showing reversible reduction processes for both polymers at redox potentials of -2.13 and -2.10 V vs. Fc/Fc + , respectively (Figure ). These values are very similar to the redox potential of -2.09 V found for the reversible two-electron reduction of bare PCT to the globally aromatic dianion in the same electrolyte, as well as to the redox potentials for the corresponding reduction of thiophene-substituted PCT derivatives. For the film measurements (Figure ), the polymers and PCT were deposited directly onto a glassy carbon electrode and measured in an acetonitrile-[n-Bu4N]PF6 electrolyte (0.1 M). As in solution, both polymers exhibited reversible reduction processes, albeit with a slightly larger difference in redox potentials. This is in sharp contrast to the film measurement of PCT, where the reduced PCT dianion dissolved in the electrolyte, preventing back oxidation to the neutral state. The film measurements revealed a redox potential of -2.26 V for poly(PCT-2T) and -2.08 V for poly(PCT-T), similar to the redox potential of -2.19 V found for PCT. In contrast to the reduction, the oxidation of the polymers at approx. 0.7 V was found to be irreversible in both cases.