POLYELECTROLYTE-PROMOTED CATALYTIC-OXIDATION OF A HYDROPHOBIC THIOL

The autoxidation of the hydrophobic 1-dodecanethiol was investigated using the hydrophilic CoPc(NaSO3)4/ionene system in water as catalyst. It was found that reaction rate largely depends on the order of addition of reactants, stirring speed, pH, thiol concentration and ionene concentration. The observed dependencies indicate that the process proceeds via a phase-boundary mechanism. Catalytic activity could be enhanced by coupling a hydrophobic group to the ionene chains, but not by introducing hydrophobic groups into the polymer backbone. Stability of the catalyst system appeared to be poor, due to coprecipitation of the cobalt complex with the reaction product and, possibly, breakdown of the phthalocyanine by accumulated hydrogen peroxide. © 1990.