The Protonation of CF₃SO₃H: Preparation and Characterization of Trifluoromethyldihydroxyoxosulfonium Hexafluoridoantimonate, CF₃SO₃H₂⁺SbF₆^–

Abstract

Abstract Trifluoromethanesulfonic anhydride reacts with superacidic solutions AF/SbF 5 (A = H, D) to form their corresponding salts CF 3 SO 3 A 2 + SbF 6 – , which are protonated forms of trifluoromethanesulfonic acid and CF 3 SO 2 F as by‐product. The salts have been characterized by vibrational spectroscopy and single‐crystal structural analysis. CF 3 SO 3 H 2 + SbF 6 – crystallizes in the triclinic space group P $\bar {1}$ with two formula units in the unit cell: a = 709.29(5) pm, b = 763.46(5) pm, c = 882.15(6) pm; α = 71.884(6)°, β = 72.488(6)°, γ = 84.509(6)°; V = 432.97(5) Å 3 . The cations are linked with two strong hydrogen bonds to SbF 6 – anions to form chains. The experimental data were also compared to quantum chemical calculations for the CF 3 SO 3 H 2 (HF) 2 + cation.