Cyclometallated Ruthenium Complex with 3,3',5,5'-Tetramethyl-1,1'-biphenyl-4,4'-bipyrazole and 2,2'-Dicarboxybipyridine: Synthesis, Optical Properties, and Quantum Chemical Modeling

Abstract

New complex [RuL(Dmdcbp)2]PF6 (I) is synthesized by the consecutive reactions of [Ru-p-cymene]2Cl4 with 3,3',5,5'-tetramethyl-1,1'-biphenyl-4,4'-bipyrazole (L) and 4,4'-dicarboxy-2,2'-bipyridine in a methanol–chloroform medium. The composition of complex I is confirmed by NMR and elemental analysis, and the optical and luminescence properties of the complex are studied. Ligand L is characterized for the first time by X-ray diffraction (CIF file CCDC no. 2118676). Quantum chemical calculations in terms of the density functional theory are performed for the interpretation of the absorption and emission spectra. Complex I is promising for using as a photosensitizer.

New ruthenium polypyridyl complexes functionalized with fluorine atom or furan: Synthesis, DNA-binding, cytotoxicity and antitumor mechanism studies

Two novel ruthenium(II) polypyridyl complexes, namely, [Ru(dmp)₂(CAPIP)](ClO₄)₂ (Ru(II)-1) and [Ru(dmp)₂(CFPIP)](ClO₄)₂ (Ru(II)-2), which respectively contain (E)-2-(2-(furan-2-yl)vinyl)-1H-imidazo[4,5-f][1,10]phen-anthroline (CAPIP) and (E)-2-(4-fluorostyryl)-1H-imidazo[4,5-f][1,10]phenanthroline. (CFPIP), were first designed and characterized (dmp = 2,9-dimethyl-1,10-phenanthroline). DNA binding experiments indicated that Ru(II) complexes interact with CT DNA through intercalative mode. In addition, the complexes Ru(II)-1 and Ru(II)-2, showed remarkable cell cytotoxicity, giving the respective IC₅₀ values of 4.1 ± 1.4 μM and 6.1 ± 1.4 μM on the A549 cancer cells. These values indicated higher activity than CAPIP, CFPIP, cisplatin (8.2 ± 1.4 μM) and other corresponding Ru(II) polypyridyl complexes. Furthermore, the Ru(II) complexes could arrive the cytoplasm through the cell membrane and accumulate in the mitochondria. Significantly, complexes Ru(II)-1 and Ru(II)-2 induced A549 cells apoptosis was mediated by increase of ROS levels and dysfunction of mitochondria, and resulted in cell cycle arrest and increased anti-migration activity on A549 cells. Overall, these results indicated that complexes Ru(II)-1 and Ru(II)-2 could be suitable candidates for further investigation as a chemotherapeutic agent in the treatment of tumors.