Preparation and characterization of bent-shaped liquid crystal containing azobenzene moieties

Lo, Jiunn Yan (2007) Preparation and characterization of bent-shaped liquid crystal containing azobenzene moieties. Universiti Malaysia Sabah. (Unpublished)


Download (2MB) | Preview


The objective of this thesis is to synthesize a compound and to study if the synthesized compound has mesogenic properties. The starting material for the synthesis was ethyl-4-aminobenzoate. This initial step of the synthesis involves the diazonium salt coupling reaction with phenol to obtain ethyl-4-( 4-hydroxyphenylazo) benzoate. The product formed then undergoes Williamson ether synthesis to obtain ethyl-4-( 4-Hexadecyloxy-phenylazo)benzoate. The ester functional group (benzoate) from this compound was hydrolyzed with sodium hydroxide to obtain 4-(4-Hexadecyloxy-phenylazo) benzoic acid. The benzoic acid was reacted with DCC and DMAP in dichloromethane to obtain 1,3-phenylene bis [4-(4-Hexadecyloxyphenylazo)benzoate] as final product that comes with a melting point at the range of 128° - 132°C. FT-IR spectrum of all the particular compounds was obtained to compare the functional groups in both compounds. From infrared spectrum, it indicates that the synthesized compound has almost all the functional group in the molecular structure as Projected. This was then followed by further analysis by using DSC to determine the phase transition temperature as well as the phase transition enthalpy changes.

Item Type: Academic Exercise
Uncontrolled Keywords: ethyl-4-aminobenzoate, diazonium salt, DSC, transition temperature, FT-IR spectrum
Subjects: T Technology > TP Chemical technology
Divisions: SCHOOL > School of Science and Technology
Date Deposited: 27 Jan 2014 05:23
Last Modified: 11 Oct 2017 04:38

Actions (login required)

View Item View Item