Synthesis and Study of Alkaline-Earth Metal Uranoborates,AI I(BUO5)2·nH2O

Previously unknown compounds A^{I I}(BUO₅)₂·nH₂O (A^{I I} = Mg, Ca, Sr, Ba; n = 0-7) were synthesized. Their structure and thermal decomposition were studied by X-ray diffraction, IR spectroscopy, and thermal analysis.     

Synthesis and Study of Uranoborates AIBUO5·nH2O (AI = Alkali Metals)

Previously unknown uranoborates of the general formula A^IBUO₅·nH₂O (A^I = Li, Na, K, Rb, Cs; n = 0-2) were prepared. The crystal structures and thermal properties of these compounds were studied by X-ray diffraction (XRD), precision IR spectroscopy, and thermal analysis.     

Thermochemistry of Alkaline-Earth Metal Uranoborates AII(BUO5)2·nH2O (n = 7-0)

Previously unknown standard enthalpies of formation at 298.15 K of crystalline alkaline-earth metal uranoborates AII(BUO₅)₂·nH₂O (AII = Mg, Ca, Sr, Ba; n = 7-0) were determined for by reaction calorimetry. The enthalpies of the synthesis reactions were calculated. A thermochemical analysis of the hydration-dehydration of these compounds and their dissolution in aqueous solutions was performed.     

Thermochemistry of Alkali Metal Uranoborates and Their Crystal Hydrates

The standard enthalpies of formation at T = 298.15 K were determined for A^IBUO₅·nH₂O (A^I = Li, Na, K, Rb, Cs). The heat capacity of crystalline NaBUO₅·H₂O was determined by adiabatic vacuum calorimetry, and its thermodynamic functions were calculated. The thermodynamic characteristics of dehydration of alkali metal uranoborates were evaluated.