A new family of Ru(II) complexes with a tridentate pyridine Schiff-base ligand and bidentate co-ligands: synthesis, characterization, structure and in vitro cytotoxicity studies

作者：Garza Ortiz Ariadna; Maheswari Palanisamy Uma; Siegler Maxime; Spek Anthony L; Reedijk Jan^*

来源：New Journal of Chemistry, 2013, 37(11): 3450-3460.

DOI：10.1039/c3nj00415e

Starting from the Ru(III) complex, [RuCl3(L1)](H2O) (L1: 2,6-bis(2,4,6-trimethylphenyliminomethyl)pyridine), the chemical reactivity and cytotoxic activity of a new family of Ru(II) complexes with a number of bidentate co-ligands have been studied. The synthesis of the Ru(II)-bis(arylimino) pyridine complexes with the co-ligands 1,10-phenanthroline (phen), 2,2%26apos;-dipyridyl-(bpy), 2-(phenylazo) pyridine (azpy), 2-(phenylazo)-3-methylpyridine (3mazpy), 2-(tolylazo) pyridine (tazpy), and 2-picolinate (pic) is reported. These new six complexes, with L1 and different bidentate N donor co-ligands, have been designed to allow the binding of a monodentate chloride ligand, which would be easily hydrolysed in vitro. Elemental analysis and several spectroscopic techniques (IR, UV-Vis, 1D and 2D H-1 NMR and ESI-MS) have been used for the characterization of the new Ru(II) compounds. In addition, the crystal structure of the chlorido(2-picolinato)(2,6-bis(2,4,6-trimethylphenyliminomethyl) pyridine) ruthenium(II) was solved and shows a slightly distorted octahedral geometry for the Ru(II) centre with the tridentate L1 ligand coordinated in a planar mer fashion, with the bidentate ligand in a perpendicular orientation and a monodentate chloride, trans to the coordinating oxygen of the picolinate ion. The in vitro cytotoxic properties of these new Ru(II) complexes in comparison with the parent, starting Ru(III)-compound (IC50 values = 11-17 mM) appear to be encouraging for a broad range of cancer cell-lines tested (IC50 values = 0.4-10 mM). Some of them show better cytotoxic effects than cisplatin on a straight comparison with the same cancer cell lines. The cytotoxicity data are discussed in the light of structure-activity relationships and these ruthenium(II) compounds could well be promising next generation candidates worth further investigation.

• 出版日期2013