New mononuclear Cu II and Zn II 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 Cu II and Zn II complexes containing the new pentadentate H 2 L ligand (H 2 L =  N -(methyl)- N ′ -(2-pyridylmethyl)- N , N ′ -bis(3,5-di- tert -butyl-2-hydroxybenzyl)-1,3-propanediamine. The [Cu II (L)] and [Zn II (L)] complexes and their one-electron oxidized [Cu II ] + ([ 1 ] + ) and [Zn II ] + ([ 2 ] + ) compounds exhibit electrochemical and spectroscopic (UV–Vis and EPR) features with relevant insight into the oxidizing half-reaction of the metalloenzyme galactose oxidase.