Redox Control of Conformation and Luminescence of a Dinuclear Ruthenium(II) Complex with a Bis-dipyridophenazine Bridging Ligand

This spectroelectrochemical study deals with an interesting luminescent dinuclear complex [{Ru(bpy)2}2(µ-bdppz)]4+ (14+), where bpy stands for 2,2′-bipyridine and bdppz for 1,1′-dipyrido[3,2-a:2′,3′-c]phenazin-1,1′-yldipyrido[3,2-a:2′,3′- c]phenazine. The electronic coupling between the phenazine moieties through the central C−C bond can be easily modified as a function of the ligand oxidation state. Upon stepwise one-electron reduction in acetonitrile, complex 14+ is reversibly transformed into 13+ and 12+, with consequent major structural and electronic changes of the bridging ligand and with quenched MLCT emission of the excited Ru(bpy)2 moieties.