UNUSUAL ELECTROCHEMICAL AND SPECTROSCOPIC BEHAVIOR IN A LIGAND-BRIDGED BINUCLEAR COMPLEX OF RUTHENIUM(II) - ,2'-BIPYRIDINE)-(MU-2,4,6-TRIS(2-PYRIDYL)TRIAZINE) DIRUTHENIUM(II)

The coordination complex [(Ru(bpy)(2))(2)tpt](PF6)(4) (bpy = 2,2'-bipy ridine; tpt=2,4,6-tris(2-pyridyl)triazine) has been prepared in 77% yi eld. Electrochemical characterization has been carried out and the ele ctrochemical properties are compared to the previously characterized m ononuclear analogue, [Ru(bpy)(2)tpt](PF6)(2). Spectroelectrochemical r esults indicate that the first reduction of the binuclear complex occu rs at the tpt ligand, but that the second reduction occurs at a bpy li gand. Both complexes are emissive in room temperature acetonitrile sol ution and their luminescence lifetimes and quantum yields have been de termined. The relationship between the electrochemical and spectroscop ic properties of this complex and its mononuclear analogue display a t rend counter to those of previously reported mono- and binuclear compl exes of Ru(II) based on bidentate bridging ligands.