Coordination and Supramolecular Assemblies of Fully Substituted Cyclopentanocucurbit[6]uril with Lanthanide Cations in the Presence of Tetrachlorozincate Anions, and Their Potential Applications.

Coordination and supramolecular assemblies of a fully substituted cyclopentanocucurbit[6]uril (CyP6 Q[6]) with a series of lanthanide cations (Ln3+ ) have been investigated in the presence of tetrachlorozincate anion ([ZnCl4 ]2- ). X-ray single-crystal diffraction analysis has revealed that the interaction of CyP6 Q[6] and a series of Ln3+ cations unexpectedly results in the formation of at least seven different CyP6 Q[6]-based coordination complex adduct and supramolecular assemblies groups, including with (1) La3+ , Ce3+ cations; (2) Pr3+ , Nd3+ cations; (3) Eu3+ , Gd3+ , Tb3+ , Dy3+ with P1̅ or P1 space group, in which CyP6 Q[6] molecules coordinate alternatively with Ln3+ cations and form linear coordination polymers; (4) CyP6 Q[6] molecules interact alternatively with [Ho(H2 O)8 ]3+ aqueous complexes and form linear supramolecular chains; CyP6 Q[6] molecules can assemble two different Ln3+ free porous supramolecular assemblies from CyP6 Q[6]-Ln(NO3 )3 -ZnCl2 -HCl systems, Ln = Tm, Yb, and Lu; however, no solid crystals were obtained from system containing Er3+ cation. Thus, these differences could lead CyP6 Q[6] to be useful in not only the isolation of lighter lanthanides from their heavier lanthanides but also special selectivity for different volatile organic compounds.