Chemical Science of p-Electron Systems (eBook)

Preface 6
Contents 8
Contributors 12
Part I Extension of Planar ?-Electron Systems 18
1 Dibenzopentalenes and Related Compounds 19
1.1 Introduction 19
1.2 Syntheses of ?-Extended Pentalenes 20
1.2.1 Synthesis of ?-Extended Pentalenes with Thiophene and Naphthalene Rings 23
1.3 Molecular Structures 23
1.4 Electronic Properties 26
1.4.1 Electronic Properties of Dibenzopentalenes 26
1.4.2 Electronic Properties of ?-Extended Pentalenes 26
1.5 Electrochemical Properties 28
1.6 Solid-State Properties 28
1.7 Conclusions 30
References 30
2 Synthesis of a Porphyrin-Fused -Electron System 32
2.1 Introduction 33
2.2 Oligoporphyrins Fused with Benzene Units 34
2.2.1 Preparation of Benzene-Fused Diporphyrins 35
2.2.2 Preparation of Benzene-Fused Tri-, Tetra-, and Pentaporphyrins 37
2.3 Diporphyrin Fused with Polycyclic Aromatic Hydrocarbons 39
2.4 Conclusion 45
2.5 Experiments 45
2.5.1 I-Shaped BCOD-Fused Triporphyrin 14a-Ni2Zn 46
2.5.2 L-Shaped BCOD-Fused Triporphyrin 16-Ni2Zn 46
2.5.3 T-Shaped BCOD-Fused Tetraporphyrin 17-Ni3Zn 46
2.5.4 Diporphyrin Fused with Ethanonaphthalene 26 47
2.5.5 Diporphyrin Fused with Naphthalene 27 47
2.5.6 Diporphyrin Fused with Ethanoanthracene 30 47
2.5.7 Diporphyrin Fused with Anthracene 31 48
2.5.8 Diporphyrin Fused with Ethanonaphthacene 35 48
2.5.9 Diporphyrin Fused with Diethanopentacene 41 48
2.5.10 Diporphyrin Fused with Chrysene 48 49
References 50
3 Higher-Order ?-Electron Systems Based on Helicene Molecules 52
3.1 Introduction 52
3.2 Aggregates of Helicene Molecules 53
3.3 Helicene Molecules Aligned in Crystals 54
3.4 Molecules with Multiple Helicenes Connected by Covalent Bonds and Their Assemblies 58
References 60
4 Planar Cyclooctatetraenes and Related Ring Systems: Antiaromaticity and Applications 62
Abbreviations 62
4.1 Introduction 63
4.1.1 Brief History of Cyclooctatetraene (COT) Chemistry 63
4.1.2 Antiaromaticity of Planar COT 65
4.2 Planar COTs and Related Ring Systems and Their Antiaromaticity 66
4.2.1 Dehydro[8]annulenes 66
4.2.2 COTs Planarized by Annelation with Small Rings 68
4.2.3 COTs Planarized by Annelation with Rigid ?-Systems 71
4.2.4 Hetero[8]circulenes 76
4.3 Optical and Electronic Applications 77
4.4 Conclusions 80
References 80
5 Synthesis, Crystal Structures, and Solid-State Optical Properties of Substituted Tetracenes 83
5.1 Substituted Tetracenes 84
5.2 Synthesis of Substituted Tetracenes 85
5.2.1 1,4,7,10-Tetra(n-alkyl)tetracenes 85
5.2.2 1,4,7,10-Tetra(isoalkyl)tetracenes 85
5.2.3 Anti-/syn-regioisomeric Tetracene Mixtures 86
5.2.4 1,4-Di(n-alkyl)tetracene 87
5.2.5 2,3-Di(n-alkyl)tetracenes 87
5.2.6 2,3,8,9-Tetra(n-alkyl)tetracenes 88
5.2.7 Octa( n-alkyl)tetracene-1,2,3,4,7,8,9,10-octacarboxylates 89
5.3 Optical Properties of Substituted Tetracenes 89
5.3.1 Solid-State Color 89
5.3.2 Solid-State Fluorescence 91
5.4 Crystal Structure of Substituted Tetracenes 93
5.4.1 Molecular Structure 93
5.4.2 Molecular Packing 96
5.5 Conclusions 100
References 101
Part II Curved ?-Electron Systems 102
6 Chiral Sumanene, Triazasumanene, and Related Buckybowls 103
6.1 Introduction 103
6.2 Enantioselective Synthesis of Chiral Buckybowl 105
6.3 Enantioselective Synthesis of Chiral Azabuckybowl 111
6.4 Stereoelectronic Effect of Curved ?-System 113
6.5 Perspectives 116
References 116
7 Heteroatom-Containing Sumanene 119
7.1 Introduction 119
7.2 Replacement of Bridging CH2 Groups by Heteroatoms 120
7.2.1 Group 14 Elements 120
7.2.1.1 Silicon Derivatives (Trisilasumanene) 120
7.2.1.2 Germanium Derivative (Trigermasumanene) 122
7.2.1.3 Tin Derivative (Tristannasumanene) 123
7.2.2 Group 15 Elements 123
7.2.3 Group 16 Elements 124
7.2.3.1 Sulfur Derivative (Trithiasumanene) 124
7.2.3.2 Selenium Derivative (Triselenasumanene) 124
7.2.4 Others 125
7.3 Replacement of Carbon Atoms in the Peripheral Benzene Rings 126
7.4 Conclusion 127
References 127
8 Open-Cage Fullerene Derivatives: Synthesis, Reactions, and Encapsulation of a Small Molecule 129
8.1 Introduction 129
8.2 C=C Bond Cleavage of Fullerene Cages 130
8.2.1 Diketo Derivative of C60 [19] 130
8.2.2 Ketolactam Derivative of C60 [26] 132
8.3 Insertion of a Sulfur Atom [24] 135
8.4 Reaction of Open-Cage C70 Derivative [40] 137
8.5 Summary 141
References 142
9 Endohedral Metallofullerenes: From Chemical Reactivity to Material Performance 144
9.1 Introduction 145
9.2 Chemical Reaction of EMFs 145
9.2.1 Diels–Alder Reaction 146
9.2.2 Enantioselective 1,3-Dipolar Cycloaddition 147
9.2.3 Silylene Addition 147
9.2.4 Bisfulleroid Formation Reaction 148
9.3 EMF-Based Donor–Acceptor Conjugates 150
9.3.1 Trimetallic Nitride Templated EMFs 150
9.3.2 Di-metallic EMFs 153
9.3.3 Monometallic EMFs 154
9.4 Carrier Transport Properties of EMFs 155
9.4.1 Conductivity of EMF Crystals 155
9.4.2 Conductivity of a Single-Molecule EMF 158
9.5 Surface-Grafted EMFs 158
9.6 Concluding Remarks 159
References 160
10 Tuning Physical Properties and Structures of ?-Electron System Formed by Single-Wall Carbon Nanotubes with Selected Chiralities 165
10.1 Control of Colors of ?-Electron Network System of SWCNTs [13] 166
10.2 Control of Conducting and Thermoelectric Properties of High-Purity Semiconducting SWCNTs [19] 170
10.3 Control of Charges of Molecules Inside the ?-Nanospace: Manipulation of Charges of Molecules Encapsulated Inside SWCNTs [25] 175
10.4 Control of ?-Electron Structure Formed by SWCNTs: Approaches to Make Ordered SWCNT Assemblies Through Self-Assembled Processes [34] 179
10.5 Summary 182
References 183
11 Recent Progress on the Chemical Reactions of Single-Walled Carbon Nanotubes 186
11.1 Introduction 187
11.2 Analysis of Sidewall-Functionalized SWNTs 188
11.2.1 Absorption Spectroscopy 188
11.2.2 Raman Spectroscopy 189
11.2.3 Thermogravimetric Analysis 190
11.3 Two-Step Reductive Alkylation of SWNTs 190
11.3.1 Reductive Alkylation and Nucleophilic Alkylation Using Organometallic Compounds 190
11.3.2 Two-Step Reductive Alkylation of SWNTs 191
11.4 Photochemical Reaction of SWNTs 195
11.4.1 Photoinduced Electron Transfer Reactions with Amines 195
11.4.2 Helicity-Selective Photooxidations with Disulfides 197
11.5 Conclusion 200
References 201
Part III Porphyrinoids 207
12 Novel ?-Conjugated Systems Based on N-ConfusedPorphyrinoids 208
12.1 Introduction 208
12.2 Reduction of NCPs to N-Confused Hydroporphyrins 212
12.3 Oxidation to N-Fused and C-oxo Analogues from N-Confused Porphyrinoids 215
12.4 Skeletal Rearrangement Toward N-Confused Porphyrinoids 217
12.5 Neo-confusion: N-Linked Porphyrinoids 219
12.6 Longitudinally Stacked N-Confused Porphyrinoids 222
12.7 Summary and Outlook 224
References 225
13 Heteroatom-Modified Porphyrinoids 229
13.1 Introduction 230
13.2 Porphyrins Bearing Phosphorus or Sulfur Functional Groups on meso Carbons 231
13.2.1 meso-Phosphanylporphyrins and Their Metal-Linked Dimers 231
13.2.2 meso-Phosphinyl- and meso-Sulfinylporphyrins and Their Cofacial Dimers 234
13.2.3 Porphyrin-Appended Phosphapalladacycles in Heck Reaction 236
13.3 Porphyrin Derivatives Containing Nitrogen Atoms at meso Positions 239
13.3.1 ?-Unsubstituted 5,15-Diazaporphyrins 239
13.3.2 Covalently Linked Bis(5,15-Diazaporphyrin)s 240
13.4 Conclusion 243
References 243
14 Synthesis of Novel Porphyrinoids from Dipyrrins 248
14.1 Introduction 248
14.2 Synthesis of Cyclic BODIPY Dimer and Trimer 249
14.3 Synthesis of Azaporphyrinoids from Bisdipyrrin 250
14.4 Synthesis of Thiaporphyrinoids 252
14.5 Synthesis of Norcorrole Ni(II) Complex 253
14.6 Reactivity of Antiaromatic Norcorrole Ni(II) Complex 255
14.7 Synthesis of Octaphyrin from Bisdipyrrin 256
14.8 Summary 258
References 258
15 Möbius Aromatic and Antiaromatic Expanded Porphyrins 261
15.1 Möbius Aromaticity 261
15.2 Metal Complexes 262
15.3 Fusion Reactions 264
15.4 Protonation and Deprotonation 266
15.5 Control of Equilibrium by Temperature and Solvent 269
15.6 Möbius Antiaromaticity 270
15.7 Peripheral Functionalizations 272
15.8 Summary and Outlook 274
References 275
16 Recent Advances in the Chemistry of Phthalocyanines as Functional Chromophores 277
16.1 Introduction 277
16.2 Synthesis of Pc Analogues with Novel ?-Conjugated Systems 279
16.2.1 Phthalocyanine Analogues 279
16.2.2 Core-Modified Phthalocyanines 281
16.2.3 Expanded Pc Analogues 283
16.3 Control of Electronic Absorption in the Visible and Near-Infrared Regions: Perturbed Chromophore Systems of Pc 284
16.3.1 Push-Pull Tetraazaporphyrins 284
16.3.2 Novel NIR-Absorbing Pc Using the Synergetic Effects of the Group 15 and 16 Elements 286
16.3.3 Longitudinally Stacked Pc Systems 288
16.4 Summary and Outlook 292
References 292
Part IV Open-Shell ?-Electron Systems 296
17 Localized Singlet 1,3-Diradicals 297
17.1 Introduction 297
17.2 Generation of Cyclopentane-1,3-diyls and Cyclobutane-1,3-diyls 298
17.3 Spin Preference in Diradicals: The Effects of “Through-Space (TS)” and “Through-Bond (TB)” Interaction 299
17.4 Substituent Effect on Ground-State Spin Multiplicity and Singlet–Triplet Energy Gap in 1,3-Diradicals 302
17.5 Spiroconjugation Effect 303
17.6 Heteroatom Effect 305
17.7 Reactivity of Type 1 and Type 2 Singlet Diradicals 306
17.8 Experimental Studies on Localized Singlet Diradicals with Type 1 Electronic Configuration 307
17.9 Generation and Reactivity of DR7,8 309
17.10 Generation and Reactivity of Singlet Diradicals with a Type 2 Electronic Configuration 310
17.11 Mechanism of the Denitrogenation Reaction of Cyclic Azoalkanes 311
17.12 Summary and Future Prospects 312
References 313
18 Unique Orbital Interactions in the Ground and Electronically Excited States of Biradicals Brought about by the Existence of “Twisted ?-Space” 317
18.1 Introduction 317
18.2 Absorption Characteristics and Orbital Interactions in the Six-Membered Cyclic 1,4-Radical Cation 2•+ that Possesses “Twisted ?-Space” 318
18.3 Luminescence Characteristics and Orbital Interactions in the Electronically Excited State of the Six-Membered Cyclic 1,4-Biradical 2••* that Possesses “Twisted ?-Space” 322
18.4 Conclusion 323
References 324
19 Recent Progress in Stable High-Spin Molecules Based on Nitroxide Radicals 325
19.1 Introduction 325
19.2 Stable Trimethylenemethane Analogues 326
19.3 Stable Radical-Substituted Radical Cation Species with Large Positive Exchange Interactions 329
19.4 Spin-State Conversion System by Oxidation: Trinitroxide-Substituted Trioxytriphenylamine 332
19.5 Conclusions 334
References 335
20 Organic Chemistry of Graphene Framework 338
20.1 Introduction 338
20.2 Electronic Structures and Chemical Reactivity of Nanoscale Graphene Frameworks 339
20.2.1 Electronic Structure of Graphene and Nanographene 339
20.2.2 Chemical Reactivity of Graphene 342
20.3 Recent Advances in Chemical Preparation of GNRs 344
20.4 Spin State of Polycyclic Aromatic Hydrocarbons (PAHs) 345
20.5 Origin of the Spin-Polarized State in PAHs: Theoretical and Experimental Studies of Anthenes 349
20.5.1 Theoretical Background 349
20.5.2 Syntheses of Anthenes 351
20.5.2.1 Straightforward Stepwise Syntheses 351
20.5.2.2 Direct Cyclization of Anthracene Oligomer 352
20.5.3 Molecular Structure 352
20.5.4 Magnetic Properties 354
20.5.5 Optical Properties 355
20.6 Concluding Remarks 356
References 356
Part V Heteroatom-Conjugated ?-Electron Systems 362
21 Boron-Containing -Electron Systems 363
21.1 Introduction 363
21.2 Boracycle-Based ?-Conjugated Systems 365
21.3 Planarized Triphenylboranes 367
21.4 Boron-Doped Nanographenes 371
21.5 Conclusion and Outlook 375
References 375
22 Doubly Bonded Silicon Compounds Showing Intramolecular Charge-Transfer Transitions 378
22.1 Disilenes Showing Intramolecular Charge-Transfer (ICT) Transitions 380
22.2 Silenes Showing Intramolecular Charge-Transfer (ICT) Transitions 384
22.3 Theoretical Study of Isomerization of Disilacyclopropanimine to 3-Silylene-2-Silaaziridine 387
22.4 Conclusion 387
References 388
23 ?-Conjugated Disilenes and Tetrasilacyclobutadiene 391
23.1 Introduction 391
23.2 ?-Conjugated Disilenes 392
23.3 Tetrasilacyclobutadiene 395
23.4 Summary 398
References 399
24 Tin-Containing ?-Electron Systems 401
24.1 Introduction 401
24.2 Stannapentafulvenes 403
24.3 Stannacyclopentadienide 406
24.4 Neutral Stannaaromatic Compounds Based on a Six-Membered Ring 412
References 415
Part VI Supramolecular Chemistry of ?-Electron Systems 419
25 Supramolecular Structures and Photoelectronic Properties of ?-Complexes Composed of Self-Assembling Cyclic Porphyrin Dimers and Fullerenes 420
25.1 Introduction 421
25.2 Inclusion of C60 and C70 Within Cyclic Porphyrin Dimers in Solution 423
25.3 Supramolecular Structures and Photoelectronic Properties of ?-Complexes of Ni2-C4-CPDPy(H) with C60 424
25.4 Supramolecular Structures and Photoelectronic Properties of ?-Complexes of H4-C4-CPDPy(H) with C60 427
25.5 Supramolecular Structures of ?-Complexes of Ni2-C4-CPDPy(H) and H4-C4-CPDPy(H) with [6,6]-Phenyl-C61-butyric Acid Methyl Ester (PCBM) 430
25.6 Supramolecular Structures of ?-Complexes of Ni2-C4-CPDPy(H) and H4-C4-CPDPy(H) with C70 431
25.7 Supramolecular Structures of ?-Complexes of H4-Ptz-CPDPy(OC3) with C60 433
25.8 Photoelectronic Properties of ?-Complexes of H4-C4-CPDPy(OC6) and Ni2-C4-CPDPy(OC6) with Li+@C60 436
25.9 Summary 436
References 437
26 Sequence Control of ?-Electron Systems 440
26.1 Introduction 440
26.2 Directed Columnar Assembly of Fused Copper Porphyrin Dimers for the Design of Liquid Crystalline Organic Semiconductors 441
26.3 The First Liquid Crystalline Corannulenes 443
26.4 A Supramolecular Spin Sequence That Exhibits Switchable Magnetic Interactions 444
26.5 Sequence Control of ?-Electron Systems at Surfaces 446
26.6 Controlled Self-Assembly of a Donor–Acceptor Dyad for the Construction of Supramolecular Heterojunction 448
26.7 Arrays of ?-Electronic Metal Complexes with a Precisely Designed Sequence 449
References 453
27 Integrated ?-Electron Systems on Artificial Cell Membranes 454
27.1 Introduction 454
27.2 Artificial Cell Membranes as Platforms for Integrated ?-Electron Systems 455
27.3 Dynamic Behavior of Artificial Cell Membranes as Molecular Devices 457
27.3.1 Supramolecular Devices for Artificial Membrane Trafficking 458
27.3.1.1 Synthetic Cell Division Induced by a Molecular Signal 458
27.3.1.2 Vesicle Propagation Controlled by Artificial Receptors 460
27.3.2 Supramolecular Devices for Artificial Signal Transduction 463
27.3.2.1 Switching of Enzymatic Activity by a Thermoresponsive Artificial Receptor 465
27.3.2.2 Switching of Enzymatic Activity by a Photoresponsive Artificial Receptor 467
27.4 Conclusions 468
References 469
28 Supramolecular Porphyrin Nanorods for LightEnergy Conversion 472
28.1 Introduction 472
28.2 Results and Discussion 473
28.2.1 Sonication-Assisted Supramolecular Nanorods of Porphyrins 473
28.2.2 Metal Coordination-Assisted Supramolecular Porphyrin Assemblies 476
28.2.3 Fullerene-Encapsulated Supramolecular Porphyrin Nanorods for Photovoltaics 479
28.2.4 Pt-/TiO2-Encapsulated Supramolecular Porphyrin Nanorods for Photocatalytic Hydrogen Evolution 482
28.3 Conclusion 484
References 485
29 Metal Nanoparticle/Porphyrinoid Hybrids 489
29.1 Au/Porphin Hybrid Nanostructures 489
29.1.1 Au/Porphyrin Hybrid Nanoparticles 489
29.1.2 Au/Phthalocyanine Hybrid Nanoparticles 493
29.2 OFET Device Fabrications 497
References 503
Part VII Innovative Function of ?-Electron Systems 505
30 Control of Chiral -Space in Highly Organized -Conjugated Polymer Nanotube Compositesand Their Functions 506
30.1 Plasmonic Hybrid Nanotubes 507
30.2 Heterojunctioned Hybrid Polymer Nanotubes 510
30.3 Chiral Magnetite–Polythiophene Nanotubes 514
30.4 Encapsulation and Release in the Nanospace of Redox-Active Cationic Polymer Nanotubes 517
References 522
31 Photoinduced Electron-Transfer Functions of -Electron Donor–Acceptor Supramolecular Complexes 523
31.1 Introduction 523
31.2 Supramolecular Complexes of Carbon Nanohorns with Fullerenes 524
31.3 Supramolecular Complexes of Graphene Oxides with Perylenediimide 526
31.4 Supramolecular Complexes of Porphyrin Dendrimers with ?-Electron Acceptors 527
31.5 Supramolecular Complexes of Porphyrin Polypeptides with Fullerenes 531
31.6 Supramolecular Complexes of Cationic and Anionic Porphyrins 532
31.7 Conclusions 534
References 535
32 Fused ?-Electron Systems Containing Group 15 Elements and Their Application to Organic Electronics 538
32.1 Introduction 538
32.2 Effect of Group 15 Heteroatoms (1): Nitrogen 539
32.2.1 Fused ?-Electron Systems Containing Nitrogen Atoms 540
32.2.2 N-HexBn-BDPs and Their Application to OLEDs 540
32.2.3 Hexaaryl-BDPs and Their Application to OLEDs 541
32.2.4 Bis(cinnoline)s and Their Application as a Buffer Layer in Solar Cells 544
32.3 Effect of Group 15 Heteroatoms (2): Phosphorus 546
32.3.1 Fused ?-Electron Systems Including Phosphorus Atoms 546
32.4 Summary 548
References 549
33 Fullerene Derivatives for Organic Solar Cells 551
33.1 Introduction 551
33.2 1,4-Bis(Silylmethyl)[60]Fullerenes and Related Compounds 552
33.3 1-Aryl-4-Silylmethyl[60]Fullerenes 554
33.4 Methano Indene Fullerenes 555
33.5 Fullerene Derivatives Having Low-Lying LUMO Levels 560
33.6 Lithium Ion-Containing Fullerene Derivatives 561
33.7 Conclusions 563
References 563
34 Efficient Organic Devices Based on ?-Electron Systems: Comparative Study of Fullerene Derivatives Blended with a High Efficiency Naphthobisthiadiazole-Based Polymer for Organic Photovoltaic Applications 566
34.1 Introduction 567
34.2 Optical Characteristics and Device Performances 569
34.2.1 Photovoltaic Performances of PNTz4T:Fullerene Derivatives 569
34.2.2 Relationship Between Light Absorption and Jsc 570
34.3 Morphology of PNTz4T:Fullerene Derivatives' Thin Films 571
34.3.1 PNTz4T Crystallinity and Crystallite Orientation 571
34.3.2 Formation of Vertical Donor-Acceptor Gradients for Efficient Charge Percolation 572
34.4 Charge Collection in PNTz4T:Fullerene Derivatives' Devices 574
34.4.1 Crystallite Orientation and Hole Conductivity 574
34.4.2 Electron Conductivities of the Various Fullerene Derivatives in the Blends 574
34.4.3 Limiting Factor in the PNTz4T:Fullerene Derivative Blends 575
34.5 Conclusion 576
34.6 Experimental Section 577
34.6.1 Device Preparation 577
34.6.2 Morphological Characterizations 577
34.6.3 Device Characterization 578
References 578
35 Solution-Processed Organic Thin-Film Transistors 580
35.1 Introduction 580
35.2 Hall Measurements on High-Mobility Organic Semiconductor Transistors 582
35.2.1 High-Mobility Organic Transistors 582
35.2.2 Hall Measurements on OFETs 584
35.3 Hall Measurements on Organic Single-Crystal Rubrene FET 585
35.4 Transistors Based on New Organic Semiconductors DNTT and C8-BTBT 588
35.4.1 DNTT Single-Crystal FET Prepared by PVT Method 588
35.4.2 C8-BTBT and C10-DNTT High-Mobility Single-Crystal FETs Prepared by Solution Crystallization Method 588
35.4.3 DNTT and C8-BTBT Polycrystalline TFTs Prepared by Solution Crystallization Method 589
35.5 Pentacene Single-Crystal and Polycrystalline FETs 592
35.6 Summary and Prospects 594
References 595
36 Unveiling Charge Carrier Transport in ?-Conjugated Molecular Wire on Micro- and Macroscopic Scales 596
36.1 Introduction 597
36.2 Evolution of Microwave Conductivity Technique 600
36.3 Unveiling Charge Carrier Transport of Molecular Wires 604
36.4 Conclusion 607
References 608
37 STM Characterization of ?-Electron Systems 612
37.1 Experimental Conditions of STM and STS 612
37.2 Molecular Resonant Tunneling Diode Demonstrated by STS 617
References 624
38 Light Amplification in Low-Dimensional Crystals of Thiophene/Phenylene Co-oligomer Derivatives 626
38.1 Introduction 627
38.2 Crystal Characterization of Thiophene/Phenylene Co-oligomer Derivatives 628
38.2.1 Molecular Modification of Thiophene/Phenylene Co-oligomers 628
38.2.2 Methoxy-Substituted Thiophene/Phenylene Co-oligomers 629
38.2.3 Cyano-Substituted Thiophene/Phenylene Co-oligomers 632
38.2.4 Epitaxial Growth of Unsubstituted Thiophene/Phenylene Co-oligomers 633
38.3 Light Amplification in Low-Dimensional Crystals of TPCO Derivatives 635
38.3.1 Light Amplification and Lasing in Platelet Crystal of BP2T-OMe 635
38.3.2 Light Amplification and Lasing in Rodlike Crystal of BP1T-CN 637
38.3.3 Light Amplification and Lasing in Epitaxially Grown BP2T Crystals 638
38.3.4 Time-Delayed Emission in Single Crystal of BP1T-OMe 640
38.4 Conclusions 643
References 644
Part VIII ?-Electron Systems in Biosystems and Biomimetics 646
39 Electron Transfer Pathway Analysis in Bacterial Photosynthetic Reaction Center 647
39.1 Introduction 647
39.2 Electron Transfer in Photosynthetic Reaction Center 648
39.3 Theory and Computational Methods 650
39.3.1 Rate of Electron Transfer 650
39.3.2 Electronic Structure Calculation of Large Molecules 651
39.3.2.1 FMO Method 651
39.3.2.2 FMO-LCMO Method 652
39.3.3 Electronic Coupling Matrix Elements 653
39.3.3.1 Two-State Picture in Nonadiabatic Regime 653
39.3.3.2 Generalized Mulliken-Hush Analysis 654
39.3.3.3 Bridge Green Function Method 654
39.3.4 Electron Transfer Pathway Analysis 655
39.4 Applications to Bacterial Photosynthetic Reaction Center 656
39.4.1 Experimental Facts 657
39.4.2 Computational Results 657
39.4.2.1 Evaluation of Electron Transfer Rate 657
39.4.2.2 Role of Nonheme Iron Complex: Spin State and Substitution 658
39.4.2.3 Electron Transfer Pathway Analysis 660
39.5 Concluding Remarks 661
References 662
40 Spectroscopic Analysis of the Redox Reactions of ?-Conjugated Cofactors in Photosynthetic Reaction Center 664
40.1 Introduction 664
40.2 Tyrosine YZ: Proton-Coupled Electron Transfer Leading to Water Oxidation 667
40.3 Chlorophyll Dimer P680: Source of Strong Oxidation Power 669
40.4 Pheophytin: Primary Electron Acceptor Regulating Forward and Backward Electron Transfer 672
40.5 Quinone-Iron Complex: Electron Acceptors Controlling PSII Reactions 673
40.5.1 Effect of Hydrogen Bonding Interaction on the Redox Potential and Molecular Vibrations of Plastoquinone 674
40.5.2 Em Shift of QA by Herbicide Binding 676
40.5.3 Long-Range Interaction Between the Mn4Ca Cluster and the Quinone-Fe Complex 678
References 680
41 Protein-Controlled Isomerization in Rhodopsins 684
41.1 Retinal Chromophore in Animal and Microbial Rhodopsins 684
41.2 Unique Photochemistry of the Retinal Chromophore in Protein 688
41.3 Photoisomerization and Energy Storage in Animal Rhodopsins 690
41.4 Photoisomerization and Energy Storage in Microbial Rhodopsins 695
41.5 Conclusion and Perspectives 699
References 701
42 ?-Diketiminates as Redox Non-innocent Supporting Ligands in Coordination Chemistry 703
42.1 Introduction 703
42.2 Ligand Reduction 704
42.3 Ligand Oxidation 707
42.4 ?-Diketiminate Ligand Carrying Additional Redox-Active Substituents 712
42.5 Concluding Remarks 716
References 716
43 Novel Functions of ?-Electron Systems in a Heme-DNA Complex 719
43.1 Introduction 719
43.2 ?-Electron Systems in G-Quadruplex DNAs 721
43.3 Spectroscopic Properties of Heme-DNA Complexes 722
43.4 Interaction Between a Heme and the G-Quartet in Heme-DNA Complexes 724
43.4.1 Heme(Fe2+)-DNA Complex 724
43.4.2 Heme(Fe3+)-DNA Complex 730
43.5 Functional Properties of the Heme-DNA Complex 734
References 735
44 Increasing the Hole Transfer Rate Through DNA by Chemical Modification 739
44.1 Introduction 740
44.2 Method for the Measurement of Hole Transfer Rate Through DNA 740
44.3 Modulating the HOMO Energy of Nucleobases to Increase the Hole Transfer Rate Through DNA 742
44.3.1 Hole Transfer Rate Strongly Depends on the HOMO Energy Gap Between Nucleobases (?HOMO) 742
44.3.2 Less Sequence-Dependent Rapid Hole Transfer Through DNA Achieved by Replacing A-T Base Pairs with Deazaadenosine (ZA)-T Base Pairs 743
44.4 Modulating the Flexibility of DNA to Increase the Hole Transfer Rate Through DNA 744
44.5 Conclusions 745
References 746
45 Theoretical Calculations of Excitation Energy Transfer 749
45.1 Introduction 749
45.2 TDFI-TI Method 751
45.3 Accuracy of the TDFI-TI Method 757
45.4 Application to Crystallochromy 760
45.5 Conclusions 763
References 763