Synthesis, characterization and anticancer activities of cationic η6-p-cymene ruthenium(II) complexes containing phosphine and nitrogenous ligands

Cellular Mechanistic Considerations on Cytotoxic Mode of Action of Phosphino Ru(II) and Ir(III) Complexes

“…Moreover, triphenylphosphine can intercalate between DNA base pairs which increases anticancer activity. [30][31][32] The above-mentioned different mechanisms of action, ligand substitution kinetics, and various oxidation states contributed to potential redox activity, lower toxic effect, and higher cellular uptake efficiency give advantages to ruthenium and iridium complexes over platinum-based compounds. [33][34][35] Currently, two piano-stool ruthenium(II) complexes Ru(η 6 -pcymene)Cl 2 PPh 2 CH 2 OH (RuPOH) and Ru(η 6 -p-cymene)Cl 2 P(p-OCH 3 Ph) 2 CH 2 OH (RuMPOH) and two half-sandwich iridium(III) complexes Ir(η 5 -Cp*)Cl 2 PPh 2 CH 2 OH (IrPOH) and Ir(η 5 -Cp*)Cl 2 P(p-OCH 3 Ph) 2 CH 2 OH (IrMPOH) have been synthesized, physiochemically characterized and evaluated in vitro in terms of their potential anticancer activity in our research groups.…”

“…Importantly, the presence of triphenylphosphine improves the antiproliferative potential of Ru complexes. Moreover, triphenylphosphine can intercalate between DNA base pairs which increases anticancer activity [30–32] . The above‐mentioned different mechanisms of action, ligand substitution kinetics, and various oxidation states contributed to potential redox activity, lower toxic effect, and higher cellular uptake efficiency give advantages to ruthenium and iridium complexes over platinum‐based compounds [33–35] …”

Effects of Substituted Triarylphosphine Ligands on Electron Transfer in [(p-cymene)Ru] Complexes

“…Compounds in this family also possess cytotoxic properties; [25][26] their potential use as anticancer agents has thus been the focus of a growing number of intriguing reports. [27][28][29][30] Conversely, the electron transfer (ET) properties of (p-cymene)RuCl2(PR3) complexes have received less attention than they deserve given the insight they could provide into strategies to tune activity in various contexts. The few investigations in this context have revealed that these complexes undergo 1eoxidation to Ru(III) at potentials that depend on the phosphine ligand platform and the Ru coordination environment.…”

“…electroactive products. 28,30,[36][37] In reports by Wright 36 and de Araujo, 28 involving diphenyl (3phenylpropyl)phosphine or chelating bis(phosphine) platforms (Chart 1a), respectively, such products have been identified as tris(nitrile) complexes resulting from the dissociation of p-cymene and binding of CH3CN upon oxidation to Ru(III). Analogous studies of complexes supported by triarylphosphine ligands, the most widely studied subset of compounds in this family, would be of particular interest.…”

“…However, as these studies were carried out in noncoordinating dichloromethane (CH2Cl2) solvent, no ET-induced reactions were observed. [28][29][30] Investigations involving coordinating solvents would reveal how such reactivity is modulated by the substituted phosphine ligands, providing insight that could be valuable in further assessing catalytic competence. To assess how coordinating solvents affect ET in these systems, we report chemical and electrochemical studies of an expanded series of (p-cymene)RuCl2(PAr X 3) complexes (1-X = OMe, Me, H, F, Cl, Br, CF3; Chart 1b) in coordinating solvent, including chemical reactivity of the nascent Ru(III) species.…”