1-Butyl-3-methylimidazolium hexafluorophosphate

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.