Bridge coordination of bidentate ligands to a dinuclear η6-arene-ruthenium(II) unit constructed by a chelating and bridging alkoxo ligand
摘要:
Dinuclear eta(6)-areneruthenium(II) complex of the formula [Ru-2{eta(6):eta(1):mu-C6H5(CH2)(3)O} (mu-Cl)](+) (2) was prepared by treatment of Ru{mu(6)-C6H5(CH2)(3)OH}Cl-2 with base. X-Ray structure analysis revealed 2 to contain two Ru centers bridged by Cl ligand as well as by two alkoxo groups, which are tethered to eta(6)-arene ligands. Treatment of 2 with Ag+ in acetonitrile afforded dicationic complex [Ru-2{eta(6):eta(1):mu-C6H5(CH)(3)O}(2)(CH3CN)(2)](2+) (3) in which two CH3CN ligands are located trans to each other with respect to the Ru2O2 plane. Irradiation with UV light (300-400 nm) of a CH3CN solution of 3 and trams-azobenzene gave cis-azobenzene complex [Ru-2{eta(6):eta(1):mu-C6H5(CH2)(3)O}(2)(mu-cis-PhN=NPh)](2+) (4). Cis-azobenzene ligand of 4 dissociated under irradiation of light (> 510 nm) to give 3 in CH3CN or disulfide complex [Ru-2{eta(6):eta(1):mu-C6H5(CH2)(3)O}(2)(mu-PhSSPh)](2+) (6) in the presence of the disulfide. X-ray structure determination of 4 and 6 established bridge coordination of cis-azobenzene and disulfide ligands. Reaction of 3 with pyridazine afforded similar dimeric complex [Ru-2{eta(6):eta(1):mu-C6H5(CH2)(3)O}(2)(mu-pyridazine)](2+) (7), while the reaction with bipyridine afforded monomeric alkoxo chelate complex [Ru{eta(6):eta(1)-C6H5(CH2)(3)O}(bipy)](+) (8). (C) 2002 Elsevier Science B.V. All rights reserved.