A new series of liquid‐crystalline bi‐1,3,4‐oxadiazole derivatives: synthesis and mesomorphic behaviour

Abstract

A new series of liquid-crystalline bi-1,3,4-oxadiazole derivatives: synthesis and mesomorphic behaviour, Liquid Crystals, 35:4, 389-394, Symmetrical bi-1,3,4-oxadiazole derivatives, namely 5,59-bis(phenyl 4-alkoxybenzoate)-2,29-bi-1,3,4-oxadiazole (BBOXD-n, n56, 10, 14, 16), were synthesised. All BBOXD-n exhibited remarkably stable SmC phases by virtue of the high transition enthalpies of SmC-I. In addition, BBOXD-6 and BBOXD-10 showed an enantiotropic nemetic phase with enthalpies of the N-I transition up to 5.16 kJ mol 21 . As confirmed by wide-angle X-ray diffraction analysis and MM2, molecules of BBOXD-n showed high-angle tilting (55-57u) within their smectic C phases.

1,3,4-Oxadiazole based liquid crystals

“…Similar to 55, the liquid crystal properties of 56 were greatly affected by the number and positions of the alkoxyl chains. All the dicatenar oxadiazoles exhibited remarkably stable SmC phases with high transition enthalpies, 98 while the tetracatenars showed a classic progression from the smectic C phase to the hexagonal columnar phase with the increase in the length of the terminal chains. However, the hexacatenars were non-mesomorphic, which is difficult to explain.…”

Evolution from Lyotropic Liquid Crystal to Helical Fibrous Organogel of an Achiral Fluorescent Twin‐Tapered Bi‐1,3,4‐oxadiazole Derivative

“…[12] In our previous work, we reported a series of fluorescent liquid-crystalline bi-1,3,4-oxadiazole derivatives. [13] Among these bi-1,3,4-oxadiazole derivatives, an achiral fluorescent twin-tapered bi-1,3,4-oxadiazole derivative (BOXD-T8) was found to exhibit a thermotropic LC phase and various self-assembled structures in solution, such as nanoparticles, helical nanobelts, and flat nanobelts.…”

Synthesis and liquid crystalline properties of substituted 2,5‐diaryl 1,3,4‐oxadiazole derivatives without flexible chains

“…Up to now, several mesogenic 1,3,4-oxadiazole derivatives with different molecular geometry, e.g. rod-like (14)(15)(16)(17), disc-like (18)(19)(20) and star-shaped (21,22), have been reported and their structure-property relationships investigated. To the best of our knowledge, all the reported mesogenic compounds contain at least one flexible alkyl or alkoxy chain.…”