Highly Active Catecholase-Like Catalyst Based on the In-Situ Combination of Benzodiazepine Derivatives and Copper (II) Salts

New excellent catalysts for the oxidation of catechol to o-quinone were developed in this study by the combination of some benzodiazepine derivatives ligands with copper(II) salts such as Cu(CH3COO)(2), CuSO4, Cu(NO3)(2) and CuCl2 at ambient conditions. The study has shown that the in-situ generated copper(II) complexes of the ligands used are excellent models for reproducing the enzymatic activity of catechol oxidase. The rates of this oxidation vary from 127 mu mol.L- 1.s(- 1) for the complex formed by ligand L-3(1-benzyl-4-phenyl-1,5-benzodiazepine-2-one) and the metal salt CuCl2 to 424.47 mu mol.L- 1. s(- 1) for the complex formed by ligand L-1(4-phenyl-1,5-benzodiazepin-2-one) and the metal salt Cu(CH3COO)(2) who shows the best catalytic activity. Also, this work demonstrates that the rate of oxidation depends on different parameters such as the nature of the ligand and the ionic salts. The combination ligand/[Cu (CH3COO)(2)] leads to the fastest catalytic process.