Thorium(iv) and uranium(vi) compounds of cucurbit[10]uril: from a one-dimensional nanotube to a supramolecular framework

Coordination of trivalent lanthanum and cerium, and tetravalent cerium and actinides (An = Th(IV), U(IV), Np(IV)) by a 4-phosphoryl 1H-pyrazol-5-olate ligand in solution and the solid state

Structural investigations of three actinide(iv) 4-phosphoryl 1H-pyrazol-5-olate complexes (An = Th(iv), U(iv), Np(iv)) and their cerium(iv) analogue display the same metal coordination in the solid state. The mononuclear complexes show the metal centre in a square antiprismatic coordination geometry composed by the two O-donor atoms of four deprotonated ligands. Detailed solid state analysis of the U(iv) complex shows that dependent on the solvent used altered arrangements are observable, resulting in a change in the coordination polyhedron of the U(iv) metal centre to bi-capped trigonal prismatic. Further, single crystal analyses of the La(iii) and Ce(iii) complexes show that the ligand can also act as a neutral ligand by protonation of the pyrazolyl moiety. All complexes were comprehensively characterized by NMR, IR and Raman spectroscopy. A single resonance in each of the 31P NMR spectra for the La(iii), Ce(iii), Ce(iv), Th(iv) and Np(iv) complex indicates the formation of highly symmetric complex species in solution. Extended X-ray absorption fine structure (EXAFS) investigations provide evidence for the same local structure of the U(iv) and Np(iv) complex in toluene solution, confirming the observations made in the solid state.

Supramolecular assembly of ionic liquid induced by UO2 2+: a strategy for selective extraction-precipitation

In this work, a novel task specific ionic liquid (TSIL) [tributyl(hexyl)phosphonium]2[diglycolic acetate] ([P6,4,4,4]2[DGA]) was prepared and used to construct a vesicle system. The addition of UO2 2+, La3+ or Th4+ exhibited different effects on the system. It was found that small amount of UO2 2+ could induce large-sized aggregation of vesicles and make the precipitation happen, while La3+ and Th4+ did not have such capacity. The whole process was characterized by dynamic light scattering and freeze-fracture transmission electron microscopy. An extraction-precipitation strategy was then developed for the selective recovery of UO2 2+. Different factors were further studied to optimize the separation efficiency of the extraction-precipitation process.

Emission enhancement of cationic tetraphenylethylene derivatives by encapsulation in a cucurbit[10]uril host in water

Encapsulation of cationic tetraphenylethylene guests in a cucurbit[10]uril host in water results in strong emission enhancement of these guests since the host–guest interaction caused restriction of intramolecular rotation.

Yttrium and lanthanide (Ln = La and Gd) complexes with cucurbit[10]uril: crystals transforming from supramolecular frameworks to coordination nanotubes

Yttrium and lanthanide complexes with cucurbit[10]uril have been investigated with crystals transforming from supramolecular structures to coordination nanotubes being revealed.