الخلاصة:
mesogen are a group of unique functional materials; it combines properties of both liquid and solid states., in this thesis we synthesis a novel nematic liquid crystal (Schiff base), by condensation reaction between amino group of 4-[5-(methylthio)-1,3,4-oxadiazole-2-yl]aniline, and aldehyde group of p-methoxybenzaldehyde. The synthesis of this material successfully takes place in five steps, and in every step we optain a new product. All intermediats products were characterized by infra-red and the final produc twas caracterized by nuclear magnetic resonance, DSCand polaried microscope. A thermodynamique and thermique study of mesogen was réalised by using gaz chromatography. Key Words: mesogen, Liquid Crystal, Nematic phase, Thermotropic, mesophase