离子液体分离能力与其分子结构间的构效关系研究

Study on the Structure Activity Relationship of Ionic Liquid Separation Ability and Its Molecular Structure

通过气液相平衡实验分别测量不同摩尔分数下[EMIM][DEP]和[BMIM][DBP]在乙酸乙酯-甲醇,[EMIM][DEP]、[BMIM][DBP]和[BMIM][DEP]在乙酸乙酯-乙醇以及[BMIM][BF4]、[BMIM][Br]和[BMIM][Ac]在乙酸乙酯-异丙醇体系中的选择性.从有机化学的角度分析这些离子液体分离性能与其分子结构的关系.结果表明阴离子极性的增加、阳离子和阴离子中烷基侧链的减短都有利于离子液体在这些体系中分离性能的提高.用COSMO-thermX量子化学计算软件对上述含有离子液体的三元体系的选择性进行计算,计算结果与实验测量得到的趋势一致.

The ternary vapor-liquid equilibrium experiments were carded out to measure the selectivity of ionic liquids （ILs） with the different mole fraction in three azeotropic systems, which include ethyl acetate ＋ methanol ＋ ILs （ [ EMIM ] [ DEP ], [ BMIM ] [ DBP ] ）, ethyl acetate ＋ 2-propanol ＋ ILs （ [ BMIM ] [ BF4 ] , [ BMIM ] [ Br ] and [ BMIM ] [ Ac] ） , and ethyl acetate ＋ ethanol ＋ ILs （ [ EMIM ] [ DEP ] , [ BMIM ] [DBP] and [ BMIM] [ DEP] ）. The relationship between the molecular structure and separation ability of these ILs was studied from the organic chemistry. The results illustrate that the separation ability of IL can be improved by increasing the polarity of anions and shortening alkyl side chain length of cations and anions. The selectivity of these ionic liquids in the three azeotropic systems was calculated using the quantum chemical calculation software（ COSMO-thermX）, and the trend of the separation ability for the ILs calculated was in good agreement with that of experiment.