Tetrakis(thione)platinum(II) complexes: synthesis, spectroscopic characterization, crystal structures, and in vitro cytotoxicity (original) (raw)

A new series of platinum(II) complexes based on thione ligands with general formula [Pt(thione) 4 ]X 2 (X − = Cl − , NO 3 − ) has been synthesized and characterized using CHNS elemental analysis, infrared, 1 H and 13 C solution-state NMR as well as 13 C and 15 N solid-state NMR spectroscopy, and X-ray crystallography. The spectroscopic methods confirm the coordination of Pt(II) with thiocarbonyl groups via sulfur of the thione ligands. The X-ray structures showed a distorted square planar geometry for 1, [Pt(MeImt) 4 ]Cl 2 (MeImt = N-Methylimidazolidine-2-thione) while the hydrogen bonding interactions in 7, [Pt(iPrImt) 4 ](NO 3 ) 2 ·0.6(H 2 O) induce a bent see-saw distortion relative to the ideal square planar geometry. The in vitro cytotoxicity studies showed that 2, [Pt(EtImt) 4 ]Cl 2 is generally the most effective, a two-fold better cytotoxic agent than cisplatin and carboplatin against MCF7 (human breast cancer).