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.