Chiral polymorphism in new imine based rod-like liquid crystals

New imine based rod-like compounds, composed of three-benzene-ring molecular core linked with azomethine as well as ester groups and terminated with (S)-3,7-dimethyloctyloxy chiral unit at one side have been synthesized. The other terminal position has been varied by using n-octyloxy/decyloxy/dodecyloxy groups to reveal chain length effect on mesophase behavior. The liquid crystalline properties of the new compounds have been investigated by polarizing optical microscopy, differential scanning calorimetry and electro-optic studies. The novel chiral calamitics derived from Schiff base or salicylaldimine-core show a chiral polymorphism comprising of blue phase and chiral nematic as well as smectics such as chiral tilted smectic and unidentified smectic mesophase. (C) 2020 Elsevier B.V. All rights reserved.