Cation-cation interactions and cation exchange in a series of isostructural framework uranyl tungstates

Chains of uranium and tungsten polyhedra are connected into a three dimensional framework by cation-cation interactions occurring between two symmetrically independent uranyl pentagonal bipyramids. Monovalent cations present in channels within the structure can be exchanged by room temperature or mild hydrothermal treatments. The framework of these compounds is robust to cation exchange and heat. (yellow polyhedra=uranium pentagonal bipyramids; blue polyhedra=tungsten octahedral, purple balls=K; yellow balls=Na; grey balls=Tl)