Ferroelectrically Switching Helical Columnar Assembly Comprising Cisoid Conformers of a 1, 2, 3‐Triazole‐based Liquid Crystal. (25th January 2019)

• Record Type: Journal Article
• Authors: Nguyen, Manh Linh; Byun, Jaeduk; Kim, Suwoong; Hyun, June Won; Hur, Kahyun; Shin, Tae Joo; Cho, Byoung‐Ki
• Is Part Of: Angewandte Chemie. Volume 131:Number 9(2019)
• Page Start: 2775
• Page End: 2779
• Publication Date: 2019-01-25
• Subjects: 1, 2, 3-Triazol -- Flüssigkristalle -- Helikale Strukturen -- Klick-Chemie -- Wasserstoffbrücken; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201813195
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The 1, 2, 3‐triazole molecule, which is a product of click chemistry, possesses a high dipole moment and can be a useful polar motif for ferroelectric columnar liquid crystal (LC) materials—though it has not been used to date. Herein, we report the helical assembly and ferroelectric switching properties of a columnar liquid crystal comprising a naphthalene core and 1, 2, 3‐triazolyl linkages. The molecule assembles into a double‐stranded helical columnar LC structure (Colhel ). The X‐ray simulations of cisoid and transoid columnar models suggest that the helical assembly comprises cisoid conformers with a non‐zero dipole moment. The helical columns in the Colhel phase are aligned homeotropically under an electric field. The ferroelectric switching of the axial polarization can be observed in the temperature range of 105–115 °C in the Colhel phase, wherein the triazolyl hydrogen bonding along the column axis is weakened. The ferroelectric switching event is attributed to the rotation of the polar triazolyl units in response to the electric field. Abstract : Strukturklar : Ein 1, 2, 3‐Triazolyl‐Linker fungiert als polares Motiv in einer ferroelektrischen Flüssigkristall(LC)‐Anordnung aus homöotrop ausgerichteten doppelsträngigen helikalen Säulen. Ferroelektrisches Umschalten erfolgt zwischen 105 und 115 °C; in diesem Temperaturbereich sind die Wasserstoffbrücken entlang der Säulenachse geschwächt, und die Triazolyleinheiten sind in der Lage zu rotieren.