Reactions of Phosphorus Pentachloride with Tin Tetrachloride. Tetrachlorophosphonium Salts with SnCl62-, Sn2Cl102-, and SnCl5- Anions: Preparation and Structure by Vibrational Spectra and X-ray Crystallography

In the PCl5-SnCl4 system, four different crystalline compounds were obtained by varying the preparative conditions such as the solvents, relative concentrations of reactants, and temperatures. Their structures were elucidated by both Raman and IR vibrational spectroscopy. Three of these were also identified by using X-ray crystallography. The four compounds are (PCl4)2(SnCl6) (1), (PCl4)3(SnCl6)(PCl6) (2), (PCl4)2(Sn2Cl10) (3), and (PCl4)(SnCl5) (4). Compound 2 is tetragonal, space group P42/mbc, with a = 14.754 (2) Å, c = 13.950 (1) Å, V = 3037 (1) Å3, and Z = 4. Compound 3 is triclinic, space group P1, with a = 9.013 (1) Å,b = 9.607 (1) Å, c = 7.066(1) Å, α = 95.67 (2)°, β = 95.81 (2)°, γ = 100.62 (3)°, V= 594 (1) Å3, and Z = 1. Compound 4 is orthorhombic, space group Cmma, with a = 12.018 (1) Å, b = 16.469 (3) Å, c = 6.488 (1) Å, V = 1284 (1) Å3, and Z = 4. All four compounds are of ionic structure with a tetrahedral PC14+ cation and appropriate anions.