Chirality-Assisted Self-Assembly of Low-Symmetry Noncovalent Capsules with Quantitative Diastereoisomeric Selection

Abstract

One of the main aspects in which artificial capsules and cages still differ from their biological counterparts is symmetry─a fundamental trait that gives natural systems exceptional selectivity in molecular recognition. While the symmetry challenge has been recently addressed within metallosupramolecular or covalent systems, the creation of purely noncovalent capsular assemblies with tunable symmetry remains elusive. One exciting avenue toward reducing symmetry is to avail chirality in chiral-sensitive self-assembly, where symmetry is altered upon component binding. Herein, we report new pathways for the self-assembly of purely noncovalent capsules, wherein both the assembly outcome and symmetry can be finely adjusted through the strategic design of hydrogen bonding motifs and chirality. Specifically, depending on the mixture composition and hydrogen bonding centers embedded on the amino acid-derived benzene-1,3,5-triamide components, the system yields purely noncovalent capsules, ranging from highly symmetrical dimers to reduced symmetry octamers and new heterochiral tetrameric assemblies of low symmetry. The self-assembly processes presented here can be selectively modulated between narcissistic self-sorting pathways and diastereoselective social mixing, as well as toward the creation of social heterocomponent libraries─all yielding distinct capsular products. By showcasing the unique ability for molecular recognition, we believe our approach will pave the way for creating new capsular-type assemblies with unique functionalities and provide a fresh perspective on intricate, nature-inspired molecular dynamics.