The 19F nuclear magnetic resonance spectra of antimony pentafluoride, cis-Sb3F16− and higher polyanions SbnF5n+1−

Abstract

The resonances in the 19F nuclear magnetic resonance (n.m.r.), spectrum of antimony pentafluoride have been reassigned and it is shown that the fine structure observed in the spectrum of antimony pentafluoride in various inert solvents can only be explained by considering the effects of magnetic nonequivalence. Solutions of t-butyl fluoride and tetra-n-butylammonium hexafluoroantimonate in excess SbF5/SO2ClF are shown to contain the Sb3F16− and Sb4F21− anions which have cis-fluorine bridged structures. The coupling constants and chemical shifts in the n.m.r. spectra of Sb3F16−, Sb4F21−, (SbF5)n and 1:1 and 2:1 complexes of SbF5 are compared and discussed.