RESUMO
We directly observe the interaction between 1-butyl-3-methylimidazolium (bmim) or 1-butyl-2,3-dimethylimidazolium (bm(2)im) and the solute, ethyl acrylate (EA), which is the popular dienophile in the Diels-Alder reaction and an H-bonding acceptor, by using specially designed electrospray mass spectrometry. In imidazolium ionic liquids, cation-anion interactions are controlled by selecting the appropriate anion, and the naked C(2)-H of imidazolium, which loosely interacts with its counterion, can readily interact with an H-bonding acceptable solute. The ion-counterion (solvent-solvent) interaction affects the ion-solute (solvent-solute) interaction. This relation is one of the key criteria for selecting the cation-anion combination in tailoring ILs.
Assuntos
Acrilatos/química , Cânfora/análogos & derivados , Imidazóis/química , Imidazolinas/química , Líquidos Iônicos/química , Cânfora/química , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Solubilidade , Solventes/química , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/instrumentação , Espectroscopia de Infravermelho com Transformada de Fourier/métodosRESUMO
[structure: see text] As a halogen-free anion for an imidazolium room temperature ionic liquid, the use of a camphorsulfonate causes an increase in the number of free (naked) imidazolium cations, which produces an effective endo/exo stereoselective Diels-Alder reaction.
