Preparation, spectroscopic, and electrochemical properties of four novel trinuclear Ru(II) polypyridyl complexes containing diazafluorene

• Published in: Inorganic chemistry communications 2010-02, Vol.13 (2), p.258-261
• Main Authors: Cheng, Feixiang, Tang, Ning, Chen, Jishu, Chen, Longhai, Jia, Lei, Chen, Guang
• Format: Article
• Language: English
• Subjects: Electrochemistry; Emission; Trinuclear Ru(II) complex; UV–Vis absorption
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2009.11.025

A new family of tripodal ligands based on diazafluorene and corresponding trinuclear Ru(II) complexes have been prepared. These complexes exhibit MLCT absorption around 410 nm and emission at around 582 nm. Cyclic voltammetry of these complexes comprise one Ru(II)-centered oxidation and three ligand-centered reduction processes. Four tripodal ligands 2,2′,2″-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxyethyl]amine (L 1), 1,1,1-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]propane (L 2), 1,3,5-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]-2,4,6-trimethylbenzene (L 3), 1,3,5-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]benzene (L 4), and corresponding Ru(II) complexes [(bpy) 6L 1–4(Ru II) 3](PF 6) 6 (Ru-L 1–4) have been synthesized. Cyclic voltammetry of these complexes comprise one Ru(II)-centered reversible oxidation and three ligand-centered reductions. Photophysical behaviors are investigated by UV–Vis absorption and luminescence spectrometry. These complexes display metal-to-ligand charge transfer absorption at around 410 nm and emission at around 582 nm.