Direct involvement of acid centers of polyaniline in charge transfer on organic acceptor

Electrochemical behavior of hydroquinone and 4F-hydroquinone has been studied on Pt/polyaniline (PANI) electrodes in 1 M H2SO4 solution. Redox transformation of quinone/hydroquinone systems takes place on PANI practically without overpotential and, probably, the two-electron charge transfer processes are realized in such systems. Reaction currents depend on PANI quantities deposited on the Pt electrode and the molecular complex is formed. There exists a great electronic exchange between acid centers of PANI and quinone/hydroquinone molecules, resulting in electronic conjugation of this surface state (adsorbed molecule) with the polymer. Existence of such complexes was confirmed by FT-IR analysis which has been carried out on free-standing polymer films. Based on these findings we have assumed that the charge transfer complexes form along the polymer chain and the acceptor molecules participate in the doping and conductivity processes.