Structural, spectroscopic and computational studies of the HgL <inf>2</inf>Cl<inf>2</inf> complex (L = 3,5-dimethyl-1-thiocarboxamide pyrazole) and the crystal structure of L

Abstract

In the present paper we report the synthesis as well as the structural and vibrational characterisation of the HgL2Cl2 complex (L = 3,5-dimethyl-1-thiocarboxamide). The crystal and molecular structures of both L and the HgL2Cl2 complex were determined by single-crystal X-ray diffraction. The coordination propensity of L to HgCl2 was explored by quantum chemical calculations. We found the preference of the monodentate coordination of L to HgCl2 through the sulfur atom (instead of the "pyridine" nitrogen) to be in agreement with Pearson's acid-base character of the atoms involved and the steric effects. The vibrational properties of HgL2Cl2 were evaluated by a joint FT-IR and quantum chemical analysis. In addition, the thermal decomposition of the complex and ligand is reported. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.