Solvolysis and cytotoxicity of dinuclear ruthenium(II)-2,2′-bipyridine complexes with various bridged-ligands

In order to reveal the solvolysis reactions of dinuclear ruthenium(II)-2,2'-bipyridine complexes with various bridged-ligands (BL), [{RuCl(bpy)(2)}(2)(mu-BL)](2+) ([Ru2Cl2-BL](2+)), we have studied the kinetics of these complexes in H2O and H2O-dmso (1:1 v/v). In H2O-dmso (1:1 v/v), time-course UV-Vis absorption and IR spectra indicate that the labile Cl ligands of [Ru2Cl2-BL](2+) are successively substituted by H2O followed by dmso, [{Ru(dmso-S)(bpy)(2)}(2)(mu-BL)](4+). Cytotoxicity assays of dinuclear ruthenium(II) complexes were performed in L1210 murine leukemia cell line. [Ru2Cl2-BL](2+) complexes exhibit much lower cytotoxicity compare to cisplatin. However, [{Ru(dmso-S)(bpy)(2)}(2)(mu-BL)](4+) complexes produced in H2O-dmso are found to much more cytotoxic than [Ru2Cl2-BL](2+) and in particular the cytotoxicity of [{Ru(dmso-S)(bpy)(2)}(2)(mu-dado)](4+) (dado = 1,12-diaminododecane) is comparable to that of cisplatin. (C) 2012 Elsevier B. V. All rights reserved.