Reactivity of diphosphines towards methyl- and phenyl-mercury(II) ions. Crystal structure of [Hg(Ph2PCH2CH2PPh2)2][O3SCF3]2

Abstract

Methyl-and phenyl-mercury(II) ions reacted, in the molar ratio 2 : 1, with bidentate phosphines L–L to give binuclear complexes of general formula [RHg(L–L)HgR]²⁺. [L–L = Ph₂P(CH₂)_nPPh₂, n= 1–3]. When an excess of the phosphine ligand is present an intermolecular exchange process occurs which leads to the formation of the symmetrically substituted compounds, HgR₂ and [Hg(L–L)₂]²⁺. The reactions in solution have been studied by multinuclear NMR spectroscopy; the structure of the bimetallic species was deduced with the aid of computer simulation. The single-crystal structure of [Hg(Ph₂PCH₂CH₂PPh₂)₂][O₃SCF₃]₂[orthorhombic, space group Pbcn, a= 17.141(3), b= 20.158(3), c= 15.614(9)Å, Z= 4] showed the mercury atom to be in a distorted-tetrahedral configuration.