Electronic structure of conducting polymers from heteroaromatic bicyclic compounds

A series of conjugated polymers based on indole and heteroaromatic bicyclic compounds (X, Y = NH, S Se) is obtained as thin films on gold or conducting glass electrodes, using controlled-potential electrochemical methods. Synthesized in an oxidized state, most of them can be reduced electrochemically, accompanied by a colour switching. X-ray photoelectron spectroscopy clearly shows the differences in electronic structure between the [2,3-b] and the [3,2-b] derivatives: two distinct redox states exist only when the conjugation pattern allows effective electron delocalization.