Oxygen, sulphur, and selenium abstraction from WCl4Y (Y = O, S, or Se) by triphenylphosphine. Crystal and molecular structure of tetrachlorobis(triphenylphosphine)tungsten(IV)

Abstract

Excess of triphenylphosphine has been allowed to react with the series of compounds WCl₄Y (Y = O, S, or Se). The products from each reaction have been analysed and subjected to spectroscopic studies which have shown that in each reaction abstraction of the chalcogen atom took place thus reducing tungsten(VI) to tungsten(IV) and yielding WCl₄·2PPh₃ and P(Y)Ph₃. With Y = O a second product, WCl₄O·P(O)Ph₃·PPh₃, was also isolated. The complex WCl₄·2PPh₃ crystallises in the monoclinic space group P2₁/n, with a= 9.605(8), b= 21.320(13), c= 9.313(8)Å, β= 117.5(1)°, and Z= 2. The WCl₄·2PPh₃ molecules are centrosymmetric with two equivalent W–Cl distances [2.320(5) and 2.344(6)Å] and a long W–P distance [2.629(6)Å].