含二苯并-18-冠-6席夫碱型液晶冠醚钾配合物的液晶行为

以顺(反)-4,4′-双4-(4′-正烷氧基联苯基-4-羧基)苯亚氨基]二苯并-18-冠-6(Ⅰ和Ⅱ)为配体合成了2种系列席夫碱型液晶冠醚钾配合物,产率分别为85.5%～92.1%和88.7%～90.7%。配合物的结构通过元素分析、IR、UV-Vis和AAS等测试技术确证。液晶行为通过DSC、POM、XRD等方法表征。实验结果表明,所有配合物均具有热致液晶性,且随分子末端烷氧基碳原子数增加,其熔点和清亮点呈规律性变化。近晶相温度范围渐增,向列相温度范围递减。与配体相比,配合物液晶态温度范围变宽。

Liquid Crystalline Behaviour of Schiff-base Type Liquid Crystalline Crown Ether Potassium Complexes Containing Dibenzo-18-crown-6 Unit

Two series of schiff-base type liquid crystalline crown ether potassium complexes containing dibenzo-18-crown-6 were synthesized from cis- and trans-4,4'-bis(4'-alkoxylbiphenyl-4-carboxy) benzylideneamino] dibenzo-18-crown-6 in yields of 85.5%～92.1% and 88.7%～90.7% respectively. Their structures and properties were characterized by elemental analysis, IR, UV-Vis, AAS, DSC, XRD and polarizing optical microscopy(POM) with a heating stage. Results show that the complexes changed into liquid crystal phase upon heated to temperatures higher than their melting points, and the melting points T_m and isotropization temperature T_i of the complexes changed regularly with the increase of the carbon number in the terminal alkoxyl groups. There is a gradual increase in smectic phase length and a gradual decrease in nemetic phase length. The liquid crystalline phase temperature range became broader after complexation.