Synthesis and Structure of Protonated Sulfur Dioxide.

Salts of protonated sulfur dioxide were synthesized by recrystallization of [FS(OX)][SbF] (X=H, D) in aprotic solvents at low temperatures. Hemiprotonated sulfur dioxide [(SO)H][SbF] was obtained from the solvent SO and the monoprotonated sulfur dioxide [OSOD][SbF], using 1,1,1,2-tetrafluoroethane as solvent. For both compounds, single crystals were obtained and an X-ray structure analysis was conducted. Furthermore, the salts were characterized by Raman spectroscopy and the results were discussed together with quantum chemical calculations on the M06-2X/aug-cc-pVTZ level of theory.