Aminoxyl functionalized polythiophene: Synthesis and electrochemical applications

2,2,6,6-Tetramethyl-4-[4-(3-thienyl)butoxycarbonyl]piperidin-1-yloxyl and the corresponding N-hydroxytosylate salt have been prepared and polymerized in good yields by chemical and electrochemical methods. The chemically prepared tetramethylpiperidin-1-yloxyl (TEMPO)-substituted polythiophenes had electronic conductivities, when doped with iodine, of ca. 10^-3 S cm^-1 and were paramagnetic. Electrochemically deposited polymers showed reversible waves at 0.59 V vs. Ag/AgCl in their cyclic voltammograms. Preparative-scale experiments with a platinum electrode coated with electrodeposited polymer showed that efficient oxidation of 4-methoxybenzyl alcohol to 4-methoxybenzaldehyde could be achieved by a much lower potential to that required without mediation.