A new family of dinuclear Ru(II) polypyridyl complexes containing dibenzo-14-crown-4

Three bis(bidentate) ligands cis-di(4,5-diazafluoren-9-ylimino)dibenzo-14-crown-4 (BL1), trans-di(4,5-diazafluoren-9-ylimino)dibenzo-14-crown-4 (BL2), and 1,4,8,11-tetraoxacyclotetradecyl[2,3:9,10]bis-dipyrido[3,2-a:2′3′-c]phenazine (BL3), and corresponding bimetallic Ru(II) complexes [(bpy)2RuBL1−3Ru(bpy)2](PF6)4 (Ru–BL1−3) have been synthesized. Cyclic voltammetry of these complexes are consistent with one Ru(II)-centered reversible oxidation and three ligand-centered reductions. These complexes show metal-to-ligand charge transfer absorption at 445–454 nm and emission at 575–592 nm.