標題: Heterocyclic pyridine-based liquid crystals: synthesis and mesomorphic properties
作者: Ong, Lay-Khoon
Ha, Sie-Tiong
Yeap, Guan-Yeow
Lin, Hong-Cheu
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: Pyridine;nematic;smectic A;enantiotropic
公開日期: 1-一月-2018
摘要: A series of new calamitic liquid crystals, 4-{[(pyridin-4-yl)methylidene]amino}phenyl 4-alkoxybenzoates comprising a heterocyclic (pyridine) and two phenyl rings core system, terminal alkoxy chain, imine and ester linkers were synthesised and characterised. This series consists of nine members wherein the members differ by the length of alkoxy chain (CnH2n+1O-, where n=2, 4, 6, 8, 10, 12, 14, 16, 18). Spectral analysis results were in accordance with the expected structure. Their thermotropic behaviours were studied by using differential scanning calorimetry, optical polarising microscopy and powder X-ray diffraction techniques. A single mesophase (nematic) was observed for the first three members of the series (n=2, 4 and 6). As the alkoxy chain increased to n=8 and n=10, the nematic phase appeared together with an additional smectic A (SmA) phase. When moving from n=12 until the highest members (n=18), the nematic phase disappeared and these compounds only exhibited a single mesophase (SmA). [GRAPHICS] .
URI: http://dx.doi.org/10.1080/02678292.2018.1455225
http://hdl.handle.net/11536/148028
ISSN: 0267-8292
DOI: 10.1080/02678292.2018.1455225
期刊: LIQUID CRYSTALS
Volume: 45
起始頁: 1574
結束頁: 1584
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