Modulating the Nucleated Self-Assembly of Tri-β3-Peptides Using Cucurbit[n]urils

The modulation of the hierarchical nucleated self-assembly of tri-beta(3)-peptides has been studied. beta(3)-Tyrosine provided a handle to control the assembly process through host-guest interactions with CB[7] and CB[8]. By varying the cavity size from CB[7] to CB[8] distinct phases of assembling tri-beta(3)-peptides were arrested. Given the limited size of the CB[7] cavity, only one aromatic beta(3)-tyrosine can be simultaneously hosted and, hence, CB[7] was primarily acting as an inhibitor of self-assembly. In strong contrast, the larger CB[8] can form a ternary complex with two aromatic amino acids and hence CB[8] was acting primarily as cross-linker of multiple fibers and promoting the formation of larger aggregates. General insights on modulating supramolecular assembly can lead to new ways to introduce functionality in supramolecular polymers.