Electrosynthesis and characterisation of poly(N-methylaniline) in organic solvents

The electropolymerisation of N-methylaniline was studied on glassy carbon and optically transparent tin oxide electrodes in the organic solvents dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) containing 1.0 M methanesulfonic acid or 1.0 M trifluoromethanesulfonic acid. Our results show that a thin film of poly(N-methylaniline) can be obtained in DMF and DMSO, although the reaction product is very soluble. The PNMA film and the soluble fraction of the reaction product was analyzed and characterised with cyclic voltammetry, mass spectroscopy, in situ UV-Visible and Raman spectroscopy. The formation of an intermediate in DMF with an absorbance maximum at 720 nm was confirmed with in situ UV-Visible measurements. This is in contrast to polymerisation in aqueous solution where the absorbance maximum of the intermediate has been reported to appear at 441-460 nm.