Interaction of Cyclopentano Cucurbit[6]uril with Alkaline Earth Cations and Supramolecular Assemblies with Aid of [ZnCl4](2-)

In this study, we investigated the interaction of a fully substituted cyclopentano cucurbit[6]uril (CyP(6)Q[6]) with alkaline earth cations (AE(2+)) and corresponding supramolecular assemblies in the presence of tetrachloridozincate anions ([Zn(H2O)Cl-3](-) or [ZnCl4](2-)). Single-crystal X-ray diffraction analysis revealed that the CyP(6)Q[6]-Mg2+ -ZnCl2 -HCl interaction system yielded an adduct of [Mg(H2O)(6)](2+) with CyP(6)Q[6]. The CyP(6)Q[6]-Ca2+, Sr2+ and Ba2+ -ZnCl2-HCl interaction systems yielded linear AE(2+)/CyP(6)Q[6]/AE(2+) -type coordination polymers that filled the cells in the [ZnCl4](2-)-based honeycomb-like framework. Unlike unsubstituted Q[n] systems in which [ZnCl4](2)- anions surround Q[n] molecules via outer surface interaction of Q[n], electrostatic interactions between [ZnCl4](2-) anions and the coordinated AE(2+) cations results in the formation of [ZnCl4](2-) -based honeycomb-like frameworks.