PREPARATION AND CHARACTERIZATION OF TRIFLUOROMETHYLANILINE OLIGOMERS

The oxidation of m-trifluoromethylaniline in the presence of trifluoro acetic acid leads to the preparation of poly(m-trifluoromethylaniline) . The dimer and a mixture of higher oligomers have been prepared using both cyclic voltammetry for the preparation of thin films, and contro lled potential electrooxidation for the preparation of powders. The CF 3 moiety attached to the backbone shifts the oxidation potential of th e thin film toward more positive potentials as might be expected becau se of the electron-withdrawing effects of the CF3 group. The conductiv ity of the film has been estimated to be on the order of 10(-8) S/cm w hen electrooxidized under the appropriate conditions of pH and potenti al. Extensive analysis of the products of electrooxidation indicates t hat the solution consists of oxidized monomer, while the dimer and hig her molecular weight oligomers precipitate. The dimer can be separated from the other oligomers by vacuum sublimation. Gel permeation chroma tography of the remaining precipitate indicates that the precipitate c onsists of 20% trimer and tetramer, 40% pentamer and hexamer, and abou t 40% higher molecular weight oligomers. (C) 1998 Elsevier Science S.A . All rights reserved.