Hydrogen-bonding interactions between [BMIM][BF4] and dimethyl sulfoxide

摘要: Mixtures of Ionic liquids and small polar organic solvent are potential green solvents for cellulose dissolution under mild conditions. In this work, the interactions between a representative imidazolium-based ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) dimethyl sulfoxide (DMSO) were investigated in detail by attenuated total reflection infrared spectroscopy (ATR-IR) density functional theory calculations (DFT). The main conclusions are: (1) C2-H is interaction site forming cation-anion, cation-DMSO, [BMIM][BF4]-DMSO complexes. (2) two turning points wavenumber shift changes may indicate that dilution process can be divided into several stages: from larger ion clusters to smaller clusters, then pairs, finally individual ions. molecules cannot break apart strong Coulombic [BMIM](+) [BF4](-) but pairs when mole fraction DMSO less than 0.9. When greater 0.9, broke (3) hydrogen-bonds aromatic C-Hs [BMIM](+). strengthened while those alkyl weakened. (4) cation strength before weakening C-Hs. These in-depth studies on properties liquid-DMSO mixed shed light exploring their applications as other practices. (C) 2014 Elsevier B.V. All rights reserved.