Preparation, photophysical, and electrochemical properties of three novel trinuclear Ru(II) polypyridyl complexes based on diazafluorenes

Three tripodal ligands 2,2′,2″-tris[(4,5-diazafluoren-9-ylimino)phenoxyethyl]amine (L1), 1,3,5-tris[(4,5-diazafluoren-9-ylimino)phenoxymethyl]-2,4,6-trimethylbenzene (L2), 1,1′,1″-tris[(4,5-diazafluoren-9-ylimino)phenoxymethyl]-1″′-(p-tosyloxymethyl)-methane (L3), and corresponding Ru(II) complexes [(bpy)6L1–3(RuII)3](PF6)6 (Ru-L1–3) have been prepared. Cyclic voltammetry of the three complexes are consistent with one Ru(II)-centered quasi-reversible oxidation and three ligand-centered reductions. Photophysical behaviors are investigated by UV–Vis absorption and fluorescence spectrometry. The three complexes display metal-to-ligand charge transfer absorption at 445 nm and emission at 578 nm.

Three novel tripodal ligands derived from diazafluorene and corresponding trinuclear Ru(II) complexes have been prepared. These complexes display MLCT absorption at 445 nm and emission at 578 nm. Cyclic voltammetry of these complexes are consistent with one Ru(II)-centered quasi-reversible oxidation and three ligand-centered reductionsFigure optionsDownload as PowerPoint slide