Thermophysical Properties of Binary Amide Anion-Based Ionic Liquids; TMPAFSA_xTFSA_1−x

抄録

An ionic liquid system based on two amide anions; bis(fluorosulfonyl)amide anion (FSA⁻) and bis(trifluoromethanesulfonyl)amide anion (TFSA⁻), with a quaternary ammonium cation; N,N,N-trimethyl-N-propylammonium cation (TMPA⁺), was investigated over entire composition range. The system showed the binary phase diagram and the eutectic point was 5.5°C around the anion ratio of 1:2 (FSA⁻: TFSA⁻). Polymorphic behavior of solidified ionic liquid was observed by X-ray diffraction (XRD) and discussed comparing with ionic liquids composed of other anion; (fluorosulfonyl) (trifluoromethylslufonyl)amide anion (FTA⁻) or tetrafluoroborate anion (BF₄⁻). In addition, the phase diagram of the ionic liquid system containing lithium cation with binary anion was confirmed. Raman spectroscopy suggested that lithium cation interacts more preferentially with TFSA⁻ than FSA⁻.