Synthesis and properties of switchable polarity ionic liquids based on organic superbases and fluoroalcohols

Switchable polarity ionic liquids (SWILs) with low moisture sensitivity were successfully synthesized from organic amidine/fluoroalcohol and guanidine/fluoroalcohol via proton transfer reaction. The ionic liquids showed low polarity and could be converted into high-polarity fluoroalkylcarbonate ILs upon the treatment with CO 2 under mild conditions. Their high polarity state could also readily be reverted to the low polarity state by the removal of CO 2 with heating. Changes in the structures and physical properties resulting from the change from low polarity to high polarity were confirmed by NMR spectroscopy, FTIR spectrophotometry , UV–vis spectroscopy, and conductivity and miscibility measurements. These SWILs have potential applications in solute separation and solvent recovery.