Main Group Strategies towards Functional Hybrid Materials

Dr. rer. nat. Thomas Baumgartner, is a Professor and Canada Research Chair in the Department of Chemistry, York University, Canada. He is the recipient of several awards, including a Liebig fellowship from the German chemical industry association, an Alberta Ingenuity New Faculty Award, a JSPS invitation fellowship, and a Friedrich Wilhelm Bessel Research Award from the Alexander von Humboldt Foundation. Dr. rer. nat. Frieder Jäkle, is a Distinguished Professor in the Department of Chemistry, Rutgers University-Newark, USA. He is the recipient of the NSF CAREER award, an Alfred P. Sloan fellowship, a Friedrich Wilhelm Bessel Research Award from the Alexander von Humboldt foundation, the ACS Akron Section Award, and the Boron Americas Award.

List of Contributors xv

Preface xix

1 Incorporation of Boron into π-Conjugated Scaffolds to Produce Electron-Accepting π-Electron Systems 1
Atsushi Wakamiya

1.1 Introduction 1

1.2 Boron-Containing Five-Membered Rings: Boroles and Dibenzoboroles 2

1.3 Annulated Boroles 8

1.4 Boron-Containing Seven-Membered Rings: Borepins 11

1.5 Boron-Containing Six-Membered Rings: Diborins 14

1.6 Planarized Triphenylboranes and Boron-Doped Nanographenes 17

1.7 Conclusion and Outlook 21

References 22

2 Organoborane Donor–Acceptor Materials 27
Sanjoy Mukherjee and Pakkirisamy Thilagar

2.1 Organoboranes: Form and Functions 27

2.2 Linear D-A Systems 29

2.3 Non-conjugated D-A Organoboranes 32

2.4 Conjugated Nonlinear D-A Systems 33

2.5 Polymeric Systems 36

2.6 Cyclic D-A Systems: Macrocycles and Fused-Rings 39

2.7 Conclusions and Outlook 43

References 43

3 Photoresponsive Organoboron Systems 47
Soren K. Mellerup and Suning Wang

3.1 Introduction 47

3.1.1 Four-Coordinate Organoboron Compounds for OLEDs 47

3.1.2 Photochromism 49

3.2 Photoreactivity of (ppy)BMes2 and Related Compounds 50

3.2.1 Photochromism of (ppy)BMes2 50

3.2.2 Mechanism 51

3.2.3 Derivatizing (ppy)BMes2: Impact of Steric and Electronic Factors on Photochromism 52

3.2.3.1 Substituents on the ppy Backbone 52

3.2.3.2 Aryl Groups on Boron: Steric versus Electronic Effect 54

3.2.3.3 π-Conjugation and Heterocyclic Backbones 56

3.2.3.4 Impact of Different Donors 58

3.2.3.5 Polyboryl Species 60

3.3 Photoreactivity of BN-Heterocycles 62

3.3.1 BN-Isosterism and BN-Doped Polycyclic Aromatic Hydrocarbons (PAHs) 62

3.3.2 Photoelimination of (2-Benzylpyridyl)BMes2 62

3.3.3 Mechanism 64

3.3.4 Scope of Photoelimination: The Chelate Backbone 65

3.3.5 Strategies of Enhancing ΦPE: Metalation and Substituents on Boron 66

3.4 New Photochromism of BN-Heterocycles 68

3.4.1 Photochromism of (2-Benzylpyridyl)BMesF 2 and Related Compounds 68

3.4.2 Mechanism 70

3.5 Exciton Driven Elimination (EDE): In situ Fabrication of OLEDs 70

3.6 Summary and Future Prospects 73

References 74

4 Incorporation of Group 13 Elements into Polymers 79
Yi Ren and Frieder Jäkle

4.1 Introduction 79

4.2 Tricoordinate Boron in Conjugated Polymers 80

4.3 Tetracoordinate Boron Chelate Complexes in Polymeric Materials 87

4.3.1 N-N Boron Chelates 88

4.3.2 N-O Boron Chelates 91

4.3.3 N-C Boron Chelates 92

4.4 Polymeric Materials with B-P and B-N in the Backbone 92

4.5 Polymeric Materials Containing Borane and Carborane Clusters 97

4.6 Polymeric Materials Containing Higher Group 13 Elements 101

4.7 Conclusions 105

Acknowledgements 106

References 106

5 Tetracoordinate Boron Materials for Biological Imaging 111
Christopher A. DeRosa and Cassandra L. Fraser

5.1 Introduction 111

5.1.1 Introduction to Luminescence 111

5.1.2 Tetracoordinate Boron Dye Scaffolds 113

5.2 Small Molecule Fluorescence Imaging Agents 114

5.2.1 Bright Fluorophores 116

5.2.2 Solvatochromophores 117

5.2.3 Molecular Motions of Boron Dyes 118

5.2.3.1 Molecular Rotors 121

5.2.3.2 Turn-On Probes 121

5.3 Polymer Conjugated Materials 124

5.3.1 Dye–Polymer Systems 124

5.3.2 Oxygen-Sensing Polymers 126

5.3.3 Energy Transfer in Polymers 129

5.3.4 Conjugated Polymers 130

5.3.5 Aggregation-Induced Emission Polymers 130

5.4 Conclusion and Future Outlook 133

References 133

6 Advances and Properties of Silanol-Based Materials 141
Rudolf Pietschnig

6.1 Introduction 141

6.2 Preparation 141

6.3 Reactivity 143

6.3.1 Adduct Formation 143

6.3.2 Metallation 145

6.3.3 Condensation 146

6.4 Properties and Application 148

6.4.1 Surface Modification 148

6.4.2 Catalysis 154

6.4.3 Bioactivity 155

6.4.3.1 Monosilanols 155

6.4.3.2 Silanediols 156

6.4.3.3 Silanetriols 157

6.4.4 Supramolecular Assembly 158

References 159

7 Silole-Based Materials in Optoelectronics and Sensing 163
Masaki Shimizu

7.1 Introduction 163

7.2 Basic Aspects of Silole-Based Materials 164

7.3 Silole-Based Electron-Transporting Materials 167

7.4 Silole-Based Host and Hole-Blocking Materials for OLEDs 170

7.5 Silole-Based Light-Emitting Materials 171

7.6 Silole-Based Semiconducting Materials 175

7.7 Silole-Based Light-Harvesting Materials for Solar Cells 179

7.8 Silole-Based Sensing Materials 185

7.9 Conclusion 189

References 190

8 Materials Containing Homocatenated Polysilanes 197
Takanobu Sanji

8.1 Introduction 197

8.2 Synthesis 197

8.3 Functional Modification of Polysilanes 198

8.4 Control of the Stereochemistry of Polysilanes 199

8.5 Control of the Secondary Structure of Polysilanes 200

8.6 Polysilanes with 3D Architectures 202

8.7 Applications 203

8.8 Summary 205

References 205

9 Catenated Germanium and Tin Oligomers and Polymers 209
Daniel Foucher

9.1 Introduction 209

9.2 Oligogermanes and Oligostannanes 209

9.3 Preparation of Polygermanes 212

9.3.1 Wurtz Coupling 212

9.3.2 Reductive coupling of Dihalogermylenes 214

9.3.3 Electrochemical Reduction of Dihalodiorganogermanes and Trihaloorganogermanes 215

9.3.4 Transition Metal-Catalyzed Polymerizations of Germanes 215

9.3.4.1 Demethanative Coupling of Germanes 216

9.3.5 Photodecomposition of Germanes 218

9.3.6 Properties and Characterization of Polygermanes 218

9.3.6.1 Thermal Properties of Polygermanes 218

9.3.6.2 Electronic Properties of Polygermanes 219

9.4 Preparation of Polystannanes 220

9.4.1 Wurtz Coupling 220

9.4.2 Electrochemical Synthesis 221

9.4.3 Dehydropolymerization 224

9.4.4 Alternating Polystannanes 227

9.4.5 Properties and Characterization of Polystannanes 227

9.4.5.1 Sn NMR 227

9.4.5.2 Thermal and Photostability 228

9.4.5.3 Electronic Properties 230

9.4.5.4 Conductivity 231

9.4.6 Molecular Modeling of Oligostannanes and Comparison of Group 14 Polymetallanes 231

9.5 Conclusions and Outlook 233

Acknowledgements 233

References 234

10 Germanium and Tin in Conjugated Organic Materials 237
Yohei Adachi and Joji Ohshita

10.1 Introduction 237

10.2 Germanium and Tin-Linked Conjugated Polymers 238

10.2.1 Germylene-Ethynylene Polymers 238

10.2.2 Fluorene- and Carbazole-Containing Germylene Polymers 240

10.2.3 Germanium- and Tin-Linked Ferrocenes and Related Compounds 241

10.3 Germanium- and Tin-Containing Conjugated Cyclic Systems 242

10.3.1 Non-fused Germoles and Stannoles 242

10.3.2 Dibenzogermoles and Dibenzostannoles 248

10.3.3 Dithienogermole and Dithienostannole 253

10.3.4 Other Fused Germoles 258

10.3.5 Germacycloheptatriene and Digermacyclohexadiene 259

10.4 Summary and Outlook 260

References 260

11 Phosphorus-Based Porphyrins 265
Yoshihiro Matano

11.1 Introduction 265

11.2 Porphyrins Bearing Phosphorus-Based Functional Groups at their Periphery 266

11.2.1 Porphyrins Bearing meso/β-Diphenylphosphino Groups 266

11.2.2 Porphyrins Bearing meso/β-Triphenylphosphonio Groups 269

11.2.3 Porphyrins Bearing meso/β-Diphenylphosphoryl Groups 273

11.2.4 Porphyrins Bearing meso/β-Dialkoxyphosphoryl Groups 276

11.2.5 Phthalocyanines Bearing Phosphorus-Based Functional Groups 280

11.3 Porphyrins and Related Macrocycles Containing Phosphorus Atoms at their Core 283

11.3.1 Core-Modified Phosphaporphyrins 284

11.3.2 Core-Modified Phosphacalixpyrroles 287

11.3.3 Core-Modified Phosphacalixphyrins 289

11.4 Conclusions 290

Acknowledgements 292

References 292

12 Applications of Phosphorus-Based Materials in Optoelectronics 295
Matthew P. Duffy, Pierre-Antoine Bouit, and Muriel Hissler

12.1 Introduction 295

12.2 Phosphines 296

12.2.1 Application as Charge-Transport Layer 296

12.2.2 Application as Host for Phosphorescent Complexes 299

12.2.3 Application as Emitting Materials 303

12.3 Four-Membered P-Heterocyclic Rings 306

12.3.1 Diphosphacyclobutanediyls 306

12.3.2 Phosphetes 307

12.4 Five-Membered P-Heterocyclic Rings: Phospholes 307

12.4.1 Application as Charge-Transport Layers 308

12.4.2 Application as Host for Phosphorescent Complexes 309

12.4.3 Application as Emitter in OLEDs 309

12.4.4 Dyes for Dye-Sensitized Solar Cells (DSSCs) 316

12.4.5 Donors in Organic Solar Cells (OSCs) 316

12.4.6 Application in Electrochromic Cells 317

12.4.7 Application in Memory Devices 318

12.5 Six-Membered P-Heterocyclic Rings 319

12.5.1 Phosphazenes 319

12.5.1.1 Application as Electrolyte for Solar Cells 319

12.5.1.2 Application as Host for Triplet Emitters in PhOLEDs 320

12.5.1.3 Application as Emitter for OLEDs 321

12.6 Conclusion 321

Abbreviations 322

References 324

13 Main-Chain, Phosphorus-Based Polymers 329
Klaus Dück and Derek P. Gates

13.1 Introduction 329

13.2 Polyphosphazenes 330

13.3 Poly(phosphole)s 333

13.4 Poly(methylenephosphine)s 336

13.5 Poly(arylene-/vinylene-/ethynylene-phosphine)s 341

13.6 Phospha-PPVs 343

13.7 Poly(phosphinoborane)s 345

13.8 Metal-Containing Phosphorus Polymers 347

13.9 Additional P-Containing Polymers 349

13.10 Summary 350

Acknowledgements 351

References 351

14 Synthons for the Development of New Organophosphorus Functional Materials 357
Robert J. Gilliard, Jr., Jerod M. Kieser, and John D. Protasiewicz

14.1 General Introduction 357

14.1.1 Phosphorus-Based Functional Materials 357

14.1.2 Phosphorus Allotropes 359

14.2 Phosphorus Transfer Reagents as Emerging Synthetic Approaches to Materials 360

14.2.1 Introduction to Phosphorus Transfer Reagents 360

14.2.2 Phosphaethynolate Salts 360

14.2.3 Phospha-Wittig Reagents 367

14.2.4 Phospha-Wittig–Horner Reagents 371

14.2.5 Phosphadibenzonorbornadiene Derivatives 373

14.3 Carbene-Stabilized Molecules as Phosphorus Reagents 375

14.3.1 Introduction to Carbene Phosphorus Complexes 375

14.3.2 N-Heterocyclic Carbene-Stabilized Phosphorus Complexes 375

14.3.3 Cyclic (Alkyl)(Amino) Carbene-Stabilized Phosphorus Compounds 376

14.3.4 Reactions of N-Heterocyclic Carbenes with Phosphaalkenes 377

14.4 Conclusions and Outlook 378

References 379

15 Arsenic-Containing Oligomers and Polymers 383
Hiroaki Imoto and Kensuke Naka

15.1 Introduction 383

15.2 Chemistry of Organoarsenic Compounds 384

15.3 Arsenic Homocycles 384

15.4 Development of C–As Bond Formation for Organoarsenic

15.4.1 Classical Methodologies 386

15.4.2 In Situ-Generated Organoarsenic Electrophiles from Arsenic Homocycles 387

15.4.3 In Situ-Generated Organoarsenic Nucleophiles from Arsenic Homocycles 388

15.4.4 Bismetallation Based on Arsenic Homocycles 388

15.5 Properties of Poly(vinylene-arsine)s 391

15.6 Properties of 1,4-Dihydro-1,4-diarsinines 391

15.7 Properties of Arsole Derivatives 394

15.8 Arsole-Containing Polymers 396

15.9 Conclusions 399

References 400

16 Antimony-and Bismuth-Based Materials and Applications 405
Anna M. Christianson and François P. Gabbaï

16.1 Introduction 405

16.2 Anion Binding and Sensing Applications 406

16.3 Small-Molecule Binding 418

16.4 Antimony and Bismuth Chromophores 426

16.5 Conclusion 430

References 430

17 High Sulfur Content Organic/Inorganic Hybrid Polymeric Materials 433
Jeffrey Pyun, Richard S. Glass, Michael M. Mackay, Robert Norwood, and Kookheon Char

17.1 Introduction 433

17.2 The Chemistry of Liquid Sulfur 434

17.2.1 Ring-Opening Polymerization of Elemental Sulfur 434

17.2.2 Synthesis of Inorganic Nanoparticles in Liquid Sulfur 435

17.2.3 Inverse Vulcanization of Elemental Sulfur 437

17.2.4 Transformation Polymerizations with Elemental Sulfur: Combining Inverse Vulcanization with Electropolymerization 441

17.3 Waterborne Reactions of Polysulfides 442

17.4 Controlled Polymerization with High Sulfur-Content Monomers 442

17.5 Modern Applications of High Sulfur-Content Copolymers 444

17.5.1 High Sulfur-Content Polymers as Cathode Materials for Li-S Batteries 444

17.5.2 High Sulfur-Content Polymers as Transmissive Materials for IR Thermal Imaging 445

17.6 Conclusion and Outlook 448

Acknowledgements 448

References 449

18 Selenium and Tellurium Containing Conjugated Polymers 451
Zhen Zhang, Wenhan He, and Yang Qin

18.1 Introduction 451

18.2 Selenium-Containing Conjugated Polymers 452

18.2.1 Background 452

18.2.2 Electron-Rich Homopolymers 453

18.2.3 Donor–Acceptor (D-A) Copolymers 457

18.2.3.1 Selenium-Containing Benzodithiophene-Benzothiadiazole (BDT-BT) Copolymer Derivatives 460

18.2.3.2 Selenium-Containing Benzodithiophene-Thienothiophene (BDT-TT) Copolymer Derivatives 462

18.2.3.3 Selenium-Containing Benzodithiophene-Diketopyrrolopyrrole (BDT-DPP) and Benzodithiophene-Thienopyrrole-4,6-dione (BDT-TPD) Copolymers 465

18.3 Tellurium-Containing Conjugated Polymers 467

18.3.1 Background 467

18.3.2 Synthesis of Tellurium-Containing Polymers 467

18.3.2.1 Early Examples of Insoluble Polymers 467

18.3.2.2 Tellurium-Bridge Polymers 469

18.3.2.3 Soluble Tellurophene-Containing Conjugated Polymers 469

18.3.2.4 Regio-Regular Poly(3-alkyltellurophene) 472

18.3.2.5 Other Tellurium-Containing Conjugated Polymers 473

18.3.3 Application of Tellurium-Containing Conjugated Polymers 473

18.4 Conclusions and Outlook 476

References 476

19 Hypervalent Iodine Compounds in Polymer Science and Technology 483
Avichal Vaish and Nicolay V. Tsarevsky

19.1 Introduction 483

19.1.1 Historical 483

19.1.2 Bonding in Hypervalent Iodine Compounds 484

19.1.3 Patterns of Reactivity Relevant to Applications in Polymer Science and Technology 486

19.2 Applications of Hypervalent Iodine Compounds in Polymer Science and Technology 487

19.2.1 HV Iodine Compounds as Initiators for Polymerization 487

19.2.1.1 Direct Application of HV Iodine Compounds 487

19.2.1.2 Functional Radical Initiators Generated as a result of Ligand-Exchange followed by Homolysis 493

19.2.2 Post-Polymerization Modifications using HV Iodine Compounds 495

19.2.3 HV Iodine Groups as Structural Elements in Polymers 496

19.2.3.1 Polymers with HV Iodine-Based Pendant Groups 496

19.2.3.2 HV Iodine Groups as part of the Polymer Backbone 505

19.3 Conclusions 508

Acknowledgements 508

References 508

Index