Supramolecular Chiral Gel Based on Triazole-Modified Triphenylene Derivative

Supramolecular gels are formed by the self-assembly of small organic molecules of which the self-assembled nanostructures are entangled to form a 3D network. During the self-assembly, gelator-solvent interactions are able to subtly regulate these interactions and play an important role during the gel formation. In this paper, we synthesized several triphenylene derivatives and lucubrated the necessary conditions for gel formation by adjusting the molecular structures of the triphenylene derivatives and the polarity of the organic solvent. Low polarity of organic solvent is favorable for supramolecular assembly. Furthermore, the triazole-modified triphenylene derivatives are easier to form a gel by self-assembling in non-polar solvent, but longer flexible chains result in unstable gels. Besides, another triphenylene derivative that the flexible chain is linked by an ester bond cannot form supramolecular gel. It indicates that the dipole-dipole and π-π interactions between 1,2,3-triazoles play a synergic effect on gel formation, which stabilize the columnar assembly of triphenylene moiety. Furthermore, shorter flexible chain can increase the stability of the resulting supramolecular gel. On this basis, (+)- or (−)-limonene is introduced as a chiral solvent during the self-assembly process of triazole-modified triphenylene derivative. As a result, a specific optically active supramolecular chiral gel is formed successfully, and the optically activity of the supramolecular assembly is maintained after removing limonene.