Structure and electrical conductivity of a solid salt obtained by electrochemical oxidation of a thiophene dodecamer

A new thiophene dodecamer having four octyl groups at the beta-position of the thiophene ring, 4Oc12T, was synthesized and its electrochemical doping and the electrical properties of the resulting electrochemically-oxidized s alt were investigated. Electrochemical doping of a film of 4Oc12T by anodic oxidation produced a d ark blue-colored salt. It was identified as a two-electron-oxidized salt fr om the electronic absorption, infrared absorption, and electron spin resona nce spectra and elemental analysis. The electrochemically-oxidized 4Oc12T w as found to exhibit a high room-temperature conductivity of ca. 10 S cm(-1) with an activation energy of 0.05 eV.