Nuclear Technology & Radiation Protection Journal


NT & RP Journal	VALENCE XPS STRUCTURE AND CHEMICAL BOND IN Cs₂UO₂Cl₄
......: info......: history......: editorial......: archive......: for authors......: subscription
Vol. XXXI, No. 1, Pp. 1-109 March 2016 UDC 621.039+614.876:504.06 ISSN 1451-3994 Back to Contents	Pages: 37-50 Authors: Yury A. Teterin, Konstantin I. Maslakov, Mikhail V. Ryzhkov, Anton Yu. Teterin, Kirill E. Ivanov, Stepan N. Kalmykov, Vladimir G. Petrov, and Dmitry N. Suglobov Abstract Quantitative analysis was done of the valence electrons X-ray photoelectron spectra structure in the binding energy (BE) range of 0 eV to ~35 eV for crystalline dicaesium tetrachloro-dioxouranium (VI) (Cs₂UO₂Cl₄). This compound contains the uranyl group UO₂²⁺. The BE and structure of the core electronic shells (~35 eV-1250 eV), as well as the relativistic discrete variation calculation results for the UO₂Cl₄^2- (D_4h) cluster reflecting U close environment in Cs₂UO₂Cl₄ were taken into account. The experimental data show that many-body effects due to the presence of cesium and chlorine contribute to the outer valence (0-~15 eV BE) spectral structure much less than to the inner valence (~15 eV-~35 eV BE) one. The filled U5f electronic states were theoretically calculated and experimentally confirmed to be present in the valence band of Cs₂UO₂Cl₄. It corroborates the suggestion on the direct participation of the U5f electrons in the chemical bond. Electrons of the U6p atomic orbitals participate in formation of both the inner (IVMO) and the outer (OVMO) valence molecular orbitals (bands). The filled U6p and the O2s, Cl3s electronic shells were found to make the largest contributions to the IVMO formation. The molecular orbitals composition and the sequence order in the binding energy range 0 eV-~35 eV in the UO₂Cl₄^2- cluster were established. The experimental and theoretical data allowed a quantitative molecular orbitals scheme for the UO₂Cl₄^2- cluster in the BE range 0-~35 eV, which is fundamental for both understanding the chemical bond nature in Cs₂UO₂Cl₄ and the interpretation of other X-ray spectra of Cs₂UO₂Cl₄. The contributions to the chemical binding for the UO₂Cl₄^2- cluster were evaluated to be: the OVMO contribution – 76%, and the IVMO contribution – 24 %. Key words: actinide, uranium, electronic structure, XPS, relativistic calculation FULL PAPER IN PDF FORMAT (1.86 MB)
Vinča Institute of Nuclear Sciences :: Designed by milas :: July 2007 Operated by acapanic :: Last updated on April, 2016

Pages: 37-50

Authors: Yury A. Teterin, Konstantin I. Maslakov, Mikhail V. Ryzhkov, Anton Yu. Teterin, Kirill E. Ivanov, Stepan N. Kalmykov, Vladimir G. Petrov, and Dmitry N. Suglobov

Abstract
Quantitative analysis was done of the valence electrons X-ray photoelectron spectra structure in the binding energy (BE) range of 0 eV to ~35 eV for crystalline dicaesium tetrachloro-dioxouranium (VI) (Cs₂UO₂Cl₄). This compound contains the uranyl group UO₂²⁺. The BE and structure of the core electronic shells (~35 eV-1250 eV), as well as the relativistic discrete variation calculation results for the UO₂Cl₄^2- (D_4h) cluster reflecting U close environment in Cs₂UO₂Cl₄ were taken into account. The experimental data show that many-body effects due to the presence of cesium and chlorine contribute to the outer valence (0-~15 eV BE) spectral structure much less than to the inner valence (~15 eV-~35 eV BE) one. The filled U5f electronic states were theoretically calculated and experimentally confirmed to be present in the valence band of Cs₂UO₂Cl₄. It corroborates the suggestion on the direct participation of the U5f electrons in the chemical bond. Electrons of the U6p atomic orbitals participate in formation of both the inner (IVMO) and the outer (OVMO) valence molecular orbitals (bands). The filled U6p and the O2s, Cl3s electronic shells were found to make the largest contributions to the IVMO formation. The molecular orbitals composition and the sequence order in the binding energy range 0 eV-~35 eV in the UO₂Cl₄^2- cluster were established. The experimental and theoretical data allowed a quantitative molecular orbitals scheme for the UO₂Cl₄^2- cluster in the BE range 0-~35 eV, which is fundamental for both understanding the chemical bond nature in Cs₂UO₂Cl₄ and the interpretation of other X-ray spectra of Cs₂UO₂Cl₄. The contributions to the chemical binding for the UO₂Cl₄^2- cluster were evaluated to be: the OVMO contribution – 76%, and the IVMO contribution – 24 %.

Key words: actinide, uranium, electronic structure, XPS, relativistic calculation

FULL PAPER IN PDF FORMAT (1.86 MB)