Angewandte Chemie | 2021
Transfer, Amplification, Storage and Complete Self-Recovery of Supramolecular Chirality in Achiral Polymer System.
Abstract
Supramolecular chirality and its complete self-recovery ability are highly mystical in nature and biological systems, which remains a major challenge today. Herein, we firstly demonstrate that the partially cross-linked azobenzene (Azo) units can be employed as the potential chiral trigger to fully heal the destroyed helical superstructure in achiral nematic polymer system. Combining the self-assembly of Azo units and terminal hydroxyl in polymer side chains allows vapor-induced chiral nematic phase and covalent fixation of the superstructure via acetal reaction. The induced helical structure of Azo units can be stored by the inter-chain cross-linking, even after the removal of chiral source. Most interestingly, the stored chiral information can trigger the perfect chiral self-recovery (CSR) behaviours after being destroyed by UV light, heat and solvent. The results pave a new way for producing novel chiroptical materials with reversible chirality from achiral sources.