Heterospin Copper(II) Catecholate Complex with the TEMPO–Iminopyridine Ligand

Abstract

The heterospin copper(II) complex, ((pyridin-2-ylmethylene)-4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl)-3,6-di-tert-butylcatecholatocopper(II) (I), is synthesized and characterized by IR spectroscopy, magnetochemistry, EPR, and X-ray diffraction analysis. The one-electron oxidation of complex I by AgBF₄ affords the biradical copper(I) complex: bis[((pyridin-2-ylmethylene)-4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl)]copper(I) (II). An analysis of the parameters of isotropic EPR spectra of complexes I and II indicates that they are biradicals with the fast (I) and intermediate (II) exchange interaction between the radical centers.