Providing a thorough overview of leading research from internationally-recognized contributing authors, this book describes methods for the preparation and application of redox systems for organic electronic materials like transistors, photovoltaics, and batteries.
- Covers bond formation and cleavage, supramolecular systems, molecular design, and synthesis and properties
- Addresses preparative methods, unique structural features, physical properties, and material applications of redox active p-conjugated systems
- Offers a useful guide for both academic and industrial chemists involved with organic electronic materials
- Focuses on the transition-metal-free redox systems composed of organic and organo main group compounds
Table of Contents
LIST OF CONTRIBUTO RS xv
PREFACE xix
1 Introduction: Basic Concepts and a Brief History of Organic Redox Systems 1
Tohru Nishinaga
1.1 Redox Reaction of Organic Molecules, 1
1.2 Redox Potential in Nonaqueous Solvents, 3
1.3 A Brief History of Organic Redox Compounds, 5
References, 10
2 Redox©\Mediated Reversible 𝞂©\Bond Formation/Cleavage 13
Takanori Suzuki, Hitomi Tamaoki, Jun©\ichi Nishida, Hiroki Higuchi, Tomohiro Iwai, Yusuke Ishigaki, Keisuke Hanada, Ryo Katoono, Hidetoshi Kawai, Kenshu Fujiwara and Takanori Fukushima
2.1 Dynamic Redox (“Dyrex”) Systems, 13
2.1.1 π©\Electron Systems Exhibiting Drastic Structural Changes upon Electron Transfer, 13
2.1.2 Redox Switching of a σ©\Bond upon Electron Transfer, 16
2.1.3 Two Types of Dyrex Systems Exhibiting Redox Switching of a σ©\Bond, 17
2.2 Advanced Electrochromic Response of “Endo”©\Type Dyrex Systems Exhibiting Redox Switching of a σ©\Bond, 19
2.2.1 Tetraaryldihydrophenanthrenes as Prototypes of “Endo”©\Dyrex Systems, 19
2.2.2 Tricolor Electrochromism with Hysteretic Color Change in Non©\C2©\Symmetric “Endo”©\Dyrex Pair, 20
2.2.3 Electrochromism with Chiroptical Output of Chiral “Endo”©\Dyrex Pair, 21
2.2.4 Multi©\Output Response System Based on Electrochromic “Endo”©\Dyrex Pair, 24
2.3 Advanced Electrochromic Response of “Exo”©\Type Dyrex Systems Exhibiting Redox Switching of a σ©\Bond, 26
2.3.1 Bis(diarylethenyl)biphenyls as Prototypes of “Exo”©\Dyrex Systems, 26
2.3.2 Electrochromism with Chiroptical Output of Chiral “Exo”©\Dyrex Systems, 26
2.3.3 Electrochromism of “Exo”©\Dyrex Systems in Aqueous Media, 28
2.4 Prospect: Redox Systems With Multiple Dyrex Units, 31
References, 33
3 Redox©\Controlled Intramolecular Motions Triggered by π©\Dimerization and Pimerization Processes 39
Christophe Kahlfuss, Eric Saint©\Aman and Christophe Bucher
3.1 Introduction, 39
3.2 Oligothiophenes, 40
3.3 Phenothiazine, 44
3.4 Naphthalene and Perylene Bisimides, 45
3.5 para©\Phenylenediamine, 47
3.6 Pyridinyl Radicals, 49
3.7 Viologen Derivatives, 50
3.8 Verdazyl, 60
3.9 Phenalenyl, 60
3.10 Porphyrins, 61
3.11 Benzenoid, 62
3.12 Cyclophane, 64
3.13 Tetrathiafulvalene, 68
3.14 Conclusion, 80
Acknowledgments, 80
References, 81
4 Tetrathiafulvalene: a Redox Unit for Functional Materials and a Building Block for Supramolecular Self©\Assembly 89
Masashi Hasegawa and Masahiko Iyoda
4.1 Introduction: Past and Present of TTF Chemistry, 89
4.2 Basic Redox Properties of TTF and Stacked TTF, 90
4.2.1 Monomeric TTFs, 90
4.2.2 Interactions in Stacked TTF Dimer, 92
4.2.3 Interactions in Stacked TTF Oligomers, 97
4.2.4 Head©\to©\Tail TTF Dimer, 98
4.3 TTF as a Faithful Redox Active Unit in Functional Materials, 100
4.3.1 Electrochromic Materials, 100
4.3.2 Optically Active TTFs, 102
4.3.3 Uses as Positive Electrode Materials for Rechargeable Batteries, 108
4.4 Electroconducting Properties of TTF Derivatives Based on Supramolecular Self©\Assembly, 112
4.4.1 Redox©\Active Nanostructure Formation in the Solid State, 113
4.4.2 Conducting Nanostructure Formation, 115
4.4.3 Conducting Nanofibers by Iodine Doping, 116
4.4.4 Conducting Nanofibers Based on Cation Radicals, 120
4.4.5 Conducting Nanowires of Neutral TTF Derivatives, 123
4.5 Summary and Outlook, 124
References, 125
5 Robust Aromatic Cation Radicals as Redox Tunable Oxidants 131
Marat R. Talipov and Rajendra Rathore
5.1 Introduction, 131
5.2 Designing Molecules for the Formation of Stable Cation Radicals (Crs) - A Case Study, 135
5.2.1 Exploring the Cause of Exceptional Stability of The©\Orange+ - , 137
5.3 Methods of Preparative Isolation of Aromatic Cation Radicals, 142
5.3.1 Nitrosonium (NO+) Salts, 143
5.3.2 Antimony Pentachloride (SbCl5), 144
5.3.3 Triethyloxonium Hexachloroantimonate (Et3O+ SbCl6 –), 148
5.3.4 Ddq and HBF4©\Ether Complex, 149
5.4 Q uantitative Oxidation of Electron Donors using THE-Orange+ - SbCl6 – as One©\Electron Oxidant, 150
5.4.1 Analysis of Two©\Electron Oxidation Processes Using MF/D Plots, 157
5.5 Readily Available Electron Donors for the Redox©\Tunable Aromatic Oxidants, 164
5.5.1 Triptycene Based Electron Donors, 164
5.5.2 Tetrabenzodifurans, 166
5.5.3 Polyaromatic Hydrocarbons, 168
5.5.4 Multi©\Electron Redox Systems, 168
5.6 Conclusion, 171
References, 173
6 Air©\Stable Redox©\Active Neutral Radicals: Topological Symmetry Control of Electronic©\Spin, Multicentered Chemical Bonding, and Organic Battery Application 177
Shinsuke Nishida and Yasushi Morita
6.1 Introduction, 177
6.2 Open©\Shell Graphene Fragment : Design and Synthesis of Air©\Stable Carbon©\Centered Neutral Radicals Based on Fused©\Polycyclic π©\System, 179
6.3 Topological Symmetry Control of Electronic©\Spin Density Distribution by Redox and other External Stimuli, 181
6.3.1 Redox©\Based Spin Diversity of Oxophenalenoxyl Sytems, 181
6.3.2 Spin©\Center Transfer and Solvato©\/Thermochromism of Tetrathiafulvalene©\Substituted 6©\Oxophenalenoxyl Neutral Radical, 183
6.4 Control of Electronic©\Spin Structure and Optical Properties of Multicentered C©¤C Bonds, 184
6.4.1 Strong Somo–Somo Interaction within π©\Dimeric Structure of Phenalenyl Derivatives, 184
6.4.2 Thermochromism Induced by Thermal Equilibrium of π©\Dimeric Structure and σ©\Dimeric Structure, 188
6.4.3 Weak Somo–Somo Interactions by Molecular Modification of Phenalenyl System, 190
6.4.4 Multidimensional Spin–Spin Interaction and π©\Staked Radical Polymer, 193
6.5 Rechargeable Batteries Using Organic Electrode©\Active Materials, 195
6.5.1 Closed©\Shell Organic Molecules as Electrode©\Active Materials, 196
6.5.2 Closed©\Shell Organic Polymers, 214
6.5.3 Stable Organic Neutral Radicals, 218
6.5.4 Stable Organic Neutral Radical Polymers, 220
6.6 Molecular Spin Batteries : Design Criteria and Performance of High Capacity Organic Rechargeable Battery Materials, 223
6.6.1 Molecular Crystalline Secondary Batteries, 223
6.6.2 Trioxotriangulene Neutral Radical (Tot) Derivatives, 224
6.6.3 Molecular Spin Batteries, 227
6.7 Conclusion, 229
Acknowledgement, 231
References, 231
7 Triarylamine©\Based Organic Mixed©\Valence Compounds: The Role of the Bridge 245
Christoph Lambert
7.1 Introduction, 245
7.2 The Mv Concept, 246
7.3 The Redox Center, 250
7.4 The Bridge, 251
7.5 The Length of the Bridge, 254
7.6 Changing the Connectivity, 256
7.7 Twisting the Bridge, 258
7.8 Saturated vs Unsaturated Bridge, 258
7.9 Meta vs Para Conjugation, 260
7.10 Switching the Bridge, 262
7.11 Metal Atoms as the Bridge, 263
7.12 And Finally: Without a Bridge, 264
Acknowledgment, 265
References, 265
8 Magnetic Properties of Multiradicals Based on Triarylamine Radical Cations 269
Shuichi Suzuki and Keiji Okada
8.1 Introduction, 269
8.2 Triarylamine Radical Cations as Synthetic Reagents for Preparation of Donor Radical Cations with Various Counter Anions, 270
8.2.1 Syntheses of Tbpa + - Pf6− and Its Counteranion Analogues, 270
8.3 Stable Triarylamines without para©\Substituents, 270
8.4 Models of Intermolecular Exchange Interaction in Heteroatomic Systems, 271
8.4.1 Dynamic Spin Polarization Model and Disjoint–Nondisjoint Model, 271
8.4.2 Dynamic Spin Polarization and Spin Delocalization, 272
8.4.3 Effect of Large Dihedral Angle between Spacer and Spin Source, 273
8.4.4 p©\Phenylene Methodology or π©\Conjugation Using Topologically Different Spin Sources, 275
8.5 Magnetic Susceptibility and Temperature Dependence, 275
8.6 Poly(Diarylamino benzene) Poly(Radical Cation)s, 276
8.7 Radical Substituted Triarylamines, 278
8.7.1 tbuno©\Substituted Triarylamines, 278
8.7.2 Nn©\Substituted Triarylamines, 279
8.8 Towards Further Developments, 282
References, 283
9 Open©\Shell π©\Conjugated Hydrocarbons 287
Takashi Kubo
9.1 Introduction, 287
9.2 Monoradicals, 288
9.2.1 Triphenylmethyl, 288
9.2.2 Phenalenyl, 289
9.2.3 Cyclopentadienyl, Indenyl, Fluorenyl, 291
9.2.4 Cycloheptatrienyl, 293
9.2.5 Bdpa , 294
9.2.6 Dinaphthofluorenyl, 294
9.3 Biradicals, 295
9.3.1 Triplet Biradicals, 295
9.3.2 Singlet Biradicals: Quinodimethanes, 296
9.3.3 Singlet Biradicals: Bisphenalenyl System, 298
9.3.4 Singlet Biradicals: Acences, 300
9.3.5 Singlet Biradicals: Anthenes, 301
9.3.6 Singlet Biradicals: Zethrenes, 303
9.3.7 Singlet Biradicals: Indenofluorenes, 304
9.4 Polyradicals, 304
References, 305
10 Indenofluorenes and Related Structures 311
Jonathan L. Marshall and Michael M. Haley
10.1 Introduction, 311
10.2 Indeno[1,2©\a]fluorenes, 313
10.2.1 Indeno[1,2©\a]fluorene©\7,12©\dione, 313
10.2.2 Truxenone, An Indeno[1,2©\a]fluorene Related Structure, 314
10.3 Indeno[1,2©\b]fluorenes, 320
10.3.1 Indeno[1,2©\b]fluorene©\6,12©\diones, 320
10.3.2 Dicyanomethylene Indeno[1,2©\b]fluorenes, 325
10.3.3 Fully Conjugated Indeno[1,2©\b]fluorenes, 327
10.4 Indeno[2,1©\a]fluorenes, 333
10.5 Indeno[2,1©\b]fluorenes, 336
10.6 Indeno[2,1©\c]fluorenes, 339
10.6.1 Indenofluorene-Related Structures, 341
10.7 Fluoreno[4,3©\c]fluorene, 342
10.8 Indacenedithiophenes, 345
10.8.1 Indacenedithiophene Diones, 345
10.8.2 Tetrathiofulvalene and Dicyanomethylene Indacenedithiophenes, 347
10.8.3 Fully Conjugated Indacenedithiophenes, 349
10.9 Diindeno[n]thiophenes, 351
10.10 Conclusions, 354
Acknowledgment, 354
References, 354
11 Thienoacenes 359
Kazuo Takimiya
11.1 Introduction, 359
11.2 Synthesis of Thienoacenes via Thienannulation, 361
11.2.1 Bdt and Adt Derivatives, 361
11.2.2 Thienannulation to Construct Thienoacenes with Terminal Thiophene Ring(s), 362
11.2.3 Thienannulation to Construct Thienoacenes with Internal Thiophene Ring(s), 366
11.3 Molecular Electronic Structures, 370
11.4 Application to Electronic Devices, 373
11.4.1 Molecular Organic Semiconductors for p©\Type OFET Devices, 373
11.4.2 Semiconducting Polymers for Pscs, 377
11.5 Summary, 379
References, 379
12 Cationic Oligothiophenes: p©\Doped Polythiophene Models and Applications 383
Tohru Nishinaga
12.1 Introduction, 383
12.2 Design Principle and Synthetic Methods, 384
12.3 Electrochemistry, 390
12.4 Structural and Spectroscopic Properties as p©\Doped Polythiophene Models, 397
12.5 Application to Supramolecular Systems, 403
12.6 Conclusion and Outlook, 406
References, 406
13 Electron©\Deficient Conjugated Heteroaromatics 411
Yutaka Ie and Yoshio Aso
13.1 Introduction, 411
13.2 Hexafluorocyclopenta[c]thiophene and its Containing Oligothiiophenes, 412
13.3 Difluoromethylene©\Bridged Bithiophene and its Containing Oligothiiophenes, 416
13.4 π©\Conjugated Systems Having Thiazole©\Based Carbonyl©\Bridged Compounds, 419
13.5 Difluorodioxocyclopentene©\Annelated Thiophene and its Containing Oligothiiophenes, 427
13.6 Dioxocycloalkene©\Annelated Thiophene and its Containing Oligothiiophenes, 433
13.7 Dicyanomethylene©\Substituted Cyclopenta[b]thiophene and its Containing π©\Conjugated System, 434
13.8 Electron©\Deficient π©\Conjugated System Containing Dicyanomethylene©\Substituted Cyclopenta[b]thiophene Toward Organic Photovoltaics, 437
13.9 Conclusion, 440
References, 441
14 Oligofurans 445
Ori Gidron
14.1 Background, 445
14.2 Synthesis and Reactivity, 446
14.3 Properties of Oligofurans in the Neutral State, 449
14.4 Properties of Cationic Oligofurans, 452
14.5 Polyfurans, 454
14.6 Devices with Furan©\Containing Materials, 455
14.7 Summary and Outlook, 459
References, 459
15 Oligopyrroles and Related Compounds 463
Masayoshi Takase
15.1 Introduction, 463
15.2 Linear Oligopyrroles, 464
15.2.1 Synthesis, 464
15.2.2 Optical and Redox Properties, 465
15.2.3 π©\Dimer of Oligopyrrole Radical Cations, 466
15.3 Cyclic Oligopyrroles, 467
15.3.1 Synthesis, 468
15.3.2 Optical and Redox Properties, 469
15.4 Pyrrole©\Fused Azacoronenes, 469
15.4.1 Synthesis, 470
15.4.2 Optical and Redox Properties, 470
15.4.3 Aromaticity, 473
15.5 Conclusions, 474
References, 474
16 Phospholes and Related Compounds: Syntheses, Redox Properties, and Applications to Organic Electronic Devices 477
Yoshihiro Matano
16.1 Introduction, 477
16.2 Synthesis of π©\Conjugated Phosphole Derivatives, 478
16.3 Redox Potentials of Phosphole Derivatives, 483
16.4 Electrochemical Behaviors of Phosphole Derivatives, 493
16.5 Applications of Phosphole©\Based Materials to Organic Electronic Devices, 495
References, 497
17 Electrochemical Behavior and Redox Chemistry of Boroles 503
Holger Braunschweig and Ivo Krummenacher
17.1 Introduction, 503
17.2 Preparation, 505
17.3 Chemical Reactivity, 507
17.3.1 Lewis Acid–Base Adducts, 507
17.3.2 Cycloaddition Reactions, 508
17.3.3 σ©\Bond Activation Reactions, 509
17.4 Redox Chemistry, 510
17.4.1 Electrochemistry, 510
17.4.2 Preparative Reduction Chemistry, 514
17.5 Conclusions and Outlook, 518
References, 519
18 Isolation and Crystallization of Radical Cations by Weakly Coordinating Anions 523
Xinping Wang
18.1 Introduction, 523
18.2 Radical Cations and Dications Based on Triarylamines, 524
18.3 Radical Cations Containing Phosphorus, 528
18.4 The Radical Cation Containing a Selenium–Selenium Three©\Electron σ©\Bond, 534
18.5 Radical Cations of Organic Oligomers (π©\Dimerization), 536
18.6 σ©\Dimerization of Radical Cations, 540
18.7 Conclusion, 541
References, 542
19 Heavier Group 14 Element Redox Systems 545
Vladimir Ya. Lee and Akira Sekiguchi
19.1 Introduction, 545
19.2 Redox Systems of the Heavier Group 14 Elements E (E = Si–Pb), 547
19.2.1 Interconversion between Cations R3E+, Radicals R3E - , and Anions R3E−, 547
19.2.2 Anion and Cation©\Radicals of the Heavy Analogs of Carbenes R2E:, 552
19.2.3 Anion©\ and Cation©\Radicals of the Heavy Analogs of Alkenes R2E¨TER2 and Heavy Analogs of Alkynes R©¤E≡E©¤R, 555
19.3 Summary, 559
References, 559
20 π©\Electron Redox Systems of Heavier Group 15 Elements 563
Takahiro Sasamori, Norihiro Tokitoh and Rainer Streubel
20.1 Introduction, 563
20.2 The Redox Behavior of Dipnictenes, 564
20.3 The Redox Behavior of π©\Conjugated Systems of Heavier Dipnictenes, 571
20.4 The Redox Behavior of d–π Electron Systems Containing Heavier Dipnictenes, 572
20.5 Conclusion, 575
References, 575
Index 579
