1-Butyl-3-methylimidazolium hexafluorophosphate, also commonly known as BMIM-PF6, is a viscous, colourless, hydrophobic and non-water-soluble ionic liquid with a melting point of −8 °C. Together with BMIM-BF4, it is one of the most extensively studied ionic liquids. It is known to very slowly decompose in the presence of water.
Preparation and uses BMIM-PF6 is commercially available. It may be obtained in two steps, as shown below.
BMIM-Cl is synthesized by alkylating the compound 1-methylimidazole with 1-chlorobutane. A metathesis reaction with potassium hexafluorophosphate and the product from the previous reaction gives the desired compound. BMIM-BF4 may be prepared by analogously using potassium tetrafluoroborate in place of the hexafluorophosphate.
BMIM-PF6 has been investigated in electrochemistry where it ambiguously serves as both a solvent and an electrolyte, and it also has potential uses in electrochemical CO2 reduction.
See also 1-Butyl-3-methylimidazolium tetrachloroferrate
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