Synthesis And Investigation On The Mesophase Property Of New Oxadiazole And Thiadiazole Derivatives

Chiral mesophase generated by some achiral molecules have been focused recently in the research of liquid crystal field and the perspectives why achiral molecules induce the chiral mesophase are vary. The achiral molecules which induce chiral mesophase have properties differing with the coventional molecules,consequently become the focus of scientists.We have designed and synthesized a series of compounds including C0N1-0XIX C0N2-0XD COB-OXD and COB-TOXD. The bond-angle between 2,5-location of 1,3,4-oxadiazole and 1,3,4-thiadiazole are different,thus the molecule which center-core is l,3>4-oxadiazole group bends a different degree comparing with that of 1,3,4-thiadiazole.We designed compounds COB-OXD and COB-TOXD in order to find the influence of different center-core on the mesophase.The two phenyl rings in biphenyl group retort a certain degree which is similar to ester group,and the two phenyls in naphthalene group are in the same plane.We aim to find the influence of terminal substituent on the mesophase via designing different terminal substituent.According to the result of ~1H NMR and FT-IR,we conlude that the compounds are the aim production we need.The Anal. Calcd testing ensures the purity.We research this series of compounds via POM DSC and XRD testing and focus on their thermal property and liquid crystal property.We find that the melting point of this series according with this law: C0N1-0XD < CON2-OXD < COB-OXD