Diastereomeric isomers of five-coordinate organoantimony compounds

A series of unsymmetrical diarylantimony trichlorides of the type PhArSbCl₃, where Ar is a substituted phenyl group have been prepared. An attempt was then made to convert these to the oxides (PhArSbCl₂)₂O. In addition to the known compound (Ph₂SbCl₂)₂O, only bis(phenyl-p-tolyldichloroantimony) oxide was obtained in pure form. An impure sample of bis(phenyl-p-fluorophenyldichloroantimony) oxide was also obtained. PMR spectra of the tolyl compound and ¹⁹F spectra of the fluoro compound revealed the presence of two diastereomeric forms for both compounds at low temperature.