Intermolecular hydrogen bonds in water@IL supramolecular complexes

Author(s)

Zanatta, Marcileia ^[1] ; Dupont, Jairton ^[1] ; Wentz, Gabriela Negruni ^[1] ; dos Santos, Francisco P. ^[1]

Affiliation

^[1] Univ Fed Rio Grande do Sul, Inst Chem, Ave Bento Goncalves, BR-91501970 Porto Alegre, RS - Brazil

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 20, n. 17, p. 11608-11614, MAY 7 2018.
• Web of Science Citations: 3

Abstract

The role of small amounts of water in ionic liquids (ILs), namely, 1-n-butyl-2,3-dimethylimidazolium imidazolate (BMMI.lm), 2-methylimidazolate (BMMI.Melm), and pyrazolate (BMMI.Pyr), is examined using NMR spectroscopy and density functional theory (DFT) calculations. The nuclear Overhauser effect (NOE) indicates that a water molecule is trapped inside the ionic network, keeping the ion pair in contact through strong H-bonds involving the hydrogen atoms of water and the nitrogen atoms of the IL anions to give a guest@host supramolecular structure. The formation of the H2O@IL pair complex with different ILs combined with the strong hydrogen bond strength within the complex is responsible for the selective H/D exchange reactions at the imidazolium C2-Me and ketone C alpha positions. (AU)

• FAPESP's process: 15/08541-6 - Nuclear magnetic resonance spectroscopy: beyond molecular structure assignment
• Grantee: Claudio Francisco Tormena
• Support Opportunities: Research Projects - Thematic Grants