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 Cu-II and Zn-II 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 [Cu-II(L)] and [Zn-II(L)] complexes and their one-electron oxidized [Cu-II](-+) ([I](-+)) 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. (C) 2004 Elsevier B.V. All rights reserved.