Spectroscopic characterization and reactivity studies of a copper(II) iminoxyl radical complex.

A Cu II complex (1) of a bis-pyridine-dioxime ligand and its one-electron oxidized analog (1-ox) were thoroughly characterized by various spectroscopic techniques, including X-ray absorption spectroscopy. 1-ox was found to be a Cu II complex of a ligand iminoxyl radical and represents the first example of such a type. Reorganization energy ( λ ) of 2.12 eV was determined for the 1-ox/1 couple, which is considerably higher than the type 1 protein and synthetic Cu III/II (OH) complexes.