Effective Nuclear Charge and Chemical Shifts in X-Ray Absorption Spectra of Polymeric Copper(II) Salicylhydroxamates

Khadikar, Padmakar V.; Mangelson, N.F.; Pandharkar, Sadhana P.

doi:10.1143/jjap.28.709

“…Figure displays the Mo Kβ 1 HERFD XAS of the complexes grouped by ligand identity, with the Mo compounds with Tp and CO ligands ( 0, I , Ib and II ) at the top and the oxides ( IV and VI ) at the bottom. Metal K‐edge positions shift towards higher energies with increasing oxidation state, as the effective nuclear charge varies . Figure (bottom) shows an energy shift of +2.6 eV in the rising edge on going from compound IV to VI .…”

Section: Resultsmentioning

confidence: 99%

Kβ X‐Ray Emission Spectroscopic Study of a Second‐Row Transition Metal (Mo) and Its Application to Nitrogenase‐Related Model Complexes

Castillo

¹

,

Henthorn

²

,

McGale

³

et al. 2020

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In recent years, X‐ray emission spectroscopy (XES) in the Kβ (3p‐1s) and valence‐to‐core (valence‐1s) regions has been increasingly used to study metal active sites in (bio)inorganic chemistry and catalysis, providing information about the metal spin state, oxidation state and the identity of coordinated ligands. However, to date this technique has been limited almost exclusively to first‐row transition metals. In this work, we present an extension of Kβ XES (in both the 4p‐1s and valence‐to‐1s [or VtC] regions) to the second transition row by performing a detailed experimental and theoretical analysis of the molybdenum emission lines. It is demonstrated in this work that Kβ2 lines are dominated by spin state effects, while VtC XES of a 4d transition metal provides access to metal oxidation state and ligand identity. An extension of Mo Kβ XES to nitrogenase‐relevant model complexes shows that the method is sufficiently sensitive to act as a spectator probe for redox events that are localized at the Fe atoms. Mo VtC XES thus has promise for future applications to nitrogenase, as well as a range of other Mo‐containing biological cofactors. Further, the clear assignment of the origins of Mo VtC XES features opens up the possibility of applying this method to a wide range of second‐row transition metals, thus providing chemists with a site‐specific tool for the elucidation of 4d transition metal electronic structure.

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“…Figure displays the Mo Kβ 1 HERFD XAS of the complexes grouped by ligand identity, with the Mo compounds with Tp and CO ligands ( 0, I , Ib and II ) at the top and the oxides ( IV and VI ) at the bottom. Metal K‐edge positions shift towards higher energies with increasing oxidation state, as the effective nuclear charge varies . Figure (bottom) shows an energy shift of +2.6 eV in the rising edge on going from compound IV to VI .…”

Section: Resultsmentioning

confidence: 99%

Kβ X‐Ray Emission Spectroscopic Study of a Second‐Row Transition Metal (Mo) and Its Application to Nitrogenase‐Related Model Complexes

Castillo

¹

,

Henthorn

²

,

McGale

³

et al. 2020

View full text Add to dashboard Cite

In recent years, X‐ray emission spectroscopy (XES) in the Kβ (3p‐1s) and valence‐to‐core (valence‐1s) regions has been increasingly used to study metal active sites in (bio)inorganic chemistry and catalysis, providing information about the metal spin state, oxidation state and the identity of coordinated ligands. However, to date this technique has been limited almost exclusively to first‐row transition metals. In this work, we present an extension of Kβ XES (in both the 4p‐1s and valence‐to‐1s [or VtC] regions) to the second transition row by performing a detailed experimental and theoretical analysis of the molybdenum emission lines. It is demonstrated in this work that Kβ2 lines are dominated by spin state effects, while VtC XES of a 4d transition metal provides access to metal oxidation state and ligand identity. An extension of Mo Kβ XES to nitrogenase‐relevant model complexes shows that the method is sufficiently sensitive to act as a spectator probe for redox events that are localized at the Fe atoms. Mo VtC XES thus has promise for future applications to nitrogenase, as well as a range of other Mo‐containing biological cofactors. Further, the clear assignment of the origins of Mo VtC XES features opens up the possibility of applying this method to a wide range of second‐row transition metals, thus providing chemists with a site‐specific tool for the elucidation of 4d transition metal electronic structure.

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X‐Ray K‐Absorption Spectroscopic Studies of Some Cobalt(II) Complexes

Kekre

¹

,

Joshi

²

,

Mishra

³

et al. 1995

Bulletin des Soc Chimique

0

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X-ray K-absorption spectra of some cobalt(l1) complexes of newly synthesized mannich bases of biological interest have been studied using Seifert X-ray generator and Cauchois type bent crystal X-ray spectrograph of 0.4 m radius. The observed X-ray parameters, e.g. chemical shift, shift of principal absorption maximum, edge-width, effective nuclear charge and percentage covalency have been used to explain the structure of the complexes, and these parameters have also been correlated with earlier chemical studies.

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Effective Nuclear Charge and Chemical Shifts in X-Ray Absorption Spectra of Polymeric Copper(II) Salicylhydroxamates

Cited by 6 publications

References 16 publications

Kβ X‐Ray Emission Spectroscopic Study of a Second‐Row Transition Metal (Mo) and Its Application to Nitrogenase‐Related Model Complexes

Kβ X‐Ray Emission Spectroscopic Study of a Second‐Row Transition Metal (Mo) and Its Application to Nitrogenase‐Related Model Complexes

Kβ X‐Ray Emission Spectroscopic Study of a Second‐Row Transition Metal (Mo) and Its Application to Nitrogenase‐Related Model Complexes

X‐Ray K‐Absorption Spectroscopic Studies of Some Cobalt(II) Complexes

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