New liquid crystals derived from thiophene connected to the 1,2,4-oxadiazole heterocycle

Abstract

In this study, eight new compounds derived from thiophene were synthesised and characterised. The four symmetrical compounds contain two heterocyclic 1,2,4-oxadiazole on each side of the 2,5-disubstituted thiophene, and the four non-symmetrical compounds contain alkyne groups as a spacer replacing one of these heterocycles. Some of the compounds presented liquid crystalline properties with smectic and nematic mesophases. The non-symmetrical compounds presented low emission of blue light. ARTICLE HISTORY

Synthesis and mesomorphic properties of new organosiloxane chiral calamitic liquid crystals

“…Liquid crystals which are the unique state of matter have a wide application area such as digital displays, sensors and LCD screens 1,2,3,4,5,6,7 . Structure-mesogenity relationship plays a major role in understanding the properties of liquid crystals.…”

Pyridine-based chiral smectogens: effects of polar end groups on liquid crystal properties

“…[7,8] Within the different classes of LCs, rod-like (calamitic) liquid crystals, characterized by their simple molecular structure and sensitivity to external stimulating effects such as electric and magnetic fields, are intensively studied and incorporated in many LC materials. [9,10,11] The calamitic structures usually consist of central rigid core, which ensure chemical anisotropy to the structure, with flexible chains at the end positions. Their liquid crystal properties can be tuned by varying the aromatic core, the type and length of end chains and incorporating of branched units or molecular chirality.…”

Synthesis and characterization of new pyridine-based chiral calamitic liquid crystals

“…1,2,3,4 This special class of materials, which keep a combination of order and mobility at the molecular level, are used in many fields such as electro-optical displays and temperature sensors. 5,6 The use of six-membered N-heterocyclic systems in mesogenic molecules impacts the mesomorphic properties due to the fact that the introduction of nitrogen atom in the molecular structures mainly effect the molecular geometry, polarity and polarisability. 7 Pyridine is one of the simplest heterocyclic aromatics used as a core system in the design of liquid crystalline molecules.…”