Construction of light-responsive phase chirality from an achiral macrogelator

To realize light-responsive phase chirality from an achiral macrogelator in the solid state, a disc-shaped achiral macrogelator (B1AZ) was newly synthesized. B1AZ was self-assembled into a lamello-columnar structure in the bulk state, while single-handed helical fibrils ( H F ) with 400 nm of helical pitch were constructed by side-by-side lateral association of achiral B1AZ molecules in carvone chiral solvents. Even after the elimination of chiral solvents, the helical morphology and its chiroptical properties were precisely preserved. However, H F was not sensitive to UV light due to intense lateral packing. For remote-controlling the helical morphology, a single-helix ( H S ) with an 18 nm helical pitch was formed by utilizing cis -B1AZ sol. Upon irradiation with UV light, H S was transformed into spheroids ( S ) because of the trans -to- cis photo-isomerization of the azobenzene (AZ) of B1AZ. The photo-switchable phase chirality can be applied in light-responsive smart materials. Phase chirality constructed from a light-responsive achiral macrogelator in a chiral solvent was remote-controlled by UV light.