论文部分内容阅读
以 4 ( 4′ 烷氧基联苯基 4 羧基 )苯甲醛和二氨基二苯并 14 冠 4为原料 ,通过溶液缩合反应 ,合成了一系列席夫碱型液晶冠醚 .并用元素分析、旋光仪、核磁共振、红外光谱、快原子轰击质谱、基质辅助激光解析电离飞行时间质谱、示差扫描量热法和偏光显微镜对其进行了表征 .发现化合物 2 ,4,8I和 8II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 .随分子末端烷氧基碳原子数增加 ,化合物 (除 2A和 4A外 )的熔点 (Tm)和液晶态的清亮点 (Ti)呈规律性变化 ,近晶相范围渐增 ,而近晶相 -向列相转变温度和向列相温度范围递减 .
A series of Schiff base type liquid crystal crown ethers were synthesized by solution condensation reaction using 4 (4’-alkoxybiphenyl 4-carboxy) benzaldehyde and diamino dibenzo 14 crown 4 as raw materials. The compounds 2, 4, 8I, and 8II were found to be heated to their respective melting points (pH 7.4) by means of X-ray absorptiometry, nuclear magnetic resonance, infrared spectroscopy, fast atom bombardment mass spectrometry, matrix-assisted laser desorption ionization time of flight mass spectrometry, differential scanning calorimetry and polarized light microscopy All of the above can form liquid crystal states, and the typical texture of chiral smectic C phase, smectic phase, cholesteric phase and nematic phase can be observed in the liquid crystal state.With the increase of the number of alkoxy carbon atoms in the terminal of the molecule, And 4A), the melting point (Tm) and the clearing point (Ti) of the liquid crystalline phase change regularly. The range of smectic phase increases gradually while the transition temperature of smectic phase-nematic phase and the temperature range of nematic phase decrease.