In situ UV–vis spectroelectrochemical studies of the copolymerization of o-aminophenol and aniline

In situ spectroelectrochemical studies of the copolymerization of o-aminophenol (OAP) with aniline (ANI) were carried out. Electropolymerization at a constant potential was performed on indium tin oxide (ITO)-coated glass electrodes in aqueous sulfuric acid (0.5 M). Spectroelectrochemical results revealed the formation of an intermediate in the initial stage of copolymerization through the cross-reaction of OAP cation radicals and ANI cation radicals resulting in a head-to-tail dimer or oligomer. An absorption peak at 520 nm in the UV–vis spectra was assigned to this intermediate. The FTIR spectral analysis of the copolymer clearly demonstrates the incorporation of OAP units into the polymer backbone during polymerization.