title: Solute-solvent hydrogen-bonding in room temperature ionic liquids studied by Raman spectroscopy.
abstract: The vibrational frequencies of the C=O + C=C band of diphenylcyclopropenone and the NH(2) stretching band of p-aminobenzonitrile were determined in various room temperature ionic liquids (RTILs). The vibrational frequency shifts of the C=O + C=C stretching mode were compared with Kamlet α values, and frequency shifts of the NH(2) stretching mode were compared with Kamlet β values. A nearly linear relationship was obtained for both parameters, although the solvatochromic parameters were more sensitive to changes of the cation species. Vibrational frequency calculations of a 1 : 1 cluster of p-aminobenzonitrile with the RTIL anions using DFT theory reproduced the observed frequency shifts of the NH(2) stretching mode fairly well. The frequency shifts of the CN stretching mode were well reproduced by the linear combination of dipolarity parameters, the hydrogen-bond donating and accepting parameters determined by the Raman shift of the solute molecule.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Koji
authors.initials: K
authors.lastname: Osawa
authors.forename: Masahide
authors.initials: M
authors.lastname: Terazima
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Kimura
mesh_terms: D003521:Cyclopropanes / Q000737:chemistry*; D006860:Hydrogen Bonding; D052578:Ionic Liquids / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman; D013696:Temperature
chemical_list: D003521:Cyclopropanes; D052578:Ionic Liquids; D009570:Nitriles; C029402:diphenylcyclopropenone; C045271:4-aminobenzonitrile