Crystal structure of benzyltriphenylphosphonium pentachlorosulphido-tungstate(VI) and a study of the vibrational spectra of salts containing [WCl5Y]–(Y = O or S) ions

Abstract

The salt [PPh₃(CH₂Ph)][WCl₅S] is formed when WCl₄S is treated with [PPh₃(CH₂Ph)]Cl (1 : 1 molar ratio) in Ch₂Cl₂ solution. Crystals are monoclinic, space group P2₁/c, with a= 10.572(9), b= 18.413(13), c= 14.250(11)Å, and β= 104.20(8)°. The salt consists of discrete [PPh₃(CH₂Ph)]⁺ and [WCl₅S]^– ions with the W–S bond length being 2.132(13)Å and the W–Cl lengths spanning the range 2.246(17)–2.461(12)Å. The i.r. and Raman spectra of a series of salts containing the [WCl₅Y]^– anion (Y = O or S) have been recorded and are reported, together with an assignment of the a₁ stretching modes.