A Multispectroscopic Study of 3 d Orbitals in Cobalt Carboxylates: The High Sensitivity of 2p3d Resonant X‐ray Emission Spectroscopy to the Ligand Field

Schooneveld, Matti M. van; Gosselink, R.J.A.; Eggenhuisen, Tamara M.; Samarai, Mustafa Al; Monney, Claude; Zhou, Kejin; Schmitt, Thorsten; Groot, Frank M. F. de

doi:10.1002/anie.201204855

Cited by 38 publications

(44 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such an observation was made also in the comparison of UV−vis and L-edge RIXS results of cobalt compounds in ref 72. We believe that these discrepancies can be explained by considering the vibrational effects.…”

Section: ■ Results and Discussionsupporting

confidence: 55%

From Ligand Fields to Molecular Orbitals: Probing the Local Valence Electronic Structure of Ni²⁺ in Aqueous Solution with Resonant Inelastic X-ray Scattering

et al. 2013

View full text Add to dashboard Cite

Bonding of the Ni 2+ (aq) complex is investigated with an unprecedented combination of resonant inelastic X-ray scattering (RIXS) measurements and ab initio calculations at the Ni L absorption edge. The spectra directly reflect the relative energies of the ligand-field and charge-transfer valence-excited states. They give element-specific access with atomic resolution to the ground-state electronic structure of the complex and allow quantification of ligand-field strength and 3d−3d electron correlation interactions in the Ni 2+ (aq) complex. The experimentally determined ligand-field strength is 10Dq = 1.1 eV. This and the Racah parameters characterizing 3d−3d Coulomb interactions B = 0.13 eV and C = 0.42 eV as readily derived from the measured energies match very well with the results from UV−vis spectroscopy. Our results demonstrate how L-edge RIXS can be used to complement existing spectroscopic tools for the investigation of bonding in 3d transition-metal coordination compounds in solution. The ab initio RASPT2 calculation is successfully used to simulate the L-edge RIXS spectra. ■ INTRODUCTION3d transition metals in aqueous solution are interesting from a fundamental point of view as their hexaaqua complexes [M(H 2 O) 6 ] n+ represent the archetype of Werner complexes with coordinative bonding in octahedral symmetry. 1 Considering hydrogen bonding between the various coordination spheres of water molecules, they could even be regarded as chelate complexes, 2 and new insight into their electronic structure could help understanding the interplay of bonding, structure, and dynamics in these complexes. This in turn forms the basis for understanding their thermodynamic properties and reactivity, having implications for modeling and understanding phenomena ranging from water exchange reactions 3,4 to photochemical processes 5 and atmospheric liquid chemistry of 3d transition-metal ions in solution. 6 While the structure of 3d transition metal (TM) ions and their complexes in aqueous solution can be addressed experimentally with numerous scattering and spectroscopic methods, 7 bonding can be assessed with a limited set of spectroscopic tools among which, historically, UV−vis spectroscopy has played a dominant role. Complementing such experimental results and due to the strongly polarized character of the coordinate bond, ligand-field theory 8,9 can be successfully applied to hexaaqua complexes. In particular, the dependence of the ligand-field (LF) state energies on ligand-field strength and 3d−3d Coulomb interactions for all 3d n complexes were first calculated by Tanabe and Sugano in their seminal work from 1954. 10,11 The low-energy electronic excited state spectrum of a typical TM coordination complex can thus be described by, with increasing photon energy, the LF excitations, followed by the charge-transfer (CT) and ligand-centered excitations. At present, the excitations to LF states of octahedral TM complexes are very well understood at the semiempirical level of ligand-field theory. Today, ab ini...

show abstract

Section: ■ Results and Discussionsupporting

confidence: 55%

From Ligand Fields to Molecular Orbitals: Probing the Local Valence Electronic Structure of Ni²⁺ in Aqueous Solution with Resonant Inelastic X-ray Scattering

et al. 2013

View full text Add to dashboard Cite

show abstract

“…14,15 In principle, however, it remains a question whether energy differences as seen in RIXS and OAS could result from probing electron–phonon states with different amounts of phonon energy contributing to the total excitation energy. 1 Given that (a) the 4 T 2 g and 4 T 1 g (O h ) features are seen at approximately 2.25 and 3.1 eV, respectively, in both techniques, that (b) the small energy differences are explainable from pure electronic arguments, and (c) knowing that these states are coupled to phonons, 14 it is likely that RIXS and OAS probe the same electron–phonon states. This may result from the femtosecond lifetime of the intermediate RIXS state, 49,50 preventing relaxation to the lowest phononic core–hole excited state before photoemission.…”

Section: Resultsmentioning

confidence: 99%

“…Synchrotron-based X-ray spectroscopies are less accessible but can provide considerable more details on for example oxidation states, coordination numbers, and bond covalency. Among them, 2p3d resonant inelastic X-ray scattering (RIXS; also resonant X-ray emission spectroscopy, RXES) is able to probe the transitions in the optical range, but with several advantages over UV/vis: 1 (1) The technique is element-specific, allowing selective transition-probing in the presence of multiple, competing chromophores (even black samples). (2) It probes transitions with energies between 0 and 20 eV, a range considerably larger than the optical one.…”

Section: Introductionmentioning

confidence: 99%

Direct Observation of Cr³⁺ 3d States in Ruby: Toward Experimental Mechanistic Evidence of Metal Chemistry

et al. 2018

View full text Add to dashboard Cite

The role of transition metals in chemical reactions is often derived from probing the metal 3d states. However, the relation between metal site geometry and 3d electronic states, arising from multielectronic effects, makes the spectral data interpretation and modeling of these optical excited states a challenge. Here we show, using the well-known case of red ruby, that unique insights into the density of transition metal 3d excited states can be gained with 2p3d resonant inelastic X-ray scattering (RIXS). We compare the experimental determination of the 3d excited states of Cr3+ impurities in Al2O3 with 190 meV resolution 2p3d RIXS to optical absorption spectroscopy and to simulations. Using the crystal field multiplet theory, we calculate jointly for the first time the Cr3+ multielectronic states, RIXS, and optical spectra based on a unique set of parameters. We demonstrate that (i) anisotropic 3d multielectronic interactions causes different scaling of Slater integrals, and (ii) a previously not observed doublet excited state exists around 3.35 eV. These results allow to discuss the influence of interferences in the RIXS intermediate state, of core–hole lifetime broadenings, and of selection rules on the RIXS intensities. Finally, our results demonstrate that using an intermediate excitation energy between L3 and L2 edges allows measurement of the density of 3d excited states as a fingerprint of the metal local structure. This opens up a new direction to pump-before-destroy investigations of transition metal complex structures and reaction mechanisms.

show abstract

“…We frankly admit that in our own previous RIXS work, we failed to properly discuss potential photoreduction processes. However, we believe that much of the original observations hold due to the fortuitous circumstance of having worked on Co 2+ ions [18,[82][83][84], where it is in general observed that metal 2+ ions are the final product of photoreduction processes.…”

Section: Introductionmentioning

confidence: 90%

A close look at dose: Toward L-edge XAS spectral uniformity, dose quantification and prediction of metal ion photoreduction

Schooneveld

DeBeer

2015

Journal of Electron Spectroscopy and Related Phenomena

View full text Add to dashboard Cite

A Multispectroscopic Study of 3 d Orbitals in Cobalt Carboxylates: The High Sensitivity of 2p3d Resonant X‐ray Emission Spectroscopy to the Ligand Field

Cited by 38 publications

References 28 publications

From Ligand Fields to Molecular Orbitals: Probing the Local Valence Electronic Structure of Ni²⁺ in Aqueous Solution with Resonant Inelastic X-ray Scattering

From Ligand Fields to Molecular Orbitals: Probing the Local Valence Electronic Structure of Ni²⁺ in Aqueous Solution with Resonant Inelastic X-ray Scattering

Direct Observation of Cr³⁺ 3d States in Ruby: Toward Experimental Mechanistic Evidence of Metal Chemistry

A close look at dose: Toward L-edge XAS spectral uniformity, dose quantification and prediction of metal ion photoreduction

Contact Info

Product

Resources

About

A Multispectroscopic Study of 3 d Orbitals in Cobalt Carboxylates: The High Sensitivity of 2p3d Resonant X‐ray Emission Spectroscopy to the Ligand Field

Cited by 38 publications

References 28 publications

From Ligand Fields to Molecular Orbitals: Probing the Local Valence Electronic Structure of Ni2+ in Aqueous Solution with Resonant Inelastic X-ray Scattering

From Ligand Fields to Molecular Orbitals: Probing the Local Valence Electronic Structure of Ni2+ in Aqueous Solution with Resonant Inelastic X-ray Scattering

Direct Observation of Cr3+ 3d States in Ruby: Toward Experimental Mechanistic Evidence of Metal Chemistry

A close look at dose: Toward L-edge XAS spectral uniformity, dose quantification and prediction of metal ion photoreduction

Contact Info

Product

Resources

About

From Ligand Fields to Molecular Orbitals: Probing the Local Valence Electronic Structure of Ni²⁺ in Aqueous Solution with Resonant Inelastic X-ray Scattering

From Ligand Fields to Molecular Orbitals: Probing the Local Valence Electronic Structure of Ni²⁺ in Aqueous Solution with Resonant Inelastic X-ray Scattering

Direct Observation of Cr³⁺ 3d States in Ruby: Toward Experimental Mechanistic Evidence of Metal Chemistry