【摘要】 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 .更多还原

【Abstract】 A series of Schiff base type liquid crystalline crown ethers were synthesized using the intermediates 4-(4′- alkoxylbiphenyl-4-carboxyl)benzaldehyde and diaminodibenzo-14-crown-4. Their structures and properties were characterized by elemental analysis, rotation polarmetric analysis, 1H NMR, IR, FAB-MS, MALDI-TOF-MS, DSC and polarizing optical microscopy with a heating stage. It was found that the compounds 2, 4, 8I and 8II formed liquid crystalline phase when heated to their melting points. In their liquid crystalline state, the typical chiral smectic C phase, smectic phase, cholesteric phase, nemetic phase texture can be observed. Except the compounds 2A and 4A, the smectic phase temperature range increases, but the smectic-nemetic transition temperature and nemetic phase temperature decrease with the increasing in the carbon numbers of end alkoxy groups. Accordingly, the melting point (T m) and isotropization temperature (T i) can change regularly.更多还原