应用化学 ›› 2009, Vol. 26 ›› Issue (07): 757-761.

• 研究论文 • 上一篇    下一篇

稀土金属在离子液体中催化甲苯的选择性硝化反应

钱德胜1,程广斌2   

  1. 1. 巢湖学院
    2. 南京理工大学化学与化工学院
  • 收稿日期:2008-07-17 修回日期:2008-09-27 出版日期:2009-07-10 发布日期:2009-07-10
  • 通讯作者: 钱德胜

Rare earth metals catalyzed nitration of toluene in ionic liquid

  • Received:2008-07-17 Revised:2008-09-27 Published:2009-07-10 Online:2009-07-10

摘要: 摘 要 将稀土金属盐负载在己内酰胺类离子液体上组成稀土金属盐和离子液体的复合物作为催化剂和溶剂,用于催化甲苯与等摩尔67%硝酸的硝化反应,利用核磁共振对离子液体的结构进行了表征。考察了不同的反应温度、反应时间及催化剂的种类和用量等因素对甲苯硝化反应的产率和对位选择性的影响。得出反应的最佳反应条件为:反应温度55℃,反应时间24h,苯磺酸镱(Yb)和苯磺酸离子液体(CPBSO)用量分别占甲苯的摩尔分数为5%和10%。产物硝基甲苯中邻、对位异构体质量比o/p=1.1,较硝硫混酸硝化(o/p=1.6)显著降低,产率达46.5 %。离子液体重复使用4次均表现出较好的催化活性及对位选择性。

关键词: 甲苯, 离子液体, 稀土金属, 硝化反应

Abstract: Abstract Rare earths metal complexes and caprolactam-cation-based Bronsted acid ionic liquids (ILs) were prepared and used as solvent and catalyst in the nitration of toluene and 1 equiv of 67% nitric acid. The structure of the ionic liquid was characterized by 1H NMR. The effects of reaction temperature, reaction time and the type and amount of catalyst on product yield and para-selectivity for the nitration of toluene were investigated. Nitrotoluene with the yield of 46.5% and ortho-para isomer ration 1.1 was obtained under the optimal conditions. In addition, the mixture of IL and rare earths metal complex could be removed easily and recycled 4 times with a little decreasing yield and the same para-selectivity, which opens up possibility of a more economic and green process.

Key words: Toluene, Ionic liquid, Rare earths metal, Nitration