1-Butyl-1-methylpyrrolidinium tetrafluoroborate

Ionic liquids (ILs) are molten salts with melting points lower than 100 °C. They usually consist of pair of organic cation and anion. ILs exhibit unique properties such as nonvolatility, high thermal stability, and high ionic conductivity and find applications as electrolytes in lithium/sodium ion batteries and dye-sensitized solar cells. They are also used as media for synthesis of conducting polymers and intercalation electrode materials.

1-Butyl-1-methylpyrrolidinium tetrafluoroborate ([BMPY][BF₄]) can be used:

• As an electrolyte along with 1,2-butylene carbonate and 3-cyanopropionic acidmethyl ester solvents, applicable in the electrochemical double-layercapacitors (EDLCs).
• As an ionic solvent in the N-alkylation reaction of acridine ester precursors with 1,3-propane sultone.
• As an inhibitor of corrosion for copper in acidic conditions.