摘要
本文通过存在于胆甾醇丁二酸单酯(MCB)和4—(4—烷氧基苯甲酰氧基)—4′—苯乙烯基吡啶(nSZ)间的氢键作用合成了一系列新的胆甾型液晶,其液晶行为通过DSC、偏光显徽镜及变温广角X光衍射等手段进行研究。对于nSZ:当n≤3时,仅呈现向列相;当n=4,5时,呈现近品A相和向列相;当n＝6,7时,还出现一种单变的近晶相(S相);当n≥8时,向列相不存在,只呈现近晶A相和单变的S_1相。MCB不是液晶,而两者的1:1复合物均呈现互变的近晶C相和胆甾相,并且当n≤3时,nSZ:MCB的相变区间比nSZ的相变区间宽。X光衍射结果表明,7SZ扣8SZ的层厚度(d值)比基分子全伸展理论长度要长,这意味着这种不含强极性基团(如硝基、氰基)的液晶分子呈双层排列。
A new series of cholesteric liquid crystals induced by intermolecular hydrogen bonding between monoc-holesterylbutanedioate (we use MCB to represent for this compound) and 4- (4 -alkoxy-benzoxy)-4'-stilbazole (we use nSZ for simplicity) were prepared. Their liquid crystalline properties were invesugated by DSC, polarized optical microscopy and x-ray diffraction. Cholesteric and tilted smectic C phase were observed.
出处
《液晶通讯》
1995年第3期160-169,共10页
