Conjugated Conducting Polymers

1. Introduction.- References.- 2. An Overview of the Theory of ?-Conjugated Polymers.- 2.1 Synopsis.- 2.2 Theoretical Concepts, Models and Methods.- 2.2.1 The Born-Oppenheimer Approximation.- 2.2.2 Ab Initio Calculations.- 2.2.3 Model Hamiltonians.- 2.3 The Huckel and SSH Models: Independent-Electron Theories.- 2.3.1 From Polyethylene to Polyacetylene.- 2.3.2 Bond Alternation.- 2.3.3 The Strength of the Electron-Phonon Coupling.- 2.3.4 Stability of the Dimerized State and the Phonon Spectrum.- 2.3.5 Spatially Localized Nonlinear Excitations: Solitons, Polarons and Bipolarons.- 2.3.6 Predictions of the Model.- 2.4 Hubbard Model: A Paradigm for Correlated Electron Theories.- 2.4.1 Ground State and Excitation Spectrum.- 2.4.2 Correlation Functions.- 2.4.3 Relevance for Conjugated Polymers.- 2.5 The One-Dimensional Peierls-Hubbard Model.- 2.5.1 The Model Hamiltonian and its Parameters.- 2.5.2 Methods.- 2.6 The Combined Effects of Electron-Phonon and Electron-Electron Interactions: Theory and Experiment.- 2.6.1 Ground State.- 2.6.2 Electronic Excitations and Excited States.- 2.6.3 Vibrational Excitation: Raman and Infrared Spectroscopy.- 2.7 Beyond Simple Models: Discussion and Conclusions.- 2.7.1 Effects of Disorder.- 2.7.2 Interchain Coupling and Three-Dimensional Effects.- 2.7.3 Lattice Quantum Fluctuations.- 2.7.4 Doping Effects and the Semiconductor-Metal Transition.- 2.7.5 Transport.- 2.7.6 Concluding Remarks.- References.- 3. Charge Transport in Polymers.- 3.1 Models for the Insulating and Semiconducting States.- 3.1.1 The Electronic Ground State.- 3.1.2 The Nature of the Charge Carriers.- 3.1.3 Disorder Along the Chains.- 3.1.4 Low and Intermediate Doping.- 3.2 Models for Transport Processes.- 3.2.1 Conduction in Extended States.- 3.2.2 Conduction in Localized States.- 3.2.3 Transport in One Dimension.- 3.2.4 Transport by Quasi-Particles.- 3.3 Experiments in the Insulating and Semiconducting State.- 3.3.1 Polyacetylene.- 3.3.2 Other Polymers.- 3.4 The Semiconductor-Metal Transition and the Metallic State.- 3.4.1 Models for the Highly Doped State.- 3.4.2 Experiments in the Highly Doped State.- 3.5 Summary.- References.- 4. Optical Properties of Conducting Polymers.- 4.1 Elementary Considerations.- 4.2 Dielectric Response Function and Band Structure.- 4.3 Band Gap and Band Structures of Undoped Conjugated Polymers.- 4.3.1 Results of Band Structure Calculations.- 4.3.2 Experimental Results.- 4.4 Photon-Phonon Interaction.- 4.4.1 General Remarks.- 4.4.2 Calculations of Vibrational Spectra of Polymers.- 4.4.3 Experimental Results.- 4.5 The Study of Elementary Excitations in Conjugated Polymers.- 4.5.1 General Considerations.- 4.5.2 The Electronic States of the Quasi-Particles.- 4.5.3 The Vibrational State of the Quasi-Particles.- 4.5.4 Experimental Results.- 4.6 Highly Conducting Conjugated Polymers.- 4.6.1 General Considerations.- 4.6.2 The Highly Conducting Phase of Trans-Polyacetylene.- 4.6.3 Polyacetylene: Experimental Results.- 4.6.4 Highly Conducting Polymers with Nondegenerate Ground State.- 4.6.5 Concluding Remarks.- References.- 5. Magnetic Properties of Conjugated Polymers.- 5.1 General Aspects of Magnetic Properties and Resonance Techniques.- 5.1.1 Susceptibility.- 5.1.2 Lineshapes, Linewidths and Lineshifts.- 5.1.3 Spin Relaxation (T1,T2,T1p).- 5.1.4 Double Resonance Techniques.- 5.1.5 High-Resolution NMR.- 5.2 Structure and Lattice Dynamics of Conjugated Polymers in the Non-Conducting Phase.- 5.2.1 Lattice Structure Determination from Dipole-Dipole Interactions.- 5.2.2 Bond Length Determination from Dipole-Dipole Interactions.- 5.2.3 Chemical Shift Tensor.- 5.3 Spin Dynamics of Conjugated Defects in the Non-Conducting Phase.- 5.3.1 ESR and ENDOR Lineshapes.- 5.3.2 Dynamic Nuclear Polarization.- 5.3.3 Nuclear Spin Lattice Relaxation.- 5.3.4 Electron Spin Relaxation.- 5.3.5 Light-Induced ESR.- 5.4 Magnetic Properties of Conjugated Polymers in the Conducting Phase.- 5.4.1 Susceptibility.- 5.4.2 ESR Lineshapes and Linewidths.- 5.4.3 NMR Results.- 5.5 Magnetic Properties of Polydiacetylenes (PDA).- 5.5.1 Structure.- 5.5.2 Solid-State Polymerization.- 5.5.3 Quasi-Particle Excitation.- 5.6 Other Conjugated Polymers.- 5.7 Conclusions and Remarks.- References.