合成了基于N-甲基咪唑、2-吡咯烷酮阳离子的两个Broensted酸性离子液体系列:[Hmim]HSO4/BF4、[Hnhp]HSO4/BF4以及两种-SO3H功能化酸性离子液体1-(3-磺酸基)丙基-3-甲基咪唑硫酸氢盐([C3SO3Hmim]HSO4)、N-(3-磺酸基)丙基吡咯烷酮硫酸氢盐([C4SO4Hnnp]HSO4)。其中,[Hnhp]HSO4/BF4[C4SO4Hnnp]HSO4是本实验设计合成的新型酸性离子液体,而咪唑类离子液体用于对照。上述6种离子液体均以核磁共振、电喷雾质谱、红外光谱和紫外光谱分析法对结构加以表征并确认;并以它们作为溶剂和催化剂对乙酸、乙醇酯化反应进行初步试验,结果表明所合成的新型酸性离子液体(尤其是引入磺酸基的)是酯化反应较理想的绿色液体酸催化剂。
Imidazolium-based and 2-pyrrolidonium-based ionic liquids, viz. [ Hmim ] HSO4/BF4 and [ Hnhp ] HSO4/BF4, and —SO3 H functionalized acidic ionic liquids, viz 1- ( 3-sulfonic acid) propyl- 3-methylimidazolium hydrogen sulfate( [ C3 SO3Hmim ] HSO4 ) and N-( 3-sulfonic acid) propylpyrrolidonium hydrogen sulfate ( [ C4SO4 Hnnp ] HSO4), were synthesized. Among them, [ Hnhp ] HSO4/BF4 and [ C4SO4 Hnnp ] HSO4 were the novel types of acidic ionic liquids designed and synthesized in this work. The imidazolium-based ionic liquids were used for comparison. The ionic liquids mentioned were all characterized by NMR, ESI MS, FT- IR and UV, respectively. They were used as both solvents and catalysts for the esterification of acetic acid with ethanol. The results showed that the acidic ionic liquids, especially the —SO3H functionalized acidic ionic liquids are environmental friendly acidic catalysts for esterification.