Chen, Chih-Shan Chiang, Ray-Kuang Kao, Hsien-Ming Lii, Kwang-Hwa High-Temperature, High-Pressure Hydrothermal Synthesis, Crystal Structure, and Solid-State NMR Spectroscopy of Cs<sub>2</sub>(UO<sub>2</sub>)(Si<sub>2</sub>O<sub>6</sub>) and Variable-Temperature Powder X-ray Diffraction Study of the Hydrate Phase Cs<sub>2</sub>(UO<sub>2</sub>)(Si<sub>2</sub>O<sub>6</sub>)·0.5H<sub>2</sub>O A new uranium(VI) silicate, Cs<sub>2</sub>(UO<sub>2</sub>)(Si<sub>2</sub>O<sub>6</sub>), has been synthesized by a high-temperature, high-pressure hydrothermal method and characterized by single-crystal X-ray diffraction and solid-state NMR spectroscopy. It crystallizes in the orthorhombic space group <i>Ibca</i> (No. 73) with <i>a</i> = 15.137(1) Å, <i>b</i> = 15.295(1) Å, <i>c</i> = 16.401(1) Å, and <i>Z</i> = 16. Its structure consists of corrugated achter single chains of silicate tetrahedra extending along the <i>c</i> axis linked together via corner-sharing by UO<sub>6</sub> tetragonal bipyramids to form a 3-D framework which delimits 8- and 6-ring channels. The Cs<sup>+</sup> cations are located in the channels or at sites between channels. The <sup>29</sup>Si and <sup>133</sup>Cs MAS NMR spectra are consistent with the crystal structure as determined from X-ray diffraction, and the resonances in the spectra are assigned. Variable-temperature in situ powder X-ray diffraction study of the hydrate Cs<sub>2</sub>(UO<sub>2</sub>)(Si<sub>2</sub>O<sub>6</sub>)·0.5H<sub>2</sub>O indicates that the framework structure is stable up to 800 °C and transforms to the structure of the title compound at 900 °C. A comparison of related uranyl silicate structures is made. space group Ibca;framework;uranyl silicate structures;UO;hydrate Cs 2;Si;133 Cs MAS NMR spectra;Cs 2;diffraction;Hydrate Phase Cs 2 2005-05-30
    https://acs.figshare.com/articles/journal_contribution/High_Temperature_High_Pressure_Hydrothermal_Synthesis_Crystal_Structure_and_Solid_State_NMR_Spectroscopy_of_Cs_sub_2_sub_UO_sub_2_sub_Si_sub_2_sub_O_sub_6_sub_and_Variable_Temperature_Powder_X_ray_Diffraction_Study_of_the_Hydrate_Phase_Cs_sub_2_sub_UO_sub/3284140
10.1021/ic0500199.s002