A study on the self-assembly mode and supramolecular framework of complexes of cucurbit[6]urils and 1-(4-methoxyphenyl)piperazine.

Self-assembly between symmetrical dicyclohexyl-substituted cucurbit[6]uril (abbreviated as (CyH)Q[6]) and cyclopentanocucurbit[6]uril (CyPQ[6]) as hosts and 1-(4-methoxyphenyl)piperazine (MeOPP) as a guest molecule has been studied by means of single-crystal X-ray diffraction analysis, NMR, MALDI-TOF mass spectrometry, and other characterization methods. The experimental results showed that the self-assembly was driven by the formation of exclusion complexes by the cucurbit[]uril and the guest, that is, supramolecular interaction between the negative charge of the cucurbit[]uril portals and a coordination polymer guest. Complexes were formed between the positive charge of the cucurbit[]uril outer wall and inorganic anions, thus generating self-assemblies with multi-dimensional and multi-level supramolecular frameworks.