Cyclometalated ruthenium(II) complexes of benzo[h]quinoline (bzqH)[Ru(bzq)(NCMe)4], [Ru(bzq)(LL)(NCMe)2], and [Ru(bzq)(LL)2] (LL = bpy, phen) |
| |
Authors: | Ronan Le Lagadec Hebert Estevez Larissa Alexandrova |
| |
Institution: | a Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 México D.F., Mexico b Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 México D.F., Mexico c Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA |
| |
Abstract: | Cyclometalation of benzoh]quinoline (bzqH) by RuCl(μ-Cl)(η6-C6H6)]2 in acetonitrile occurs in a similar way to that of 2-phenylpyridine (phpyH) to afford Ru(bzq)(MeCN)4]PF6 (3) in 52% yield. The properties of 3 containing ‘non-flexible’ benzoh]quinoline were compared with the corresponding Ru(phpy)(MeCN)4]PF6 (1) complex with ‘flexible’ 2-phenylpyridine. The Ru(phpy)(MeCN)4]PF6 complex is known to react in MeCN solvent with ‘non-flexible’ diimine 1,10-phenanthroline to form Ru(phpy)(phen)(MeCN)2]PF6, being unreactive toward ‘flexible’ 2,2′-bipyridine under the same conditions. In contrast, complex 3 reacts both with phen and bpy in MeCN to form Ru(bzq)(LL)(MeCN)2]PF6 {LL = bpy (4) and phen (5)}. Similar reaction of 3 in methanol results in the substitution of all four MeCN ligands to form Ru(bzq)(LL)2]PF6 {LL = bpy (6) and phen (7)}. Photosolvolysis of 4 and 5 in MeOH occurs similarly to afford Ru(bzq)(LL)(MeCN)(MeOH)]PF6 as a major product. This contrasts with the behavior of Ru(phpy)(LL)(MeCN)2]PF6, which lose one and two MeCN ligands for LL = bpy and phen, respectively. The results reported demonstrate a profound sensitivity of properties of octahedral compounds to the flexibility of cyclometalated ligand. Analogous to the 2-phenylpyridine counterparts, compounds 4-7 are involved in the electron exchange with reduced active site of glucose oxidase from Aspergillus niger. Structure of complexes 4 and 6 was confirmed by X-ray crystallography. |
| |
Keywords: | Ruthenium Cyclometalation Electrochemistry Electron transfer Photosolvolysis |
本文献已被 ScienceDirect 等数据库收录! |
|