Syntheses, structures and intermolecular interactions of tetraorganoammonium, -phosphonium and -stibonium dimethyl- and diphenyltetrahaloantimonates

The syntheses and spectroscopic (NMR, MS) investigations of the antimonates [Ph4P]+[Me2SbCl4]− (1), [Me4Sb]+[Me2SbCl4]− (2), [Et4N]+[Ph2SbCl4]− (3), [Bu4N]+[Ph2SbCl4]− (4), [Me4Sb]+[Ph2SbCl4]− (5), [Et3MeSb]+[Ph2SbCl4]− (6), [Et4N]+[Ph2SbF4]− (7) and [Et4N]+[Ph2SbBr4]− (8) are reported. Halogen scrambling reactions of Et4NBr or Ph4EBr (E = P, Sb) with R2SbCl3 (R = Me, Ph) produce mixtures of compounds from which crystals of [Et4N]+[Ph2SbBr1.24Cl2.76]− (9), [Et4N]+[Ph2SbBr2.92Cl1.08]− (10) or [Ph4Sb]+[Me2SbCl4]− (11) were isolated. The crystal and molecular structures of 1 and 3–11 are reported.

The antimonates [R4E]+[R′2SbX4]− (R = Me, Et, Bu, Ph; E = N, P, Sb; R′ = Me, Ph; X = F, Cl, Br) were prepared and characterized (NMR, MS). Halogen scrambling reactions of Et4NBr or Ph4EBr (E = P, Sb) with R2SbCl3 (R = Me, Ph) produce mixtures of compounds including mixed-halogen species. The ionic nature and the almost uniform structure of the tetrahedral cations and the octahedral antimony anions with the organic groups in trans positions are clearly demonstrated by single-crystal X-ray diffraction.Figure optionsDownload as PowerPoint slide