title: Assessment of intercomponent interaction in phenylene bridged dinuclear ruthenium(II) and osmium(II) polypyridyl complexes.
abstract: The synthesis and characterisation of [Ru(bipy)(2)(L1)](2+) and the homodinuclear complexes [M(bipy)(2)(L1)M(bipy)(2)](4+)(where M = Ru or Os), employing the ditopic ligand, 1,4-phenylene-bis(1-pyridin-2-ylimidazo[1,5-a]pyridine)(L1), are reported. The complexes are identified by elemental analysis, UV/Vis, emission, resonance Raman, transient resonance Raman and (1)H NMR spectroscopy, mass spectrometry and electrochemistry. The X-ray structure of the complex [Ru(bipy)(2)(L1)(bipy)(2)Ru](PF(6))(4) is also reported. DFT calculations, carried out to model the electronic properties of the compounds, are in good agreement with experiment. Minimal communication between the metal centres is observed. The low level of ground state electronic interaction is rationalized in terms of the poor ability of the phenyl spacer in facilitating superexchange interactions. Using the electronic and electrochemical data a detailed picture of the electronic properties of the RuRu compound is presented.
authors.affiliation: National Centre for Senior Research, School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
authors.forename: Adrian L
authors.initials: AL
authors.lastname: Guckian
authors.forename: Manfred
authors.initials: M
authors.lastname: Doering
authors.forename: Michael
authors.initials: M
authors.lastname: Ciesielski
authors.forename: Olaf
authors.initials: O
authors.lastname: Walter
authors.forename: Johan
authors.initials: J
authors.lastname: Hjelm
authors.forename: Noel M
authors.initials: NM
authors.lastname: O'Boyle
authors.forename: William
authors.initials: W
authors.lastname: Henry
authors.forename: Wesley R
authors.initials: WR
authors.lastname: Browne
authors.forename: John J
authors.initials: JJ
authors.lastname: McGarvey
authors.forename: Johannes G
authors.initials: JG
authors.lastname: Vos