The Osmium(VIII) Oxofluoro Cations OsO2F3 + and F(cis-OsO2F3)2 +: Syntheses, Characterization by 19F NMR Spectroscopy and Raman Spectroscopy, X-ray Crystal Structure of F(cis-OsO2F3)2 +Sb2F11 -, and Density Functional Theory Calculations of OsO2F3 +, ReO2F3, and F(cis-OsO2F3)2 + †

Osmium dioxide tetrafluoride, cis-OsO(2)F(4), reacts with the strong fluoride ion acceptors AsF(5) and SbF(5) in anhydrous HF and SbF(5) solutions to form orange salts. Raman spectra are consistent with the formation of the fluorine-bridged diosmium cation F(cis-OsO(2)F(3))(2)(+), as the AsF(6)(-) and Sb(2)F(11)(-) salts, respectively. The (19)F NMR spectra of the salts in HF solution are exchange-averaged singlets occurring at higher frequency …