2,5-二取代-1,3,4-噁二唑不对称弯曲形液晶合成与性能研究  

Synthesis and Property of Unsymmetric Bent-core Liquid Crystals Based on 2,5-Disubstitueted-1,3,4-oxadiazole

作　　者：毛志鹏[1] 游红军[1] 王坤[1] 张智勇[1] 关金涛[1] 戴志群[1] 项颖[2] 

机构地区：[1]武汉轻工大学化学与环境工程学院,武汉430023 [2]广东工业大学信息工程学院,广州510006

出　　处：《有机化学》2015年第12期2575-2582,共8页Chinese Journal of Organic Chemistry

基　　金：国家自然科学基金(Nos.11074054;11374067)资助项目~~

摘　　要：以2,5-二取代-1,3,4-噁二唑为中心核,酯基(COO)为桥键,烷基(n=5~9)为末端基团,在单侧苯环侧位上引入氟原子,设计合成了两个系列新型不对称弯曲形液晶化合物9a^9e和10a^10e;并通过IR,1H NMR,13C NMR,19F NMR和MS对其结构进行鉴定,经差热扫描仪(DSC)和偏光显微镜(POM)测定其液晶相态.结果表明:所有目标化合物的分子结构正确,都呈现向列相态,向列相态温度范围最宽达78℃;侧位单氟苯环结构化合物9a^9e的向列相态温度范围没有二氟苯环结构10a^10e的宽,并且化合物9a^9e都呈现奇偶效应.Two novel series of bent-core liquid crystals （9a-9e and 10a-10e） were prepared with a central bent core based on 2,5-disubstitueted-1,3,4-oxadiazole, ester group bridge （coo）, alkyl tails with different carbon numbers （n = 5-9）, and one side wing substituted by fluorine atom. The structures of the target compounds were confirmed by IR, ^1H NMR, ^13C NMR, MS, and their transition temperatures and phase textures were investigated by using differential scanning calorimetric （DSC） and polarizing optical microscopy （POM）. The result suggested that all target compounds had right chemical structure. All compounds 9a-9e and 10a-10e exhibited nematic phase and existed wide temperature range of nematic phase. The widest range of nematic phase was 78 ℃. The temperature range of nematic phase of compounds 9a-9e with lateral monofluoro-substituted benzene was more narrow than compounds 10a-10e with lateral difluoro-substituted benzene. Moreover, compounds 9a-9e showed odd-even effect.

关 键 词：噁二唑 不对称弯曲形液晶 向列相 合成 

分 类 号：O626.2[理学—有机化学] O753.2[理学—化学]