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ISRN Materials Science
Volume 2014 (2014), Article ID 904657, 7 pages
Research Article

Synthesis and Mesomorphic Properties of New Fluorinated Schiff Base Liquid Crystals

Department of Chemical Science, Universiti Tunku Abdul Rahman, Jln Universiti, Bandar Barat, 31900 Kampar, Perak, Malaysia

Received 10 September 2013; Accepted 21 October 2013; Published 16 January 2014

Academic Editors: S. X. Dou, H. Higashimura, V. Ji, and B. Li

Copyright © 2014 Sie-Tiong Ha and Teck-Leong Lee. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Two new compounds, 4-alkanoyloxybenzylidene- -fluoroaniline and 4-fluorobenzylidene- -n-alkanoyloxyaniline comprising a terminal fluorosubstituent were studied. The fluoro substituent contributes to the molecular polarizability, thus affecting intermolecular interactions and hence resulting in smectic mesomorphism. The mesomorphic properties were studied using differential scanning calorimetry and polarizing optical microscopy techniques. The mesomorphic properties of compounds studied are strongly dependent on the orientation of the imine (CH=N) linkage. The former Schiff base exhibited smectic A phase whereas the latter compound did not display any mesophase. Reversed imine linkage has caused depression of mesomorphic property in the compound studied (4-fluorobenzylidene- -n-alkanoyloxyaniline). The mesomorphic properties of the present compounds were compared with other structurally related series to establish the chemical structure-mesomorphic property relationship.