Organotin(IV) complexes of 2-hydroxyacetophenone-N(4)-cyclohexylthiosemicarbazone (H2dact): Synthesis, spectral characterization, crystal structure and biological studies

• Published in: Inorganica Chimica Acta 2012-05, Vol.387, p.219-225
• Main Authors: Affan, M.A., Salam, M.A., Ahmad, Fasihuddin B., White, Fraser, Ali, Hapipah M.
• Format: Article
• Language: English
• Subjects: 2-Hydroxyacetophenone-N-cyclohexylthiosemicarbazone; Antibacterial activity; Crystal structure; Cytotoxicity; Organotin(IV) complexes; Spectral analyses
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2012.01.020

Four new organotin(IV) complexes with 2-hydroxyacetophenone-N(4)-cyclohexylthiosemicarbazone [H2dact, (1)], [MeSnCl(dact)] (2), [BuSnCl(dact)] (3), [PhSnCl(dact)] (4) and [Ph2Sn(dact)] (5) were synthesized, structurally characterized and their biological studies were carried out. The crystal structure of complex (5) revealed that the dinegative tridentate ligand coordinating the tin atom through thiolate-S, azomethine-N and phenoxide-O atoms. In vitro antibacterial activity screening showed that the complexes (2–5) possess better activity. Complexes have also been found in vitro cytotoxic against Artemia salina. [Display omitted] ► Organotin(IV) complexes of 2-hydroxyacetophenone-N(4)-cyclohexylthiosemicarbazone are described. ► X-ray structure of [Ph2Sn(dact)] (5) is presented. ► The Sn(IV) environment is five-coordinated in a distorted trigonal bipyramidal geometry. ► Complexes have exhibited the better cytotoxic and antibacterial activity. ► The ligand (1) and its organotin(IV) complexes (2-5) are stable under N2 atmosphere. Four new organotin(IV) complexes of the type [MeSnCl(dact)] (2), [BuSnCl(dact)] (3), [PhSnCl(dact)] (4) and [Ph2Sn(dact)] (5) were synthesized by the direct reaction of 2-hydroxyacetophenone-N(4)-cyclohexylthiosemicarbazone [H2dact, (1)] and organotin(IV) chloride(s) in absolute methanol. The ligand [H2dact, (1)] and its organotin(IV) complexes (2–5) have been characterized by CHN analyses, molar conductivity, UV–Vis, FT-IR, 1H, 13C and 119Sn NMR spectral studies. The molecular structure of complex (5) has also been determined by single-crystal X-ray diffraction. The crystal structure of complex (5) showed that the ligand is doubly deprotonated at the oxygen and sulfur atoms and is coordinated to the tin(IV) atom through thiolate-S, azomethine-N and phenoxide-O atoms. X-ray diffraction studies indicated that complex (5) is a monomer and the central tin(IV) atom is five coordinated in a distorted trigonal bipyramidal geometry. The cytotoxicity of the ligand (1) as well as its organotin(IV) complexes (2–5) was studied against Artemia salina. The in vitro antibacterial activities of these compounds were also evaluated. The screening results have shown that the organotin(IV) complexes (2–5) have better antibacterial activity than the free ligand. Furthermore, it has been shown that diphenyltin(IV) derivative (5) exhibits significantly better activity than the monoorganotin(IV) derivatives (2–4).