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 β-position of the thiophene ring, 4Oc12T, was synthesized and its electrochemical doping and the electrical properties of the resulting electrochemically-oxidized salt were investigated. Electrochemical doping of a film of 4Oc12T by anodic oxidation produced a dark blue-colored salt. It was identified as a twoelectron oxidized salt from the electronic absorption, infrared absorption, and electron spin resonance spectra and elemental analysis. The electrochemically-oxidized 4Oc12T was found to exhibit a high room-temperature conductivity of ca. 10 S cm−1 with an activation energy of 0.05 eV.