Supramolecular assemblies constructed from inverted cucurbit[7]uril and lanthanide cations: synthesis, structure and sorption properties†
Qing Li,Sheng-Chao Qiu,Yun-Qian Zhang,Sai-Feng Xue,Zhu Tao,Timothy J. Prior,Carl Redshaw,Qian-Jiang Zhu,Xin Xiao
RSC Advances Pub Date : 08/08/2016 00:00:00 , DOI:10.1039/C6RA15559F
Abstract

The interaction of a series of lanthanide cations (Ln3+) with inverted cucurbit[7]uril (iQ[7]) in the presence of [ZnCl4]2− anions as a structure-directing agent have been investigated. Single-crystal X-ray diffraction analysis has revealed that the [ZnCl4]2− anions surround the iQ[7] molecules via the outer surface interactions of iQ[7]. This results in the formation of honeycomb-like frameworks, and ultimately linear supramolecular chains of iQ[7] in which Ln3+ cations occupy voids within the framework. Moreover, these iQ[7]/Ln3+-based supramolecular assemblies exhibit excellent thermal stability as well as permanent porosity, and in one case screening revealed a high CH3OH uptake capacity compared with other porous organic materials assembled solely through hydrogen bonding under ambient conditions.

Graphical abstract: Supramolecular assemblies constructed from inverted cucurbit[7]uril and lanthanide cations: synthesis, structure and sorption properties