title: Regional electrophilic and nucleophilic Fukui functions efficiently highlight the Lewis acidic/basic regions in ionic liquids.
abstract: The origin of catalysis and selectivity induced by room temperature ionic liquids in several organic reactions has putatively been associated with the concept of cation effect (hydrogen bond donor ability of the ionic liquids) or anion effect (hydrogen bond accepting ability of the ionic liquids). We show that there may be cases where this a priori classification may not be correctly assigned. Cations may concentrate both Lewis acidity and basicity functions in one fragment of the ionic liquid: an effect we tentatively call bifunctional distribution of the molecular Lewis acidity/basicity. Bifunctionality on the cation is however anion dependent through electronic polarization effects. The molecular distribution of the Lewis acidity/basicity may simply be assessed by evaluating the regional Fukui function within a reference ion pair structure. The model is tested for a set of nine ionic liquids based on the 1-butyl-3-methylimidazolium cation commonly used as solvent to run organic reactions.
authors.affiliation: Archroma Chile Ltda., Emulsion Products, Melipilla Drive, 15170 Maipu, Santiago, Chile.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cerda-Monje
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Ormazábal-Toledo
authors.forename: Carlos
authors.initials: C
authors.lastname: Cárdenas
authors.forename: Patricio
authors.initials: P
authors.lastname: Fuentealba
authors.forename: Renato
authors.initials: R
authors.lastname: Contreras
mesh_terms: D002412:Cations / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry*; D008962:Models, Theoretical; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry
chemical_list: C525963:1-butyl-3-methylimidazolium; D002412:Cations; D007093:Imidazoles; D052578:Ionic Liquids; D058116:Lewis Acids; D012997:Solvents