基于葡萄糖的星型胆甾相液晶化合物的合成及相行为

Synthesis and Characteristic of Star-Shaped Cholesteric Liquid Crystal Containing Glucose as Core

以葡萄糖为手性中心,6-(4-(苯甲酸基)苯)己二酸单酯(M1)、6-(4-(4-烷氧基苯甲酸基)苯)己二酸单酯(M2～M3)为侧臂,采用N,N′-二环己基碳化二亚胺(DCC)/4-二甲氨基吡啶(DMAP)成酯法,合成了星型化合物(GM1～GM3)。通过红外光谱(FT-IR)、核磁共振(1H-NMR)、偏光显微镜(POM)、差示扫描量热(DSC)和X射线衍射(XRD)等手段研究了星型化合物的结构和性能。结果表明,当侧臂具有液晶性时,星型化合物也表现出液晶性;葡萄糖手性中心诱导带有向列相侧臂的星型液晶化合物产生了胆甾相。随着侧臂尾链的增长,星型胆甾相液晶的熔点降低,液晶区间增宽;随着侧臂尾链的增长,星型化合物的比旋光度增大。

Three star-shaped compounds（GM1～GM3） were synthesized by using glucose as the chiral core,monacid（M1,M2 and M3） as side arms and N,N′-dicyclohexyl carbodiimide（DCC）/ 4-dimethylamino pyridine（DMAP） as dehydration agent.The chemical structures and mesomorphic properties of GM1-GM3 were investigated by means of Fourier transform infrared spectrum（FT-IR）,1H nuclear magnetic resonance spectrum（1H-NMR）,polarizing microscope（POM）,differential scanning calorimetry（DSC） and X-ray.Experiment results show that star-shaped compounds display liquid crystal（LC） properties only when the side arms are LCs.Chiral core plays an important role on inducing cholesteric mesophase of star-shaped LCs,which containing nematic LC as side arms.With the terminal chain length of side arms increases,the specific rotation of the star-shaped compounds increases,the melting point of star-shaped compounds decreases and mesomorphic region increases.Compared with that in heating cycle,the mesomorphic region in cooling cycle is wider.