Structural, spectroscopic and computational studies of the HgL2Cl2 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.