One-pot sustainable synthesis of tetrabutylammonium bis(trifluoromethanesulfonyl)imide ionic liquid

Tetrabutylammonium bis(trifluoromethanesulfonyl)imide (TBA TFSI) and tetrafluororate-based anion ionic liquids (ILs) were obtained simultaneously by using a fast, versatile, cheap, low cost, and one-pot process. The process relies on dissolving tetrabutylammonium tetrafluoroborate salt, an organic-based bis(trifluoromethanesulfonyl) imide, ILs, such as 1-ethyl-3-methylimidazolium, N-trimethyl-N-butylammonium, 1-butyl-1-methylpyrrolidinium, 1-methyl-1-propylpiperidinium derivatives in dimethylformamide. A further extraction process using water and ether allows the selective recovery of the TBA TFSI in the organic phase, and the organic-based tetrafluoroborate IL in the aqueous phase. All the ionic liquids synthetized were characterized using Infrared Spectroscopy and Nuclear Magnetic Resonance, and compared with commercially available samples.