Synthesis characterization of antimony((III) halide compounds of some aromatic thiosemicarbazones and investigation of their biological properties

The antiproliferative and antibacterial activities of thiosemicarbazones increase markedly with the presence of metal ions. One of the factors determining the activity of metal thiosemicarbazone complexes is the coordination structure. In this study, the biological effects of new antimony(III) and bismuth(III) thiosemicarbazone complexes with different binding modes and geometrical structures were demonstrated. Four new complexes, with the formulae {[SbCl3(µ2-S-Hacptsc)(η1-S-Hacptsc)]2} (1), {[SbCl3(κ2-S,N-Hacpmtsc)(η1-S-Hacpmtsc)2]} (2), were elucidated by a melting point, elemental analysis, molar conductivity, FT-IR, FT-Raman, UV-Visible, 1H and 13C NMR spectroscopic techniques, as well as by the Thermogravimetric-Differential Thermal Analysis (TG-DTA). The molecular structure of complexes 1 and 2 was confirmed by single-crystal X-ray diffraction analysis. The complex 1 have been tested for their in vitro cytotoxic activity against human adenocarcinoma cervical cancer (HeLa) cells. Antimony(III) complex 1 is the most active complex of this study. Further, antibacterial activity of the complexes has been screened against two gram-negative (Pseudomonas aeruginosa and Escherichia coli) and two gram positive (Staphylococcus epidermidis and Staphylococcus aureus) pathogenic bacteria. From the results, it is found that all the complexes exhibited significant activity against the gram-negative pathogenic bacteria.