Catalytic Polymerization of Aniline and Its Derivatives by Using Copper(II) Salts and Oxygen. New Type of Polyaniline with Branched Structure

Article abstract of DOI:10.1246/bcsj.67.1947

The catalytic polymerization of aniline and its derivatives was performed by stirring the solution of the corresponding monomer and copper(II) salts (50/5, mmol/mmol) in acetonitrile and water (1/1, v/v) under oxygen at room temperature for 24 h.Among copper salts, CuBr2 and CuCl2 are more active than the others.In each case the copper salts do not work as a stoichiometrical oxidant but work as a catalyst, which can be proved on the basis of turn-over-frequency.The polymers isolated were characteristic of polyaniline with an Emeraldine structure, although a small amount of branched structures were by-produced by an addition reaction at ortho-position.Thus, heat treatment of the polymer at 284 deg C results in partial decomposition to produce the stable polymer and aniline.Although the resulting polymer had an Emeraldine type structure, a strong doping effect on its electroconductivity was not observed, probably because of the amorphous morphology.The UV-vis spectra of the reaction solution have suggested that the catalytic polymerization of aniline proceeds through the formation of the copper(II) complex of aniline.