Amplification of Asymmetry via Structural Transitions in Supramolecular Polymer-Surfactant Coassemblies.

Asymmetric structures are widespread in nature and essential for life and biointeractive materials. Although nature uniformly operates with homochirality, the hierarchical control of asymmetry in synthetic, water-soluble molecular systems is still underexplored. In this work, we present the amplification of helical asymmetry of benzene-1,3,5-tricarboxamide (BTA) supramolecular polymers by coassembly with homochiral nonionic surfactants. For these mixtures, a strong amplification of asymmetry was observed from the surfactant's molecular chirality to a preferred helicity of the coassembled polymers. This amplification showed maxima at identical stoichiometric ratios for structurally distinct chiral surfactants, demonstrating the similarity of the coassembly mechanism. Notably, the surfactant-induced asymmetry was completely overridden by the introduction of stereogenic centers into the BTA structure, emphasizing the subtlety of the amplification process. Using a combination of spectroscopy and microscopy, we found that surfactants coassemble with the supramolecular polymers to change fiber morphology from racemic double helices to single helices with a preferred handedness. Furthermore, the coassemblies showed a unique combination of structures and dynamics. Our results elucidate the consequences of supramolecular polymer-surfactant coassembly, offering valuable insights into the resulting asymmetric structures.