Synthesis and characterization of bent shaped liquid crystals having azobenzene mesogenics cores

Soon, Gim Seong (2008) Synthesis and characterization of bent shaped liquid crystals having azobenzene mesogenics cores. Universiti Malaysia Sabah. (Unpublished)

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Abstract

The objective of this study was to synthesize and characterize bent shaped liquid crystals with azobenzene mesogenic cores. The starting material for the synthesis was methyl-4-aminobenzoate. The initial step of the synthesis involved the diazonium salt coupling reaction with phenol to obtain 4-(4-methyl-diazobenzoate) phenol. The product formed then undergoes Williamson ether synthesis to obtain [4-(4-methyldiazobbenzoate) phenyloxy] hexadecane. Then, this compound was hydrolyzed with potassium hydroxide to obtain 4-(4-hexadekanyloxy-phenyazo) benzoic acid. The benzoic acid was reacted with DCC and DMAP in dichloromethane to obtain 1, 2- phenylene bis [4-( 4-hexadekanyloxy-phenyazo) benzoate] as the final product. Yield of final product was 0.013 grams. The structure and characteristic of compounds synthesized were confirmed by spectroscopic analysis with FT-JR, ¹H NMR, and DSC. FT-IR spectrum indicated the presence of functional groups included alkyl, ester, ether etc. ¹H NMR spectrum showed the molecular structure of the intermediate compound whereas DSC thermogram point out the phase transition temperature and phase transition enthalpy of the final compound. From DSC thermogram, the crystalline temperature of final compound was 176.47 °c and the maximum melting point of final compound was 202.65 °C.

Item Type: Academic Exercise
Uncontrolled Keywords: azobenzene mesogenic, benzoic acid, DSC thermogram, crystalline, FT-IR spectrum, liquid crystal, diazonium salt
Subjects: Q Science > QD Chemistry
Divisions: SCHOOL > School of Science and Technology
Depositing User: Unnamed user with email storage.bpmlib@ums.edu.my
Date Deposited: 16 May 2016 05:17
Last Modified: 30 Oct 2017 02:37
URI: http://eprints.ums.edu.my/id/eprint/13158

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