In Situ Conductivity of a Polythiophene from a Branched Alkoxy-Substituted Tetrathiophene. Enhancement of Conductivity by Conjugated Cross-Linking of Polymer Chains

Anodic coupling of 2,3,5-tris(4-pentoxy-2-thienyl)thiophene (an α,α-coupled terthiophene thiophene branched at the central thiophene ring) produces a polyconjugated polymer with a linear structure segmented by the thiophene branches. The conductivity (15 S cm - 1 ), confined in a narrow potential window (0.3 V) by charge localization in tetrathiophene sequences, is strongly enhanced by occasional cross-linking in comparison with that of the polymer methyl-capped at the thiophene branches (0.02 S cm - 1 ).