长链离子液体的合成及性质  

Synthesis and properties of long-chain ionic liquids

作　　者：崔锐博[1] 章靖[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）》2009年第3期33-36,共4页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：江苏省高校自然科学基础研究基金资助项目(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3种长链离子液体1烷基3甲基咪唑溴盐(CnmimBr,n=12、14、16),并以C16mimBr为中间体,经过阴离子交换得到1十六烷基3甲基咪唑四氟硼酸盐(C16mimBF4),研究4种离子液体的咪唑环上质子化学位移、熔点和在不同溶剂中溶解性等性能.结果表明:N1上取代的烷基对咪唑环质子化学位移影响不大,而阴离子易于与咪唑环上H2形成氢键,使其化学位移向低场移动;CnmimBr的熔点随着N1取代基链长的增加而升高,当C16mimX(X=Br或BF4)的阳离子相同时,阴离子体积小的离子液体的熔点较高;离子液体在水、乙醇、乙酸中能较好地溶解,而在乙醚、苯、正己烷中不溶解或难溶.Three kinds of long-chain ionic liquids 1-alkyl-3-methylimidazolium bromides （CnmimBr, n = 12, 14 and 16） were synthesized from N-methylimidazolium and alkyl bromides under microwave irradiation. C16mimBr was converted into C16mimBF4 after anionic exchange. Proton chemical shifts of imidazolium ring and melting point of four ionic liquids, as well as their dissolution in different solvents were investigated. The results showed that the substituent on the N1 had the weaker effect on proton chemical shifts of imidazolium ring. The anion was so easy to form hydrogen bonding with H2 of the imidazolium ring as to make chemical shift of H2 move downfield. The melting point of Cn mimBr increased with the increasing of alkyl chain length on the N1. The melting point of C16mimX （X = Br or BF4 ） increased with the decreasing of the volume of anion. Ionic liquids could be dissolved better in water, ethanol and acetic acid, but not be dissolved in ethyl ether, benzene and hexane.

关 键 词：长链离子液体 微波 化学位移 熔点 溶解性 

分 类 号：O626.23[理学—有机化学] TQ252.3[理学—化学]