Fluorescent columnar liquid crystals based on BTD hexacatenars with salicylaldimine and benzaldimine core:

Self-assembly and multifunctional properties

By:Chen, Shibo;Li, Yixian;Guo, Zilong; Ma, Tao; Duan, Yuantang ; Yang, Yu; Cheng, Xiaohong

Journal  of Molecular Liquids

DOI：https://doi.org/10.1016/j.molliq.2024.124803

Published：2024-06-01

Abstract

Two series of hexacatenars SB/n and BB/n containing a benzothiadiazole (BTD) central core with triple alkyl chains at both ends via salicylaldehyde or benzaldehyde derivated Schiff base links, respectively, were prepared. Different Schiff base links lead to different self-assembly and photophysical behaviors. Both series can selfassemble into columnar liquid crystal (LC) phases but with different lattices (p6mm for SB/n, p4mm for BB/n) in bulk states, and SB/n can additionally form gels in organic solution. Interestingly, SB/n series were characterized with excited state intramolecular proton transfer (ESIPT) and aggregation-induced emission enhancement (AIEE) effects, and displayed high fluorescence in their solid, LC and gel states with large Stokes shifts and environmental sensitive unique spectra patterns. The effect of photoisomerization driven by ESIPT process on LC state of SB/n was observed. The applications of SB/n as fingerprint imaging device, Al3+ fluorescence chemosensor, white light emitting diodes (WLED) as well as light-emitting liquid crystal displays (LE-LCD) have been successfully realized.