Organic Redox Systems

Tohru Nishinaga, PhD, is an Associate Professor of Chemistry at Tokyo Metropolitan University. His current research interest is the design, synthesis and application of pi-electron systems with novel electronic properties. Dr. Nishinaga has published over 80 scientific papers and 10 book chapters.

• LIST OF CONTRIBUTO RS xvPREFACE xix1 Introduction: Basic Concepts and a Brief History of Organic Redox Systems 1Tohru Nishinaga1.1 Redox Reaction of Organic Molecules, 11.2 Redox Potential in Nonaqueous Solvents, 31.3 A Brief History of Organic Redox Compounds, 5References, 102 Redox©\Mediated Reversible 𝞂©\Bond Formation/Cleavage 13Takanori Suzuki, Hitomi Tamaoki, Jun©\ichi Nishida, Hiroki Higuchi, Tomohiro Iwai, Yusuke Ishigaki, Keisuke Hanada, Ryo Katoono, Hidetoshi Kawai, Kenshu Fujiwara and Takanori Fukushima2.1 Dynamic Redox (“Dyrex”) Systems, 132.1.1 π©\Electron Systems Exhibiting Drastic Structural Changes upon Electron Transfer, 132.1.2 Redox Switching of a σ©\Bond upon Electron Transfer, 162.1.3 Two Types of Dyrex Systems Exhibiting Redox Switching of a σ©\Bond, 172.2 Advanced Electrochromic Response of “Endo”©\Type Dyrex Systems Exhibiting Redox Switching of a σ©\Bond, 192.2.1 Tetraaryldihydrophenanthrenes as Prototypes of “Endo”©\Dyrex Systems, 192.2.2 Tricolor Electrochromism with Hysteretic Color Change in Non©\C2©\Symmetric “Endo”©\Dyrex Pair, 202.2.3 Electrochromism with Chiroptical Output of Chiral “Endo”©\Dyrex Pair, 212.2.4 Multi©\Output Response System Based on Electrochromic “Endo”©\Dyrex Pair, 242.3 Advanced Electrochromic Response of “Exo”©\Type Dyrex Systems Exhibiting Redox Switching of a σ©\Bond, 262.3.1 Bis(diarylethenyl)biphenyls as Prototypes of “Exo”©\Dyrex Systems, 262.3.2 Electrochromism with Chiroptical Output of Chiral “Exo”©\Dyrex Systems, 262.3.3 Electrochromism of “Exo”©\Dyrex Systems in Aqueous Media, 282.4 Prospect: Redox Systems With Multiple Dyrex Units, 31References, 333 Redox©\Controlled Intramolecular Motions Triggered by π©\Dimerization and Pimerization Processes 39Christophe Kahlfuss, Eric Saint©\Aman and Christophe Bucher3.1 Introduction, 393.2 Oligothiophenes, 403.3 Phenothiazine, 443.4 Naphthalene and Perylene Bisimides, 453.5 para©\Phenylenediamine, 473.6 Pyridinyl Radicals, 493.7 Viologen Derivatives, 503.8 Verdazyl, 603.9 Phenalenyl, 603.10 Porphyrins, 613.11 Benzenoid, 623.12 Cyclophane, 643.13 Tetrathiafulvalene, 683.14 Conclusion, 80Acknowledgments, 80References, 814 Tetrathiafulvalene: a Redox Unit for Functional Materials and a Building Block for Supramolecular Self©\Assembly 89Masashi Hasegawa and Masahiko Iyoda4.1 Introduction: Past and Present of TTF Chemistry, 894.2 Basic Redox Properties of TTF and Stacked TTF, 904.2.1 Monomeric TTFs, 904.2.2 Interactions in Stacked TTF Dimer, 924.2.3 Interactions in Stacked TTF Oligomers, 974.2.4 Head©\to©\Tail TTF Dimer, 984.3 TTF as a Faithful Redox Active Unit in Functional Materials, 1004.3.1 Electrochromic Materials, 1004.3.2 Optically Active TTFs, 1024.3.3 Uses as Positive Electrode Materials for Rechargeable Batteries, 1084.4 Electroconducting Properties of TTF Derivatives Based on Supramolecular Self©\Assembly, 1124.4.1 Redox©\Active Nanostructure Formation in the Solid State, 1134.4.2 Conducting Nanostructure Formation, 1154.4.3 Conducting Nanofibers by Iodine Doping, 1164.4.4 Conducting Nanofibers Based on Cation Radicals, 1204.4.5 Conducting Nanowires of Neutral TTF Derivatives, 1234.5 Summary and Outlook, 124References, 1255 Robust Aromatic Cation Radicals as Redox Tunable Oxidants 131Marat R. Talipov and Rajendra Rathore5.1 Introduction, 1315.2 Designing Molecules for the Formation of Stable Cation Radicals (Crs)—A Case Study, 1355.2.1 Exploring the Cause of Exceptional Stability of The©\Orange+·, 1375.3 Methods of Preparative Isolation of Aromatic Cation Radicals, 1425.3.1 Nitrosonium (NO+) Salts, 1435.3.2 Antimony Pentachloride (SbCl5), 1445.3.3 Triethyloxonium Hexachloroantimonate (Et3O+ SbCl6 –), 1485.3.4 Ddq and HBF4©\Ether Complex, 1495.4 Q uantitative Oxidation of Electron Donors using THE-Orange+·SbCl6 – as One©\Electron Oxidant, 1505.4.1 Analysis of Two©\Electron Oxidation Processes Using MF/D Plots, 1575.5 Readily Available Electron Donors for the Redox©\Tunable Aromatic Oxidants, 1645.5.1 Triptycene Based Electron Donors, 1645.5.2 Tetrabenzodifurans, 1665.5.3 Polyaromatic Hydrocarbons, 1685.5.4 Multi©\Electron Redox Systems, 1685.6 Conclusion, 171References, 1736 Air©\Stable Redox©\Active Neutral Radicals: Topological Symmetry Control of Electronic©\Spin, Multicentered Chemical Bonding, and Organic Battery Application 177Shinsuke Nishida and Yasushi Morita6.1 Introduction, 1776.2 Open©\Shell Graphene Fragment : Design and Synthesis of Air©\Stable Carbon©\Centered Neutral Radicals Based on Fused©\Polycyclic π©\System, 1796.3 Topological Symmetry Control of Electronic©\Spin Density Distribution by Redox and other External Stimuli, 1816.3.1 Redox©\Based Spin Diversity of Oxophenalenoxyl Sytems, 1816.3.2 Spin©\Center Transfer and Solvato©\/Thermochromism of Tetrathiafulvalene©\Substituted 6©\Oxophenalenoxyl Neutral Radical, 1836.4 Control of Electronic©\Spin Structure and Optical Properties of Multicentered C©¤C Bonds, 1846.4.1 Strong Somo–Somo Interaction within π©\Dimeric Structure of Phenalenyl Derivatives, 1846.4.2 Thermochromism Induced by Thermal Equilibrium of π©\Dimeric Structure and σ©\Dimeric Structure, 1886.4.3 Weak Somo–Somo Interactions by Molecular Modification of Phenalenyl System, 1906.4.4 Multidimensional Spin–Spin Interaction and π©\Staked Radical Polymer, 1936.5 Rechargeable Batteries Using Organic Electrode©\Active Materials, 1956.5.1 Closed©\Shell Organic Molecules as Electrode©\Active Materials, 1966.5.2 Closed©\Shell Organic Polymers, 2146.5.3 Stable Organic Neutral Radicals, 2186.5.4 Stable Organic Neutral Radical Polymers, 2206.6 Molecular Spin Batteries : Design Criteria and Performance of High Capacity Organic Rechargeable Battery Materials, 2236.6.1 Molecular Crystalline Secondary Batteries, 2236.6.2 Trioxotriangulene Neutral Radical (Tot) Derivatives, 2246.6.3 Molecular Spin Batteries, 2276.7 Conclusion, 229Acknowledgement, 231References, 2317 Triarylamine©\Based Organic Mixed©\Valence Compounds: The Role of the Bridge 245Christoph Lambert7.1 Introduction, 2457.2 The Mv Concept, 2467.3 The Redox Center, 2507.4 The Bridge, 2517.5 The Length of the Bridge, 2547.6 Changing the Connectivity, 2567.7 Twisting the Bridge, 2587.8 Saturated vs Unsaturated Bridge, 2587.9 Meta vs Para Conjugation, 2607.10 Switching the Bridge, 2627.11 Metal Atoms as the Bridge, 2637.12 And Finally: Without a Bridge, 264Acknowledgment, 265References, 2658 Magnetic Properties of Multiradicals Based on Triarylamine Radical Cations 269Shuichi Suzuki and Keiji Okada8.1 Introduction, 2698.2 Triarylamine Radical Cations as Synthetic Reagents for Preparation of Donor Radical Cations with Various Counter Anions, 2708.2.1 Syntheses of Tbpa +·Pf6− and Its Counteranion Analogues, 2708.3 Stable Triarylamines without para©\Substituents, 2708.4 Models of Intermolecular Exchange Interaction in Heteroatomic Systems, 2718.4.1 Dynamic Spin Polarization Model and Disjoint–Nondisjoint Model, 2718.4.2 Dynamic Spin Polarization and Spin Delocalization, 2728.4.3 Effect of Large Dihedral Angle between Spacer and Spin Source, 2738.4.4 p©\Phenylene Methodology or π©\Conjugation Using Topologically Different Spin Sources, 2758.5 Magnetic Susceptibility and Temperature Dependence, 2758.6 Poly(Diarylamino benzene) Poly(Radical Cation)s, 2768.7 Radical Substituted Triarylamines, 2788.7.1 tbuno©\Substituted Triarylamines, 2788.7.2 Nn©\Substituted Triarylamines, 2798.8 Towards Further Developments, 282References, 2839 Open©\Shell π©\Conjugated Hydrocarbons 287Takashi Kubo9.1 Introduction, 2879.2 Monoradicals, 2889.2.1 Triphenylmethyl, 2889.2.2 Phenalenyl, 2899.2.3 Cyclopentadienyl, Indenyl, Fluorenyl, 2919.2.4 Cycloheptatrienyl, 2939.2.5 Bdpa , 2949.2.6 Dinaphthofluorenyl, 2949.3 Biradicals, 2959.3.1 Triplet Biradicals, 2959.3.2 Singlet Biradicals: Quinodimethanes, 2969.3.3 Singlet Biradicals: Bisphenalenyl System, 2989.3.4 Singlet Biradicals: Acences, 3009.3.5 Singlet Biradicals: Anthenes, 3019.3.6 Singlet Biradicals: Zethrenes, 3039.3.7 Singlet Biradicals: Indenofluorenes, 3049.4 Polyradicals, 304References, 30510 Indenofluorenes and Related Structures 311Jonathan L. Marshall and Michael M. Haley10.1 Introduction, 31110.2 Indeno[1,2©\a]fluorenes, 31310.2.1 Indeno[1,2©\a]fluorene©\7,12©\dione, 31310.2.2 Truxenone, An Indeno[1,2©\a]fluorene Related Structure, 31410.3 Indeno[1,2©\b]fluorenes, 32010.3.1 Indeno[1,2©\b]fluorene©\6,12©\diones, 32010.3.2 Dicyanomethylene Indeno[1,2©\b]fluorenes, 32510.3.3 Fully Conjugated Indeno[1,2©\b]fluorenes, 32710.4 Indeno[2,1©\a]fluorenes, 33310.5 Indeno[2,1©\b]fluorenes, 33610.6 Indeno[2,1©\c]fluorenes, 33910.6.1 Indenofluorene-Related Structures, 34110.7 Fluoreno[4,3©\c]fluorene, 34210.8 Indacenedithiophenes, 34510.8.1 Indacenedithiophene Diones, 34510.8.2 Tetrathiofulvalene and Dicyanomethylene Indacenedithiophenes, 34710.8.3 Fully Conjugated Indacenedithiophenes, 34910.9 Diindeno[n]thiophenes, 35110.10 Conclusions, 354Acknowledgment, 354References, 35411 Thienoacenes 359Kazuo Takimiya11.1 Introduction, 35911.2 Synthesis of Thienoacenes via Thienannulation, 36111.2.1 Bdt and Adt Derivatives, 36111.2.2 Thienannulation to Construct Thienoacenes with Terminal Thiophene Ring(s), 36211.2.3 Thienannulation to Construct Thienoacenes with Internal Thiophene Ring(s), 36611.3 Molecular Electronic Structures, 37011.4 Application to Electronic Devices, 37311.4.1 Molecular Organic Semiconductors for p©\Type OFET Devices, 37311.4.2 Semiconducting Polymers for Pscs, 37711.5 Summary, 379References, 37912 Cationic Oligothiophenes: p©\Doped Polythiophene Models and Applications 383Tohru Nishinaga12.1 Introduction, 38312.2 Design Principle and Synthetic Methods, 38412.3 Electrochemistry, 39012.4 Structural and Spectroscopic Properties as p©\Doped Polythiophene Models, 39712.5 Application to Supramolecular Systems, 40312.6 Conclusion and Outlook, 406References, 40613 Electron©\Deficient Conjugated Heteroaromatics 411Yutaka Ie and Yoshio Aso13.1 Introduction, 41113.2 Hexafluorocyclopenta[c]thiophene and its Containing Oligothiiophenes, 41213.3 Difluoromethylene©\Bridged Bithiophene and its Containing Oligothiiophenes, 41613.4 π©\Conjugated Systems Having Thiazole©\Based Carbonyl©\Bridged Compounds, 41913.5 Difluorodioxocyclopentene©\Annelated Thiophene and its Containing Oligothiiophenes, 42713.6 Dioxocycloalkene©\Annelated Thiophene and its Containing Oligothiiophenes, 43313.7 Dicyanomethylene©\Substituted Cyclopenta[b]thiophene and its Containing π©\Conjugated System, 43413.8 Electron©\Deficient π©\Conjugated System Containing Dicyanomethylene©\Substituted Cyclopenta[b]thiophene Toward Organic Photovoltaics, 43713.9 Conclusion, 440References, 44114 Oligofurans 445Ori Gidron14.1 Background, 44514.2 Synthesis and Reactivity, 44614.3 Properties of Oligofurans in the Neutral State, 44914.4 Properties of Cationic Oligofurans, 45214.5 Polyfurans, 45414.6 Devices with Furan©\Containing Materials, 45514.7 Summary and Outlook, 459References, 45915 Oligopyrroles and Related Compounds 463Masayoshi Takase15.1 Introduction, 46315.2 Linear Oligopyrroles, 46415.2.1 Synthesis, 46415.2.2 Optical and Redox Properties, 46515.2.3 π©\Dimer of Oligopyrrole Radical Cations, 46615.3 Cyclic Oligopyrroles, 46715.3.1 Synthesis, 46815.3.2 Optical and Redox Properties, 46915.4 Pyrrole©\Fused Azacoronenes, 46915.4.1 Synthesis, 47015.4.2 Optical and Redox Properties, 47015.4.3 Aromaticity, 47315.5 Conclusions, 474References, 47416 Phospholes and Related Compounds: Syntheses, Redox Properties, and Applications to Organic Electronic Devices 477Yoshihiro Matano16.1 Introduction, 47716.2 Synthesis of π©\Conjugated Phosphole Derivatives, 47816.3 Redox Potentials of Phosphole Derivatives, 48316.4 Electrochemical Behaviors of Phosphole Derivatives, 49316.5 Applications of Phosphole©\Based Materials to Organic Electronic Devices, 495References, 49717 Electrochemical Behavior and Redox Chemistry of Boroles 503Holger Braunschweig and Ivo Krummenacher17.1 Introduction, 50317.2 Preparation, 50517.3 Chemical Reactivity, 50717.3.1 Lewis Acid–Base Adducts, 50717.3.2 Cycloaddition Reactions, 50817.3.3 σ©\Bond Activation Reactions, 50917.4 Redox Chemistry, 51017.4.1 Electrochemistry, 51017.4.2 Preparative Reduction Chemistry, 51417.5 Conclusions and Outlook, 518References, 51918 Isolation and Crystallization of Radical Cations by Weakly Coordinating Anions 523Xinping Wang18.1 Introduction, 52318.2 Radical Cations and Dications Based on Triarylamines, 52418.3 Radical Cations Containing Phosphorus, 52818.4 The Radical Cation Containing a Selenium–Selenium Three©\Electron σ©\Bond, 53418.5 Radical Cations of Organic Oligomers (π©\Dimerization), 53618.6 σ©\Dimerization of Radical Cations, 54018.7 Conclusion, 541References, 54219 Heavier Group 14 Element Redox Systems 545Vladimir Ya. Lee and Akira Sekiguchi19.1 Introduction, 54519.2 Redox Systems of the Heavier Group 14 Elements E (E = Si–Pb), 54719.2.1 Interconversion between Cations R3E+, Radicals R3E ·, and Anions R3E−, 54719.2.2 Anion and Cation©\Radicals of the Heavy Analogs of Carbenes R2E:, 55219.2.3 Anion©\ and Cation©\Radicals of the Heavy Analogs of Alkenes R2E¨TER2 and Heavy Analogs of Alkynes R©¤E≡E©¤R, 55519.3 Summary, 559References, 55920 π©\Electron Redox Systems of Heavier Group 15 Elements 563Takahiro Sasamori, Norihiro Tokitoh and Rainer Streubel20.1 Introduction, 56320.2 The Redox Behavior of Dipnictenes, 56420.3 The Redox Behavior of π©\Conjugated Systems of Heavier Dipnictenes, 57120.4 The Redox Behavior of d–π Electron Systems Containing Heavier Dipnictenes, 57220.5 Conclusion, 575References, 575Index 579