Synthesis and Characterization of New Ruthenium (II) Complexes of Stoichiometry [Ru(p-Cymene)Cl(2)L] and Their Cytotoxicity against HeLa-Type Cancer Cells

When the [Ru(p-cymene)(μ-Cl)Cl](2) complex is made to react, in dichloromethane, with the following ligands: 2-aminobenzonitrile (2abn), 4-aminobenzonitrile (4abn), 2-aminopyridine (2ampy) and 4-aminopyridine (4ampy), after addition of hexane, the following compounds are obtained: [Ru(p-cymene)Cl(2)(2abn)] (I), [Ru(p-cymene)Cl(2)(4abn)] (II), [Ru(p-cymene)Cl(2)(2ampy] (III) and [Ru(p-cymene)Cl(2)(μ-(4ampy)] (IV). All the compounds are characterized by elemental analysis of carbon, hydrogen and nitrogen, proton nuclear magnetic resonance, COSY (1)H-(1)H, high-resolution mass spectrometry (ESI), thermogravimetry and single-crystal X-ray diffraction (the crystal structure of III is reported and compared with the closely related literature of II). The cytotoxicity effects of complexes were described for cervical cancer HeLa cells via 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) assay. The results demonstrate a low in vitro anticancer potential of the complexes.