TITLE:
Synthesis and Characterization of Novel Brønsted-Lewis Acidic Ionic Liquids
AUTHORS:
Hualiang An, Lijuan Kang, Wei Gao, Xinqiang Zhao, Yanji Wang
KEYWORDS:
Brønsted-Lewis Acidic Ionic Liquids; Synthesis; Characterization
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.3 No.2A,
May
27,
2013
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.