Intermolecular interactions in mixtures of 1-n-butyl-3-methylimidazolium acetate and water: Insights from IR, Raman, NMR spectroscopy and quantum chemistry calculations

The intermolecular interactions in 1-n-butyl-3-methylimidazolium acetate (BmimAc)/water mixture were studied by examining the mole fraction dependence of the vibrational modes measured with infrared and Raman spectroscopy, as well as of the 1H, 13C, 15N and 17O NMR chemical shifts. Quantum chemistry calculations were carried out to assign as clearly as possible the vibrational modes of the cation and anion as well as to get information on the expected effect of the mixture composition on the vibrational modes and charge distribution in BmimAc.