Synthesis of v-shaped liquid crystals containing azo chromophores

Lee, Mei Yin (2009) Synthesis of v-shaped liquid crystals containing azo chromophores. Universiti Malaysia Sabah. (Unpublished)


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Ethyl-4-aminobenzoate was used as the starting material, it undergone diazo coupling reaction with phenol to produced 4-(4-hydroxyphenylazo)-ethyl benzoate. The product formed was then reacted with bromohexadecane to produced 4-(4- hexadecyloxyphenylazo)-ethyl benzoate. This is known as the Williamson ether synthesis. After that, the ester compound undergone base-catalysed hydrolysis with potassium hydroxide to produced 4-(4-hexadecyloxyphenylazo)-benzoic acid. Finally, the benzoic acid was reacted with catechol in the presence of 4-dimethylaminopyridine as catalyst and l,3-dicycIohexylcarbodiimide as dehydrating agent. The final compound produced was 1 ,2-phenylene-bis-[ 4-( 4-hexadecyloxyphenylazo )-benzoate}. The molecular structures and characteristics of the target compounds produced were investigated by using Fourier Transform Infrared (FT-IR) spectroscopy, Differential Scanning Calorimetry (DSC) and UV-Vis spectroscopy. The FT-IR spectra show that the target compounds contain functional group including alkyl, aryl, ether, ester and carboxylic acid. The DSC thermogram shows that the synthesized final compound did not have liquid crystal mesophase but crystalline phase. The UV Nis absorption spectra shows that the final compound contain azo group.

Item Type: Academic Exercise
Uncontrolled Keywords: Ethyl-4-aminobenzoate, bromohexadecane, Williamson ether synthesis, base-catalysed hydrolysis, diazo coupling reaction
Subjects: Q Science > QD Chemistry
Divisions: SCHOOL > School of Science and Technology
Depositing User: Unnamed user with email
Date Deposited: 14 Jul 2016 04:51
Last Modified: 20 Nov 2017 03:37

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