The siting of Cu(II) in mordenite: a theoretical spectroscopic study

Delabie, Annelies; Pierloot, Kristine; Groothaert, Marijke H.; Weckhuysen, Bert M.; Schoonheydt, Robert A.

doi:10.1039/b105799p

Cited by 47 publications

(93 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…So far this has not been supported by computational analysis of the spin Hamiltonian parameters or of the splitting of the electronic energy levels in Cu-CHA. The results from the DFT calculations performed on Cu-MOR are in line with the arguments given here for Cu-CHA [50]. The electronic spectra of CuOH + species in 8mr sites may also be contributing this region.…”

Section: Assignment Of Epr Spectra Of Cu 2+ In 6mr Sitessupporting

confidence: 72%

“…On the other hand the assignments are well corroborated by the stability of the sites for Cu-MOR [37,50]. A similar argument can be made for Cu-CHA, since Gao et.…”

Section: This Contribution Has Not Yet Been Identifiedsupporting

confidence: 63%

“…The positions in the structure of the sites giving these EPR signals have been discussed [37,50], and largely follow the assignment of the signals in Cu-MFI that possess similar zeolite building units.…”

Section: This Contribution Has Not Yet Been Identifiedmentioning

confidence: 99%

“…This is significantly different from the usual parameters observed for tetragonal Cu 2+ and such an EPR signal has never been observed on Cu zeolites. This was used to argue that this species could not be present in Cu-MFI [44], or in Cu-MOR [50].…”

Section: +mentioning

confidence: 99%

See 3 more Smart Citations

Identification and Quantification of Copper Sites in Zeolites by Electron Paramagnetic Resonance Spectroscopy

et al. 2016

View full text Add to dashboard Cite

Recent quantitative electron paramagnetic resonance spectroscopy (EPR) data on different copper species present in copper exchanged in CHA zeolites are presented and put into context with the literature on other copper zeolites. The information were obtained using ex-situ and in-situ EPR on copper ion exchanged into a CHA zeolite with Si/Al = 14±1 to obtain Cu/Al = 0.46 ±0.02. The results shed light on the identity of different copper species present after activation in air. Since the EPR signal is quantifiable, the content of the different EPR active species has been elucidated and Cu 2+ in 2Al positions in the 6-membered rings (6mr) of the CHA structure has been characterized. sites of the CHA structure under the applied conditions.

show abstract

Section: Assignment Of Epr Spectra Of Cu 2+ In 6mr Sitessupporting

confidence: 72%

“…On the other hand the assignments are well corroborated by the stability of the sites for Cu-MOR [37,50]. A similar argument can be made for Cu-CHA, since Gao et.…”

Section: This Contribution Has Not Yet Been Identifiedsupporting

confidence: 63%

Section: This Contribution Has Not Yet Been Identifiedmentioning

confidence: 99%

Section: +mentioning

confidence: 99%

See 2 more Smart Citations

Identification and Quantification of Copper Sites in Zeolites by Electron Paramagnetic Resonance Spectroscopy

et al. 2016

View full text Add to dashboard Cite

show abstract

“…However, fairly good results for g-tensors and d-d transition energies were also obtained by Pierloot and co-workers using the CASPT2 method in conjunction with SOS theory. 85,86 In two respects these calculations are more approximate that the present ones: (1) only the SOC of the copper has been treated using an even more approximate SOC operator that we have and (2) the many-electron wavefunctions were of the CASSCF type and do not include dynamic correlation while the state energies are accurate from CASPT2. The neglect of the relaxation in the wavefunction potentially poses some problems.…”

Section: Discussionmentioning

confidence: 97%

Sum-over-states based multireferenceab initio calculation of EPR spin Hamiltonian parameters for transition metal complexes. A case study

Neese

2004

Magn. Reson. Chem.

View full text Add to dashboard Cite

The recently developed spectroscopy oriented multireference configuration interaction variant (SORCI) is applied to the problem of the prediction of electron paramagnetic resonance parameters in transition metal complexes within a sum-over-states (SOS) framework. The prototypical complex [Cu(NH(3))(4)](2+) is taken as an example in order to test the validity and convergence properties of several computational approximations. The results show that the SORCI method affords accurate results for the g-tensor, the metal dipolar hyperfine coupling (HFC), the spin-orbit coupling contribution to the metal HFC and the isotropic and dipolar ligand HFCs. Accurate prediction of the isotropic metal HFC is challenging and requires flexible basis sets in the core region together with explicit inclusion of the core electrons and high-lying core-like virtual orbitals in the CI. Comparison of SORCI and density functional theory (DFT) results reveals that the latter are far off experiment (g-tensor) or achieve reasonable results only through a fortunate cancellation of large errors (metal HFC). The ligand HFC is overestimated by DFT owing to overly covalent bonding which leads to too much spin transfer on to the ligands.

show abstract

The Coordination of CuII in Zeolites − Structure and Spectroscopic Properties

Delabie

Pierloot

Groothaert

et al. 2002

Eur. J. Inorg. Chem.

Self Cite

View full text Add to dashboard Cite

Keywords: Zeolites / Copper / Ab initio calculations / Density functional calculations / ESR spectroscopy / UV/Vis spectroscopy / Heterogeneous catalysis Zeolites loaded with transition metal ions are promising heterogeneous catalysts. Knowledge about the location and structure of the metal centers is of paramount importance for the understanding of the catalytic potential of these materials. In this work, the spectroscopic studies of the coordination of Cu II in zeolite A, ZK4, X, Y and mordenite are reviewed. Experimentally, diffuse reflectance spectroscopy [a] teaches general chemistry and computational chemistry. Her main research interest is the application of ab initio methods for the study of spectroscopic and magnetic properties of systems containing transition metals. Marijke H. Groothaert (left center) was born in Neerpelt, Belgium in 1975. In 1998 she received her M. S. degree from the . Since 1998 she is a PhD student at the Center for Surface Chemistry and Catalysis under the supervision of Professor Robert A. Schoonheydt. Her research is concentrated on the coordination of transition metal ions in zeolites and combines spectroscopic techniques with computational methods. Robert A. Schoonheydt (left bottom) received his M. S. degree in 1966 and . Hab. in Leuven, where he teaches quantum chemistry, computational chemistry, and inorganic chemistry. His main research interests are in the application of computational methods in different areas of chemistry.MICROREVIEWS: This feature introduces the readers to the authors' research through a concise overview of the selected topic. Reference to important work from others in the field is included. 515(DRS) and electron spin resonance (ESR) spectroscopy have been applied to study the coordination of Cu II in zeolites. Ab initio calculations on model clusters, representing the Cu II sites in zeolites, are used for the interpretation of the experimental data. The combination of experimental spectroscopic information with theoretical results leads to a new and profound insight into the Cu II −zeolite interaction.

show abstract

The siting of Cu(II) in mordenite: a theoretical spectroscopic study

Cited by 47 publications

References 38 publications

Identification and Quantification of Copper Sites in Zeolites by Electron Paramagnetic Resonance Spectroscopy

Identification and Quantification of Copper Sites in Zeolites by Electron Paramagnetic Resonance Spectroscopy

Sum-over-states based multireferenceab initio calculation of EPR spin Hamiltonian parameters for transition metal complexes. A case study

The Coordination of CuII in Zeolites − Structure and Spectroscopic Properties

Contact Info

Product

Resources

About