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

Abstract

Coordination and supramolecular assemblies of a fully substituted cyclopentanocucurbit[6]uril (CyP 6 Q[6]) with a series of lanthanide cations (Ln 3+ ) have been investigated in the presence of tetrachlorozincate anion ([ZnCl 4 ] 2– ). X-ray single-crystal diffraction analysis has revealed that the interaction of CyP 6 Q[6] and a series of Ln 3+ cations unexpectedly results in the formation of at least seven different CyP 6 Q[6]-based coordination complex adduct and supramolecular assemblies groups, including with (1) La 3+, Ce 3+ cations; (2) Pr 3+, Nd 3+ cations; (3) Eu 3+, Gd 3+, Tb 3+, Dy 3+ with P 1̅ or P 1 space group, in which CyP 6 Q[6] molecules coordinate alternatively with Ln 3+ cations and form linear coordination polymers; (4) CyP 6 Q[6] molecules interact alternatively with [Ho(H 2 O) 8 ] 3+ aqueous complexes and form linear supramolecular chains; CyP 6 Q[6] molecules can assemble two different Ln 3+ free porous supramolecular assemblies from CyP 6 Q[6]–Ln(NO 3 ) 3 –ZnCl 2 –HCl systems, Ln = Tm, Yb, and Lu; however, no solid crystals were obtained from system containing Er 3+ cation. Thus, these differences could lead CyP 6 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.