The Formation of Imidazolium Salt Intimate (Contact) Ion Pairs in Solution1. (24th September 2014)

• Record Type: Journal Article
• Authors: Zanatta, Marcileia; Girard, Anne‐Lise; Simon, Nathalia M.; Ebeling, Gunter; Stassen, Hubert K.; Livotto, Paolo R.; dos Santos, Francisco P.; Dupont, Jairton
• Is Part Of: Angewandte Chemie. Volume 126:Number 47(2014)
• Page Start: 13031
• Page End: 13035
• Publication Date: 2014-09-24
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201408151
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>1‐<italic>n</italic>‐Butyl‐2, 3‐dimethylimidazolium (BMMI) ionic liquids (ILs) associated with different anions undergo H/D exchange preferentially at 2‐Me group of the imidazolium in deuterated solvents. This process is mainly related to the existence of ion pairs rather than the anion basicity. The H/D exchange occurs in solvents (CDCl₃ and MeCN for instance) in which intimate contact ion pairs are present and the anion possesses a labile H in its structure, such as hydrogen carbonate and prolinate. In D₂O, separated ion pairs are formed and the H/D exchange does not occur. A plausible catalytic cycle is that the IL behaves as a neutral base in the course of all H/D exchange processes. NMR experiments, density functional calculations, and molecular dynamics simulations corroborate these hypotheses.</p> </abstract>