New supramolecular liquid crystals induced by hydrogen bonding between pyridyl‐1,2,4‐oxadiazole derivatives and 2,5‐thiophene dicarboxylic acid

Abstract

Supramolecular liquid crystalline complexes were obtained from binary mixtures of 3‐(4‐pyridyl)‐5‐(4‐n‐alkoxy)phenyl‐1,2,4‐oxadiazoles and 2,5‐thiophene dicarboxylic acid. Although the oxadiazole derivatives and the dicarboxylic acid are non‐mesomorphic, the H‐bonded complexes exhibit mesomorphism. Their liquid crystalline properties were investigated by differential scanning calorimetry and polarizing optical microscopy. The complexes exhibit enantiotropic nematic phases. A structural study involving AM1 semi‐empirical calculations is also described.

Acknowledgement

This work was supported by FONDECYT (Grant 1000521) and ‘Dirección de Investigación, Universidad de Concepción’.