Hydrogen-Bond Encoding in a Structurally Minimal Cyclochiral Monomer Enables Assembly of Large Cavities Displaying Supramolecular Isomerism.

Abstract

Large, well-defined molecular cavities are typically constructed from rigid covalent scaffolds, which can limit structural adaptability and increase synthetic complexity. Here, we introduce a hydrogen-bond encoded supramolecular strategy that enables structurally minimal, flexible monomers to assemble into discrete fullerene-binding capsules. The monomer combines intra- and intermolecular hydrogen-bonding motifs that restrict conformational freedom, induce cyclochirality, and guide controlled self-assembly into oligomeric or cyclic aggregates. Spectroscopic and crystallographic analyses show that guest-induced self-sorting with fullerenes drives the formation of homochiral tetrameric capsules with high binding affinity and distinct structural isomerism. X-ray structures confirm compact host-guest complexes stabilized by cooperative hydrogen bonding and C─H···π interactions. This work demonstrates that minimal monomer design can encode complex supramolecular behaviour, providing an adaptive platform for molecular recognition, catalysis, and materials science.