Selective Se-for-S substitution in Cs-bearing uranyl compounds

Nine phases representing the Cs2[(UO2)2(TO4)3] (T= S, Se) solid solution series with variable amount of S and Se have been prepared by isothermal evaporation from aqueous solutions and characterized using a number of experimental and theoretical techniques. No immiscibility is observed between the pure sulfate and selenate compounds. The Se-for-S substitution in tetrahedral sites is highly selective with smaller S6+ cation showing a strong preference for the more tightly bonded 4-connected site.217