液晶性芳香醛化合物的合成  

Synthesis of Liquid Crystalline Aromatic Aldehyde Compounds

作　　者：何可可[1] 张晓静[1] 李自法[1] 张淑媛[2] 郑世军[1] 杨振华[1] 郭凯[1] 周其凤[3] 

机构地区：[1]郑州大学材料工程学院,郑州450052 [2]郑州大学化学系,郑州450052 [3]北京大学化学与分子工程学院高分子科学与工程系,北京100871

出　　处：《高等学校化学学报》2002年第10期2000-2004,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 99740 2 6);河南省自然科学基金 (批准号 :0 2 110 2 110 0 )资助

摘　　要：以对羟基苯甲醛和对烷氧基联苯酰氯为原料 ,采用爱因宏反应 ,合成了一系列 4-(4 -烷氧基联苯基 -4-羧基 )苯甲醛 .化合物的结构通过元素分析、红外光谱、核磁共振和质谱等方法确证 .化合物的液晶行为用示差扫描量热法、偏光显微镜和旋光仪等方法表征 .结果表明 ,所有的化合物加热至各自的熔点以上都能形成液晶态 .在液晶态可以观察到手性近晶 C相、近晶相、胆甾相和向列相的典型织构 .含手性中心的化合物都有较高的旋光性 ,而且在合成反应中旋光性得到保持 .随着分子末端烷氧基碳原子数增加 ,化合物 (除2 a和 4a外 )的熔点 (Tm)和液晶态的清亮点 (Ti)呈规律性变化 ,近晶相范围和近晶相 -向列相转变温度渐增 ,而向列相温度范围递减 ,至十二烷基时 。A series of novel 4-(4-alkoxybiphenyl-4-carboxy)benzaldehyde was synthesized via Einhorn raction by using 4-hydroxybenzaldehyde and p-alkoxybiphenylyl carbonyl chloride as the raw materials. The compounds were identified by using elemental analysis, infrared spectrum, nuclear magnetic resonance, and mass spectrometry. The liquid-crystalline behavior of the compounds was characterized by differential scanning calorimetery(DSC), polarizing optical microscopy(POM), and polarimetric analysis. It was found that all the compounds went into liquid crystal phase over the T m. The typical chiral smectic C phase or smectic phase or cholesteric phase, and nemetic phase texture can be observed. In this study, we found that the rotation was maintained during the synthesis process and all the chiral compounds were optically highly active. Both melting point(T m) and isotropization temperature(T i) except those of compounds 2a and 4a change regularly with the carbon numbers of the end alkoxy increased. There is a gradual increase in smectic phase length and in the smectic-nemetic transition temperature. At the same time there is a gradual decrease in nemetic phase length until in the dodecyl, purely smectic properties are encountered.

关 键 词：合成 芳香醛化合物 液晶态 热致液晶 结构表征 液晶行为 

分 类 号：O625.41[理学—有机化学] O753.2[理学—化学]