Studies on CoSalen immobilized onto N-(4-pyridylmethylidene)-chitosan

A chitosan (CS) derivative, N-(4-pyridylmethylidene)-CS (PMC) was synthesiz ed and a cobalt(II) complex of bis(salicylideneethylene diamine) (CoSalen) was immobilized on it. The structure of the immobilized CoSalen was charact erized by elemental analysis, IR, XPS, fluorescence and ESR spectrocopy. It was demonstrated that the immobilization of CoSalen was realized through t he coordination of nitrogen atom of the pendant group, pyridyl in PMC to th e Co(II) in CoSalen. The polymer supported complex is more efficient than t he corresponding monomeric complex in catalysing the oxidation of DOPA usin g oxygen as an oxidizer. The results may be attributed to site isolation ef fect offered by the supporting polymer chain. A mechanism similar to that f or an enzymatic catalysis was proposed. (C) 2001 Elsevier Science B.V. All rights reserved.