烷基咪唑类离子液体的合成及其性质  

Synthesis and properties of imidazolium-based ionic liquids

作　　者：章靖[1] 祝艳琳[1] 李万博[1] 田丹碧[1] 

机构地区：[1]南京工业大学理学院,江苏南京210009

出　　处：《南京工业大学学报（自然科学版）》2008年第4期29-33,共5页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：江苏省高校自然科学基础研究资助项目(07KJB430041)

摘　　要：以N-甲基咪唑和溴代烷烃为原料,通过微波法合成了6种离子液体1-烷基-3-甲基咪唑类溴盐:1-正丙基-3-甲基咪唑溴盐([n-Pmim]Br)、1-异丙基-3-甲基咪唑溴盐([i-Pmim]Br)、1-正丁基-3-甲基咪唑溴盐[n-Bmim]Br)、1-仲丁基-3-甲基咪唑溴盐([s-B mim]Br)、1-正戊基-3-甲基咪唑溴盐([n-Amim]Br)、1-正己基-3-甲基咪唑溴盐([n-Hmim]Br).然后以[n-Bmim]Br为中间体,经过阴离子交换得到1-正丁基-3-甲基咪唑四氟硼酸盐([n-Bmim]BF4).在25℃时测定了7种离子液体的密度,结果表明:含有相同阴离子的离子液体密度随着阳离子烷基链长度的增加而减小;含有相同阳离子的离子液体,阴离子体积越大,密度越高.通过循环伏安法测定了[n-Bmim]Br和[n-Bmim]BF4的电化学窗口,分别为2.0 V和3.4 V.[n-Bmim]BF4的DSC曲线表明,其只有玻璃化温度(-95℃),而没有结晶温度和熔点.Six kinds of ionic liquids 1-alkyl-3-methylimidazolium bromides were synthesized from N-methylimidazolium and alkyl bromides with microwave irradiation. The ionic liquids investigated here were 1-n-propyl-3-methylimidazolium bromide, and 1-/so-propyl-3-methylimidazolium bromide, 1-n-butyl-3-methylimidazolium bromide, 1-sec- butyl-3-methylimidazolium bromide, 1-n-amyl-3-methylimidazolium bromide, and 1-n-hexyl-3-methylimidazolium bromide. 1-n-butyl-3-methylimidazolium bromide was converted into 1-n-butyl-3-methylimidazolium tetrafluoroborate after anionic exchanging. Density of ionic liquids was measured at 25 ℃. The results showed that density of ionic liquids with same anion decreased as the length of the alkyl chain on the cation increased. For a given cation, the density increased as the volume of the anion increased. Cyclic voltammograms study revealed that the potential windows of 1-n-butyl-3- methylimidazolium bromide and 1-n-butyl-3-methylimidazolium tetrafluoroborate were 2.0 V and 3.4 V, respectively. DSC curve of 1-n-butyl-3-methylimidazolium tetrafluoroborate showed that it had glasstransition temperature （-95 ℃ ） and had not crystallization and melting temperatures.

关 键 词：离子液体 合成 性质 

分 类 号：O626.23[理学—有机化学] TQ252.3[理学—化学]