Generation of Long-Lived Phenoxyl Radical in the Binuclear Copper(II) Pivalate Complex with 2,6-Di- tert- butyl-4-(3,5-bis(4-pyridyl)pyridyl)phenol

A new binuclear copper(II) complex Cu 2 (Piv) 4 (L) 2 , where Piv – = pivalate, L = 2,6-di- tert -butyl-4-(3,5-bis(4-pyridyl)pyridyl)phenol, was synthesized, and its molecular and crysral structures were determined at temperatures of 160, 173, and 296 K (CIF files CCDC no. 2144104, 2144105, and 2144106, respectively). Cyclic voltammetry measurements revealed three irreversible oxidation processes in the potential range of 0.5–1.2 V versus Fc + /Fc. Analysis of the temperature dependence of the magnetic susceptibility of Cu 2 (Piv) 4 (L) 2 showed that antiferromagnetic interactions of Cu 2+ ions predominate in the complex. It was found that the oxidation of Cu 2 (Piv) 4 (L) 2 upon grinding with PbO 2 or treatment of a solid sample with an aqueous solution of K 3 [Fe(CN) 6 ] affords long-lived phenoxyl radical, which can be detected by ESR spectroscopy.