Protonation of Imines by Water in the Presence of Salts: Role of Cooperative Effects in Water-Shared Ion Pairs

Article abstract of DOI:10.1021/j100380a068

An IR spectroscopic study of lithium and magnesium salt solutions in acetonitrile in the presence of an organic base such 1,8-diazabicyclo<5.4.0>undec-7-ene (DBU) shows that this base may be protonated by water when added.The formation of a water-separated ion pair is essential to this protonation.The replacement of a solvent molecule by a DBU molecule in the first solvation shell of the cation in this solvent-separated ion pair leads to the elimination of protonated DBUH⁺X^- ion pair.