The enhancement by visible light of the catalytic activity of Co(II)-tetrasulphophthalocyanine on the oxidation of mercapto-ethanol

The rate of the selective oxidation of mercaptoethanol by dioxygen to disulphide, catalysed by Co(II)-tetrasulphophthalocyanine, is enhanced with a factor 2 à 4 by irradiation with light in the range of 600-700 nm. This effect can be ascribed to the conversion of dimers of Co(II)-tetrasulphophthalocyanine to catalytically active monomers