A Dinuclear Ruthenium(II) Polypyridyl Complex Containing A terpy-like Fragment for Cu2+ Probing

The dinuclear Ru-II complex [{Ru(bpy)(2)}(2)(mu(2)-H2L)](4+) (bpy = 2,2'-bipyridine, H2L = 2,6-bis{4-(1,10-phenanthroline-[5,6-d]imidazol-2-yl)}pyridine) was synthesized and characterized. The effects of the cation on the UV/Vis absorption and fluorescence spectra as well as the electrochemical properties of the complex were studied. It served as a fluorescent sensor with high selectivity and sensitivity toward Cu2+ among 17 metal ions. The complex showed 2:1 binding ratio with Cu2+ in H2O/CH3CN solution (1:1, v/v) with a high binding constant of 2.69 x 10(11) M-1.