Molecular structure and catechol oxidase activity of a new copper(I) complex with sterically crowded monodentate N-donor ligand

The attempted alkylation of 1,3-bis(2′-pyridylimino)isoindoline (indH) by the use of n-BuLi and subsequent alkyl halides led to quaternization of the pyridine nitrogens and the zwitterionic monodentate N-ligand (Me2ind)I was formed. By the use of the ligand the copper(I) complex [CuI(Me2ind)I2][CuI(Me2ind)I2] was prepared and its structure determined. It was found to be good catalyst for the oxidation of 3,5-di-tert-butylcatechol (DTBCH2) to 3,5-di-tert-butyl-1,2-benzoquinone (DTBQ) and H2O2 by dioxygen. Detailed kinetic studies revealed first-order dependence on the catalyst and dioxygen concentration and saturation type behavior with respect to the substrate.