Spectroelectrochemistry of [(bpy)2Ru(tatpp)]Cl2,

R. O. LEZNA; N.R. DE TACCONI; F.M. MACDONNELL

ECS TRANSACTIONS

THE ELECTROCHEMICAL SOCIETY

Lugar: PENNINGTON, NEW JERSEY; Año: 2008 vol. `11 p. 37 - 43

1938-6737

The mononuclear ruthenium(II) complex [(bpy)2Ru(tatpp)]2+ (with bpy = bypyridine, tatpp = 9,11,20,22-tetraaza tetrapyrido[3,2-a:2’3’-c:3”,2”-l:2”’,3”’]-pentacene) is photoactive and capable of proton-coupled electron transfer reactions. Electrochemical characterization in acetonitrile and aqueous media indicate that four electrons are accepted by this complex, the first two reaching the aza sites of the tetraazapentacene unit of the tatpp ligand.  A rich array of electroreduced and protonated products was determined by UV-visible transmittance and reflectance spectroelectrochemistry. The multiple-electron uptake capability and appropriate energy levels in this complex is shared by its analog, the dinuclear [(bpy)2Ru(tatpp)(bpy)2]4+ complex, and therefore both are considered potential photocatalysts for hydrogen generation. Their photocatalytic lifetime was found significantly longer than the standard Ru(bpy)3+ photocatalyst.