Spectroelectrochemical investigations of polyxylidines

Aniline derivatives carrying two methyl substituents in different ring positions (2,3-, 2,5- and 2,6-xylidine) were polymerised electrochemically. The obtained polymers were characterised by cyclic voltammetry, in situ UV-vis spectroscopy and in situ Resonance Raman spectroscopy. With poly(2,5-xylidine) in situ conductivity measurements were performed. The polymers show various degrees of electrochromism. Vibrational spectra of poly(2,3-xylidine) and poly(2,5-xylidine) show a reversible change of the ring from a benzoid into a quinoid state depending upon the degree of oxidation. A structure analogous to the one proposed for polyaniline is suggested.