Binuclear mercury(II) complexes of sulfonium ylides: Synthesis, structural characterization and anti-bacterial activity

Reaction of α-keto stabilized sulfonium ylides (Me)2SCHC(O)C6H4R (R = p-Me (a); p-Cl (b)) with HgX2 (X = Cl, Br and I) in equimolar ratios using methanol as solvent leads to binuclear products of the type [HgX2(ylide)]2 (X = Cl (1), Br (2) and I (3)). Single crystal X-ray diffraction analysis reveals the presence of unexpected asymmetric halide-bridged dinuclear structures for 1a and 2b. Characterization of the compounds by IR, 1H- and 13C NMR spectroscopy confirmed coordination of the ylide to the metal through the carbon atom. In addition, the antibacterial effects of DMSO-solutions of the complexes were investigated by the disc diffusion method against three Gram positive and three negative bacteria. All complexes represent antibacterial activity against these bacteria with high levels of inhibitory potency exhibited against the Gram-positive species.