Wang, G.; Walley, J. E.; Dickie, D. A.; Pan, S.; Frenking, G.; Gilliard Jr., R. J. A Stable, Crystalline Beryllium Radical Cation. Journal of the American Chemical Society 2020, 142, 4560–4564.
Abstract
The alkaline-earth elements (Be, Mg, Ca, Sr, and Ba) strongly favor the formation of diamagnetic compounds in the +2 oxidation state. Herein we report a paramagnetic beryllium radical cation, [(CAAC)2Be]+• (2) [CAAC = cyclic (alkyl)(amino)carbene], prepared by oxidation of a zero-valent beryllium complex with 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO). Compound 2 was characterized by EPR spectroscopy, elemental analysis, X-ray crystallography, and DFT calculations. Notably, the isolation of 2 represents the first s-block charged radical and the first crystalline beryllium radical.