Polytypism and oxo-tungstate polyhedra polymerization in novel complex uranyl tungstates†
Abstract
Three new uranyl tungstates, α-, β-Cs2[(UO2)2(W2O9)], and Rb6[(UO2)7(WO5)2(W3O13)O2], have been obtained by high temperature solid state reactions. All three compounds display novel structure topologies: α- and β-Cs2[(UO2)2(W2O9)] are based upon layers with a new topology that can be related to the uranophane topology; Rb6[(UO2)7(WO5)2(W3O13)O2] is a rare example of a non-molecular inorganic phase with layers containing oxo-tungstate trimers. The structural relationship between α- and β-Cs2[(UO2)2(W2O9)] can be assigned to polytypism.