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The coordination of pentacyclohexanocucurbit[5]uril (PCyHQ[5]) to alkali metal cations and the formation of supramolecular assemblies in the absence and presence of [CdCl4]2– or [ZnCl4]2– anions as inorganic structure inducers have been investigated by single-crystal X-ray diffraction analysis. Studies of the crystal structures have revealed that the [CdCl4]2– or [ZnCl4]2– anions do not form honeycomb structures owing to the presence of alkyl substituents on the surface of the outer walls of PCyHQ[5], which can seriously perturb the interaction of the anions with the outer walls. Moreover, in the presence of [ZnCl4]2– anions, the formation of a new Rb-PCyHQ[5]-based 2D six-membered “bracelet” network suggests that larger ions such as Ba2+ and even Ra2+ could form this new type of supramolecular assembly.

In the present study, the lanthanide(III) contraction effect induced coordination architectures of HCyHQ[6] have been studied. The results, including fifteen crystal structures, indicate that although lanthanide metal ions have similar chemical properties mostly, their slightly different ionic radii play a key role in the formation of different supramolecular self-assembly types of HCyHQ[6]. As a result, the ionic radius-dependent complexes of HCyHQ[6] can be structurally classified into four groups: HCyHQ[6]-pair, HCyHQ[6]-molecular bowl, Ln–HCyHQ[6] one dimensional coordination polymer, and HCyHQ[6]-molecular capsule.