INCORPORATION OF ANIONIC COBALT PORPHYRIN BY ANION-EXCHANGE INTO POLYPYRROLE FILMS CONTAINING ALKYLAMMONIUM GROUPS

Polypyrrole films containing alkylammonium groups have been deposited on ITO transparent electrodes and platinum electrodes by oxidative electropolymerisation of an N-substituted pyrrole monomer. These polymers exhibit anion-exchange behaviour that has been assessed with ferricyanide ions. The incorporation of tetra-anionic cobalt porphyrin is easily achieved in the pre-formed films, to reach total saturation of the alkyl-ammonium sites. Thus, the porphyrin content and the distribution coefficient of the complex between the film and the aqueous solution have been estimated by absorptiometric measurements. Finally, the electrocatalytic behaviour of the polymer containing cobalt porphyrin has been assessed by cyclic voltammetry against the oxidation of N-acetyl-L-cysteine in aqueous solution.