Dipeptide heterochirality directs global chirality and mesoscale morphology during supramolecular co-assembly.

Abstract

HYPOTHESIS The origin of biological homochirality and the principles governing heterochiral molecular interactions remain poorly understood. In self-assembling chiral systems, a linear CD-ee relationship generally indicates self-sorting driven by unfavorable heterochiral interactions, whereas nonlinear CD-ee dependences often give rise to the majority-rule effect. This work reports an unusual "minority-preference" behavior in the co-assembly of dipeptide-tetraphenylethylene conjugates with homochiral or heterochiral configurations. EXPERIMENTS Co-assembly of the two homochiral counterparts, LALA and DADA, exhibits a typical majority-rule. Strikingly, co-assembly of LALA with the heterochiral molecule LADA yields a completely different outcome: even a low fraction of the homochiral component dictates the supramolecular helicity and transforms the morphology from nanotubes into chiral nanoscrolls. FINDINGS Detailed NMR analyses and DFT analyses reveal that cooperative heterochiral interactions promote asymmetric molecular packing and chirality amplification, enabling the minor component to dominate the co-assembled system. Furthermore, the assemblies exhibit tunable circularly polarized luminescence. This work advances the fundamental understanding of chiral communication in non-covalent systems and provides a molecular platform for designing adaptive chiroptical materials.