A combination of FTIR and DFT to study the microscopic structure and hydrogen-bonding interaction properties of the [BMIM][BF4] and water

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

1 Scopus Citations
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Author(s)

  • Yan-Zhen Zheng
  • Yu Zhou
  • Geng Deng
  • Rui Guo
  • Da-Fu Chen

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number117624
Journal / PublicationSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
Volume226
Online published7 Oct 2019
Publication statusPublished - 5 Feb 2020

Abstract

The structure and hydrogen-bond interaction property of water and a model ionic liquid (IL): 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) were studied using the combination of Fourier transform infrared spectroscopy (FTIR) and density functional theory (DFT) calculations. The O‒D stretching vibration region of the deuterated water was an area of special focus. Excess infrared spectroscopy with enhanced resolution was applied to analyse the original infrared spectra of v(O‒D). It is found that: (1) [BMIM][BF4] forms stable hydrogen-bonds with water in the mixture. (2) The hydrogen-bonds are weak strength, closed shell and electrostatic dominant interactions. The preferred interaction site of [BMIM]+ cation is the hydrogen atom at the C2. (3) Cage hexamer water, cyclic tetramer water, cyclic trimer water, ion cluster-water complex, ion pair−water, and anion-water complexes are identified in the mixture. When the mole fraction of D2O (x(D2O)) is larger than 0.9, ion cluster and ion pair were broken apart into individual cations and anions. The cage hexamer water, cyclic tetramer water, and cyclic trimer water disappear at x(D2O) < 0.8, 0.5, and 0.3, respectively. HDO formed by H/D isotope exchange was detected when x(D2O) is less than 0.3.

Research Area(s)

  • Density functional theory, Excess infrared spectra, Fourier transform infrared spectroscopy, Hydrogen-bond, Ionic liquids, Water

Citation Format(s)

A combination of FTIR and DFT to study the microscopic structure and hydrogen-bonding interaction properties of the [BMIM][BF4] and water. / Zheng, Yan-Zhen; Zhou, Yu; Deng, Geng; Guo, Rui; Chen, Da-Fu.

In: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, Vol. 226, 117624, 05.02.2020.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review