The Synthesis And Electro-optical Properties Of The Alkenyl Alkoxy Azobenzene Molecules

A series of alkenyl alkoxy azobenzene molecules were synthesized in this thesis. The synthetic process of these molecules involved the etherification of phenol, the reduction of the nitro group, the protection of the aromatic amine, the diazotization of the aromatic amine, the transformation of aldehyde group and cyan group and the esterification of carboxylic acid with phenol. By improving the experimental conditions, higher yields compared with those by the conventional conditions were gotten. Their phase transition behaviors were analyzed by polarization optical microscopy (POM) and a differential thermal analyzer (DTA). The alkenyl alkoxy azo molecule11, which contains strong electron-withdrawing groups and shows N liquid crystal phase, was chosen for electro-optical research. The molecule11was polymerized by controlling the certain external conditions. Because the linear polymer was expected, the molecule11was exposed under UV while the compound was on liquid crystal phase. In order to characterize the polymerization of molecule11, the UV-Vis absorption spectrum and the IR spectrum were tested before and after exposure, the visible light absorption spectra of the material with no voltage or applying voltage. By analysis of these spectra it was found that the molecule11was not polymerized. Moreover in the case of applying voltage, the isomerization of cis-trans did not happen. The reason was analyzed and the suggestion for improvement was given.