Covalency in the uranyl ion: A polarized x-ray spectroscopic study

@article{ ISI:000178625500023,
Author = {Denning, RG and Green, JC and Hutchings, TE and Dallera, C and
   Tagliaferri, A and Giarda, K and Brookes, NB and Braicovich, L},
Title = {{Covalency in the uranyl ion: A polarized x-ray spectroscopic study}},
Journal = {{JOURNAL OF CHEMICAL PHYSICS}},
Year = {{2002}},
Volume = {{117}},
Number = {{17}},
Pages = {{8008-8020}},
Month = {{NOV 1}},
Abstract = {{Polarized oxygen Kalpha x-ray absorption and emission spectra, near 530
   eV, of a single crystal of Cs2UO2Cl4 are reported. With the aid of
   density functional theory calculations and the absorption data, the
   relative energies of the empty molecular orbitals having primarily
   uranium 5f and 6d character are assigned. The emission spectra give
   access to the energy of excitations to these orbitals from the various
   filled valence-shell orbitals. These energies support the conclusion
   from the optical spectra that valence excitations from the sigma(u)
   occupied valence orbitals occur at substantially lower energies than
   those from the sigma(g), pi(g), and pi(u) orbitals. This latter group of
   molecular orbitals have much larger oxygen-2p character. The
   participation of the pseudocore 6p shell in the covalent bonding is
   established directly by the presence of a charge-transfer transition in
   emission. With the aid of previous work on the polarized uranium L1- and
   L3-edge absorption spectra, the order of the empty metal-centered
   antibonding valence orbitals is established as 5f(pi)<5f(sigma)similar
   to6d(delta)similar to6d(sigma)<6d(pi). The greater antibonding character
   of 6d(pi) compared with 6d(sigma) can be explained by the relatively
   small overlap of the latter orbital with oxygen 2p. However, the
   relative energies of 5f(pi) and 5f(sigma) cannot be due to differences
   in overlap and are attributed instead to a strong hybridization between
   5f(sigma) and 6p(sigma). This superposition is confirmed by the linear
   dichroism in the U L1-edge absorption spectrum. (C) 2002 American
   Institute of Physics.}},
Publisher = {{AMER INST PHYSICS}},
Address = {{CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
   MELVILLE, NY 11747-4501 USA}},
Type = {{Article}},
Language = {{English}},
Affiliation = {{Denning, RG (Corresponding Author), Univ Oxford, Inorgan Chem Lab, S Parks Rd, Oxford OX1 3QR, England.
   Univ Oxford, Inorgan Chem Lab, Oxford OX1 3QR, England.
   Politecn Milan, Dipartimento Fis, INFM, I-20133 Milan, Italy.
   European Synchrotron Radiat Facil, F-38043 Grenoble, France.}},
DOI = {{10.1063/1.1510445}},
ISSN = {{0021-9606}},
Keywords-Plus = {{OXYGEN K-EDGE; ELECTRONIC-STRUCTURE; ACTINYL IONS; HELICAL UNDULATOR;
   PHOTOELECTRON-SPECTROSCOPY; 2-PHOTON SPECTROSCOPY;
   EMISSION-SPECTROSCOPY; INORGANIC-COMPOUNDS; SYMMETRY-BREAKING; SPECTRUM}},
Research-Areas = {{Chemistry; Physics}},
Web-of-Science-Categories  = {{Chemistry, Physical; Physics, Atomic, Molecular & Chemical}},
ResearcherID-Numbers = {{Green, Jennifer/F-2195-2018
   Brookes, Nicholas B/C-6718-2019
   Tagliaferri, Alberto/L-2903-2015
   }},
ORCID-Numbers = {{Green, Jennifer/0000-0002-2933-2303
   Brookes, Nicholas B/0000-0002-1342-9530
   Tagliaferri, Alberto/0000-0001-8001-1786
   Braicovich, Lucio/0000-0001-6548-9140}},
Number-of-Cited-References = {{60}},
Times-Cited = {{93}},
Usage-Count-Last-180-days = {{0}},
Usage-Count-Since-2013 = {{40}},
Journal-ISO = {{J. Chem. Phys.}},
Doc-Delivery-Number = {{604MN}},
Unique-ID = {{ISI:000178625500023}},
DA = {{2020-12-22}},
}