New Nickel Metal Complex towards Biomimetic Catecholase Enzyme Oxidation: Synthesis and Kinetics Studies

Pyrano[2,3-c]pyrazole ligand and their transition metal complex with nickel (NiIIMPC) were synthesized and characterization by elemental analyses, magnetic susceptibility, FT IR, UV-Vis, and mass spectroscopy. Complex have been investigated as functional models for catechol oxidase activity by using a catechol as a model substrate. According to the kinetic measurement results, the rate of catechol oxidation follows first order kinetics. Nickel complex has been used in homogenous oxidation of catechol in presence of a green oxidant H2O2. kinetic parameters were obtained Vmax= 2.698×10-3MS-1, Km = 7.878M, kcat= 4.496×10-2S-1 and kcat/Km = 0.5707 M-1S-1