Effects of Polycyclic Aromatic Hydrocarbon Pendant-Armed Ligands on the Catecholase Activity of Dinuclear Copper(II) Complexes

Herein, we present three new binuclear copper(II) complexes containing different polycyclic aromatic hydrocarbons, able to catalyze the oxidation of 3,5-di-tert-butylcathecol, a model substrate for catechol oxidase. The ligands and complexes were successful characterized in solid and solution states. The structure of C1 was determined by X-ray crystallography and it contains a [Cu^II₂(L1-µ-phenoxo)(OAc)(H₂O)₂] unit, with two coppers in a pyramidal square geometry and a large distance of 3.715 Å between the copper(II) centers. All complexes (C1, C2 and C3) were found to be effective catalysts in the oxidation of 3,5-di-tert-butylcathecol to its quinone and C1 provided the highest catalytic constants at the three pH values studied. In addition to their potential use as a biomimetic catalyst in catechol oxidation, the interaction of these complexes with deoxyribonucleic acid from calf thymus (CT-DNA) was also studied, and C3 showed the greatest affinity with nucleic acids.

Keywords:
copper (II) dinuclear complexes; catecholase-like activity; polycyclic aromatic hydrocarbons; CT-DNA interaction studies