Wrapping Chiral Nanoribbons into Coiled and Condensed Microstructures in Supramolecular Hydrogels

Hierarchical self-assembly of small molecules into supramolecular structures across various length scales is of prominent importance to deeply understand and mimic the biological systems. Here, chiral nanoribbons that assembled from chiral phenylalanine and achiral coumarin derivatives can curve and grow into higher ordered hollow microstructures, which exhibit enhanced acid and alkali resistance. This is predominantly facilitated by the subtle hydrogen bonding interactions and specific steric hindrance between the two molecules. With the addition of metal ions and consequently, the extra association via coordination, these nanoribbons can wrap in a more condensed fashion and eventually form solid microstructures. This study provides implications in understanding the hierarchically biological self-assembly process and is helpful for the construction of advanced artificial biomedical materials.