Syntheses and vibrational spectra of some tris(alkanethiolato)mercurate(II) complexes, and crystal structure of the Hexakis(methanethiolato)dimercurate(II) dianion

Abstract

The complexes [cation] [Hg(SR)₃](R = Me, cation = Et₄N⁺; R = Bu^t, cation = Et₄N⁺, Bu₄N⁺, [N(Ph₃P)₂]⁺) have been prepared. The crystal structure of the methanethiolate complex shows that it contains centrosymmetric dinuclear anions [(MeS)₂Hg(µ-SMe)₂Hg(SMe)₂]^2- with distorted tetrahedral geometry about the mercury atoms. Vibrational spectroscopic evidence suggests that this complex dissociates on dissolution in ethanol to give mononuclear [Hg(SMe)₃]- species. The Bu^tS- complexes appear to exist as mononuclear [Hg(SBu^t)₃]- species both in the solid state and in solution. The metal-sulfur stretching frequencies are assigned for all of the complexes studied, and the vibrational spectra are discussed in terms of the structures of the complex anions involved. Crystal data for [(C₂H₅)₄N]₂Hg₂(SCH₃)₆ : a 8.656(5), b gS130(6), c 12.368(8) Å; α 102.16(4), β 105.51(4), γ 105.29(4)º; space group P1, Z 1, R 0.034, R_w 0.042.