Electronic spectra of tris(.mu.-halo)bis(triammineruthenium)(2+) ions: evidence for delocalized mixed-valence D3h ruthenium(II, III) ground states

X-ray Crystallographic Study of the Ruthenium Blue Complexes [Ru2Cl3(tacn)2](PF6)2·4H2O, [Ru2Br3(tacn)2](PF6)2·2H2O, and [Ru2I3(tacn)2](PF6)2: Steric Interactions and the Ru−Ru “Bond Length”

“…The structures of [Ru 2 (μ-Cl) 3 (NH 3 ) 6 ](BPh 4 ) 2 ( 1a ) and [Ru 2 (μ-Br) 3 (NH 3 ) 6 ](ZnBr 4 ) ( 2a ) have since been reported , and both confirm the tris(μ-halo) geometry proposed from earlier measurements . In addition, the crystal structures show the complexes to have nearly perfect D 3 h symmetry, consistent with a delocalized description of the mixed-valence electronic structure, as indicated by the interpretation of the electronic spectrum …”

“…In 1969, Lever and Powell first isolated a blue solid from the reaction of hydrochloric acid with a warm solution of hexaammineruthenium(II) chloride. Subsequent analyses suggested that the complex was a mixed-valence Ru(III,II) species bridged by three halo ions, and interpretation of the infrared, electronic absorption, , and resonance Raman spectra proceeded without definitive evidence from a crystal structure. The structures of [Ru 2 (μ-Cl) 3 (NH 3 ) 6 ](BPh 4 ) 2 ( 1a ) and [Ru 2 (μ-Br) 3 (NH 3 ) 6 ](ZnBr 4 ) ( 2a ) have since been reported , and both confirm the tris(μ-halo) geometry proposed from earlier measurements .…”

Excited-State Contributions to Ground-State Properties of Mixed-Valence Dimers: Spectral and Electronic-Structural Studies of [Fe2(OH)3(tmtacn)2]2+ Related to the [Fe2S2]+ Active Sites of Plant-Type Ferredoxins

“…D 3 h Molecular- Orbital Diagram. The electronic structures of D 3 h M 2 L 9 cofacial-bioctahedral complexes have been studied using a variety of calculational − and spectroscopic − approaches. On the basis of these studies, a qualitative dimer molecular-orbital energy diagram can be composed for [Fe 2 (OH) 3 (tmtacn) 2 ] 2+ that delineates the effects of both metal−ligand and metal−metal interactions in a cofacial-bioctahedral geometry.…”

Halide-bridged arsine- and phosphine-capped diruthenium complexes, [(R3As)3Ru(μ-X)3Ru(AsR3)3]+ and [(R3P)3Ru(μ-X)3Ru(PR3)3]+ (X = Cl or Br), as precursors to confacial mixed-valence ruthenium ‘blues’: spectroelectrochemical studies spanning the binuclear oxidation states II,II, II,III and III,III

“…39 ) Accordingly, an orderly empirical trend is evident whether the strength of electronic coupling ) at 20 K, unless stated otherwise. c Visible spectrum recorded in dmso, 10 EPR in dmso-glycerol glass at 60 K. 11 d The EPR spectrum was recorded as dmso glass at 10 K. 14 e Visible spectrum recorded in aqueous solution, EPR as aqueous glass at 150 K. f g || too broad and weak to assign.…”