侧向二氟取代二苯乙炔类液晶的合成及热性能  

Syntheses and Thermal Properties of Lateral Difluorine Substituted Tolan-type Liquid Crystals

作　　者：李建[1] 胡明刚[1] 安忠维[1] 贾林[1] 

机构地区：[1]西安近代化学研究所,陕西西安710065

出　　处：《精细化工》2007年第9期860-862,913,共4页Fine Chemicals

摘　　要：用邻二氟苯为起始原料，在-78℃经过两次选择性“邻位金属化”反应、醚化反应、氧化反应制得2，3-二氟4-碘-1-烷氧基苯，再与4-烷基苯乙炔在氩气保护下进行Sonogashira偶联反应，制备出6种侧向二氟取代二苯乙炔类液晶。反应的：总收率为27．8％～41．9％，产物气相色谱纯度均大于99％，产物结构经IR、^1HNMR确认。用DSC和POM对化合物的相变温度进行了测试，发现固定右端烷基链n=2，当左端烷基链m≥5时出现向列相；固定左端烷基链m=5，当右端烷基链n≥2时出现向列相。Six lateral difluorine substituted tolan-type liquid crystals were synthesized via Sonogashira cross-coupling of 4-alkylphenylacetylene and 4-iodo-2,3-difluoro-1-alkoxybenzene under the protection of argon. 4-Iodo-2, 3-difluoro-1-alkoxybenzene were obtained via double ortho-metalation reaction, etherification and oxidation by using ortho-difluorobenzene as starting material. The overall yield was 27.8% -41.9% with purity above 99%. Structures of the compounds were identified by IR and ^1HNMR. Phase transitions of the compounds were tested by DSC and POM. It was found that nematic phase formed when the right terminal alkyl chain n =2 and the left terminal alkyl chain m ≥5, and the left terminal alkyl chain m =5 and the right terminal alkyl chain n≥2.

关 键 词：液晶 二苯乙炔 侧向二氟取代 相变 SONOGASHIRA偶联反应 功能材料 

分 类 号：O621[理学—有机化学] O753.2[理学—化学]