New mononuclear CuII and ZnII complexes capable of stabilizing phenoxyl radicals as models for the active form of galactose oxidase

Herein, we describe the synthesis and crystal structure of mononuclear CuII and ZnII complexes containing the new pentadentate H2L ligand (H2L = N-(methyl)-N′-(2-pyridylmethyl)-N,N′-bis(3,5-di-tert-butyl-2-hydroxybenzyl)-1,3-propanediamine. The [CuII(L)] and [ZnII(L)] complexes and their one-electron oxidized [CuII]radical dot+ ([1]radical dot+) and [ZnII]radical dot+ ([2]radical dot+) compounds exhibit electrochemical and spectroscopic (UV–Vis and EPR) features with relevant insight into the oxidizing half-reaction of the metalloenzyme galactose oxidase.