Advances in Organometallic Chemistry (eBook)

Cover 1
Contents 6
Contributors 10
Intramolecular Interconversions in Cyclosilazane Chemistry: A Joint Experimental-Theoretical Study 12
Summary 12
Introduction 13
Formation of Four-, Six- and Eight-Membered -Rings 13
Dimerization of Iminosilenes 15
Electrophilic 1,3-Silyl Group Migration 16
Nucleophilic 1,3-Methanide-Ion Migration 17
Cyclodisilazane Anions 18
Cyclodisilazane Cations 20
2,2,4,4,6,6-Hexamethylcyclotrisilazane 21
Isomeric Cyclotri- and Cyclodisilazanes, DFT Calculations 21
Isomeric Cyclotri- and Cyclodisilazane-Anions and -Dianions, DFT Calculations 23
Substitution Reactions 26
Interconversion Reactions 29
Equilibrium between Silyl-Substituted Cyclotri- and Isomeric Cyclodisilazane-Anions 29
Position of the Si-N-Bond Cleavage, Formation of the Silyl-Bridged Cyclodisilazanes 32
Disubstitution of HMCTS with Ring Contraction 33
Ring Contraction, Methanide-Ion Migration and Formation of Bicyclic Compounds 35
2,2,4,4,6,6,8,8-Octamethylcyclotetrasilazane, OMCTS 38
Conformers and Isomeric Compounds of OMCTS, DFT Calculations 38
Substitution Reactions, Synthesis of Mono- and Disubstituted Eight-Membered Rings and Bicyclic Compounds 41
Interconversion Reactions 42
Structural Isomers of the Mono-Anion of OMCTS, DFT Calculations 42
Experimental Results 46
Ring Contractions of the Mono-Anion of OMCTS with Triorganyl Chlorosilanes and Borazines 46
DFT Calculations, Structural Isomers of the Dianion of OMCTS 47
Experimental Results 50
Ring Contraction and Formation of Unsymmetrically Substituted Four-Membered Rings 50
Outlook 56
References 56
Molecular Alumo-Siloxanes and Base Adducts 60
Introduction 60
Structures of Compounds of the General Composition (RSiO1.5)n(AlOX)m 61
Structures of Compounds of the General Composition (R2SiO)n(AlOX)m 64
General Reactions and Structures of Compounds Derived from (Ph2SiO)8[AlO(OH)]4 66
Synthesis of (Ph2SiO)8[AlO(OH)]4 and reactions with water and ammonia 66
Simple Base-Adducts of (Ph2SiO)8[AlO(OH)]4 69
Base-Adducts of (Ph2SiO)8[AlO(OH)]4 with Poly-Methylene-Diamines H2N(CH2)nNH2 72
Conclusions 81
Acknowledgments 81
References 81
Progress in the Chemistry of Stable Disilenes 84
Introduction 84
Synthesis 86
Acyclic Disilenes 95
Cyclic Disilenes 97
Cyclotetrasilenes 97
Cyclotrisilenes 99
Other Endocyclic Disilenes 100
Exocyclic Disilenes 101
Silicon-Based Dienes 101
Tetrasila-1,3-diene 101
Spiropentasiladiene 102
Trisilaallene 102
Disilynes 103
Cations, Anions, and Radicals with SiSi Double Bonds 103
Bonding and Structures 105
An Overview of Si=Si Double Bonds 105
Strain Energies of Cyclic Disilenes 109
Molecular Structures 111
Acyclic Disilenes 111
Cyclic Disilenes 112
Silicon-Based Dienes 112
Disilyne 115
Ionic Disilenes 115
UV– vis Absorption and Fluorescence Spectra 116
Acyclic Disilenes 116
Cyclic Disilenes 117
Silicon-Based Dienes 117
Disilyne 119
Ionic Disilenes 119
Cyclic Voltammetry 119
29Si NMR Spectra 120
Acyclic Disilenes 120
Cyclic Disilenes 122
Silicon-Based Dienes 122
Disilyne 123
Ionic Disilenes 123
Vibrational Spectra 123
Reactions and Mechanisms 124
Unimolecular Reaction 124
E,Z-Isomerization 124
Dissociation into Two Silylenes 126
1,2-Migration of Substituents and Related Isomerizations 128
Skeletal Isomerization of Cyclic Disilenes 129
Oxidation and Reduction 132
Oxidation 132
Reduction 134
1,2-Addition of Water, Alcohols, and Ammonia 136
Addition of Halogens and Haloalkanes 140
Carbometallation and Hydrometallation 142
Ene Reaction 143
Cycloaddition 144
[2+1] and [2+2] Cycloaddition 144
[2+3] and [2+4] Cycloadditions 147
Miscellany 148
Disilene-Transition Metal Complexes 149
Synthesis 149
Bonding and Structure 151
Reactions 153
Conclusion 155
Acknowledgment 155
References 155
Metallacycloalkanes – Synthesis, Structure and Reactivity of Medium to Large Ring Compounds 160
Introduction 160
Metallacyclopentanes 161
Group 4 Metallacyclopentanes 161
Titanium 161
Zirconium 167
Hafnium 175
Group 5 Metallacyclopentanes 176
Group 6 Metallacyclopentanes 178
Chromium 178
Molybdenum 179
Tungsten 181
Group 7 Metallacyclopentanes 185
Manganese 185
Rhenium 186
Group 8 Metallacyclopentanes 187
Group 9 Metallacyclopentanes 191
Cobalt 191
Rhodium 192
Iridium 193
Group 10 Metallacyclopentanes 195
Nickel 195
Palladium 197
Platinum 200
Metallacyclohexanes 203
Group 4 Metallacyclohexanes 203
Titanium 203
Hafnium 204
Groups 5, 6, 7 204
Group 8 Metallacyclohexanes 205
Group 9 Metallacyclohexanes 206
Rhodium 206
Iridium 206
Group 10 Metallacyclohexanes 206
Metallacycloheptanes 208
Groups 4, 5, 6, 7 208
Group 8 Metallacycloheptanes 209
Group 9 Metallacycloheptanes 210
Rhodium 210
Group 10 Metallacycloheptanes 211
Metallacyclooctanes and Larger Rings 212
Groups 4, 5, 6, 7 and 9 212
Group 8 Metallacyclooctanes and Larger Rings 212
Group 9 Metallacyclooctanes and Larger Rings 212
Conclusion 213
Acknowledgments 213
References 213
The Chemistry of Cyclometallated Gold(III) Complexes with C,N-Donor Ligands 218
Introduction 218
Synthesis of Five-Membered Ring Cycloaurated Complexes 219
Direct Cycloauration Reactions 220
Silver Ion-Assisted Cycloauration Reactions 222
Transmetallation Reactions 223
Complexes Containing Two Potentially Cycloaurating Ligands 229
Miscellaneous Syntheses 232
Unsuccessful Cycloauration Systems 232
Related Compounds with Anionic Nitrogen Donor Ligands 234
Synthesis of Six-Membered Ring Cycloaurated Complexes 234
Direct Cycloauration Reactions 234
Chemically Assisted Cycloauration Reactions 240
Reactivity of Cycloaurated Complexes 241
Phosphine Ligands 241
Neutral Nitrogen Donor and Other Ligands 245
Halide and Pseudohalide Ligands 246
Carboxylate Derivatives 247
Complexes with Ancillary Aryl Ligands 248
Acetonyl Complexes 250
Ligand Displacement Reactions of Pincer Complexes 251
Bidentate Anionic Ligands with C-, N- and O-Donor Groups 254
Bidentate Ligands with S-Donor Groups 258
Reactions Involving Displacement of the Coordinated N-Donor Ligand 264
With Halide and Cyanide Ligands 264
With Dithiocarbamate Ligands 265
With Thiosemicarbazone Ligands 266
Reactions Involving Complete Displacement of the Cycloaurated Ligand 269
Properties and Applications 270
Biological Activity 270
Electrochemical Properties 272
Photophysical Properties 272
Acknowledgments 273
References 273
Sterically Demanding Phosphinimides: Ligands for Unique Main Group and Transition Metal Chemistry 278
Introduction 278
Group 1: Lithium 279
Group 2: Magnesium 279
Group 4 280
Titanium 280
Zirconium 293
Group 5 295
Vanadium 295
Tantalum 296
Group 8: Iron 297
Group 13 297
Boron 297
Aluminum 298
Group 14 298
Summary and Future Directions 300
Acknowledgments 300
References 300
Transition Metal Complexes of Tethered Arenes 304
Introduction 304
Preparative Methods 305
General Considerations 305
Syntheses via Initial Arene Coordination (Scheme 1a) 306
Syntheses via Initial Donor Atom Coordination (Scheme 1b) 310
Syntheses via Intramolecular Construction of the Strap (Scheme 1c) 324
Syntheses via Alkyne Condensation (Scheme 1d) 326
Tethered Arene-Phosphine Complexes of Ruthenium(II) 327
General Considerations 327
Structural Features 327
Reactivity 328
Redox Behaviour 334
Tethered Non-Benzenoid Aromatic Complexes 336
Acknowledgments 339
References 339
Index 344
Cumulative List of Contributors for Volumes 1-36 350
Cumulative Index for Volumes 37-54 354