A Redox-active Double Radical Salt

The reaction of [FeII(L•)2][BF4]2 with LiTCNQF4 results in the formation of [FeII(L•)2][TCNQF4•-]2·2CH3CN (1) (L• is the neutral aminoxyl radical ligand, 4,4-dimethyl-2,2di(2-pyridyl)oxazolidine-N-oxide; TCNQF4 is 2,3,5,6-tetrafluoro-7,7,8,8tetracyanoquinodimethane). Single crystal X-ray diffraction; Raman, Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopies; and electrochemical studies are all consistent with the presence of: a low-spin FeII ion; the neutral radical form (L•) of the ligand; and the radical anion, TCNQF4•-. 1 is largely diamagnetic and the electrochemistry shows five well resolved, diffusion-controlled, reversible, one electron processes.