Structural dependence of polyanilines on reaction medium

Abstract

The structures of the complexes obtained from the chemical oxidation of leucoemeraldine by Cu(ClO4)2·6H2O and from the simultaneous polymerization and oxidation of aniline by Cu(ClO4)2·6H2O in various solvents were studied using X-ray photoelectron spectroscopy (XPS) and infrared (IR) absorption spectroscopy. When acetonitrile was used as the reaction medium, the structures of the complexes obtained by the two different methods appeared similar, with a nitrogenonium ion structure analogous to that in emeraldine-hydrochloride. No significant imine structures were formed. In contrast, oxidation of some of the amine units of leucoemeraldine to the imine structure by Cu(ClO4)2·6H2O could occur with tetrahydrofuran, methanol and H2O. The complexes formed from the simultaneous polymerization and oxidation of aniline in protic solvents were electrically non-conducting and structurally different from that synthesized in acetonitrile. A partial loss of ClO4 - anions also occurred when leucoemeraldine-perchlorate complexes were exposed to protic solvents. © 1991.