Reactions of polysulphide with metal–phosphine species. Synthesis and X-ray crystal structure of [{Ni(bppte)(µ-OH)}2][ClO4]2·(CH3)2CO

Abstract

The reaction of [Ni(H₂O)₆][ClO₄]₂ in the presence of 1,1,1-tris(diphenylphosphinomethyl)ethane, tppme, with [S_n]^2– leads to the formation of the dimeric hydroxo-complex [{Ni(bppte)(µ-OH)}₂][ClO₄]₂·(CH₃)₂CO, bppte = PPh₂SCH₂C(CH₃)(CH₂PPh₂)₂, which was structurally characterized by X-ray diffraction. Crystal data are: a= 19.046(7), b= 18.195(6), c= 13.349(5)Å, β= 97.76(4)°, space group P2₁/a, and Z= 2. In the centrosymmetric dimeric hydroxo-bridged cation each metal atom displays square-planar co-ordination, the third arm of the ligand, PPh₂SCH₂, being unco-ordinated. The unexpected formation of hydroxo complexes is discussed.