Polyaniline Versus Polyacetylene, or, Rings Versus Bonds and the Roles of Barriers and Crystallinity

摘要: Wide-spread study of polyacetylene for the past decade has demonstrated that energy gap trans-polyacetylene is due to electron-phonon interaction with some contribution from Coulomb interaction. Injected charge carriers in soliton and polaron states have modest masses, order me. The time dynamics relaxation photoinduced indicate there are no very long-lived states. leucoemeraldine emeraldine forms polyaniline differs substantially polyacetylene. Their large gaps origin electronic structure C6 rings. Additional injected charges form states, masses which 50–100 dramatic difference behavior respect reflects important role ring-torsion angles. Highly doped New-polyacetylene conductivity o excess 104 S/cm. Combined conductivity, thermopower, susceptibility magneto-resistance studies show motion three-dimensional barrier limited. In contrast, heavily (emeraldine salt) conductivities up 102 Extensive transport though three-dimensional, “metallic” regions sufficiently small such charging limited tunneling dominates measured resistance. ability derivatize system enables control separation between chains. Systematic this shown localization as chains separated. Recent advances synthesis processing including oriented films, fibers, even a self-doped derivative opened new opportunities basic applications.