Synthesis and Characterization of the Phosphorus Halide−Boron Halide Complexes X3PBY3 (X = Cl, Br, I; Y = Br, I) by31P MAS NMR, IR, and Raman Spectroscopy and the Crystal Structure of Br3PBBr3

Abstract

The phosphorus halide−boron halide complexes X3PBY3 (X = Cl, Br, I; Y = Br, I) were prepared and characterized by Raman and IR spectroscopy. Density functional theory (B3LYP) was applied to calculate structural and vibrational data. Assignments of the vibrational normal modes for these Lewis acid−base adducts were made on the basis of their Raman and IR spectra in comparison with computational results. The compounds Cl3PBBr3, Br3PBBr3, I3PBBr3, and I3PBI3 were also studied by solid-state 31P MAS NMR spectroscopy. Second-order 31P−79,81Br dipolar coupling effects were observed in the 31P MAS NMR spectrum of Br3PBBr3. The molecular structure of Br3PBBr3 was determined by X-ray diffraction.