Preparation and crystal structures of [PPh4]2[M2(SPh)6](M = Zn or Cd)

Abstract

The compounds [PPh₄]₂[Zn₂(SPh)₆] and [PPh₄]₂[Cd₂(SPh)₆] have been prepared by reaction between the hydrated metal(II) nitrate and [PPh₄][SPh] in methanol–acetonitrile solution. The compounds are isostructural (space group P2₁/c) and the dimeric anion has crystallographic inversion symmetry, imposing an anti arrangement of the two bridging benzenethiolate ligands. The metal atoms have a distorted tetrahedral co-ordination with two terminal and two bridging ligands. The central M₂S₂ rings are exactly planar and essentially square [Zn–S 2.424(1), 2.431(1)Å, S–Zn–S 90.7(1)°; Cd–S 2.611(1), 2.611(1)Å S–Cd–S = 91.8(1)°]. Proton and ¹³C n.m.r. spectra indicate a rapid exchange of terminal and bridging ligands of the anions in solution.