Poly (3-substituted) thiophenes electroactive in water

Three thiophene rings bearing n-ethoxy arylsulfonamide pendant groups were synthesized and their electropolymerization was performed at a platinum electrode. The electrochemical behaviour of the polythiophene matrix was studied both in organic and in aqueous solvent. If all polymers present a reversible n- and p-doping process in organic solvents, only one of them particularly possess a reversible p-doping in aqueous media. This phenomenon was shown to be directly related to the nature of the spacer between the thiophene ring and the aryl sulfonamide unit.