Dinuclear Ruthenium (II) Diphen Complex of HAT

by Marutharaj, Tamelselvi; Durham, Bill; Millett, Francis Spencer

The photoredox properties of ruthenium(II) polypyridine complexes are well known and there are many examples of the application of these properties to engineering, chem. and biochem. problems. These applications rely on a reasonably long lived excited state, favorable absorption properties, high thermal stability and appropriate photoredox properties. Despite the growth in this area new complexes with suitable properties are in const. demand. One particular application in which we are involved is the investigation of the electron-transfer reaction of metalloproteins. We wish to report the prepn. and characterization of dinuclear ruthenium complexes contg. HAT (1, 4, 5, 8, 9, 12-hexaazatriphenylene) ligand. Mononuclear complexes with these ligands are noted for their extreme redox potentials which is an advantage in the investigation of electron transfer. Dinuclear complexes posses many of the features of the mononuclear complexes but have a larger overall charges. By refluxing diruthenium diphen complex [Ru2(diphen)Cl4] with excess of Hat ligand, we have prepd. the dinuclear ruthenium (II) diphen complex of HAT [Ru(HAT)2]2diphen which has a charge of +4. In the intended application high overall charge has proven to be a significant advantage and ultimately results in higher overall yield of photoproducts.