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Updated: May 9, 2026

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Shaping crystals with light: crystal-to-crystal isomerization and photomechanical effect in fluorinated azobenzenes
Oleksandr S Bushuyev1, Anna Tomberg, Tomislav Friščić
1Department of Chemistry and FRQNT Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke Street West, H3A 0B8, Montreal, Canada.
Abstract:
Unusually long thermal half-lives of perhalogenated cis-azobenzenes enabled their structural characterization and the first evidence of a crystal-to-crystal cis → trans azobenzene isomerization. Irradiation with visible light transforms a perhalogenated cis-azobenzene single crystal into a polycrystalline aggregate of its trans-isomer in a photomechanical transformation that involves a significant, controllable, and thermally irreversible change of crystal shape. This is the first demonstration of permanent photomechanical modification of crystal shape in an azobenzene.

