Synthesis, crystal structure, and anticancer studies of organoruthenium(II) p-cymene N-phenyldithiocarbamate complex

Abstract

Organoruthenium(II) p-cymene N-phenyldithiocarbamate complex, [Ru(phdtc)(η⁶-p-cym)]₂, was synthesized and characterized by elemental analysis, spectroscopic techniques, and single crystal X-ray crystallography. The single crystal X-ray structure of the complex shows that the compound crystallizes in a monoclinic crystal system with a P21/c space group to form a centrosymmetric binuclear complex. The structure consists of two divalent ruthenium(II) ions, two N-phenyldithiocarbamato anions and two p-cymene molecules. Each N-phenyldithiocarbamato anion acts as a chelating ligand to one ruthenium(II) and a bridging ligand to second ruthenium(II) ion in a classic “three-legged piano-stool” arrangement with a pseudo-tetrahedral geometry. The geometry around the ruthenium(II) ions is completed through η6 coordination to the p-cymene carbon atoms. Anticancer studies showed that the compound is potently cytotoxic (complete kill between 10 and 50 μM) when tested up to 100 μM for up to 48 h against two cell lines, HeLa and MRC5-SV2, models of cervical and lung cancer, respectively, and in some instances outperformed the standard platinum-based anticancer drug cisplatin for cytotoxic potency, highlighting the anti-cancer prospect of the complex.