%0 Journal Article %A Katsyuba, Sergey A. %A Griaznova, Tatiana P. %A Vidiš, Ana %A Dyson, Paul J. %D 2009 %T Structural Studies of the Ionic Liquid 1-Ethyl-3-methylimidazolium Tetrafluoroborate in Dichloromethane Using a Combined DFT-NMR Spectroscopic Approach %U https://acs.figshare.com/articles/journal_contribution/Structural_Studies_of_the_Ionic_Liquid_1_Ethyl_3_methylimidazolium_Tetrafluoroborate_in_Dichloromethane_Using_a_Combined_DFT_NMR_Spectroscopic_Approach/2863249 %R 10.1021/jp8083327.s001 %2 https://acs.figshare.com/ndownloader/files/4561075 %K C 2 atom %K imidazolium ring %K chemical shifts %K computation %K NMR data %K dichloromethane solutions %K EMIM %K Structural Studies %K NMR spectroscopy %K latter structures %K C 5 %K anion %K IL %K NMR spectra %K ion pairs %X DFT methods in combination with NMR spectroscopy are used to investigate possible variants of the molecular structure of the ion pairs of the ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF4], in dichloromethane. According to the computations of the chemical shifts, experimental NMR spectra can be rationalized by an equilibrium between ca. 70−80% of structures with the anion positioned near to the C2 atom of the imidazolium ring and ca. 20−30% of structures with the anion close to the C5 and/or C4 atoms. The content of the latter structures, according to the computed Gibbs free energies, does not exceed 10%. Both the computations and the experimental NMR data suggest that the ratio of the two above-mentioned types of structures of the imidazolium-based ILs is influenced by the concentration/polarity of their dichloromethane solutions. %I ACS Publications