula C20H31AlBr2N2 Formula weight 486.27 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, C2/c Unit cell dimensions a = 20.0676(11) Å b = 13.2261(7) Å c = 19.3315(16) Å = 90° = 114.2240(10)° = 90° Volume 4679.1(5) Å3 Z, Calculated density 8, 1.381 Mg/m3 Absorption coefficient 3.508 mm-1 F(000) 1984 Crystal size 0.43 x 0.30 x 0.10 mm Theta range for data collection 2.23 to 25.00 deg. Limiting indices -23<=h<=23, -15<=k<=15, -22<=l<=22 Reflections collected / unique 23975 / 4128 [R(int) = 0.0353] Completeness to theta = 25.00 100.00% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.7205 and 0.3139 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 4128 / 0 / 226 Goodness-of-fit on F^2 1.032 Final R indices [I>2sigma(I)] R1 = 0.0361, wR2 = 0.0867 R indices (all data) R1 = 0.0487, wR2 = 0.0952 Largest diff. peak and hole 0.859 and -0.926 e.Å-3

265

Table 59. Bond Lengths [Å] for MesAlBr2(:L) (20) Atoms Distance Atoms Distance Al(1)-C(1) 1.989(3) C(2)-C(9) 1.513(5) Al(1)-C(10) 2.050(3) C(3)-C(4) 1.379(5) Al(1)-Br(1) 2.3364(10) C(4)-C(5) 1.376(5) Al(1)-Br(2) 2.3373(10) C(4)-C(8) 1.518(5) N(1)-C(10) 1.358(4) C(5)-C(6) 1.391(5) N(1)-C(11) 1.386(4) C(6)-C(7) 1.521(5) N(1)-C(18) 1.483(4) C(11)-C(12) 1.347(5) N(2)-C(10) 1.357(4) C(11)-C(17) 1.499(5) N(2)-C(12) 1.390(4) C(12)-C(16) 1.500(4) N(2)-C(13) 1.479(4) C(13)-C(14) 1.516(6) C(1)-C(2) 1.413(4) C(13)-C(15) 1.531(6) C(1)-C(6) 1.418(5) C(18)-C(19) 1.514(5) C(2)-C(3) 1.389(5) C(18)-C(20) 1.524(5)

266

Table 60. Bond Angles [°] for MesAlBr2(:L) (20) Atoms Angle Atoms Angle C(1)-Al(1)-C(10) 111.10(13) C(5)-C(4)-C(8) 121.2(4) C(1)-Al(1)-Br(1) 109.43(9) C(3)-C(4)-C(8) 121.3(4) C(10)-Al(1)-Br(1) 114.61(9) C(4)-C(5)-C(6) 122.0(3) C(1)-Al(1)-Br(2) 119.11(10) C(5)-C(6)-C(1) 121.2(3) C(10)-Al(1)-Br(2) 97.78(9) C(5)-C(6)-C(7) 117.6(3) Br(1)-Al(1)-Br(2) 104.53(4) C(1)-C(6)-C(7) 121.2(3) C(10)-N(1)-C(11) 110.8(2) N(2)-C(10)-N(1) 105.0(2) C(10)-N(1)-C(18) 122.6(2) N(2)-C(10)-Al(1) 133.0(2) C(11)-N(1)-C(18) 126.5(3) N(1)-C(10)-Al(1) 121.9(2) C(10)-N(2)-C(12) 110.4(2) C(12)-C(11)-N(1) 106.7(3) C(10)-N(2)-C(13) 123.3(3) C(12)-C(11)-C(17) 127.4(3) C(12)-N(2)-C(13) 126.2(3) N(1)-C(11)-C(17) 125.8(3) C(2)-C(1)-C(6) 115.9(3) C(11)-C(12)-N(2) 107.1(3) C(2)-C(1)-Al(1) 125.7(2) C(11)-C(12)-C(16) 127.2(3) C(6)-C(1)-Al(1) 118.4(2) N(2)-C(12)-C(16) 125.6(3) C(3)-C(2)-C(1) 121.1(3) N(2)-C(13)-C(14) 111.9(3) C(3)-C(2)-C(9) 117.1(3) N(2)-C(13)-C(15) 111.3(4) C(1)-C(2)-C(9) 121.7(3) C(14)-C(13)-C(15) 113.3(3) C(4)-C(3)-C(2) 122.3(3) N(1)-C(18)-C(19) 111.2(3) C(5)-C(4)-C(3) 117.4(3) N(1)-C(18)-C(20) 111.3(3) C(19)-C(18)-C(20) 114.3(3)

267

Structural Data for [MesInBr2(:L)][InBr3(:L)] (21)

Table 61. Crystal data and structural refinement for [MesInBr2(:L)][InBr3(:L)] (21)

Empirical formula C31H51Br5In2N4 Formula weight 1108.95 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Triclinic, P-1 Unit cell dimensions a = 9.6832(15) Å b = 10.9013(17) Å c = 20.164(3) Å = 95.520(3)° = 99.865(3)° = 95.363(3)° Volume 2074.2(6) A3 Z, Calculated density 2, 1.776 Mg/m3 Absorption coefficient 5.952 mm-1 F(000) 1076 Crystal size 0.17 x 0.11 x 0.04 mm Theta range for data collection 2.25 to 25.00 deg. Limiting indices -11<=h<=11, -12<=k<=12, -23<=l<=23 Reflections collected / unique 16339 / 7294 [R(int) = 0.0894] Completeness to theta = 25.00 99.80% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.7967 and 0.4310 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 7294 / 0 / 379 Goodness-of-fit on F^2 1 Final R indices [I>2sigma(I)] R1 = 0.0581, wR2 = 0.1209 R indices (all data) R1 = 0.1541, wR2 = 0.1522 Largest diff. peak and hole 1.303 and -0.926 e.A-3

268

Table 62. Bond Lengths [Å] for [MesInBr2(:L)][InBr3(:L)] ,(21) Atoms Angle Atoms Angle In(1)-C(12) 2.170(13) C(14)-C(15) 1.429(18) In(1)-C(1) 2.224(10) C(15)-C(16) 1.349(18) In(1)-Br(2) 2.5365(16) C(15)-C(19) 1.494(17) In(1)-Br(1) 2.5630(17) C(16)-C(17) 1.392(17) N(1)-C(1) 1.332(13) C(17)-C(18) 1.520(17) N(1)-C(2) 1.397(13) In(2)-C(21) 2.175(10) N(1)-C(9) 1.504(13) In(2)-Br(4) 2.4847(17) N(2)-C(1) 1.333(13) In(2)-Br(5) 2.4928(18) N(2)-C(3) 1.391(13) In(2)-Br(3) 2.4966(16) N(2)-C(4) 1.477(14) N(3)-C(21) 1.344(12) C(2)-C(3) 1.332(16) N(3)-C(22) 1.397(12) C(2)-C(8) 1.511(16) N(3)-C(29) 1.479(13) C(3)-C(7) 1.496(16) N(4)-C(21) 1.360(12) C(4)-C(5) 1.480(16) N(4)-C(23) 1.400(13) C(4)-C(6) 1.538(16) N(4)-C(24) 1.464(13) C(9)-C(11) 1.499(15) C(22)-C(23) 1.321(14) C(9)-C(10) 1.536(15) C(22)-C(28) 1.502(14) C(12)-C(13) 1.385(16) C(23)-C(27) 1.498(15) C(12)-C(17) 1.427(16) C(24)-C(25) 1.512(16) C(13)-C(20) 1.307(17) C(24)-C(26) 1.528(17) C(13)-C(14) 1.472(18) C(29)-C(31) 1.497(18) C(29)-C(30) 1.535(16)

269

Table 63. Bond Angles [°] for [MesInBr2(:L)][InBr3(:L)] (21) Atoms Angle Atoms Angle C(12)-In(1)-C(1) 119.1(4) C(16)-C(15)-C(14) 115.6(13) C(12)-In(1)-Br(2) 119.0(3) C(16)-C(15)-C(19) 124.5(14) C(1)-In(1)-Br(2) 102.0(3) C(14)-C(15)-C(19) 119.7(14) C(12)-In(1)-Br(1) 109.9(3) C(15)-C(16)-C(17) 123.6(14) C(1)-In(1)-Br(1) 102.8(3) C(16)-C(17)-C(12) 120.3(13) Br(2)-In(1)-Br(1) 101.66(6) C(16)-C(17)-C(18) 117.2(13) C(1)-N(1)-C(2) 109.0(10) C(12)-C(17)-C(18) 122.6(12) C(1)-N(1)-C(9) 124.6(9) C(21)-In(2)-Br(4) 115.3(3) C(2)-N(1)-C(9) 126.4(10) C(21)-In(2)-Br(5) 110.2(3) C(1)-N(2)-C(3) 109.9(10) Br(4)-In(2)-Br(5) 107.08(7) C(1)-N(2)-C(4) 122.8(9) C(21)-In(2)-Br(3) 109.2(3) C(3)-N(2)-C(4) 127.3(11) Br(4)-In(2)-Br(3) 108.74(6) N(1)-C(1)-N(2) 107.2(9) Br(5)-In(2)-Br(3) 106.02(6) N(1)-C(1)-In(1) 125.6(8) C(21)-N(3)-C(22) 110.4(9) N(2)-C(1)-In(1) 127.1(8) C(21)-N(3)-C(29) 122.4(9) C(3)-C(2)-N(1) 107.5(10) C(22)-N(3)-C(29) 127.1(9) C(3)-C(2)-C(8) 126.7(12) C(21)-N(4)-C(23) 109.6(9) N(1)-C(2)-C(8) 125.8(12) C(21)-N(4)-C(24) 122.3(9) C(2)-C(3)-N(2) 106.4(10) C(23)-N(4)-C(24) 128.1(9) C(2)-C(3)-C(7) 127.9(12) N(3)-C(21)-N(4) 105.5(9) N(2)-C(3)-C(7) 125.5(13) N(3)-C(21)-In(2) 130.6(8) N(2)-C(4)-C(5) 114.3(11) N(4)-C(21)-In(2) 124.0(7) N(2)-C(4)-C(6) 110.7(10) C(23)-C(22)-N(3) 107.1(9) C(5)-C(4)-C(6) 112.3(12) C(23)-C(22)-C(28) 127.7(10) C(11)-C(9)-N(1) 112.7(10) N(3)-C(22)-C(28) 125.1(10) C(11)-C(9)-C(10) 112.6(11) C(22)-C(23)-N(4) 107.4(9) N(1)-C(9)-C(10) 110.9(9) C(22)-C(23)-C(27) 128.4(12) C(13)-C(12)-C(17) 121.1(13) N(4)-C(23)-C(27) 124.2(11) C(13)-C(12)-In(1) 120.5(10) N(4)-C(24)-C(25) 112.5(11) C(17)-C(12)-In(1) 118.4(10) N(4)-C(24)-C(26) 110.1(10) C(20)-C(13)-C(12) 121.5(16) C(25)-C(24)-C(26) 115.4(12) C(20)-C(13)-C(14) 123.7(14) N(3)-C(29)-C(31) 111.9(11) C(12)-C(13)-C(14) 114.6(13) N(3)-C(29)-C(30) 111.7(11) C(15)-C(14)-C(13) 124.5(13) C(31)-C(29)-C(30) 114.7(11)

270

Structural Data for [MesGaCl(:L)]2 (22)

Table 64. Crystal data and structural refinement for [MesGaCl(:L)]2 (22) Empirical formula C40H62Cl2Ga2N4 Formula weight 809.28 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, P2(1)/c Unit cell dimensions a = 15.0926(19) Å c = 20.160(3) Å b = 14.3561(19) Å = 90° = 103.844(2)° = 90° Volume 4241.2(9) A3 Z, Calculated density 4, 1.267 Mg/m3 F(000) 1704 Crystal size 0.14 x 0.11 x 0.05 mm Theta range for data collection 2.08 to 25.00 deg. Limiting indices -17<=h<=17, -17<=k<=17, -23<=l<=23 Reflections collected / unique 44092 / 7454 [R(int) = 0.1737] Completeness to theta = 25.00 100.00% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9321 and 0.8252 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 7454 / 0 / 433 Goodness-of-fit on F^2 1.025 Final R indices [I>2sigma(I)] R1 = 0.0570, wR2 = 0.1235 R indices (all data) R1 = 0.1683, wR2 = 0.1766 Largest diff. peak and hole 0.524 and -0.585 e.Å-3

271

Table 65. Bond Distances [Å] for [MesGaCl(:L)]2 (22) Atoms Distance Atoms Distance Ga(1)-C(12) 2.028(7) C(9)-C(11) 1.523(10) Ga(1)-C(1) 2.101(7) C(12)-C(17) 1.391(10) Ga(1)-Cl(1) 2.300(2) C(12)-C(13) 1.414(10) Ga(1)-Ga(2) 2.4474(11) C(13)-C(14) 1.383(10) Ga(2)-C(32) 2.014(7) C(13)-C(20) 1.526(10) Ga(2)-C(21) 2.084(7) C(14)-C(15) 1.373(12) Ga(2)-Cl(2) 2.324(2) C(15)-C(16) 1.371(11) N(1)-C(1) 1.345(8) C(15)-C(19) 1.528(11) N(1)-C(2) 1.383(9) C(16)-C(17) 1.400(10) N(1)-C(9) 1.488(9) C(17)-C(18) 1.516(10) N(2)-C(1) 1.350(8) C(22)-C(23) 1.336(10) N(2)-C(3) 1.401(9) C(22)-C(28) 1.500(10) N(2)-C(4) 1.477(9) C(23)-C(27) 1.510(10) N(3)-C(21) 1.356(8) C(24)-C(25) 1.536(10) N(3)-C(22) 1.381(8) C(24)-C(26) 1.521(10) N(3)-C(29) 1.476(9) C(29)-C(31) 1.519(10) N(4)-C(21) 1.347(8) C(29)-C(30) 1.530(10) N(4)-C(23) 1.404(9) C(32)-C(33) 1.424(9) N(4)-C(24) 1.490(9) C(32)-C(37) 1.417(9) C(2)-C(3) 1.362(11) C(33)-C(34) 1.355(10) C(2)-C(8) 1.487(11) C(33)-C(40) 1.511(10) C(3)-C(7) 1.475(11) C(34)-C(35) 1.388(11) C(4)-C(6) 1.503(11) C(35)-C(36) 1.371(10) C(4)-C(5) 1.518(11) C(35)-C(39) 1.513(11) C(9)-C(10) 1.508(11) C(36)-C(37) 1.393(9) C(37)-C(38) 1.531(10)

272

Table 66. Bond Angles [°] for [MesGaCl(:L)]2 (22) Atoms Angle Atoms Angle C(12)-Ga(1)-C(1) 106.7(3) C(13)-C(12)-Ga(1) 121.2(6) C(12)-Ga(1)-Cl(1) 103.8(2) C(12)-C(13)-C(14) 120.9(8) C(1)-Ga(1)-Cl(1) 105.7(2) C(12)-C(13)-C(20) 122.5(7) C(12)-Ga(1)-Ga(2) 132.2(2) C(14)-C(13)-C(20) 116.5(7) C(1)-Ga(1)-Ga(2) 101.59(19) C(15)-C(14)-C(13) 122.1(8) Cl(1)-Ga(1)-Ga(2) 104.64(6) C(16)-C(15)-C(14) 117.9(8) C(32)-Ga(2)-C(21) 103.0(3) C(16)-C(15)-C(19) 121.1(9) C(32)-Ga(2)-Cl(2) 108.2(2) C(14)-C(15)-C(19) 121.0(9) C(21)-Ga(2)-Cl(2) 95.2(2) C(15)-C(16)-C(17) 121.5(8) C(32)-Ga(2)-Ga(1) 117.1(2) C(12)-C(17)-C(16) 121.3(7) C(21)-Ga(2)-Ga(1) 122.57(19) C(12)-C(17)-C(18) 122.1(7) Cl(2)-Ga(2)-Ga(1) 108.12(7) C(16)-C(17)-C(18) 116.7(7) C(1)-N(1)-C(2) 112.0(7) N(4)-C(21)-N(3) 104.6(6) C(1)-N(1)-C(9) 122.1(6) N(4)-C(21)-Ga(2) 125.0(5) C(2)-N(1)-C(9) 125.8(7) N(3)-C(21)-Ga(2) 130.4(5) C(1)-N(2)-C(3) 110.7(6) C(23)-C(22)-N(3) 106.7(7) C(1)-N(2)-C(4) 121.7(6) C(23)-C(22)-C(28) 127.3(7) C(3)-N(2)-C(4) 127.5(7) N(3)-C(22)-C(28) 125.9(7) C(21)-N(3)-C(22) 111.4(6) C(22)-C(23)-N(4) 106.8(6) C(21)-N(3)-C(29) 122.4(6) C(22)-C(23)-C(27) 128.5(8) C(22)-N(3)-C(29) 125.9(6) N(4)-C(23)-C(27) 124.7(7) C(21)-N(4)-C(23) 110.5(6) N(4)-C(24)-C(25) 111.3(7) C(21)-N(4)-C(24) 123.1(6) N(4)-C(24)-C(26) 111.1(6) C(23)-N(4)-C(24) 126.3(6) C(25)-C(24)-C(26) 113.6(7) N(2)-C(1)-N(1) 104.9(6) N(3)-C(29)-C(31) 112.3(6) N(2)-C(1)-Ga(1) 130.8(5) N(3)-C(29)-C(30) 112.9(6) N(1)-C(1)-Ga(1) 124.2(5) C(31)-C(29)-C(30) 111.8(7) C(3)-C(2)-N(1) 106.0(7) C(33)-C(32)-C(37) 115.7(7) C(3)-C(2)-C(8) 127.8(8) C(33)-C(32)-Ga(2) 124.3(6) N(1)-C(2)-C(8) 126.2(9) C(37)-C(32)-Ga(2) 119.8(5) C(2)-C(3)-N(2) 106.4(7) C(34)-C(33)-C(32) 120.8(8) C(2)-C(3)-C(7) 127.3(9) C(34)-C(33)-C(40) 118.7(7) N(2)-C(3)-C(7) 126.2(9) C(32)-C(33)-C(40) 120.4(7) N(2)-C(4)-C(6) 112.4(7) C(33)-C(34)-C(35) 122.9(8) N(2)-C(4)-C(5) 112.5(7) C(36)-C(35)-C(34) 117.4(7) C(6)-C(4)-C(5) 111.5(7) C(36)-C(35)-C(39) 120.2(9) N(1)-C(9)-C(10) 113.0(7) C(34)-C(35)-C(39) 122.4(8)

273

Table 66 con’t. Bond Angles [°] for [MesGaCl(:L)]2 (22) Atoms Angle Atoms Angle N(1)-C(9)-C(11) 112.4(7) C(35)-C(36)-C(37) 121.6(8) C(10)-C(9)-C(11) 112.1(7) C(36)-C(37)-C(32) 120.9(7) C(17)-C(12)-C(13) 116.4(7) C(36)-C(37)-C(38) 118.3(7) C(17)-C(12)-Ga(1) 122.4(6) C(32)-C(37)-C(38) 120.7(7)

274

Structural Data for Mes4Ga6(:L)2 (23)

Table 67. Crystal data and structural refinement for Mes4Ga6(:L)2 (23)

Empirical formula C72H100Ga6N4 Formula weight 1439.88 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Orthorhombic, Fddd Unit cell dimensions a = 19.6044(13) Å b = 22.9053(15) Å c = 32.804(2) Å = 90 = 90 deg.deg = 90 deg. Volume 14730.6(17) Å3 Z, Calculated density 8, 1.299 Mg/m3 Absorption coefficient 2.203 mm-1 F(000) 5968 Crystal size 0.13 x 0.11 x 0.05 mm Theta range for data collection 2.17 to 26.00 deg. Limiting indices -24<=h<=24, -28<=k<=28, -40<=l<=40 Reflections collected / unique 41534 / 3633 [R(int) = 0.1157] Completeness to theta = 26.00 100.00% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.8978 and 0.7627 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 3633 / 3 / 241 Goodness-of-fit on F^2 1.049 Final R indices [I>2sigma(I)] R1 = 0.0570, wR2 = 0.1483 R indices (all data) R1 = 0.1176, wR2 = 0.1814 Largest diff. peak and hole 0.491 and -0.383 e.Å-3

275

Table 68. Bond Distances [Å] for Mes4Ga6(:L)2 (23) Atoms Distance Atoms Distance Ga(1)-C(1) 1.966(11) C(8)-C(9) 1.38(3) Ga(1)-Ga(3) 2.5109(12) C(8)-C(13')#3 1.540(18) Ga(1)-Ga(3)#1 2.5109(12) C(9)-C(10) 1.36(3) Ga(1)-Ga(2)#2 2.5905(11) C(10)-C(11) 1.35(3) Ga(1)-Ga(2) 2.5905(11) C(10)-C(14) 1.54(2) Ga(2)-C(7) 1.955(11) C(11)-C(12) 1.44(2) Ga(2)-Ga(3) 2.5165(12) C(12)-C(13) 1.528(18) Ga(2)-Ga(3)#1 2.5165(12) C(13')-C(8)#3 1.540(18) Ga(2)-Ga(1)#2 2.5905(11) N(1)-C(15) 1.355(9) Ga(3)-C(15) 1.982(11) N(1)-C(16) 1.399(9) Ga(3)-Ga(1)#2 2.5109(12) N(1)-C(18) 1.481(10) Ga(3)-Ga(2)#2 2.5165(12) C(15)-N(1)#2 1.355(9) C(1)-C(2) 1.422(10) C(16)-C(16)#2 1.347(16) C(1)-C(2)#1 1.422(10) C(16)-C(17) 1.511(11) C(2)-C(3) 1.382(12) C(18)-C(19) 1.484(14) C(2)-C(6) 1.495(13) C(18)-C(20) 1.526(14) C(3)-C(4) 1.393(12) C(21)-C(22) 1.39 C(4)-C(3)#1 1.393(12) C(21)-C(26) 1.39 C(4)-C(5) 1.491(17) C(21)-C(27) 1.57(2) C(7)-C(8)#3 1.369(19) C(22)-C(23) 1.39 C(7)-C(8) 1.369(19) C(23)-C(24) 1.39 C(7)-C(12) 1.536(19) C(24)-C(25) 1.39 C(7)-C(12)#3 1.536(19) C(25)-C(26) 1.39

276

Table 69. Bond Angles [°] for Mes4Ga6(:L)2 (23) Atoms Angle Atoms Angle C(1)-Ga(1)-Ga(3) 136.72(3) C(8)-C(7)-Ga(2) 124.7(8) C(1)-Ga(1)-Ga(3)#1 136.72(3) C(12)-C(7)-Ga(2) 114.2(7) Ga(3)-Ga(1)-Ga(3)#1 86.56(5) C(12)#3-C(7)-Ga(2) 114.2(7) C(1)-Ga(1)-Ga(2)#2 134.88(3) C(7)-C(8)-C(9) 124.9(15) Ga(3)-Ga(1)-Ga(2)#2 59.09(3) C(7)-C(8)-C(13')#3 113(2) Ga(3)#1-Ga(1)-Ga(2)#2 59.09(3) C(9)-C(8)-C(13')#3 119(2) C(1)-Ga(1)-Ga(2) 134.88(3) C(7)-C(8)-C(13)#3 104.2(17) Ga(3)-Ga(1)-Ga(2) 59.09(3) C(9)-C(8)-C(13)#3 123.0(19) Ga(3)#1-Ga(1)-Ga(2) 59.09(3) C(10)-C(9)-C(8) 122.9(18) Ga(2)#2-Ga(1)-Ga(2) 90.24(5) C(10)-C(9)-C(12)#3 127.1(16) C(7)-Ga(2)-Ga(3) 136.84(3) C(9)-C(10)-C(11) 118.7(16) C(7)-Ga(2)-Ga(3)#1 136.84(3) C(9)-C(10)-C(14) 125(2) Ga(3)-Ga(2)-Ga(3)#1 86.32(5) C(11)-C(10)-C(14) 116(2) C(7)-Ga(2)-Ga(1)#2 135.12(3) C(11)-C(10)-C(24) 121(2) Ga(3)-Ga(2)-Ga(1)#2 58.88(3) C(10)-C(11)-C(12) 119.0(18) Ga(3)#1-Ga(2)-Ga(1)#2 58.88(3) C(10)-C(11)-C(8)#3 104.3(17) C(7)-Ga(2)-Ga(1) 135.12(3) C(13')-C(12)-C(11) 113(2) Ga(3)-Ga(2)-Ga(1) 58.88(3) C(11)-C(12)-C(13) 113(2) Ga(3)#1-Ga(2)-Ga(1) 58.88(3) C(13')-C(12)-C(7) 113(2) Ga(1)#2-Ga(2)-Ga(1) 89.76(5) C(11)-C(12)-C(7) 121.9(15) C(15)-Ga(3)-Ga(1)#2 133.28(3) C(13)-C(12)-C(7) 124.0(19) C(15)-Ga(3)-Ga(1) 133.28(3) C(15)-N(1)-C(16) 109.6(6) Ga(1)#2-Ga(3)-Ga(1) 93.44(5) C(15)-N(1)-C(18) 123.2(7) C(15)-Ga(3)-Ga(2) 133.16(3) C(16)-N(1)-C(18) 127.1(7) Ga(1)#2-Ga(3)-Ga(2) 62.03(3) N(1)#2-C(15)-N(1) 106.5(9) Ga(1)-Ga(3)-Ga(2) 62.03(3) N(1)#2-C(15)-Ga(3) 126.8(4) C(15)-Ga(3)-Ga(2)#2 133.16(3) N(1)-C(15)-Ga(3) 126.8(4) Ga(1)#2-Ga(3)-Ga(2)#2 62.03(3) C(16)#2-C(16)-N(1) 107.1(4) Ga(1)-Ga(3)-Ga(2)#2 62.03(3) C(16)#2-C(16)-C(17) 128.7(5) Ga(2)-Ga(3)-Ga(2)#2 93.68(5) N(1)-C(16)-C(17) 124.1(7) C(2)-C(1)-C(2)#1 116.9(11) C(19)-C(18)-N(1) 110.3(8) C(2)-C(1)-Ga(1) 121.6(5) C(19)-C(18)-C(20) 114.7(9) C(2)#1-C(1)-Ga(1) 121.6(5) N(1)-C(18)-C(20) 112.7(9) C(3)-C(2)-C(1) 120.1(9) C(22)-C(21)-C(26) 120 C(3)-C(2)-C(6) 119.3(9) C(22)-C(21)-C(27) 76(6) C(1)-C(2)-C(6) 120.6(8) C(26)-C(21)-C(27) 164(6) C(2)-C(3)-C(4) 123.7(10) C(21)-C(22)-C(23) 120

277

Table 2.69. Bond Angles [°] for Mes4Ga6(:L)2 (23) Atoms Angle Atoms Angle C(3)-C(4)-C(3)#1 115.4(12) C(22)-C(23)-C(24) 120 C(3)-C(4)-C(5) 122.3(6) C(25)-C(24)-C(23) 120 C(3)#1-C(4)-C(5) 122.3(6) C(25)-C(24)-C(10) 130(6) C(8)-C(7)-C(12) 107.3(11) C(23)-C(24)-C(10) 110(6) C(8)#3-C(7)-C(12)#3 107.3(11) C(24)-C(25)-C(26) 120 C(8)#3-C(7)-Ga(2) 124.7(8) C(25)-C(26)-C(21) 120

278

Structural Data for glyoxal-bis-(1-adamantyl)imine (24)

Table 70. Crystal data and structural refinement for glyoxal-bis-(1-adamantyl)imine (24)

Empirical formula C22H32N2 Formula weight 324.5 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, C2/c Unit cell dimensions a = 11.5780(8) Å b = 6.9162(8) Å c = 23.232(2) Å = 90° = 90.027(2)° = 90° Volume 1860.3(3) A3 Z, Calculated density 4, 1.159 Mg/m3 Absorption coefficient 0.067 mm-1 F(000) 712 Crystal size 0.40 x 0.35 x 0.30 mm Theta range for data collection 3.43 to 26.00 deg. -14<=h<=14, -8<=k<=8, - Limiting indices 28<=l<=28 Reflections collected / unique 10311 / 1835 [R(int) = 0.0261] Completeness to theta = 26.00 99.90% Semi-empirical from Absorption correction equivalents Max. and min. transmission 0.9801 and 0.9736 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 1835 / 0 / 110 Goodness-of-fit on F^2 1.068 Final R indices [I>2sigma(I)] R1 = 0.0497, wR2 = 0.1192 R indices (all data) R1 = 0.0556, wR2 = 0.1243 Extinction coefficient 0.0230(18) Largest diff. peak and hole 0.161 and -0.257 e.A-3

279

Table 71. Bond Distances [Å] for glyoxal-bis-(1-adamantyl)imine (24) Atoms Distance Atoms Distance N(1)-C(1) 1.2592(16) C(4)-C(5) 1.526(2) N(1)-C(2) 1.4691(15) C(4)-C(10) 1.525(2) C(1)-C(1)#1 1.466(2) C(5)-C(6) 1.526(2) C(2)-C(7) 1.5376(17) C(6)-C(7) 1.5305(18) C(2)-C(3) 1.5295(17) C(6)-C(11) 1.525(2) C(2)-C(8) 1.5323(18) C(8)-C(9) 1.5292(18) C(3)-C(4) 1.5323(17) C(9)-C(11) 1.524(2) C(9)-C(10) 1.525(2)

Table 72. Bond Angles [°] for glyoxal-bis-(1-adamantyl)imine (24) Atoms Angle Atoms Angle C(1)-N(1)-C(2) 121.69(11) C(3)-C(4)-C(10) 109.31(12) N(1)-C(1)-C(1)#1 120.18(15) C(4)-C(5)-C(6) 109.46(11) N(1)-C(2)-C(7) 107.11(10) C(7)-C(6)-C(5) 109.15(11) N(1)-C(2)-C(3) 116.27(9) C(7)-C(6)-C(11) 109.39(12) C(7)-C(2)-C(3) 109.00(11) C(5)-C(6)-C(11) 109.76(12) N(1)-C(2)-C(8) 106.98(10) C(6)-C(7)-C(2) 110.20(10) C(7)-C(2)-C(8) 108.09(10) C(9)-C(8)-C(2) 110.37(10) C(3)-C(2)-C(8) 109.10(10) C(11)-C(9)-C(10) 109.45(13) C(4)-C(3)-C(2) 110.03(10) C(11)-C(9)-C(8) 109.18(12) C(5)-C(4)-C(3) 109.38(12) C(10)-C(9)-C(8) 109.55(11) C(5)-C(4)-C(10) 109.82(12) C(9)-C(10)-C(4) 109.57(11) C(9)-C(11)-C(6) 109.63(10)

280

Structural Data for Arduengo’s Carbene (26)

Table 73. Crystal data and structural refinement for Arduengo’s Carbene (26)

Empirical formula C23H32N2 Formula weight 336.51 Temperature 273(2) K Wavelength 0.71073 Å Crystal system, space group Monoclinic, P2(1)/c Unit cell dimensions a = 7.5954(5) Å b = 19.7470(12) Å c = 12.8016(8) Å = 90° = 106.5400(10)° = 90° Volume 1840.6(2) Å3 Z, Calculated density 4, 1.214 Mg/m3 Absorption coefficient 0.070 mm-1 F(000) 736 Crystal size 0.30 x 0.17 x 0.08 mm Theta range for data collection 2.65 to 30.19 deg. -10<=h<=10, -27<=k<=27, - Limiting indices 18<=l<=18 Reflections collected / unique 28547 / 5462 [R(int) = 0.0388] Completeness to theta = 30.19 99.90% Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9944 and 0.9792 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 5462 / 0 / 226 Goodness-of-fit on F^2 1.009 Final R indices [I>2sigma(I)] R1 = 0.0485, wR2 = 0.1217 R indices (all data) R1 = 0.0803, wR2 = 0.1422 Largest diff. peak and hole 0.296 and -0.187 e.Å-3

281

Table 74. Bond Distances [Å] for Arduengo’s Carbene (26) Atoms Distance Atoms Distance N(1)-C(1) 1.3624(16) C(8)-C(9) 1.5343(18) N(1)-C(2) 1.3851(16) C(10)-C(11) 1.532(2) N(1)-C(14) 1.4814(16) C(11)-C(12) 1.5317(19) N(2)-C(1) 1.3661(16) C(11)-C(13) 1.528(2) N(2)-C(3) 1.3843(16) C(14)-C(22) 1.5286(17) N(2)-C(4) 1.4841(15) C(14)-C(15) 1.5345(17) C(2)-C(3) 1.3384(19) C(14)-C(19) 1.5333(17) C(4)-C(5) 1.5353(17) C(15)-C(16) 1.5318(18) C(4)-C(9) 1.5343(17) C(16)-C(23) 1.527(2) C(4)-C(12) 1.5297(18) C(16)-C(17) 1.527(2) C(5)-C(6) 1.5353(18) C(17)-C(18) 1.526(2) C(6)-C(13) 1.534(2) C(18)-C(20) 1.528(2) C(6)-C(7) 1.5293(19) C(18)-C(19) 1.5311(19) C(7)-C(8) 1.5280(19) C(20)-C(21) 1.530(2) C(8)-C(10) 1.522(2) C(21)-C(23) 1.526(2) C(21)-C(22) 1.5331(19)

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Table 75. Bond Angles [°] for Arduengo’s Carbene (26) Atoms Angle Atoms Angle C(1)-N(1)-C(2) 112.00(11) C(10)-C(11)-C(12) 109.63(12) C(1)-N(1)-C(14) 124.60(10) C(10)-C(11)-C(13) 109.77(12) C(2)-N(1)-C(14) 123.14(10) C(12)-C(11)-C(13) 109.12(11) C(1)-N(2)-C(3) 112.19(11) C(11)-C(12)-C(4) 109.95(10) C(1)-N(2)-C(4) 122.29(10) C(6)-C(13)-C(11) 109.29(11) C(3)-N(2)-C(4) 125.49(10) N(1)-C(14)-C(22) 110.34(10) N(1)-C(1)-N(2) 102.62(10) N(1)-C(14)-C(15) 109.20(10) C(3)-C(2)-N(1) 106.82(11) C(22)-C(14)-C(15) 108.65(10) C(2)-C(3)-N(2) 106.38(11) N(1)-C(14)-C(19) 110.45(10) N(2)-C(4)-C(5) 109.38(10) C(22)-C(14)-C(19) 109.24(10) N(2)-C(4)-C(9) 110.50(10) C(15)-C(14)-C(19) 108.93(10) C(5)-C(4)-C(9) 108.75(10) C(14)-C(15)-C(16) 109.86(10) N(2)-C(4)-C(12) 109.90(10) C(23)-C(16)-C(17) 109.35(12) C(5)-C(4)-C(12) 108.86(10) C(23)-C(16)-C(15) 109.26(12) C(9)-C(4)-C(12) 109.43(10) C(17)-C(16)-C(15) 109.65(12) C(4)-C(5)-C(6) 109.92(10) C(18)-C(17)-C(16) 109.73(12) C(13)-C(6)-C(7) 109.64(11) C(17)-C(18)-C(20) 109.61(12) C(13)-C(6)-C(5) 109.70(11) C(17)-C(18)-C(19) 108.87(11) C(7)-C(6)-C(5) 109.06(11) C(20)-C(18)-C(19) 109.89(12) C(8)-C(7)-C(6) 109.19(11) C(18)-C(19)-C(14) 110.21(11) C(7)-C(8)-C(10) 110.35(12) C(21)-C(20)-C(18) 109.02(11) C(7)-C(8)-C(9) 109.74(11) C(20)-C(21)-C(23) 109.46(13) C(10)-C(8)-C(9) 108.91(11) C(20)-C(21)-C(22) 110.03(12) C(8)-C(9)-C(4) 109.75(10) C(23)-C(21)-C(22) 109.38(11) C(11)-C(10)-C(8) 109.38(11) C(14)-C(22)-C(21) 109.88(11) C(16)-C(23)-C(21) 109.45(11

283

APPENDIX B

RESEARCH PUBLICATIONS

Co-Authored by Brandon Quillian

1. Wang, Y.; Quillian, B.; Wei, P.; Yang, X.-J.; Robinson, G. H., New Pb-Pb bonds: “Syntheses and molecular structures of hexabiphenyldiplumbane and tri(trisbiphenylplumbyl)plumbate”, Chem. Commun. 2004, 2224-2225.

2. Yang, X.-J.; Quillian, B.; Wang, Y.; Wei, P.; Robinson, G. H., “A Metallocene with Ga-Zr Bonds: Cp2Zr(GaR)2 (Cp = C5H5; R = -C6H3-2,6-(2,4,6-iPr3C6H2)2)”, Organometallics 2004, 23, 5119-5120.

3. Wang, Y.; Quillian, B.; Wei, P; Wang, H.; Yang, X.-J.; Xie, Y.; King, R. B.; Schleyer, P. v. R.; Schaefer, H. F. III; Robinson, G. H., “On the Chemistry of Zn-Zn Bonds, RZn-ZnR (R = i [{2,6-Pr2 C6H3)N(Me)C}2CH]): Synthesis, Structure, and Computations”, J. Am. Chem. Soc. 2005, 127, 11944-11945.

4. Wang, Y.; Quillian, B.; Yang, X.-J.; Wei, P.; Chen, Z.; Wannere, C. S.; Schleyer, P. v. R.; Robinson, G. H., “A Metallocene-Complexed Dibismuthene: Cp2Zr(BiR)2 (Cp = C5H5;R = C6H3-2,6-Mes2)”, J. Am. Chem. Soc. 2005, 127, 7672-7673.

5. Yang, X.-J.; Wang, Y.; Quillian, B.; Wei, P.; Chen, Z.; Schleyer, P. v. R.; Robinson, G. H., “Syntheses, Structures and Bonding of Cp2M(ER)2 (Cp = C5H5; M = Ti, Zr; E = Ga, In; R = - C6H3-2,6-(2,4,6-iPr3C6H2)2)”, Organometallics 2006, 25, 925-929.

6. Yang, X.-J.; Wang, Y.; Wei, P.; Quillian, B.; Robinson, G. H., “Syntheses and structures of new diaryl lead(II) compounds PbR2 (1, R = 2,4,6-triphenyl; 2, R = 2,6-bis(1’- naphthyl)phenyl)”, Chem. Commun. 2006, 403-405.

7. Quillian, B.; Wang, Y.; Wei, P.; Handy, A.; Robinson, G. H., “2,6-Di(4-t- butylphenyl)phenyl-group 13 Organometallic Compounds”, J. Organomet. Chem. 2006, 691, 3765-3770.

8. Wang, Y.; Quillian, B.; Wei, P.; Wannere, C. S.; Schleyer, P. v. R.; Robinson, G. H., “A Self-Assembled Organometallic Sphere: [{t-BuC5H4)(t-BuC5H3)Zr(μ-H)Na}2]4”, Organometallics 2006, 25, 3286-3288.

284

9. Wang, Y.; Quillian, B.; Wannere, C. S.; Wei, P.; Schleyer, P. v. R.; Robinson, G. H., “A Trimetallic Compound Containing Zn-Zr bonds: Cp2Zr(ZnR)2 (Cp = C5H5;R = -C6H3-2,6- (2,4,6-i-Pr3C6H2)2)”, Organometallics 2007, 26, 3054-3056.

10. Wang, Y.; Quillian, B.; Wei, P.; Wannere, C. S.; Xie, Y.; King, R. B.; Schaefer, H. F. III; Schleyer, P. v. R.; Robinson, G. H., “A Stable Neutral Diborene Containing a B=B Double Bond”, J. Am. Chem. Soc. 2007, 129 12412-12413.

11. Quillian, B.; Wang, Y.; Wei, P.; Wannere, C. S.; Schleyer, P. v. R.; Robinson, G. H., “Gallepins. Neutral Gallium Analogues of the Tropylium Ion: Synthesis, Structure, and Aromaticity”, J. Am. Chem. Soc. 2007, 129, 13380-13381.

12. Quillian, B.; Wang, Y.; Wannere, C. S.; Wei, P.; Schleyer, P. v. R.; Robinson, G. H., “A Trimetallic Fulvalene-bridged Dizirconocene-gallium Complex”, Angew. Chem. Int. Ed. 2007, 46, 1836-1838.

13. Quillian, B.; Wang, Y.; Wei, P.; Robinson, G. H., “An m-Terphenyl derivative of titanium(III): Cp2TiR (Cp = C5H5; R = 2,6-(4-MeC6H4)2C6H3)”, J. Coord. Chem. 2008, 61, 137-142.

14. Quillian, B.; Wang, Y.; Wei, P.; Robinson, G. H., “Organometallic Compounds Containing new Hf–Ga and Hf–In Bonds: Cp2Hf(ER)2 (Cp = C5H5; E = Ga, In; R = -C6H3-2,6-(2,4,6-i- Pr3C6H2)2)”, New J. Chem. 2008, 32, 774-776.

15. Wang, Y.; Quillian, B.; Wei, P.; King, R. B.; Schaefer, H. F. III; Schleyer, P. v. R., Robinson, G. H., “Planar, Twisted, and Trans-Bent: Conformational Flexibility of Neutral Diborenes”, J. Am. Chem. Soc. 2008, 130, 3298-3299.

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