Quantum mechanics

Quark

Catalysis

Self-assembly

Isomerization

Photochemistry

Materials science

Photoswitch

Nambu–Jona-Lasinio model

Photoisomerization

Molecule

Visible spectrum

Physics

Organic chemistry

Azobenzene

Molecular switch

Crystallography

Chirality (physics)

Chemistry

Chiral symmetry breaking

Liquid crystal

Optoelectronics

Angewandte Chemie International Edition

A series of macrocyclic azobenzene-based chiral photoswitches have been judiciously designed, synthesized, and characterized. In the molecular structures, binaphthyl is covalently linked to ortho-positions of azobenzene, and four different substituents are linked to 6,6'-positions of binaphthyl. The photoswitches show enhanced helical twisting power (HTP) when doping in commercially available achiral liquid crystals to form self-organized helical superstructures, i.e., cholesteric liquid crystals (CLCs). All the photoswitches exhibit reversible photoisomerization driven by visible light of different wavelengths in both organic solvent and liquid crystals. The photoswitches with shorter substituents enable handedness inversion of CLCs upon photoisomerization. These are the first examples of ortho-linked azobenzene-based photoswitches that enable handedness inversion in CLCs. The photoswitches with longer substituents display only HTP values decreasing while maintaining the same handedness.

Reversible Handedness Inversion and Circularly Polarized Light Reflection Tuning in Self‐Organized Helical Superstructures Using Visible‐Light‐Driven Macrocyclic Chiral Switches