Characterization of the ruthenium–dinitrogen tetraamine complexes by XAFS spectroscopy

Okamoto, Kaoru; Takahashi, Tomohiro; Kohdate, Kenji; Kondoh, Hiroshi; Yokoyama, Toshihiko; Ohta, Toshiaki

doi:10.1107/s0909049500015971

Cited by 8 publications

(3 citation statements)

References 3 publications

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“…Solid and solution samples in each state gave the same spectra. They all showed the typical shape of Ru O h complex with a small edge shift to a higher energy at each oxidation step. This suggests that the coordination environment around the Ru ion is maintained during the oxidation process.…”

Section: Resultsmentioning

confidence: 90%

Structural Study on Highly Oxidized States of a Water Oxidation Complex [Ru^III(bpy)₂(H₂O)]₂(μ-O)⁴⁺ by Ruthenium K-Edge X-ray Absorption Fine Structure Spectroscopy

et al. 2003

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The oxidation-induced structural change of a water-oxidizing diruthenium complex, [(bpy)(2)(H(2)O)Ru(III)(micro-O)Ru(III)(OH(2))(bpy)(2)](4+) (bpy = 2,2'-bipyridine), was investigated by means of X-ray absorption spectroscopy. Ru K-edge XANES (X-ray absorption near-edge structure) spectra from the acidic solution and solid precipitates obtained by oxidation showed that the absorption edge shifts toward higher energy with a preedge feature slightly more enhanced than those of the lower oxidation states. This indicates that the higher oxidation state has a lower symmetry due to shortening of the Ru-O bonds that originated from the water ligands. The EXAFS (extended X-ray absorption fine structure) spectra were similar to those of the lower oxidation states, whose analysis revealed the existence of short Ru-O double bonds and an almost linear Ru-O-Ru angle (169 +/- 2 degrees ). Ab initio EXAFS simulations for several possible structural models suggest that the dimeric structure is maintained during the water oxidation reaction.

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Section: Resultsmentioning

confidence: 90%

Structural Study on Highly Oxidized States of a Water Oxidation Complex [Ru^III(bpy)₂(H₂O)]₂(μ-O)⁴⁺ by Ruthenium K-Edge X-ray Absorption Fine Structure Spectroscopy

et al. 2003

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“…The raw data were energy calibrated (Ru K-edge energy of RuCl 3 : 22.12 keV [38], first inflection point), background corrected and normalized using the WINXAS 3.1 software [38] according to typical procedures described earlier [39,40]. Fourier transformation of EXAFS data was applied to the k 1 -weighted functions in the interval k = 3-13Å −1 .…”

Section: X-ray Absorption (Xas) Measurementsmentioning

confidence: 99%

Selective oxidation of alcohols with oxygen on Ru–Co-hydroxyapatite: A mechanistic study

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et al. 2005

Journal of Molecular Catalysis A: Chemical

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“…Finally, the shift is similar for commercial RuCl 3 , and we could presume that the oxidation state of the ruthenium in the colloidal solution is 3+. The XANES spectrum for the colloids shows some similar features to those obtained by Ohta et al 32,33 and was attributed to RuO h complex structure. A shoulder is also visible on the Ru colloids sample in the rising edge (pre-edge) of the spectrum.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Ruthenium Trichloride Catalyst in Water: Ru Colloids versus Ru Dimer Characterization Investigations

et al. 2019

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An easy-to-prepare ruthenium catalyst obtained from ruthenium(III) trichloride in water demonstrates efficient performances in the oxidation of several cycloalkanes with high selectivity toward the ketone. In this work, several physicochemical techniques were used to demonstrate the real nature of the ruthenium salt still unknown in water and to define the active species for this Csp 3 -H bond functionalization. From transmission electron microscopy analyses corroborated by SAXS analyses, spherical nanoobjects were observed with an average diameter of 1.75 nm, thus being in favor of the formation of reduced species. However, further investigations, based on X-ray scattering and absorption analyses, showed no evidence of the presence of a metallic Ru−Ru bond, proof of zerovalent nanoparticles, but the existence of Ru−O and Ru−Cl bonds, and thus the formation of a water-soluble complex. The EXAFS (extended X-ray absorption fine structure) spectra revealed the presence of an oxygen-bridged diruthenium complex [Ru(OH) x Cl 3−x ] 2 (μ-O) with a high oxidation state in agreement with catalytic results. This study constitutes a significant advance to determine the true nature of the RuCl 3 •3H 2 O salt in water and proves once again the invasive nature of the electron beam in microscopy experiments, routinely used in nanochemistry.

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Characterization of the ruthenium–dinitrogen tetraamine complexes by XAFS spectroscopy

Cited by 8 publications

References 3 publications

Structural Study on Highly Oxidized States of a Water Oxidation Complex [Ru^III(bpy)₂(H₂O)]₂(μ-O)⁴⁺ by Ruthenium K-Edge X-ray Absorption Fine Structure Spectroscopy

Structural Study on Highly Oxidized States of a Water Oxidation Complex [Ru^III(bpy)₂(H₂O)]₂(μ-O)⁴⁺ by Ruthenium K-Edge X-ray Absorption Fine Structure Spectroscopy

Selective oxidation of alcohols with oxygen on Ru–Co-hydroxyapatite: A mechanistic study

Ruthenium Trichloride Catalyst in Water: Ru Colloids versus Ru Dimer Characterization Investigations

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Characterization of the ruthenium–dinitrogen tetraamine complexes by XAFS spectroscopy

Cited by 8 publications

References 3 publications

Structural Study on Highly Oxidized States of a Water Oxidation Complex [RuIII(bpy)2(H2O)]2(μ-O)4+ by Ruthenium K-Edge X-ray Absorption Fine Structure Spectroscopy

Structural Study on Highly Oxidized States of a Water Oxidation Complex [RuIII(bpy)2(H2O)]2(μ-O)4+ by Ruthenium K-Edge X-ray Absorption Fine Structure Spectroscopy

Selective oxidation of alcohols with oxygen on Ru–Co-hydroxyapatite: A mechanistic study

Ruthenium Trichloride Catalyst in Water: Ru Colloids versus Ru Dimer Characterization Investigations

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Structural Study on Highly Oxidized States of a Water Oxidation Complex [Ru^III(bpy)₂(H₂O)]₂(μ-O)⁴⁺ by Ruthenium K-Edge X-ray Absorption Fine Structure Spectroscopy

Structural Study on Highly Oxidized States of a Water Oxidation Complex [Ru^III(bpy)₂(H₂O)]₂(μ-O)⁴⁺ by Ruthenium K-Edge X-ray Absorption Fine Structure Spectroscopy