1H, 19F-HOESY and PGSE diffusion studies on ionic liquids: The effect of co-solvent on structure

1H, 19F-HOESY studies on the ionic liquid based on 1-butyl-3-methylimidazolium tetrafluoroborate, [C4C1im]BF4, [C4C1im][N(OTf)2], and, partially, [C4C1im]PF6, are reported. The addition of methanol separates the ions; however, in dichloromethane solution the anions and cations show strong HOESY contacts even after dilution and taken together with the PGSE diffusion measurements, the data suggest strong ion pairing in this solvent.

Graphical abstractNMR HOESY and diffusion studies on 1-butyl-3-methylimidazolium tetrafluoroborate, [C4C1im]BF4 and [C4C1im][N(OTf)2], reveal an ion-paired structure for the ionic liquid in dichloromethane solution, but separated, solvated ions in methanol solution.Figure optionsDownload full-size imageDownload as PowerPoint slide