Equatorial Electronic Structure in the Uranyl Ion: Cs 2 UO 2 Cl 4 and Cs 2 UO 2 Br 4
Electric field gradient (EFG) tensors in the equatorial plane of the linear UO ion have been measured by nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) experiments and computed by relativistic Kohn-Sham methods with and without environment embedding for Cs UO Cl and Cs UO Br...
Gespeichert in:
Veröffentlicht in: | Inorganic chemistry 2022-03, Vol.61 (9), p.3821-3831 |
---|---|
Hauptverfasser: | , , , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Electric field gradient (EFG) tensors in the equatorial plane of the linear UO
ion have been measured by nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) experiments and computed by relativistic Kohn-Sham methods with and without environment embedding for Cs
UO
Cl
and Cs
UO
Br
. This approach expands the possibilities for probing the electronic structure in uranyl complexes beyond the strongly covalent U-O bonds. The combined analyses find that one of the two largest principal EFG tensor components at the halogen sites points along the U-X bond (X = Cl, Br), and the second is parallel to the UO
ion; in Cs
UO
Cl
, the components are nearly equal in magnitude, whereas in Cs
UO
Br
, due to short-range bromide-cesium interactions, the equatorial component is dominant for one pair of Br sites and the axial component is larger for the second pair. The directions and relative magnitudes of the field gradient principal axes are found to be sensitive to the σ and π electron donation by the ligands and the model of the environment. Chlorine-35 NQR spectra of
U-depleted and
U-enriched Cs
UO
Cl
exhibited no uranium-isotope-dependent shift, but the resonance of the depleted sample displayed a 58% broader line width. |
---|---|
ISSN: | 0020-1669 1520-510X |
DOI: | 10.1021/acs.inorgchem.1c02832 |