The physical chemistry of the compounds M^IP(As)UO₆(M^I=H, Li, Na, K, Rb, Cs) and their crystalline hydrates

Abstract

Problems concerning the structures of compounds of the series MIP(As)UO6.nH 2O (MI = H, Li, Na, K, Rb, Cs; n = 4 for MI = H, Li and n = 3 for MI = Na, K, Rb, Cs) are examined. The results of X-ray powder diffraction, thermographic, and IR spectroscopic studies on the above compounds are analysed. The experimental standard enthalpies of formation (ΔfHo) of the compounds MI P(As)UO6 and their crystalline hydrates are discussed. The characteristic features of the variation of ΔfHo as a function of the structural characteristics of the compounds and of the physical properties of the Group I elements in the series of phosphorus and arsenic compounds are described. The enthalpies of dehydration and ion exchange involving the compounds investigated are presented. The bibliography includes 103 references.