Synthesis and study of a mixed-ligand ruthenium(II) complex in its ground and excited states: bis(2,2′-bipyridine)(dipyrido[3,2-a : 2′,3′-c]phenazine-N4N5)ruthenium(II)

摘要: The ruthenium (II) complex [Ru(bipy)2(dppz)]2+(bipy = 2,2′-bipyridine, dppz dipyrido[3,2-a : 2′,3′-c]phenazine) was synthesized, characterized, and studied. Its oxidation first reduction potentials are respectively 1.24 –1.02 V (vs. saturated calomel electrode). maxima of the metal-to-ligand charge-transfer absorption emission occur at 448 610 nm. These data suggest that [Ru(bipy)2(dppz)]2+ is made up two electronically independent units, one behaving as a [Ru(bipy)3]2+-like chromophore, other phenazine-like electron acceptor. Excited-state spectra were obtained for its parent [Ru(bipy)3]2+. Above 500 nm latter shows only maximum (at 510 nm), former (around 526 557 whereas radical anions both bipyridine phenazine or dipyridophenazine show 512 552 phenazine). In case these results can be interpreted in terms light-induced directed charge transfer from to part ligand, localization on this ligand moiety. Photochemical properties studied ethanol. excited state quenched by an acceptor (methylviologen, kq= 1.37 × 109 dm3 mol–1 s–1) donor (triethanolamine, 4.40 107 mol–1s–1).