ИСТИНА

Session: AC+AS+M I-ThP1 Nature of Chemical Bond in Сs2UO2Cl4 Abstract # 1859 Author(s) Presenter Correspond Yury Teterin; NRC “Kurchatov Institute”, Russian Federation X Anton Teterin; NRC “Kurchatov Institute”, Russian Federation Kirill Ivanov; NRC “Kurchatov Institute”, Russian Federation Mikhail Ryzhkov; Ural Department of RAS, Institute of Solid State Chemistry, Russian Federation Konstantin Maslakov; Lomonosov Moscow State University, Russian Federation Stepan Kalmykov; Lomonosov Moscow State University, Russian Federation Vladimir Petrov; Lomonosov Moscow State University, Russian Federation X Dmitry Suglobov; V.G. Khlopin Radium Institute, Russian Federation Abstract: In Cs2UO2Cl4 compound ion of U(VI) is located at a relatively short distance from the oxygen ions. This leads to a strong interaction between U6p- and O2s-electrons in the axial direction of the chemical bond. This interaction is effectively observed in X-ray photoelectron spectra. Quantitative analysis was done of the valence electrons xray photoelectron spectra structure in the binding energy (BE) range of 0 eV to ~35 eV for Сs2UO2Cl4 single crystal. This compound contains the uranyl group UO2 2+. The BEs and structure of the core electronic shells (~35 eV ‒ 1250 eV), as well as the relativistic discrete variation (RDV) calculation results for the UO2Cl4 2- (D4h) cluster reflecting U close environment in Сs2UO2Cl4 were taken into account. The experimental data show that the manybody effects due to the presence of cesium and chlorine contribute to the outer (0 – ~15 eV BE) valence molecular orbitals (OVMO) spectral structure much less than to the inner (~15 – ~35 eV BE) (IVMO) one. The filled U 5f electronic states were theoretically calculated and experimentally confirmed to present in the valence band of Сs2UO2Cl4. It corroborates the suggestion on the direct participation of the U 5f electrons in the chemical bond. The U 6p atomic orbitals (AO) participate in formation of both the inner (IVMO) and the outer OVMO valence molecular orbitals (bands). The filled U 6p and the O 2s, Cl 3s electronic shells were found to take the maximum part in the IVMO formation. The MO composition and the sequence order in the binding energy range 0 eV ‒ ~35 eV in Сs2UO2Cl4 were established. The experimental and theoretical data allowed a quantitative MO scheme for Сs2UO2Cl4 in the BE range 0 – ~35 eV, which is fundamental for both understanding the chemical bond nature in Сs2UO2Cl4 and the interpretation of other x-ray spectra of Сs2UO2Cl4. The contributions to the chemical binding for the UO2Cl4 2- cluster were evaluated to be: the OVMO contribution – 76%, the IVMO contribution – 24%. The work was supported by the RFBR grant #13-03-00214-a.