Room-Temperature Columnar Liquid Crystals from Hydrogen-Bonded Dendritic Assemblies

Abstract

Dendrimers represent a distinctive class of synthetic macromolecules with broad utility across soft matter, materials science, nanotechnology, and biomedical sciences. In this study, we describe the synthesis of carboxylic acid-functionalized first and second-generation dendrimers using CuAAC (copper-catalyzed azide, alkyne cycloaddition) click chemistry. Dendrimers exhibit thermotropic mesomorphic behavior and form robust hydrogen-bonded supramolecular complexes with benzotriazole or benzimidazole derivatives. Notably, the hydrogen-bonded complexes also exhibit mesomorphism. Interestingly, some of these exhibit a room-temperature columnar hexagonal mesophase and transition to cubic phases. By underscoring the pivotal role of noncovalent interactions in modulating liquid-crystalline order, this work provides a systematic investigation of the mesomorphic properties of all of the newly synthesized dendrimers and their supramolecular assemblies.