Synthesis and mesomorphic properties of new heterocyclic liquid crystals with Central Ester–Chalcone linkages. Issue 1 (1st January 2017)

• Record Type: Journal Article
• Authors: Lim, Yong-Wei Cheryl; Ha, Sie-Tiong; Yeap, Guan-Yeow; Sastry, S. Sreehari
• Is Part Of: Journal of Taibah University for science. Volume 11:Issue 1(2017)
• Page Start: 133
• Page End: 140
• Publication Date: 2017-01-01
• Subjects: Pyridyl -- Chalcone -- Smectic A -- Mesomorphic; Science -- Periodicals; Science; Periodicals; 505
• DOI: 10.1016/j.jtusci.2015.12.004
• Languages: English
• ISSNs: 1658-3655

Abstract

Abstract: A series of new calamitic liquid crystals, 4-[3-(pyridin-4-yl)prop-2-enoyl]phenyl 4-alkyloxybenzoates, comprising a pyridyl core, ester–chalcone central linkage and terminal alkyloxy chain were synthesized and characterized. This series consists of four members that differ by the length of the alkyloxy chain (C n H2 n +1 O–, where n = 10, 12, 14, 16). The structures of the title compounds were elucidated using spectroscopic and spectrometric techniques, such as FT-IR, NMR ( 1 H and 13 C) and EI-MS. The mesomorphic properties were studied using differential scanning calorimetry and optical polarizing microscopy. The decyloxy-containing compound was found to be non-mesogenic, whilst the compounds containing n -dodecyloxy to n -hexadecyloxy chains exhibited an enantiotropic smectic A phase with a fan-shaped texture. From the structure–property relationship study, it was proposed that the number of carbons in the alkyloxy chain must be at least 12 ( n ≥ 12) to generate the smectic phase in the corresponding substituted ArCOOArCOCH=CHC5 H4 N compounds.