基于季戊四醇的新型硅碳烷液晶树状物:外围含12个丁氧基/己氧基偶氮苯基团(英文)

Novel pentaerythritol-based carbosilane liquid crystalline dendri mers containing 12 butoxy/hexaoxy-azobenzene groups onthe periphery

制备了基于季戊四醇外围含丁氧基/己氧基偶氮苯基团的新型硅碳烷液晶树状物。利用Williamson反应和偶氮反应合成了4-[4-(6-羟己氧基)苯基]丁氧基偶氮苯与4-[4-(6-羟己氧基)苯基]己氧基偶氮苯两种液晶基元。以基于季戊四醇端基为Si—Cl键的硅碳烷树状物为脚手架,分别以上述两种偶氮苯液晶基团对其表面进行修饰,得到两种树状液晶化合物。采用偏光显微镜(POM)和示差扫描量热法(DSC)对修饰单元和树状物的液晶性进行表征,表明其均示向列相。

Liquid crystalline dendrimers with peripheral mesogenic groups have been prepared. Azo-reaction and Williamson synthesis were used in the preparation of the mesogenic groups, 4-[4-（6-hydroxyhexyloxy）phenyl] butoxyazobenzene and 4-[-4-（6- hydroxyhexyloxy）phenyl] hexaoxyazobenzene. A terminal Si-Cl functional carbosilane dendrimer based on pentaerythritol was used as dendritic scaffold and was subsequently funetionalized with the aforementioned groups. Investigation of the liquid crystalline properties of both the mesogenie groups and the mesogen-funetionalized dendrimers by polarized optical microscopy （POM） and differential scanning calorimetry （DSC） showed that they exhibited nematic phases.