Synthesis, structure, and properties of compounds with the general formula A1[HSiUO6] · nH2O (A1 = Rb, Cs)

The results of investigation into before unknown rubidium and cesium uranium silicates of Rb[HSiU)6] · H2O and Cs[HSiUO6] · H2O compositions are presented. Rubidium and cesium uranium silicates were obtained in hydrothermal conditions at molar ratios of reagents ACl : UO2(NO3)2· 6H2O : SiO2 (quartz) = 10 : 1 : 100 (A = Rb, Cs). Structure of derived compounds and thermal degradation products were studied by means of X-ray diffraction, IR-spectroscopy and thermogravimetry methods. On evidence derived from X-ray diffraction synthesized rubidium and cesium uranium silicates are the full analogs of known previously ammonium, lithium and potassium uranium silicates. IR-spectroscopy data demonstrates that bands at 921 and 913 cm-1 are adequate to oscillations of UO22+ uranyl group for rubidium and cesium derivatives correspondingly. The process of Rb[HSiU)6] · H2O and Cs[HSiUO6] · H2O degradation is fully completed at 690 and 650 Deg C accordingly