Construction of secondary and tertiary chiral structures in side-chain azobenzene polymers with flexible main chains

Abstract

Herein, we synthesized a series of side-chain azobenzene (Azo) polymers with different distances from the chiral stereocenter to the main chain and evaluated their chiral expression in both the macromolecular-dissolved state and the supramolecular aggregated state. It is demonstrated that when the chiral stereocenter is close to the main chain, the secondary chiral structure of Azo polymers can stably exist in the dissolved state. In contrast, reduced steric hindrance in the side chain adversely affects this stability. Furthermore, we found that the tertiary chiral structure in side-chain Azo polymers can only exist stably when both the chiral stereocenter and liquid crystallinity are present simultaneously.