一类新的液晶性芳香羧酸化合物的合成

Synthesis of a New Kind of Liquid Crystalline Aromatic Carboxylic Acid Compounds

合成了一系列新的液晶性芳香羧酸化合物 .化合物的结构通过元素分析、红外光谱、核磁共振波谱和质谱等方法确证 .化合物 5的液晶行为用示差扫描量热法 (DSC)和偏光显微镜 (POM)表征 .发现化合物 5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向列相的丝状织构和纹影织构 .随分子中末端烷氧基碳原子数增加 ,化合物 5的熔点 (Tm)和液晶态的清亮点 (Ti)呈规律性变化 ,液晶态温度范围变宽 .

A series of novel liquid crystalline aromatic carboxylic acid compounds are synthesized. The compounds are identified by using elemental analysis,infrared spectrum,nuclear magnetion reasonance and mass spectrometry. The liquid-crystalline behavior of the compound 5 is characterized by differential scanning calorimetery(DSC) and polarizing optical microscopy(POM). It is found that the compound 5 go into liquid crystal phase when heated to their T _m. The threaded texture and Schlieren texture of nematic phase can be observed. Both melting point( T _m) and isotropization temperature( T _i) of compound 5 change regularly with the carbon numbers of the end alkoxy groups increasing,accordingly,the temperature range of the liquid crystal phase of the compound 5 becomes wide.