X-ray crystal structure and spectral characterization of pseudo five-coordinate Hg(II) polymeric and four-coordinate binuclear complexes of an ambidentate sulfonium ylide

The reaction of ambidentate sulfonium ylide (Me)(2)SCHC(O)C6H4-p-OCH3(Y) with HgX2 [X = Cl (1), Br (2) and I (3)] in equimolar ratios using methanol as the solvent leads to two types of products. Single-crystal X-ray diffraction analysis reveals (i) a two-dimensional polymer, [{HgCl2(Y)}(4)](n), in which the mercury(II) atom is five-coordinated and ligand Y displays C-coordination as well as an additional interaction, including O-coordination to different mercury centers and (ii) an asymmetric halide-bridged binuclear structure of the type [HgBr2(Y)](2), in which the mercury(II) center is four-coordinate and ligand Y displays C-coordination to the metal. The characterization of these compounds by IR, H-1- and C-13 NMR spectroscopy confirms the coordination of the ylide to the metal through the carbon atom. Analytical data indicate a 1:1 stoichiometry between the ylide and the Hg(II) halide in all complexes. (C) 2014 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.