Extended Linear Chain Compounds

Linear chain substances span a large cross section of contemporary chemistry ranging from covalent polymers, to organic charge transfer com­ plexes to nonstoichiometric transition metal coordination complexes. Their commonality, which coalesced intense interest in the theoretical and exper­ imental solid state physics/chemistry communities, was based on the obser­ vation that these inorganic and organic polymeric substrates exhibit striking metal-like elec,trical and optical properties. Exploitation and extension of these systems has led to the systematic study of both the chemistry and physics of highly and poorly conducting linear chain substances. To gain a salient understanding of these complex materials rich in anomalous aniso­ tropic electrical, optical, magnetic, and mechanical properties, the conver­ gence of diverse skills and talents was required. The constructive blending of traditionally segregated disciplines such as synthetic and physical organic, inorganic, and polymer chemistry, crystallography, and theoretical and ex­ perimental solid state physics has led to the timely development of a truly interdisciplinary science. This is evidenced in the contributions of this monograph series. Within the theme of Extended Linear Chain Compounds, experts in important, but varied, facets of the discipline have reflected upon the progress that has been made and have cogently summarized their field of speciality. Consequently, up-to-date reviews of numerous and varied aspects of "extended linear chain compounds" have developed. Within these vol­ umes, numerous incisive contributions covering all aspects of the diverse linear chain substances have been summarized.

1. An Added Dimension—Two-Dimensional Analogs of One-Dimensional Materials.- 1. Introduction—General Considerations.- 1.1. Intercalation.- 1.2. Other Properties.- 2. Carbon and Other Elemental Phases.- 2.1. Carbon.- 2.2. Sulfur and Phosphorus.- 2.3. (SN)x and (BN)x.- 3. Transition Metal Dichalcogenides and Trichalcogenides.- 3.1. Dichalcogenides.- 3.2. Trichalcogenides.- 4. Phosphates, Phosphonates, and Phosphinates.- 4.1. Metal Salts.- 4.2. Biological Chains and Layers.- 5. Silicates, Clays, and Related Substances.- 5.1. Structures Derived from Silica.- 5.2. Clays.- 6. Metal Halides, Oxyhalides, and Related Compositions.- 6.1. Halides.- 6.2. Oxyhalides.- 6.3. Ziegler–Natta Catalysts.- 7. Metal Cyanide, Macrocyclic, and Related Coordination Compounds.- 8. New Directions and Conclusions.- Notation.- Addendum.- References.- 2. The Electronic Structure of Semiconducting Polymers.- 1. Introduction.- 2. Electronic Excitations: Measurements and Concepts.- 2.1. Ground Versus Excited State Properties.- 2.2. Measured Spectra.- 2.3. Models.- 3. The Molecular Solid State.- 3.1. Structure and Molecular Dynamics.- 3.2. Comparison of Gas Phase and Solid State Spectra.- 3.3. Relaxation.- 3.4. Fluctuations.- 4. Localization and Transport.- 4.1. Figures of Merit.- 4.2. Relations between Structure and Transport.- 4.3. Doped Polymers.- 4.4. Model Calculations.- 5. Synopsis.- Notation.- References.- 3. Band Structures of One-Dimensional Inorganic, Organic, and Polymeric Conductors.- 1. Introduction.- 2. Energy Band.- 3. Band Theory.- 3.1. Linear Combination of Atomic Orbitals—Band Orbitals.- 3.2. Total Electronic Energy.- 4. Electron—Electron Repulsion and Orbital Occupancy.- 4.1. Low-Spin and High-Spin States of a Molecular Dimer.- 4.2. Metallic and Magnetic Insulating States of a Crystalline Chain.- 5. Band Structures of Some Conducting Polymer Chains.- 5.1. Conjugated Polymers.- 5.2. Polymer Chains of Transition Metal Ions.- 6. Concluding Remarks.- Notation.- References.- 4. Quasi-One-Dimensional Conductors: The Peierls Instability, Pressure and Fluctuation Effects.- 1. Introduction.- 2. Phase transitions.- 3. Phase Transitions: Theoretical Treatment.- 4. Commensurate CDW State under Pressure.- 5. Fluctuations in Quasi-One-Dimensional Conductors.- 6. Fröhlich Fluctuation Conductivity.- 7. Single-Particle versus Fluctuating Conductivity.- Notation.- References.- 5. Optical Properties of One-Dimensional Systems.- 1. Introduction.- 2. Optical Properties of Solids.- 2.1. The Complex Dielectric Function.- 2.2. Anisotropic Materials.- 2.3. Experimental Techniques.- 2.4. Physical Models for One-Dimensional Systems.- 3. The Platinum Chain Salts.- 3.1. Unoxidized Tetracyanoplatinates.- 3.2. Optical Properties of K2Pt(CN)4Br0.3·3H2O, KCP(Br).- 3.3. Optical Properties of Other Platinum Chain Systems.- 4. Linear Chain Organic Systems.- 4.1. The Simple Insulating Salts.- 4.2. The Complex Insulating Salts.- 4.3. The “Metal-Like” Compounds.- 4.4. The Tetrathiafulvalenium 7,7,8,8-Tetracyano-p-quinodimethanide, (TTF)(TCNQ) Family.- 4.5. The Radical Cation Chain Compounds.- 5. Conducting Polymers.- 5.1. Poly(sulfurnitride), (SN)x.- 5.2. Polyacetylene.- 6. Conclusion.- Notation.- References.- 6. Superstructures and Phase Transitions in One-Dimensional Inorganic and Organic Materials.- 1. Structural Changes and Phase Transitions in One-Dimensional Conductors.- 1.1. Uniform 2kF Transitions.- 1.2. Uniform 4kF and 4kF–2kF Transitions.- 2. X-Ray Diffraction Patterns of Sinusoidal Structure.- 3. 2kF Superstructures of Partially Oxidized Bis(oxalato)platinate Complexes.- 3.1. K1.81[(Pt(C2O4)2]·2H2O, ?-K-OP.- 3.2. Rb1.67[Pt(C2O4)2]·1.5H2O, Rb-OP.- 3.3. Coulomb Interaction between Pt Chains with Charge Density Waves.- 4. 4kF–2kF Transition in K1.75[Pt(CN)4]·1.5H2O, K(def)TCP.- 5. Monomer—Dimer (M-D) Transition of (Alkali Metal) (TCNQ) Complexes.- 6. Phase Transitions in N-Methyl-N-Ethylmorpholinium-bis-(7,7,8,8-tetracyano-p-quinodimethanide)(MeEtM) (TCNQ)2—A Large-U Model for 1 : 2 TCNQ Salts.- 7. High-Pressure Structures and Phase Transitions in K2[Pt(CN)4]Br0.3·3H2O, KCP(Br).- Notation.- References.- 7. X-ray, Neutron, and Electron Scattering Studies of One-Dimensional Inorganic and Organic Conductors.- 1. Introduction.- 1.1. Charge Density Waves in Electronically One-Dimensional Conductors.- 1.2. Principles of Observation of Soft Phonons and Superstructures by Structural Measurements.- 2. Structural Results in K2Pt(CN)4Br0.3·3H2O.- 3. Organic Solids—7,7,8,8-Tetracyano-p-quinodimethane (TCNQ) Charge Transfer Salts.- 3.1. Charge Density Waves in Tetrathiofulvalene (TTF) and Tetraselenafulvalene (TSeF) Charge Transfer Salts of TCNQ.- 3.2. Charge Density Waves in TCNQ Salts of Hexamethylenetetrathio- and Hexamethylenetetraselenafulvalene.- 3.3. Charge Density Waves in N-Methylphenazinuum-7,7,8,8-Tetracyano-p-quinodimethanide.- 4. Structural Results in MX3 (M = Ta, Nb; X = S, Se).- 4.1. Charge Density Waves in TaS3.- 4.2. Charge Density Waves in NbSe3.- 5. Concluding Remarks.- Notation.- References.- 8. Photoconductive Properties of Organic Assemblies and a Comparison with Dark Conductors.- 1. Introduction.- 2. Some Chemical Aspects of Charge Generation and Transport.- 3. Some Qualitative Energetics of Light-Induced Charge Generation—Comparison with Dark Conductors.- 4. Three-Dimensional versus Low-Dimensional Interactions—The Importance of Surface Area.- 5. Three-Dimensionally Ordered Systems—Anthracene.- 5.1. Thick Crystals d ?l, d ? 1/?.- 5.2. Thin Crystals.- 6. Low-Dimensional Photoconductive Systems.- 6.1. Dye-Monolayer Assemblies.- 6.2. Multilayer Dye Assemblies.- 7. From Excitons to Charge Carriers.- 8. Geminate Recombination.- 8.1. The Poole-Frenkel Effect.- 8.2. The Onsager Formalism.- 9. Charge Generation in Polymers.- 9.1. Poly(N-vinylcarbazole) and [(Poly(N-vinylcarbazole))(2,4,7-trinitro-9-fluorenone)].- 9.2. Molecularly Doped Polymers.- 9.3. Visible Sensitization of Molecularly Doped Polymers.- 10. Charge Transport.- 11. Charge Transport in Polymers.- 11.1. Poly(N-vinylcarbazole and [(Poly(N-vinylcarbazole))(2,4,7-trinitro-9-fluorenone)].- 11.2. Triphenylamine-Doped Polycarbonate.- 11.3. Triphenylamine plus N-Isopropylcarbazole-Doped Polycarbonate.- 12. Summary and Conclusions.- Notation.- References.- 9. Cation-Radical Salts of Tetrathiotetracene and Tetraselenotetracene: Synthetic Aspects and Physical Properties.- 1. Introduction.- 2. Synthesis and General Chemical and Physical Properties of Tetrathiotetracene (TTT) and Tetraselenotetracene (TSeT).- 2.1. Synthesis.- 2.2. Purification of Tetrathiotetracene (TTT) and Tetraselenotetracene (TSeT).- 2.3. General Chemical and Physical Properties.- 3. Cation–Radical Salts of Tetrathiotetracene (TTT) and Tetraselenotetracene (TSeT) with Inorganic Anions.- 3.1. Synthesis and Conducting Properties.- 3.2. Iodides of TTT.- 3.3. Optical Properties of the salts of TTT and TSeT.- 4. Complexes of Tetrathiotetracene (TIT) and Tetraselenotetracene (TSeT) with Organic and Metal–Organic Acceptors.- 5. Peierls Transition in Nonstoichiometric Series of (TTT)2 I3+? Compounds.- 5.1. Peculiarities of the Crystal Structure and Energy Spectrum of Carriers.- 5.2. The Influence of the Nonstoichiometry on the Metal-to-Insulator Transition.- 5.3. Shift of the Metal-to-Insulator Transition by Pressure.- 5.4. Discussion.- 6. Peierls-Type Transition in the Isostructural Salts (TSeT)2C1 and (TSeT)2Br.- 6.1. Peculiarities of the Crystal Structure and Energy Spectrum of Carriers.- 6.2. Phase Transition and Properties of the Low-Temperature State.- 6.3. Shift of the Transition Point in (TSeT)2C1 under the Action of Magnetic Field.- 6.4. Shift of the Phase Transition under the Action of Pressures. Phase Diagram of (TSeT)2C1.- Notation.- References.- 10. Structural Aspects of One-Dimensional Conductors Based on Tetrathiafulvalene and Tetrathiatetracene.- 1. Introduction.- 2. Structures of Charge Transfer Complexes Based on Tetrathiatetracene (TTT) and Tetraselenotetracene (TSeT).- 2.1. The Crystal Structures of TTT, TSeT, and Tetratellurotetracene (TTeT).- 2.2. Halides of TSeT.- 2.3. Halides of TTT.- 2.4. Tetrathiatetracene Complexes with Metallocomplexes.- 2.5. The Internal Structure of a Conducting Stack of Cation–Radical Salts of TTT (TSeT).- 2.6. Comparison of the Geometries of the (TTT)+ Cation Radical with the TTT Neutral Molecule.- 3. Structures of Charge Transfer Complexes Based on Tetrathiafulvalene (TTF).- 3.1. Halides of TTF.- 3.2. Cation–Radical Salts of Tetramethyltetrathiafulvalene (Me4TTF).- 3.3. Complexes of Dibenzotetrathiafulvalene (DBTTF).- 4. Conclusion.- Notation.- References.- 11. Metal Complexes of Tetrathiafulvalene and Related Compounds.- 1. Introduction.- 2. Characterization.- 3. Tetrathiafulvalene Salts.- 3.1. Titanium and Tin Derivatives.- 3.2. Chromium Derivatives.- 3.3. Iron and Ruthenium Derivatives.- 3.4. Cobalt and Iridium Derivatives.- 3.5. Platinum Derivatives.- 3.6. Copper, Silver, and Gold Derivatives.- 3.7. Mercury Derivatives.- 4. Derivatives of Neutral Tetrathiafulvalene.- 5. Complexes with Metal—Sulfur Bonds.- 5.1. Platinum and Palladium Metrallotetrathiaethylenes.- 6. Metal—Tetrathialene Complexes.- 7. Bis(dithiolene) Metal—Thiacarbon Complexes.- Notation.- References.