Stepwise Elongation of a Trinuclear Ruthenium Unit in Pyrazine-Bridged Linear Oligomers with Use of [Ru3(<i>μ</i>3-O)(<i>μ</i>-CH3COO)6(pyridine)(CO)(H2O)]

Kido, Hiroaki; Nagino, Haruko; Ito, Tasuku

doi:10.1246/cl.1996.745

Cited by 45 publications

(37 citation statements)

References 9 publications

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“…Complexes 1-3 were prepared as described previously (Kido et al 1996). Solvents for this study were chosen such that the mixed-valence state of the complex is soluble and is stable over a wide range of temperatures.…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

Electron transfer at the class II/III borderline of mixed valency: dependence of rates on solvent dynamics and observation of a localized-to-delocalized transition in freezing solvents

Glover

Lear

Salsman

et al. 2007

Phil. Trans. R. Soc. A.

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The dependence of the rates of intramolecular electron transfer (ET) of mixed-valence complexes of the type {[Ru 3 O(OAc) 6 (CO)(L)] 2 -BL} K1 , where L is the pyridyl ligand and BL is the pyrazine on solvent type and temperature is described. Complexes were reduced chemically to obtain the mixed-valence anions in acetonitrile (CH 3 CN) and methylene chloride (CH 2 Cl 2 ). Rate constants for intramolecular ET were estimated by simulating the observed degree of n(CO) infrared (IR) bandshape coalescence in the mixed-valence state. In the strongly coupled mixed-valence states of these complexes, the electronic coupling, H AB , approaches l/2, where l is the total reorganization energy. The activation energy is thus nearly zero, and rate constants are in the 'ultrafast' regime where they depend on the pre-exponential terms within the frequency factor, n N . The frequency factor contains both external (solvent dynamics) and internal (molecular vibrations) contributions. In general, external solvent motions are slower than internal vibrations, and therefore control ET rates in fluid solution. A profound increase in the degree of n(CO) IR bandshape coalescence is observed as the temperature approaches the freezing points of the solvents methylene chloride (f.p. K928C) and acetonitrile (f.p. K448C). Decoupling the slower solvent motions involved in the frequency factor n N for ET by freezing the solvent causes a transition from solvent dynamics to internal vibration-limited rates. The solvent phase transition causes a localized-to-delocalized transition in the mixed-valence ions that accelerates the rate of ET.

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Section: Synthesis and Characterizationmentioning

confidence: 99%

Electron transfer at the class II/III borderline of mixed valency: dependence of rates on solvent dynamics and observation of a localized-to-delocalized transition in freezing solvents

Glover

Lear

Salsman

et al. 2007

Phil. Trans. R. Soc. A.

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“…Assim, utilizando principalmente pirazina e 4,4'-bipiridina foram obtidos dímeros 41 A estratégia sintética utilizada envolve a reação de um cluster contendo um sítio lábil e outro com um ligante de ponte. Alternativamente pode-se utilizar um cluster totalmente assimétrico [Ru 3 O(CH 3 CO 2 ) 6 (py)(CO)(H 2 O)] que possua um sítio inerte, um lábil e outro fotodissociável de modo a permitir a construção de oligômeros 47 (Figura 5). Trabalhos recentes de Ito et al 52 tem focalizado os efeitos da transferência eletrônica entre duas unidades de clusters unidas por ponte de pirazina ou de 1,4-di(isociano)-benzeno.…”

Section: Considerações Finaisunclassified

Propriedades e aplicações de clusters trinucleares de carboxilatos de rutênio

Alexiou¹,

Dovidauskas²,

Toma³

2000

Quím. Nova

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Recebido em 8/12/99; aceito em 16/3/00 PROPERTIES AND APPLICATIONS OF TRINUCLEAR RUTHENIUM CARBOXYLATE CLUS-TERS. A review with 94 references focusing on µ µ µ µ µ 3 -oxo-triruthenium carboxylate clusters is presented. The electronic, magnetic, electrochemical, and catalytic properties of these compounds are discussed. Main synthetic routes and structural characteristics, including their use as building blocks in supramolecular systems are described.Keywords: ruthenium-acetate clusters; oxo-ruthenium clusters; ruthenium-carboxylated clusters; catalysis. Nas décadas passadas alguns trabalhos de revisão focalizaram a química dos clusters de rutênio [20][21][22][23][24] , e mais recentemente, apenas estudos mais específicos tem sido publicados [25][26][27] . O objetivo deste trabalho é apresentar uma visão abrangente da química destes compostos, considerando que a maioria dos trabalhos foram feitos nos anos 90 e que os aspectos recentes, mais relevantes, não foram ainda apresentados. REVISÃO INTRODUÇÃO ASPECTOS SINTÉTICOSNesse ítem, descrevemos a síntese dos clusters simétricos

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“…The mixed‐valence state thus formed has been the subject of measurements of electron‐exchange rates between the cores as followed by ν(CO) coalescence in the infrared spectra 22–25. Furthermore, it has been reported that higher degree oligomeric forms of the triruthenium unit bridged by aromatic pyridyl ligands also show redox interactions between the triruthenium units 26–28. By combining these observations with the ligand–ligand redox interactions described above, it may be possible to construct extended electron mediating systems based on oxo‐centered trimetal clusters and π‐conjugated aromatic bridging ligands.…”

Section: Resultsmentioning

confidence: 99%