Lyotropic supramolecular helical columnar phases formed by C3-symmetric and unsymmetric rigid molecules

Unlike thermotropic liquid-crystalline C(3)-symmetric molecules with flexible chains, the herein-designed fully rigid three-armed molecules (C(3)-symmetric and unsymmetric) create a fancy architecture for the formation of lyotropic liquid crystals in water. First, hollow columns with triple-stranded helices, analogous to helical rosette nanotubes, are spontaneously constructed by self-organization of the rigid three-armed molecules. Then, the helical nanotubes arrange into hexagonal liquid-crystalline phases, which show macroscopic chirality as a result of supramolecular chiral symmetry breaking. Interestingly, the helical nanotubes constructed by the fully rigid molecules are robust and stable over a wide concentration range in water. They are hardly affected by ionic defects at the molecular periphery, that is, further decoration of functional groups on the molecular arms can presumably be realized without changing the helical conformation. In addition, the formed columnar phases can be aligned macroscopically by simple shear and show anisotropic ionic conductivity, which suggests promising applications for low-dimensional ion-conductive materials.