A chiral uranyl-Kemp's tricarboxylate cubic framework: structure-directing effect of counterions with three-fold rotational symmetry.

In the presence of PPhMe cations, Kemp's tricarboxylate (kta) complexes the uranyl cation to give [PPhMe][UO(kta)] (1), a triperiodic framework with cubic symmetry and srs topology. The PPhMe cation is held by weak interactions into cavities with matching three-fold rotational symmetry. Comparison with the diperiodic hemi-hydrate polymorph previously reported points to the disrupting role of OHO hydrogen bonds in the latter.