具有液晶相的四烷氧基苯并菲-1,4-二醌的合成

研究合成了 6,7,10,11-四戊氧基苯并菲-1,4-二醌和 6,7,10,11-四庚氧基苯并菲-1,4- 二醌两个新化合物，经核磁氢谱和碳谱、质谱、IR 及元素分析等测定，对其结构进行了表征。该类化合物在紫外可见光区 250～630 nm 的范围有光吸收。采用偏光显微镜和示差扫描量热仪对其性能进行了研究，结果表明，该材料具有液晶性。此外，本文对该类化合物的合成方法也进行了改进，利用亚硝酸钠/三氟乙酸/二氯甲烷体系替代了常用的硝酸铈铵/四氢呋喃/水体系，反应时间可从原来的 2 h 缩短至 15 min，并在室温下完成；在合成中间体 1,2-二甲氧基-6,7,10,11-四烷氧基苯并菲时，采用二氯甲烷作为溶剂，将三氯化铁与 3,3＇,4,4＇-四烷氧基联苯的摩尔比从 8∶ 1 提高到 10∶1，反应时间可从原来的 5 h 缩短至 2 h。

Synthesis of mesomorphic 6,7,10,11-tetraalkoxytriphenylene-1,4-diones

Two novel compounds,6,7,10,11-tetrapentyloxytripheynlene-1,4-diones and 6,7,10,11-tetraheptyloxytripheynlene-1,4-diones,were synthesized and investigated. Their structures were characterized by 1 H NMR,13C NMR,MS,IR techniques and elemental analysis.Both products have broad absorption in visible range from 250nm to 630nm,and show liquid crystalline phases,which were proved by using the combination of polarized optical microscopy and differential scanning calorimetry.Furthermore,the approach to obtain the compounds was also improved.The typical method is using aqueous solution of cerium（IV） ammonium nitrate in tetrahydrofurane as oxidant,and has a reaction time of 2 h.However,the reaction can be smoothly finished within 15 min.at room temperature,when using sodium nitrite as oxidant in the mixed solvent of trifluoroacetic acid and dichloromethane.In addition,when preparing the intermediates of 1,4-dimethoxy-6,7,10,11-tetraalkoxytirphenylene,the reaction time was reduced from 5 h to 2 h,if the molar ratio of FeCl3 and 3,3′,4,4′-tetraalkoxybiphenyl was raised from 8∶1 to 10∶1.