title: The Effect of C4H and C5H on the Microstructure of Aqueous Solutions of 1-Alkyl-3-methylimidazolium Tetrafluoroborate Ionic Liquids.
abstract: As is well-known, the C2H proton of 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim]BF4) and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) has a strong ability to form hydrogen bonds. The purpose of this work is to evaluate the effect of the interactions of the C4H and C5H protons on the microstructure of [Emim]BF4and [Bmim]BF4with water by using1H NMR spectroscopy. The differences between the relative1H NMR chemical shifts of C2H, C4H, and C5H and between the interaction-energy parameters obtained from these chemical shifts are minor, thus suggesting that the interactions of C4H and C5H may have a considerable effect on the microstructure. To confirm this, the viscosities of the systems are estimated by using the interaction-energy parameters obtained from the1H NMR chemical shifts of the three studied aromatic protons and water, showing that the interactions of C4H and C5H also play an important role in the microstructure.
authors.affiliation: Department of Chemistry, Shaoxing University, Huancheng West Road 508, Shaoxing (China).
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Chemistry, Zhejiang University, Zheda Road 38, Hangzhou (China).
authors.forename: Haoran
authors.initials: H
authors.lastname: Li
keywords: NMR spectroscopy; ionic liquids; local composition model; microstructure; viscosity