Hydrogen bonding and the self‐assembly of supramolecular liquid‐crystalline materials

Novel supramolecular liquid‐crystalline materials have been obtained by the hydrogen bond formation between different and independent molecules. The self‐assembly of carboxylic acid and pyridine moieties that function as H‐bond donors and acceptors, respectively, results in the formation of mesogenic complex structures. A wide variety of liquid‐crystalline low molecular weight complexes have been prepared using this approach. This concept has been extended to the polymeric systems. Hydrogen‐bonded liquid‐crystalline polymers that exhibit mesophases over wide temperature ranges, ferroelectricity or photo‐responsibility have been prepared by the molecular association. Moreover, liquid‐crystalline polymer networks that show reversible smectic‐isotropic phase transitions have been formed by the hydrogen bonds. The dynamics of the hydrogen bonding may contribute to the induction of the mesomorphism of the networks.