Electronic structure of uranium halides and oxyhalides in the solid state. An X-ray photoelectron spectral study of bonding ionicity

Journal Article · Wed Oct 06 00:00:00 EDT 1982 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00384a002· OSTI ID:6056189

Thibaut, E ^[1]; Boutique, J P; Verbist, J J; Levet, J C; Noel, H

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1. Notre-Dame de la Paix, Namur, Belgium

Core and valence X-ray photoelectron spectra of 18 uranium halides (U/sup 3 +/ to U/sup 5 +/) and oxyhalides (U/sup 3 +/ to U/sup 6 +/) (fluorides, chlorides, and bromides) are described. The results are discussed, as a function of halogen nature and compounds stoichiometry, in terms of ionicity of the bonds, of U 5f participation in bonding, and effect of oxygen. Evidence is produced that UF/sub 3/ has an unexpectedly strong covalent character. The experimental study of uranium halides (F, Cl, Br) and oxyhalides has brought to light some important information about the nature of chemical bonding in these compounds: (a) The combined examination of valence photoelectron peaks (particularly U 5f), core levels, and U 4f shake-up satellites is a powerful tool in the determination of the ionicity of the solid. Only core level chemical shifts are not sufficient by themselves. (b) There is evidence for U 5f participation in chemical bonding; this contribution increases when the compound becomes more covalent. (c) Ionicity is largest for the higher halides (higher uranium oxidation state) and with the more electronegative halogens; and exception to this rule is UF/sub 3/, which is more covalent than UCl/sub 3/. (d) The oxygen in oxyhalides shows a growing tendency to form uranyl groups, as the uranium oxidation state goes up. These uranyl groups have covalent bonding and behave as a single species vs. the halogen.

• OSTI ID: 6056189
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 104:20; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACTINIDE COMPOUNDS
BINDING ENERGY
BROMIDES
BROMINE COMPOUNDS
CHLORIDES
CHLORINE COMPOUNDS
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
ENERGY
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
OXYBROMIDES
OXYCHLORIDES
OXYFLUORIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
SPECTROSCOPY
URANIUM BROMIDES
URANIUM CHLORIDES
URANIUM COMPOUNDS
URANIUM FLUORIDES