Polynuclear Cu<sub>4</sub>L<sub>4</sub> Copper(II) Aminyl Radical Coordination Complexes

We describe the structural features and magnetic properties of two polynuclear copper­(II) complexes containing a redox-active ligand. These neutral complexes each bear the formula RL<sub>4</sub>Cu<sub>4</sub> (R = <sup>t</sup>Bu, Me) with the ligand in a dianion-aminyl radical oxidation state. X-ray data and density functional theory calculations support an aminyl-type radical character in these complexes, making these the first polynuclear metal aminyl radical complexes.