Low-melting, low-viscous, hydrophobic ionic liquids:: N-alkyl(alkyl ether)-N-methylpyrrolidinium perfluoroethyltrifluoroborate

A series of new hydrophobic ionic liquids comprising N-alkyl (alkyl ether)-N-methylpyrrolidinium and perfluoroethyltrifluoroborate were prepared and characterized. The new [C2F5BF3](-)-based salts show lower melting points than the corresponding [BF4](-)-based ones. Of these new salts, five are liquids at room temperature and show very low viscosities (37-71 cP at 25 degreesC), high ionic conductivities (3.0-6.8 mScm(-1)) and wide electrochemical windows.