PHENYLANTIMONY(V) FLUORIDE HALIDES - ISOLATION AND CRYSTAL-STRUCTURES OF SBPH2BR2F.SBPH2BR3, (SBPH2BRF)2O AND SBPH3CL1.8F0.2

Oxidation of diphenylantimony fluoride with chlorine leads to diphenylantimony trichloride as the only isolable product, while the corresponding reaction with bromine gives, in addition to SbPh2Br3, the bromide fluorides, Sb2Ph4Br5F, SbPh2Br2F, Sb2Ph4Br3F3 and SbPh2BrF2. The structure of the first compound has been confirmed by X-ray diffraction as a fluorine-bridged diantimony compound, SbPh2Br2F.SbPh2Br3, where the antimony atoms are, respectively, in trigonal-bipyramidal and distorted-octahedral co-ordination. Hydrolysis during attempts to obtain crystals of the second compound produced the oxygen-bridged (SbPh2BrF)2O, which contains a strong intramolecular fluorine bridge, again giving antimony atoms in both trigonal-bipyramidal and octahedral co-ordination. As an alternative approach to the preparation of mixed chloride fluorides, reactions between diphenylantimony trichloride and KF, AgF and arsenic trifluoride were investigated. There was no reaction with the first two reagents but the product with arsenic trifluoride was a disordered mixed halide, shown by X-ray crystallography to be SbPh3Cl1.8F0.2.