Synthesis, spectral and X-ray structural studies on Hg(II) dithiocarbamate complexes: A new precursor for HgS nanoparticles

Bis(N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S')mercury(II) (1), bis((furan-2-yl)methyl(2-(thiophen-2-yl)ethyl)dithiocarbamato-S,S')mercury(II) (2), bis(N-benzyl-N-(2-(thiophen-2-yl)ethyl)dithiocarbarnato-S,S')mercury(II) (3) and bis(N-furfuryl-N-propyldithiocarbamato-S,S')mercury(II) (4) have been prepared and characterized by IR and NMR spectroscopy. Compounds 1 and 2 have also been characterized by the X-ray diffraction technique. In complexes 1 and 2, the metal centres are five and four coordinated, respectively. The coordination geometry of 1 is intermediate between a square pyramidal and trigonal bipyramidal coordination polyhedron, with tau(5) = 0.53. Hg(II) is in a distorted [HgS4] tetrahedral environment in compound 2. This difference in geometry between complexes 1 and 2 is probably due to the effect of the N-bound organic moiety of the dithiocarbamate ligand and the crystal packing. The crystal structures show the presence of C-H...S interactions. Complex 2 has been dissolved in ethylenediamine and refluxed for 15 mm and 1 h to yield ethylenediamine capped mercury sulfide and mercury sulfide without a capping agent (en), respectively. The resulting nanoparticles have been characterized by powder X-ray diffraction (PXRD), SEM, EDAX, IR, UV-Vis and fluorescence spectroscopy. The powder Xray diffraction data confirm the particles to be very crystalline with the alpha phase (cinnabar) present in both samples. (C) 2015 Elsevier Ltd. All rights reserved.