Physicochemical and Structural Properties of a Hydrophobicity/Hydrophilicity Switchable Ionic Liquid.

Herein, we report the physicochemical and structural properties of a new solubility-switchable ionic liquid (IL) comprising the glycerammonium (GA) cation with a hydrophilic group, the GA cation attached to an acetal-based protective group [protected GA (PGA)], and bis(trifluoromethanesulfonyl)amide (TFSA). The interionic volumes () of the hydrophobic [PGA][TFSA] and hydrophilic [GA][TFSA] ILs were evaluated based on solution density, revealing weaker ion-ion interactions in these relative to conventional ILs. The [PGA][TFSA] and [GA][TFSA] also exhibit poor ion-conducting properties, with up to an order of magnitude lower ionic conductivity (σ) and self-diffusion coefficient (), as compared with conventional ILs.