A cucurbituril-pillararene ring-on-ring complex.

A new type of non-intertwined ring-on-ring assembly was formed by the portal binding between a perfunctionalized polycationic pillar[5]arene and a cucurbit[10]uril, demonstrating a facile approach to solubilize a large macrocycle in water. Different binding behaviors towards guests were observed for the high-order complex, enriching the functional supramolecular systems.