NETWORKS BASED ON CHITOSAN AND OXIDIZED CYCLODEXTRIN - II - STRUCTURAL AND CATALYTIC FEATURES OF A COPPER(II)-LOADED NETWORK

Chitosan is well known for its binding properties toward transition me tal ions. We prepared a chemical hydrogel based on chitosan using as c ross-linking agent a polyfunctionalized beta-cyclodextrin and studied the structural and catalytic features of this hydrogel loaded with cop per(il) ions in aqueous medium. Stability of the complex and its struc tural characteristics were determined by isothermal microcalorimetry a nd EPR spectroscopy, respectively. Kinetics of the oxidation of (D, L) -adrenaline and of L-adrenaline catalyzed by copper (II) bound to the matrix was monitored with a Clark-type O-2(-) sensitive electrode. The advantages of working with a heterogenous system are coupled with the preservation of both structural and catalytic features of copper (ll) site in the matrix with respect to copper(ll) ions bound to chitosan derivatives in solution. (C) 1998 Elsevier Science Ltd. All rights res erved.