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Updated: Nov 18, 2025

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Room-Temperature, Deep-Red/NIR-Emissive, C 3-Symmetric (n,π-conjugated) Columnar Liquid Crystals: C 3
Rashmi Ashwathama Nayak1, Bhyranalyar Nagarajappa Veerabhadraswamy1, Doddamane S Shankar Rao1
1Centre for Nano and Soft Matter Sciences, P.B. No. 1329, Jalahalli, Bangalore 560013, India.
Abstract:
The first examples of deep-red/near-infrared (NIR) photoluminescent, (n,π-conjugated) discotics, namely, C 3 -tris(keto-hydrazone)s, which are the tautomers of tris(azo-enol)s, have been synthesized via a facile one-step triple azo-coupling and characterized. The n,π-resonance-assisted intramolecular H-bonding, rendering planarity and shape persistence to the central core, facilitates their self-assembly into either a hexagonal columnar (Colh) phase (p6mm lattice) or a columnar rectangular (Colr) phase (p2mm lattice), over an extended thermal range including room temperature, fluorescing in the deep-red/NIR-I region. The low band gap with deep-red/NIR emission makes them ideal candidates for NIR-organic light-emitting diodes (OLEDs) and bioimaging.
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