Novel aqueous soluble cobalt phthalocyanine: synthesis and catalytic activity on oxidation of 2-mercaptoethanol

A new aqueous soluble phthalocyanine, cobalt tetra(N-carbonylacrylic)aminephthalocyanine, was synthesized by modification of cobalt tetraaminophthalocyanine with maleic anhydride. The product was characterized by elemental analysis, FT-IR, and TGA. It is soluble in dilute sodium hydroxide solution. Its catalytic efficiency in the oxidation of 2-mercaptoethanol (MEA) was also evaluated in DMF and aqueous solution. Compared with cobalt tetraaminophthalocyanine and cobalt tetracarboxylphthalocyanine, cobalt tetra(N-carbonylacrylic)aminephthalocyanine had greater catalytic activity and solubility in aqueous solution. The UV-VIS spectra showed that the aggregation of the phthalocyanine molecular was restrained due to the bulky peripheral substitutions on the cobalt phthalocyanine rings, which leads to the increase of catalytic activity in the oxidation of MEA.