Synthesis, characterization, luminescent and redox properties of some mononuclear and dinuclear ruthenium(II) polypyridyl complexes

A series of mononuclear and dinucleor Ru(II) complexes of the type [RuL(X)( 2)](n+) and [Ru2L'(X)(4)](n+), L=(LH)-H-1, n =1; L=L-2 n=2; L'=(LH2)-H-3, n =2; L'=L-4, n =4 and X=2,2'- bipyridyl as well us 1,10-phenanthroline, have been prepared and characterized by IR, H-1-NMR UV-vis spectra, FAB Mass an d elemental analysis data. The complexes display metal-ligand charge-transf er (MLCT) transitions in the visible region and show hyperchromic shift upo n addition of DNA solution. Emission observed in the range 580-595 nm is qu enched upto 7.3-40.5% upon addition of buffered solution of calf thymus DNA . Acetonitrile solution of the complexes show electrochemical oxidation of the ligands.