Chirality Evolution in Supramolecular Polymers: Homochiral Aggregation and Temperature-Dependent Chirality Reversal

The evolution of chirality in supramolecular polymers presents significant complexity and challenges, particularly in elucidating the underlying mechanisms. In this study, we investigated the supramolecular assembly of chiral <i>C</i> ₃ triarylamine tris-amide (TATA) monomers. Homochiral aggregation coupled with temperature-induced chirality reversal phenomenon was discovered. The enantiomeric monomers form supramolecular polymers with identical chirality, and temperature variations rapidly trigger inversion of chirality. These phenomena occur simultaneously in a binary solvent system comprising 1,2-dichloroethane (DCE) and a hydrocarbon solvent. The internal structures of the supramolecular polymers play a vital role in these chirality-related anomalies, and the fundamental mechanisms were successfully elucidated. Homochiral aggregation results from parallel alignment of adjacent chromophores with aligned transition dipole moments in a single column, yielding an identical positive monosignate Cotton effect in the circular dichroism (CD) spectra. Furthermore, temperature fluctuations influence the configuration of central triarylamine moieties, redirecting transition dipole moments whose directions are entirely inverted, thereby causing a rapid chirality reversal. Our discoveries highlight the crucial role of internal triarylamine moieties and provide valuable insights into mechanisms of chirality-related anomalies.