Dual Liquid Crystalline/Gel Behavior with AIE Effect Promoted by Self-assembly of Pyrazole Dendrons

This work describes the rich self-assembly behavior obtained by grafting a pyrazole-derived platform at the focal point of poly(benzyl ether) dendrons. Liquid crystals and supergels made out of fibers are obtained by supramolecular organization of non-discoid entities, and they notably increment the photoluminescence in these aggregated states (Aggregation-Induced Emission, AIE). The novel focal point, which is derived from 3,5-dimethyl-4-phenyl-1H-pyrazole, shows great tendency to arrange both wedge-shaped or cone-shaped dendrons in columnar arrangements by the formation of supramolecular polymers by hydrogen-bonding following the cylinder model. Two different linkers, amide or ether groups, connecting with the pyrazole-based apex are investigated, obtaining similar mesomorphic behavior, but different luminescent properties. A combined study of NMR, IR and X-ray diffraction allows establishing analogies between the fiber mesoscopic organization and the columnar organization in the liquid crystalline phase. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).