Synthesis and Characterization of Novel BrΦnsted Acidic Ionic Liquids
WU Qin1,2, DONG Bin-qi1, HAN Ming-han1*, ZUO Yi-zan1, JIN Yong1
1. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China 2. School of Chemical Engineering and the Environment, Beijing Institute of Technology, Beijing 100081, China
Abstract：Several water-stable BrΦnsted-acidic ionic liquids with an alkane sulfonic acid group were synthesized, and were characterized by nuclear magnetic resonance (NMR), infrared spectrum (IR), electrospray ionization mass spectrum (ESI-MS) and thermogravimetry (TG.). It was found that their structures were consistent with the designed one and all of their purities were more than 95%. These ionic liquids possess high thermal stability and wide liquid range, and their decomposition temperatures are higher than 300 ℃ by analyzing TG. In addition, they were found to have four kinds of ionic form, in which hydrogen ion can exist independently by analyzing ESI-MS. Moreover, the solubility of these ionic liquids was studied in some common solvents. All the ionic liquids are miscible with water and methanol, but are insoluble in ether, toluene and ethyl acetate.
Key words：Ionic liquids;Infrared spectrum;Nuclear magnetic resonance;Electrospray ionization mass spectrum;Thermogravimetry
[1] Sheldon R. Chem. Commun., 2001, (23): 2399. [2] Dupont J, de Souza R F, Suarez P A Z. Chem. Rev., 2002, 102(10): 3667. [3] Wasserscheid P, Keim W. Angew. Chem. Int. Ed., 2000, 39(21): 3773. [4] GU Yan-long, SHI Feng, DENG You-quan(顾彦龙, 石 峰, 邓有全). Chinese Science Bulletin(科学通报), 2004, 49(6): 515. [5] Welton T. Chem. Rev., 1999, 99(8): 2071. [6] Zhao D B, Wu M, Kou Y, et al. Catal. Today, 2002, 74(1-2): 157. [7] Xin H L, Wu Q, Han M H, et al. Applied Catalysis A: General, 2005, 292(1-2): 354. [8] Thornazeau C, Olivier-Bourbigou H, Magna L, et al. J. Am. Chem. Soc., 2003, 125(18): 5264. [9] Steven P W, Robert J G, Krishna M P, et al. Anal. Chem., 1988, 60(20): 2228. [10] WU Qin, DONG Bin-qi, HAN Ming-han, et al(吴 芹, 董斌琦, 韩明汉, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2007, 27(3): 460. [11] Yoo K, Namboodiri V V, Varma R S, et al. Journal of Catalysis, 2004, 222(2): 511. [12] Cole A C, Jensen J L, Ntai L, et al. J. Am. Chem. Soc., 2002, 124(21): 5962. [13] Yoshizawa M, Hirao M, Ito-Akita K, et al. J. Mater. Chem., 2001, 11(4): 1057. [14] ZHANG Zheng-xing, FENG Fang, HANG Tai-jun(张正行, 冯 芳, 杭太俊). Analysis of Organic Spectrum(有机光谱分析). Beijing: People Health Press(北京：人民卫生出版社), 1995. [15] CHEN Ru-yu(陈茹玉). Practical Guide to Infrared Spectrum(红外光谱实用指南). Tianjin: Tianjin Science Technology Press(天津：天津科学技术出版社), 1992. [16] WU Bo-wan, ZHANG Bing, YU Xin-qiao, et al(仵博万, 张 兵, 于新桥, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2006, 26(1): 106.
