STRUCTURE AND MERCAPTAN OXIDATION ACTIVITY OF COBALT(II) PHTHALOCYANINES COVALENTLY BONDED TO SILICA OF LOW SURFACE-AREA

Cobalt(II) 2,9,16,23-tetracarboxyphthalocyanine and cobalt(II) 2,9,16,23-tetraaminophthalocyanine were covalently bonded to two different species of modified silica with low surface area. The immobilized phthalocyanines exhibit high catalytic activity in the oxidation of 2-mercaptoethanol, being comparable to that of the dissolved low molecular weight tetracarboxy- or tetrasulfo-phthalocyanine cobalt complexes. The diffuse reflectance spectra of the complexes bonded to nonporous silica exhibit a vibrational fine structure which clearly appears in the Soret band region, indicating a coupling between the electronic 1A1g --> 1E(u) transition and a vibrational transition of the aromatic ring system around 1600 cm-1.