Combined Pyrazole and Cu (II), Co (II) Metals: An Excellent Catalyst for Catecholase, Tyrosinase, Phenoxazinone Synthase, and Laccase for Oxygen Activation

This study explores the catalytic behavior of pyrazole-based copper (II) and cobalt (II) complexes as biomimetic models for key oxidative enzymes (Catecholase, tyrosinase, phenoxazinone synthase, and laccase for oxygen activation). The primary objective was to activate molecular oxygen and oxidize phenolic substrates through the use of structurally designed transition metal complexes. Complexes were prepared in situ and characterized using UV-Vis, FTIR, and XRD spectroscopy. The catalytic performance was evaluated in aerobic conditions and three solvents with differing polarities. Copper-based systems exhibited superior efficiency in mimicking enzymatic activities due to their favorable coordination properties. Because the acetate ligand allows easy substrate access to the metal center, Cu(II)-acetate complexes yielded the most effective oxidation outcomes. These findings suggest that rational design of metal-ligand systems inspired by natural enzymes can enhance selective oxidation reactions. The approach provides a science- and technology-driven foundation for environmentally benign catalysis in chemical and environmental applications.