A 19F nuclear magnetic resonance investigation of the formation of Sb2F11− and SbnF5n+1− in the CsF–SbF5, t-butyl halide–SbF5, and tetraalkylammonium hexafluoroantimonate–SbF5 systems

Fluorine nuclear magnetic resonance spectra have been obtained for the t-butyl fluoride–SbF 5 , t-butyl chloride–SbF 5 , tetraethylammonium hexafluoroantimonate–SbF 5 , and cesium fluoride–SbF 5 systems, both with and without SO 2 solvent. In SO 2 solution the anion is Sb 2 F 11 − for all the systems, any remaining SbF 5 being converted to SbF 5 •SO 2 . It is concluded that in the systems that do not contain SO 2 , higher polymeric anions Sb n F 5n+1 − , where n > 2, are present. t-Butyl chloride and t-butyl fluoride give the t-butyl carbonium ion, as has been previously reported. Tetrabutylammonium and benzyltri-methylammonium cations appear to decompose to a carbonium ion and an adduct SbF 5 •NR 3 in the presence of SbF 5 .