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

Abstract

In the presence of PPh₃Me⁺ cations, Kemp's tricarboxylate (kta³⁻) complexes the uranyl cation to give [PPh₃Me][UO₂(kta)] (1), a triperiodic framework with cubic symmetry and srs topology. The PPh₃Me⁺ 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 OH⋯O hydrogen bonds in the latter.