title: Probing the Electronic Structure and Chemical Bonding of Mono-Uranium Oxides with Different Oxidation States: UOx(-) and UOx (x = 3-5).
abstract: Uranium oxide clusters UOx(-) (x = 3-5) were produced by laser vaporization and characterized by photoelectron spectroscopy and quantum theory. Photoelectron spectra were obtained for UOx(-) at various photon energies with well-resolved detachment transitions and vibrational resolution for x = 3 and 4. The electron affinities of UOx were measured as 1.12, 3.60, and 4.02 eV for x = 3, 4, and 5, respectively. The geometric and electronic structures of both the anions and the corresponding neutrals were investigated by quasi-relativistic electron-correlation quantum theory to interpret the photoelectron spectra and to provide insight into their chemical bonding. For UOx clusters with x ≤ 3, the O atoms appear as divalent closed-shell anions around the U atom, which is in various oxidation states from U(II)(fds)(4) in UO to U(VI)(fds)(0) in UO3. For x > 3, there are no longer sufficient valence electrons from the U atom to fill the O(2p) shell, resulting in fractionally charged and multicenter delocalized valence states for the O ligands as well as η(1)- or η(2)-bonded O2 units, with unusual spin couplings and complicated electron correlations in the unfilled poly oxo shell. The present work expands our understanding of both the bonding capacities of actinide elements with extended spdf valence shells as well as the multitude of oxygen's charge and bonding states.
authors.affiliation: Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University , Beijing 100084, China.|Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201800, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Su
authors.affiliation: Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Li
authors.affiliation: Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Gary V
authors.initials: GV
authors.lastname: Lopez
authors.affiliation: Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Tian
authors.initials: T
authors.lastname: Jian
authors.affiliation: Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University , Beijing 100084, China.
authors.forename: Guo-Jin
authors.initials: GJ
authors.lastname: Cao
authors.affiliation: Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University , Beijing 100084, China.
authors.forename: Wan-Lu
authors.initials: WL
authors.lastname: Li
authors.affiliation: Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University , Beijing 100084, China.|Physical and Theoretical Chemistry, University of Siegen , Siegen 57068, Germany.
authors.forename: W H Eugen
authors.initials: WH
authors.lastname: Schwarz
authors.affiliation: Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Lai-Sheng
authors.initials: LS
authors.lastname: Wang
authors.affiliation: Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University , Beijing 100084, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li