3-Aminophenol based bent-shaped liquid crystals with an amide linking group

Abstract

A series of new bent-shaped liquid crystals based on 3-aminophenol was synthesised and their mesomorphic behaviour studied by differential scanning calorimetry, polarised optical microscopy and X-ray diffraction. Generally, the introduction of an amide group leads to a small increase in the clearing temperatures and stabilisation of the formed mesophases in comparison with the structurally related resorcinol based materials. The role of the linking group orientation on mesomorphic properties was also studied. Compounds with an identical orientation of ester groups in the same direction with respect to the central benzene core exhibited the columnar B₁ phase for the shortest length of the terminal chain and the lamellar B₂ phase for longer homologues. The reorientation of the ester unit(s) in another series resulted in the appearance of another type of columnar phase (B_1REV).

Keywords:

• bent-core liquid crystals
• amide linking group
• orientation of linking groups
• mesomorphic properties

Acknowledgements

This project was supported by the Czech Science Foundation (project no. P204/11/0723).