Unusual octahedral Hg(II) dithiocarbamate: Synthesis, spectral and structural studies on Hg(II) complexes with pyrrole based dithiocarbamates and their utility for the preparation of α- and β-HgS

Abstract Bis(N-(pyrrol-2-ylmethyl)-N-butyldithiocarbamato-S,S′)mercury(II) ( 1 ) and bis(N-(pyrrol-2-ylmethyl)-N-(2-phenylethyl)dithiocarbamato-S,S′)mercury(II) ( 2 ) were prepared and characterized by microanalysis, spectroscopy (IR, 1 H and 13 C NMR) and their structures were elucidated by X-ray crystallography. Complexes 1 and 2 exist as monomer and polymer, respectively. The central mercury atom in 1 is asymmetrically chelated by two dithiocarbamate ligands leading to a distorted tetrahedral geometry. In complex 2 , the mercury is six coordinate with distorted octahedral coordination geometry. In this case, both dithiocarbamate ligands function as bridging triconnective ligand. This indicates that small changes in R groups of dithiocarbamate ligand gave different structures. Complexes 1 and 2 were used as single source precursors for the preparation of mercury sulfide nanoparticles. Mercury sulfides were characterized by XRD, TEM, EDAX, IR, UV and fluorescence spectra. Solvothermal decomposition of 1 yielded three different morphological (hexagonal, cube and spherical) α-mercury sulfide nanoparticles and 2 gave only spherical β-mercury sulfide nanoparticles.