Complex formation between antimony trifluoride and alkali-metal sulphates: the X-ray crystal structure of K2SO4·SbF3 and antimony-121 Mössbauer studies of some related compounds

The X-ray crystal structure of K2SO4·SbF3 is reported. It crystallizes in the orthorhombic space group P212121, with a= 5.601(2), b= 9.072(4), c= 14.180(6)A, and Z= 4 and a final R= 0.035. The antimony environment is that of a distorted octahedron, SbF3O2E, where E represents the non-bonding electron pair of SbIII The 121Sb Mossbauer data of this and other M2SO4·SbF3 complexes are interpreted in terms of SbX5E and SbX6E environments. In all cases the non-bonding electron pair is stereochemically active.