低聚噻吩衍生物的合成及液晶性能

Synthesis and Liquid Crystal Properties of Oligothiophene Derivatives

设计合成了一系列新型低聚噻吩衍生物N ,N’ 双烷烃基 5 ,5” 二溴基 2 ,2’ :5’ ,2” 三噻吩 4 ,4” 二酰胺 (DNCnDBr3T ,n=5 ,8,1 6 ,1 8) .示差扫描量热法测定及偏光光学显微镜观察的结果显示 ,DNC18DBr3T、DNC16 DBr3T、DNC8DBr3T具有近晶A相液晶性质 .研究结果表明 ,烷基链的长度以及分子间氢键对于液晶的形成起着重要作用 .另外 ,还考察了DNCnDBr3T(n =8,1 6 ,1 8)的光。

With the aim of developing new oligothiophene based liquid crystals involving hydrogen bonding, new terthio phene derivatives containing an alkylamide group,N,N' dialkyl 5,5' dibromo 2,2':5',2' terthiophene 4,4' dica rboxamide (DNC n DBr3T, n =5,8,16,18), were designed and synthesized, and their thermal behavior were examined. While DNC n DBr3T compounds with n =8, 16, 18 were found to form smectic A phase. It is shown that the alkyl chain length greatly affects liquid crystal phase formation. The absence of liquid crystallinity in the corresponding ester derivatives suggests that intermolecular hydrogen bonding also plays a role in the formation of liquid crystal phase in the DNC n DBr3T system. The electrical ,opticaal and gelation properties of DNC n DBr3T( n = 8,16,18) were reported.