Structure and toxicity of N-donor thionate Zn complexes

Abstract

The reaction of thiosaccharin (thiosaccharin: the thione form of saccharin) and N-donor bases with Zn2+ yielded three new thionate complexes: [Zn(tsac)2(imidazole)2], [Zn(tsac)2(benzimidazole)2]·H2O and [Zn(tsac)2(2-methylimidazole)2]·2 H2O (tsac: thiosaccharinate, C6H4C(S)NSO2). The new complexes were characterized employing Fourier Transform Infrared Spectroscopy (FTIR) and elemental analysis (EA). [Zn(tsac)2(imidazole)2] and [Zn(tsac)2(benzimidazole)2]·H2O crystal structures were determined with the aid of single crystal X-ray diffraction analysis (XRD). Both complexes exhibit a tetrahedral S2N2Zn environment, with the thiosaccharinate anions coordinated through their exocyclic Sulphur atoms. The structure of [Zn(tsac)2(2-methylimidazole)2]·2 H2O was proposed based on spectroscopic analysis. Moreover, a study on the effects of the three coordination compounds on erythrocyte sedimentation rate and osmotic fragility of red blood cells were held. Results revealed that these compounds at concentrations up to 10 μg/mL do not affect the activity of pro-sedimentation and anti-sedimentation factors. Only [Zn(tsac)2(2-methylimidazole)2]·2 H2O at 10 μg/mL induced fragility on red blood cells membrane.