title: Synthesis, structure, and redox and catalytic properties of a new family of ruthenium complexes containing the tridentate bpea ligand.
abstract: We have prepared a new family of ruthenium complexes containing the bpea ligand (where bpea stands for N,N-bis(2-pyridyl)ethylamine), with general formula [Ru(bpea)(bpy)(X)](n+) (2, X = Cl(-); 3, X = H(2)O; 4, X = OH(-)), and the trisaqua complex [Ru(bpea)(H2O)(3)](2+), 6. The complexes have been characterized through elemental analyses, UV-vis and (1)H NMR spectroscopy, and electrochemical studies. For complex 3, the X-ray diffraction structure has also been solved. The compound belongs to the monoclinic P2(1)/m space group, with Z = 2, a = 7.9298(6) A, b = 18.0226(19) A, c = 10.6911(8) A, and beta = 107.549(8) degrees. The Ru metal center has a distorted octahedral geometry, with the O atom of the aquo ligand placed in a trans position with regard to the aliphatic N atom of the bpea ligand so that the molecule possesses a symmetry plane. NMR spectra show that the complex maintains its structure in aqueous solution, and that the corresponding chloro complex also has a similar structural arrangement. The pH dependence of the redox potential for the complex [Ru(bpea)(bpy)(H2O)](PF(6))(2) is reported, as well as the ability of the corresponding oxo complex to catalyze the oxidation of benzylic alcohol to benzaldehyde in both chemical and electrochemical manners.
authors.affiliation: Institute of Chemistry, University of Neuchatel, Av. Bellevaux 51, CH-2000 Neuchatel, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez
authors.forename: I
authors.initials: I
authors.lastname: Romero
authors.forename: A
authors.initials: A
authors.lastname: Llobet
authors.forename: A
authors.initials: A
authors.lastname: Deronzier
authors.forename: M
authors.initials: M
authors.lastname: Biner
authors.forename: T
authors.initials: T
authors.lastname: Parella
authors.forename: H
authors.initials: H
authors.lastname: Stoeckli-Evans