Synthesis And Mesomorphic Properties Of Liquid Crystalline Compounds With AZO-Ester Central Linkages And Differen Terminal Groups

Azo liquid has became a hot research subject nowadays because of their widely application in optical switching, liquid crystal display,holography,data storage in various media. Liquid crystal displays industry as an emerging industry has been the focus of people attention. Aromatic azo-containing compounds (Ar-N=N-Ar’) can undergo a much easier photo-induced cis-trans isomerisation than C=C and thus can form more interesting photoactive liquid crystals.This article sees azobenzene as a rigid center, and links the chalcone ketones and esters synthesized all the benzenes,both the mixed naphthalene and benzene ring of the two types of liquid crystal compounds.Using nuclear magnetic resonance (HNMR) spectroscopy, infrared spectrum and ultraviolet spectrum of its structures to characterized, and using differential scanning calorimetry (DSC), orthogonal polarizing microscope (POM) on its liquid crystal study.Through unilateral (left or right), in the center of the rigid or bilateral introduction of flexible chain, increasing the chain length and the number of single chain adjusting to its liquid crystalline property of these compounds. As a result, unilateral compounds containing flexible chain, side chain contains a flexible chalcone and at the side of the ester base contains three flexible chain compounds with no liquid crystalline property, on one side and ester base, there is a flexible chain, compounding with liquid crystal; Bilateral contains flexible chain compounds with liquid crystalline property. In this liquid crystal line compound,the compound with one sided flexible chain’s liquid crystal line range is wider than that of two side.Naphthalene ring with mixed benzene ester base side, contains a flexible chain compound of interface chip interval, and most the breadth of about 150℃; The second, the full benzodiazepines in ester side contains a flexible chain compound interface chip interval of about 80℃. On both sides with flexible chain of naphthalene ring and mixed benzene compounds structure interval about 65℃. The benzene ring of bilateral with flexible chain liquid crystal compound structure of a class interval of about 30℃. And by changing the length of flexible chain, we find the result that, with the increase of carbon chain length,the melting pointc reduces gradually,although influence on the dielectric chip interval is not so big, it increases the mesomorphic state type of crystal shape.