title: Efficient energy transfer via the cyanide bridge in dinuclear complexes containing Ru(II) polypyridine moieties.
abstract: We report the synthesis, structure and properties of the cyanide-bridged dinuclear complex ions [Ru(L)(bpy)(μ-NC)M(CN)(5)](2-/-) (L = tpy, 2,2';6',2''-terpyridine, or tpm, tris(1-pyrazolyl)methane, bpy = 2,2'-bipyridine, M = Fe(II), Fe(III), Cr(III)) and the related monomers [Ru(L)(bpy)X](2+) (X = CN(-) and NCS(-)). All the monomeric compounds are weak MLCT emitters (λ = 650-715 nm, ϕ ≈ 10(-4)). In the Fe(II) and Cr(III) dinuclear systems, the cyanide bridge promotes efficient energy transfer between the Ru-centered MLCT state and a Fe(II)- or Cr(III)-centered d-d state, which results either in a complete quenching of luminescence or in a narrow red emission (λ ≈ 820 nm, ϕ ≈ 10(-3)) respectively. In the case of Fe(III) dinuclear systems, an electron transfer quenching process is also likely to occur.
authors.affiliation: Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cadranel
authors.forename: Pablo
authors.initials: P
authors.lastname: Alborés
authors.forename: Shiori
authors.initials: S
authors.lastname: Yamazaki
authors.forename: Valeria D
authors.initials: VD
authors.lastname: Kleiman
authors.forename: Luis M
authors.initials: LM
authors.lastname: Baraldo