Spontaneous formation of chiral macrostructures in achiral hockey-stick liquid crystals

Abstract

We report the synthesis and properties of a homologous series of asymmetrically substituted 4-(5-(4-benzyloxyphenyl)-1,3,4-oxadiazol-2-yl)phenyl 2-X-4-dodecyloxybenzoates, which have pronounced hockey-stick molecular architectures. The structure was varied through the lateral substitution with various groups, X (H, Me, MeO, Cl, F) in the outer benzene ring. The effect of the lateral group on liquid crystal phase behaviour was investigated by thermal optical microscopy and differential scanning calorimetry. Nematic and dark conclomerate phases were observed with both displaying macroscopically chiral domains.

Keywords:

• hockey-stick
• oxadiazole
• bent-core
• dark conglomerate
• nematic
• soft crystal
• macroscopic chirality

Acknowledgements

This work was supported by the Engineering and Physical Science Research Council (EPSRC) UK under Project No. EP/G023093/1.