Synthesis and Characterization of Novel Brønsted-Lewis Acidic Ionic Liquids

Hualiang An, Lijuan Kang, Wei Gao, Xinqiang Zhao, Yanji Wang

Hebei Provincial Key Lab of Green Chemical Technology and High Efficient Energy Saving, Hebei University of Technology, Tianjin, China.

DOI: 10.4236/gsc.2013.32A005                

Abstract

To meet the demands of some kinds of reactions catalyzed simultaneously by Br?nsted acid and Lewis acid catalyst, two novel Br?nsted-Lewis acidic ionic liquids, 1-carboxyethylene-3-(4-zinc acetate sulfobutyl) imidazolium chloride ([CH₃COO-Zn-O₃S-bim-CH₂CH₂COOH]Cl) and 1-(1,2-dicarboxy) ethylene-3-(4-zinc acetate sulfobutyl) imidazolium chloride ([CH₃COO-Zn-O₃S-bim-C₄H₅O₄]Cl) were synthesized, in which both Br?nsted and Lewis acidic sites existed in the cation. The structures of the ionic liquids were determined by means of FT-IR, ¹H NMR and elemental analysis. The results of Py-IR analysis indicated that the two novel ionic liquids have both Br?nsted and Lewis acid properties. The acid strength values (H₀) of the ionic liquids were measured utilizing the UV-visible spectroscopy combined with Hammett indicator method, and the acid amount of them was determined by acid-base titration.

Keywords

Brønsted-Lewis Acidic Ionic Liquids; Synthesis; Characterization

Conflicts of Interest

The authors declare no conflicts of interest.

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