名称:
Preparation, photophysical, and electrochemical properties of three trinuclear Ru(II) complexes: Bridging ligands composed of 2,2′-bipyridine and 4,5-diazafluorene fragments
摘要:
Three bridging.ligands 5,5 '-bis[(4,5-diazafluoren-9-ylimina)methyl]-2,2 '-bipyridine (L-1), 5,5 '-bis[2-(4,5diazafluoren-9-ylimino)phenoxymethyl]-2,2 '-bipyridine (L-2), 5,5 '-bis[4-(4,5-diazafluoren-9-ylimino) phenoxymethyl]-2,2 '-bipyridine (L-3), and corresponding Ru(11) complexes [(bpY)(6)Ru-3(L1-3)](PF6)(6) (bPY=2,2 '-bipyridine) have been synthesized. The three ligands have two kinds of nonequivalent chelating sites: one involving the 2,2 '-bipyridine moiety, and the other involving the 4,5-diazafluorene moiety. The emission intensities of complexes [(bPY)(6)Ru-3(L-2)](6+) and 1(bPY)6Ru3(L3)l(6+) are almost equal to that of complex [(bPY)(6)Ru-3(L-1)](6+) in CH3CN solution at room temperature, but weaker than that of complex [(bPY)(6)Ru-3(L-1)](6+) in EtOH-MeOH (4:1, v/v) glassy matrix at 77 K. Cyclic voltammetry and differential pulse voltammetry studies of the three complexes show one Ru(11)-centered oxidation at around 1.33 V for the Ru (II/III) couple. (C) 2014 Elsevier B.V. All rights reserved.