This thesis consists of the synthesis of new liquid crystalline compounds N-{(nalkoxy-4``-bezoyloxy)-4`-benzylidene}-4-butyl aniline which were synthesized according to the following Scheme:
The synthesized compounds were characterized using FTIR,HNMR CNMR,EI-Mass spectroscopy and CHN analysis. The liquid crystalline properties of the prepared compounds which were verified using differential scanning calorimeter (DSC) and hot-stage polarizing optical microscope (POM) were discussed. The relation between the liquid crystalline behavior with chemical constitution was discussed on the basis of the effect of terminal group (Alkoxy group). Compound (4d) was used as stationary phases in gas chromatography for separation of positional isomer hydrocarbons (o-, m-, p-cresol) and poly aromatic hydrocarbons (naphthalene, flourene, phenanthrene and anthracene). Stationary phase for gas chromatography were prepared by loading the 4d compound on solid support (chromosorb W/AW 60-80 mesh) at 20%. These stationary phases were packed on glass gas chromatographic columns. A gas- liquid chromatographic study of the interaction and elution characteristics of positional isomer hydrocarbons and poly aromatic hydrocarbons using liquid crystalline phases and at different column temperatures of 100ºC-180ºC for 2.The best chromatographic conditions for the separation of hydrocarbons were characterized by measuring column efficiency N , resolution Rs, and selectivity factors α in order to assess the performance and separation ability of these columns. It was found that best chromatographic performance can be achieved with operating temperature at which the thermal stability of the nematic mesophase starts to form.
