Phenylmercury(ii) sulfanylpropenoates: an example of symmetrization with the 3-(2-methoxyphenyl)-2-sulfanylpropenoato ligand

We investigated the reactions of phenylmercury(II) acetate with 3-(substituted phenyl)-2-sulfanylpropenoic acids H2L [L = xspa, where spa = 2-sulfanylpropenoato and x is an element of {o-mp = 3-(2-methoxyphenyl)-), p-mp = 3-(4-methoxyphenyl)-, o-tfmp = 3-(2-trifluoromethoxyphenyl)-, p-tfmp = 3-(4-trifluoromethoxyphenyl)-] in the presence of diisopropylamine in ethanol. The 1:1:1 reactions gave compounds of type [HQ][PhHg(L)] [where HQ = diisopropylammonium cation]. All the new compounds were isolated and characterized by elemental analysis, FAB mass spectrometry and IR, and NMR (H-1, C-13, Hg-199) spectroscopy. The crystal structures of the [HQ][PhHg(L)] compounds show the presence of diisopropylammonium cations and [PhHg(L)](-) anions, in which the Hg atom adopts a HgCOS distorted T-environment. For the o-mpspa derivative, a symmetrization process, followed in solution by NMR spectroscopy, was detected and crystals of [HQ][PhHg(o-mpspa)]center dot 0.5HgPh(2) were isolated and studied by X-ray diffraction.