摘要
考察了1-甲基咪唑硫酸氢盐、1-甲基-3-烷基咪唑硫酸氢盐([Cnmim]HSO4,n=2,4,8,12)、1-甲基-3-(3-磺丙基)咪唑硫酸氢盐[C3SO3Hmim]HSO4)等6种质子化咪唑硫酸氢盐离子液体的酸性、溶解性及其对6个酯化反应的催化性能的影响。实验结果表明,离子液体的酸性和溶解性对其在酯化反应中的催化活性均有一定的影响。酸性最强的[C3SO3Hmim]-HSO4对所有酯化反应的催化活性皆为最高,并且在反应完成后均能与酯产物自行分相。在合成3种乙酸酯的反应条件下,反应完成后能与酯产物分相的离子液体催化活性比不能分相的要高。可见,咪唑环上的取代基影响离子液体的酸性及其与酯化体系中各组分的互溶性,从而影响其催化活性和分相性能。
Esterification of alcohols with carboxylic acids in six ionic liquids, including 1-methylimidazolium hydrogen sulfate （ [ Hmim ] HSO4 ）, 1-alkyl-3-methyiimidazolium hydrogen sulfate （[Cnmim] HSO4, n=2, 4, 8, 12）, 1-（ 3-sulfopropyl ）-3- methylimidazolium hydrogen sulfate （ [ C3SO3Hmim] HSQ4 ） used as catalysts had been investigated. The relationship between the substituent groups attached to the imidazole ring and the catalytic activity of ionic liquid for esterification were studied. [C3SO3Hmim] HSO4 with the strongest acidity had the best catalytic activity for all cases of esterification. Under the reaction conditions for synthesizing three acetates, the ionic liquids in the reaction system with phase-separation had better catalytic activity than those without phase-separation when the reaction was brought to completion. The test results showed that the substituent group attached to the imidazolinm cation could affect the miscibility with the related components existing in the reaction to influence the catalytic activity and the biphasic behavior.
出处
《化学试剂》
CAS
CSCD
北大核心
2009年第6期423-426,共4页
Chemical Reagents
基金
广东省科技计划项目(2006B13801007)
广州市科技计划项目(2005J1-C0231)
关键词
离子液体
咪唑硫酸氢盐
酸性
溶解性
催化
酯化
ionic liquids
imidazolium hydrogen sulfate
acidity
solubility
catalysis
esterification
