Lewis-Acid Properties of Technetium(VII) Dioxide Trifluoride, TcO2F3: Characterization by 19F, 17O, and 99Tc NMR Spectroscopy and Raman Spectroscopy, Density Functional Theory Calculations of TcO2F3, M+TcO2F4 - [M = Li, Cs, N(CH3)4], and TcO2F3·CH3CN, and X-ray Crystal Structure of Li+TcO2F4 - †

Technetium(VII) dioxide trifluoride, TcO2F3, behaves as a Lewis acid toward the fluoride ion and acetonitrile forming M+TcO2F4 - [M = Li, Cs, N(CH3)4] salts and TcO2F3·CH3CN. Fluorine-19 NMR spectroscopy established that the TcO2F4 - anion has a cis-dioxo geometry in CH3CN solution. Variable-temperature 19F NMR studies of TcO2F4 - and TcO2F3·CH3CN in CH3CN revealed that the one-bond couplings between 99Tc and the two fluorine environments …