Synthesis, structure and in vitro anticancer activity of ruthenium(II) and platinum(II) complexes with chiral aminophosphine ligands

(R)-[Ru(η6-p-MeC6H4iPr)Cl2{Ph2PNHCH(CH3)(C6H4-4-F)}] (1) and cis-(R,R)-[PtCl2{Ph2PNHCH(CH3)(C6H4-4-F)}2] (2) have been obtained by the reaction of the chiral aminophosphine (R)-Ph2PNHCH(CH3)(C6H4-4-F) with [{RuCl(μ-Cl)(η6-p-MeC6H4iPr)}2] or [PtCl2(cod)] (cod = cycloocta-1,5-diene). Both complexes were characterized by physico-chemical and spectroscopic methods. Compound 1 was also characterized by X-ray crystallography. The antitumor potential of both compounds was investigated by using the crystal violet antiproliferation assay. Complexes 1 and 2 were found to inhibit the growth of three human cancer cell lines, whereby the Ru complex was considerably more potent than the Pt complex, with IC50 values between 1 and 3 and 12–15 µM, respectively, but still less potent than cisplatin in the same three cell lines.