Physicochemical and Thermal Behaviors of Room-Temperature Phosphonium Ionic Liquids Based on Fluorosulfonyl(trifluoromethylsulfonyl)Amide Anion As Potential Electrolytes

The physicochemical properties of novel room-temperature ionic liquids based on quaternary phosphonium cations in combination with asymmetric fluorosulfonyl(trifluoromethylsulfonyl)amide anion were reported. It was found that such phosphonium ionic liquids showed lower melting points than those of the conventional amide anion-based ionic liquids. Typical density and transport property behaviors for ionic liquids were observed. Several phosphonium ionic liquids based on fluorosulfonyl(trifluoromethylsulfonyl)amide anion exhibited low viscosities. The phosphonium ionic liquids based on fluorosulfonyl(trifluoromethylsulfonyl)amide anion exhibited relatively low thermal stability when compared to the corresponding conventional amide anion-based ionic liquids.