Structural influences on the oxidation and anticancer activities of dicopper(ii) complexes containing different selenium and sulfur ligands

Abstract

This paper describes the synthesis, structural analysis, and magnetic and spectroscopic characterizations of six new dicopper(II) complexes with dinucleating phenol-based ligands containing different thioether and selenoether donor substituents. The compounds appear as a cation complex [Cu₂(L)(μ-SO₄)]⁺. Temperature-dependent magnetometry reveals the presence of ferromagnetic coupling for all of the six complexes. The bioinspired catalytic activities of these complexes, related to catechol oxidase, were studied using 3,5-di-tert-butylcatechol as the substrate, and those related to phenoxazinone synthase activity were studied using o-aminophenol. It was observed that the complexes containing withdrawing groups showed the highest values of catalytic efficiency (E). The complexes were cytotoxic against MDA-MB-231 (triple negative breast adenocarcinoma) and MG-63 (human osteosarcoma), surpassing the activity of the metallodrug cisplatin.