CoSalen immobilized to chitosan and its electrochemical behavior

A chitosan (CS) immobilized cobalt complex (CS-CoSalen) was prepared by imm ersing a CS film into the saturated aqueous solution of a cobalt(II) comple x of N,N ' -bis(salicylaldehyde)ethylenediimino (CoSalen). The CS-CoSalen w as characterized, and it was found that CoSalen was immobilized onto CS thr ough the coordination of the amino group of CS. The cobalt(II) ion in the C S-CoSalen has a five-coordination structure. Its vacant sixth coordination site was found to bind molecular oxygen reversibly. Electrochemical studies demonstrated that the CS-CoSalen is active for the catalysis of the electr ochemical reduction of oxygen to hydrogen peroxide in an aqueous medium. (C ) 2001 Elsevier Science Ltd. All rights reserved.