Effect of supermolecular structure of cellulosic materials on chiral discrimination

以三苯氨基甲酸酯纤维素为手性载体，研究了涂层的滞后效应。根据Shibata等人之前的文章，使用醋酸纤维素作为手性分离相时，不同的涂层溶剂导致对映体的洗脱顺序不同。为了进一步研究涂层溶剂与手性选择聚合物之间的关系，我们选择了三苯基氨基甲酸纤维素及其有机溶剂的组合，从异向液晶中报道。首先，我们按照Schroeder和他的同事的方法合成了三苯氨基甲酸纤维素，将其溶解在甲基丙基酮（MPK）、二甘醇等有机溶剂中，并检查该体系是否形成胆甾液晶。由于所得的纤维素衍生物溶液似乎表现出较差的胆甾性，我们对已经衍生的纤维素材料重复了合成反应，得到了典型的胆甾液晶。在重复反应过程中聚合度可能发生了变化。用偏光显微镜观察、紫外光谱、紫外光谱等方法确定了三苯氨基甲酸酯纤维素的胆甾性。然后，将10wt%的三苯氨基甲酸酯纤维素MPK或二lyme稀释溶液倒在平均粒径为7 μm、平均孔径为100 nm的多孔硅胶上，去除溶剂。溶剂的蒸发在MPK的通风室中进行，二lyme的蒸发在30℃的真空烘箱中进行，两种溶剂的蒸发时间都在1周以上。获得手性载体后，将其装入不锈钢柱中制备实验室自制的光学分辨柱，并对其手性识别能力进行评估。以MPK为包衣溶剂制备的手性分辨柱具有较强的分辨能力，在分辨因子（α）和理论板数方面与商品色谱柱相当，而另一种色谱柱由于包衣溶剂蒸发不足而表现出较差的结果。对映体的洗脱顺序在不同的色谱柱中是相同的。少

Studies on the hysteretic effect of coating were investigated using cellulose triphenylcarbamate as a chiral separating phase of chiral support for HPLC. According to the previous paper by Shibata et al., the different kinds of coating solvent resulted in the different elution order of enantiomers with the use of cellulose acetate as a chiral separating phase. For further investigations of the relationship between coating solvents and chiral selecting polymers, we have selected the combination of cellulose trhiphenylcarbamate and its organic solvents reported to from alyotropic liquid crystal.Firstly, we have synthesized cellulose triphenylcarbamate according to the method of Schroeder and his coworker, dissolved it in the organic solvent such as methylpropylketone (MPK), diglyme, and e.t.c., and checked if the system forms a cholesteric liquid crystal. Because the resultant solution of cellulose derivative seemed to show a poor cholesteric nature, we repeated the synthetic reaction fo … More r the already derivatized cellulosic material and obtained typical cholesteric liquid crystals. Degree of polymerization could have changed during the repeated reaction. Cholesteric nature was recognized by observations using polarizing microscope, and the measurements of spectrum of UV, ORD.Then, the dilute solution (10wt%) of cellulose triphenylcarbamate either in MPK or in diglyme was poured onto porous silica gel (mean particle size 7 μm and mean pore diameters 100 nm), and the solvent was removed. The evaporation of the solvent was performed ether in a draft chamber for the MPK or in a vacuum oven at 30℃ for the diglyme, and the duration required for the evaporation was more than 1weeks for both solvents. After obtaining the chiral support, we prepared the laboratory-made columns for optical resolution by packing it into stain-less steel columns, and estimated their chiral recognizing ability.The chiral resolving column prepared by using MPK as a coating solvent showed a prominent resolving power and comparable to the commercial column in terms of resolution factors (α) and theoretical plate numbers, although the other column showed poor results due to the insufficient evaporation of the coating solvent. The order of elution for enantiomer was found to be the same among the tested colums. Less