PREPARATION AND CHARACTERIZATION OF POLY(3-ARYLTHIOPHENE)S

A series of 3-(p-X-phenyl)thiophene monomers (X = -CMe3, -Me, -OMe, -H, -F, -Cl, -Br, -CF3, -SO2Me) was electrochemically polymerized to form polymer films that could be reversibly reduced and oxidized (n- and p-doped). The oxidation potentials of the monomers and formal potentials of the n- and p-doping processes of polymers were correlated with the resonance and inductive effects of the substituents on the phenyl ring. The charge obtained by integrating the cyclic voltammetric peak was affected by the polymerization efficiency and, in some cases, the ion transport rate. The ionic resistance of poly[3-(p-chlorophenyl)thiophene] (PCPT) and poly[3-(p-fluorophenyl)thiophene] (PFPT) films measured by impedance spectroscopy, together with scanning electron microscopy results, demonstrate that the ion transport in these films is affected by their morphology.