Induction and Photo-Locking of Supramolecular Chiral Structures in Achiral Liquid Crystalline Polymers

Supramolecular chirality usually plays an important role in biological processes and living systems. A novel achiral liquid crystalline polymer where the molecular chirality can be transferred is described, which provides a simple method to realize the chiral selfassembly in achiral polymer systems. However, the supramolecular chiral structures are often easily destroyed by external stimulus due to the weak non-covalent interactions between building blocks, which limits the application of the chiral supramolecular materials to a large extent. In the most systems composed of achiral precursors, the destroyed chiral ordered structures cannot be recovered in the absence of the pre-chiral resource. In order to improve the stability of supramolecular chiral structure and overcome its strong dependence on the chiral resource, a series of achiral liquid crystalline polymers containing phenyl benzoate groups as the mesogens and cinnamic acid groups as the cross-linkable center in the polymer side-chains are designed and synthesized. Combining with the induction of chiral limonene and photo-crosslinking, the supramolecular chirality constructed from achiral polymers can be permanently memorized in a simple way. Even when the helical structure is destroyed by polar solvent or high temperature, the memorized chiral information enables the complete self-recovery behavior without any pre-chiral resource. The current research will provide a new strategy for the preparation of chiral supramolecular materials with stored chiral information.