Microheterogeneity in imidazolium and piperidinium cation-based ionic liquids: 1D and 2D NMR studies

Sumit Kumar Panja; Satyen Saha

doi:10.1002/mrc.4610

Microheterogeneity in imidazolium and piperidinium cation-based ionic liquids: 1D and 2D NMR studies

Magn Reson Chem. 2018 Feb;56(2):95-102. doi: 10.1002/mrc.4610. Epub 2017 Jun 16.

Authors

Sumit Kumar Panja¹, Satyen Saha¹

Affiliation

¹ Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.

PMID: 28503908
DOI: 10.1002/mrc.4610

Abstract

Existence of microheterogeneity of imidazolium and piperidinium cation-based ionic liquids (ILs) containing PF₆ and NTf₂ anions has been investigated by 1D and 2D NMR spectroscopy. 2D NMR (especially NOESY and HOESY) has been employed for studying the interactions present between cation and anion as well as the intermolecular interaction among cations. HOESY spectrum shows that fluorine of anion ( PF6- and NTf2-) significantly interacts with proton of the cations. Combined results of HOESY and NOESY for imidazolium IL indicate that the PF6- and imidazolium cation are distributed in organized manner, resulting a heterogeneous environment in liquid state. We have also observed existence of heterogeneous environment for piperidinium cation-based ILs which is different from imidazolium ILs. It appears that existence of microheterogeneity in IL is ubiquitous and therefore open up the ILs field to revisit. Copyright © 2017 John Wiley & Sons, Ltd.

Keywords: NOESY and HOESY; imidazolium; ionic liquids; microheterogeneity; piperidinium cation.

Publication types

Research Support, Non-U.S. Gov't