Mesomorphic Properties and Hydrogen Bonding Formation of Asymmetrical Triphenylene Discotic Liquid Crystals

摘要

Asymmetrical triphenylene derivatives containing ester or carboxylic acids as terminal substituents were synthesized and characterized by DSC, optical microscopy and X-ray diffraction. It was found that in the ester homologues, only one compound exhibits a monotropic nematic (N_D) mesophase, while most of the carboxylic acid derivatives show a hexagonal columnar (Col_h) mesophase. Temperature dependent infrared spectra of the carboxylic acid derivatives indicate the existence o strong hydrogen bonding interactions in the isotropic, mesomorphic and solid phases.