Preparation and Characterization of a Material of Composition BiP (Bismuth Phosphide) and Other Intergroup 15 Element Phases

The reaction between equimolar quantities of BiCl3 and the silylphosphine P(SiMe3)3 in toluene or THF (tetrahydrofuran) solution affords a black precipitate with the composition of bismuth phosphide, BiP, which has been examined by EDXA, SEM, XPS, powder XRD, solid-state 31P NMR spectroscopy, and elemental analysis. Alternative possible routes to BiP involving the reactions between Na3P and BiCl3 and between Bi(NMe2)3 and P(SiMe3)3 have also been investigated, both of which afford black powders of composition close to BiP, although in the latter case there is some contamination with bismuth metal. Analogous reactions with either SbCl3 or AsCl3 and P(SiMe3)3 afford black and dark brown precipitates, respectively, which are formulated as the materials antimony phosphide, SbP, and arsenic phosphide, AsP, on the basis of similar analyses. Preliminary experiments have also shown that the related arsenides, BiAs and SbAs, can be prepared from reactions between either BiCl3 or SbCl3 and the silylarsine As(SiMe3)3, and that a ternary phase with the composition BiSbP2 is formed in the reaction between BiCl3, SbCl3, and P(SiMe3)3 in a 1:1:2 mole ratio. A material of composition close to elemental phosphorus is obtained from the reaction between PCl3 and P(SiMe3)3.