Synthesis, characterization, antibacterial, and cytotoxic activities of organotin(IV) complexes derived from N(4)-cyclohexylthiosemicarbazone: X-ray crystal structure of [Ph₂SnCl(L)]

Abstract

Reaction of organotin(IV) chloride(s) with 2-benzoylpyridine-N(4)-cyclohexylthiosemicarbazone, [HL] (1) yielded [MeSnCl₂(L)] (2), [BuSnCl₂(L)] (3), [Me₂SnCl(L)] (4), and [Ph₂SnCl(L)] (5). The ligand (1) and its organotin(IV) complexes have been characterized by CHN analyses, molar conductivity, UV-Vis, FT-IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectral studies. The molecular structure of 5 was also determined by X-ray diffraction. There are two independent molecules in the asymmetric unit and the central tin(IV) atom is six-coordinate in distorted octahedral geometry. The ligand (1) and complexes were screened for their in vitro antibacterial activities. The cytotoxic activities of 1–5 were tested against A2780 and A2780/Cp8 cancer cell lines. The compounds have better antibacterial activities than the free ligand; 2–5 are more potent cytotoxic agents than 1, while the diphenyltin(IV) 5 is more active with IC₅₀ values of 0.05 and 0.54 µmol L⁻¹ against A2780 and A2780/Cp8 cell lines, respectively.

Keywords:

• Organotin(IV) complexes
• Spectral analyses
• Crystal structure
• Antibacterial activity
• Cytotoxicity

Acknowledgments

This work was financially supported by the Ministry of Science, Technology and Innovation under a research grant (no. 06-01-09-SF0046). The authors thank Universiti Malaysia Sarawak for the facilities to carry out the research work. The authors also thank Universiti Putra Malaysia for the X-ray diffraction analysis.