含二苯并-18-冠-6席夫碱型液晶冠醚钾配合物的液晶行为

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

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。

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 Tm and isotropization temperature Ti 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.