Reaction of the dimers [Ru(h6-arene)Cl2]2 (arene = C6H6, C6H5Me, p-iPrC6H4Me, C6Me6) with 2 equiv of the ferrocenoyl pyridine (NC5H4(OOCC5H4FeC5H5)-4) affords Ru(II) complexes [Ru(h6-arene)Cl2(NC5H4OOCC5H4FeC5H5)] (arene = C6H6 (1, 85% yield), C6H5Me (2, 81%), p-iPrC6H4Me (3, 91%), C6Me6 (4, 38%)) or with 1 equiv of the dipyridylferrocene deriv. ligand, 1,1'-ferrocene dicarboxylic acid pyridin-4-yl ester (NC5H4OOCC5H4FeC5H4COOC5H4N,) gives [Ru(h6-arene)Cl2]2(NC5H4OOCC5H4FeC5H4COOC5H4N) (arene = p-iPrC6H4Me (5, 74%), C6Me6 (6, 92%)). The mol. structures of these complexes was confirmed by single-crystal x-ray structure anal. of complex 4 as a representative example. The redox properties and in vitro anticancer activities of complexes 1-6 were studied. All the compds. are moderately cytotoxic toward the A2780 and A2780cisR (cisplatin-resistant) human ovarian carcinoma cell lines. The diruthenium arene complexes 5 and 6 are about twice as active as their mononuclear analogs 3 and 4. Cyclic voltammetry revealed a good correlation of the RuII/RuIII redox potentials of 1-4 and the no. of alkyl substituents in the arene ligand.
Rosario Scopelliti, Kay Severin, Farzaneh Fadaei Tirani, Ophélie Marie Planes
Paul Joseph Dyson, Farzaneh Fadaei Tirani, Mouna Hadiji
Kay Severin, Nicolai Cramer, Carl Thomas Bormann, Florian Gérald Abela, Jin Fay Tan, Frederick Mark Chadwick