1-Butyl-3-methylimidazolium

hexafluorophosphate Hexafluorophosphate is an anion with chemical formula of . It is an octahedral species that imparts no color to its salts. is isoelectronic with sulfur hexafluoride, , and the hexafluorosilicate dianion, , and hexafluoroantimonate . In this anio ...

, also known as BMIM-PF₆, is a viscous, colourless,

hydrophobic In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water. Hydrophobic molecules tend to be nonpolar and, th ...

and non-water-soluble

ionic liquid An ionic liquid (IL) is a salt in the liquid state. In some contexts, the term has been restricted to salts whose melting point is below a specific temperature, such as . While ordinary liquids such as water and gasoline are predominantly made of ...

with a melting point of -8 °C. Together with 1-butyl-3-methylimidazolium tetrafluoroborate, BMIM-BF₄, it is one of the most widely studied ionic liquids. It is known to very slowly decompose in the presence of water.

Preparation

BMIM-PF₆ is commercially available. It may be obtained in two steps: BMIM-Cl is synthesized by alkylating

1-methylimidazole 1-Methylimidazole or ''N''-methylimidazole is an aromatic heterocyclic organic compound with the formula CH3C3H3N2. It is a colourless liquid that is used as a specialty solvent, a base, and as a precursor to some ionic liquids. It is a fundament ...

with 1-chlorobutane. A metathesis reaction with

potassium hexafluorophosphate Potassium hexafluorophosphate is the chemical compound with the chemical formula, formula KPF6. This colourless salt consists of potassium cations and hexafluorophosphate anions. It is prepared by the reaction: :Phosphorus pentachloride, PCl5 + ...

gives the desired compound; the tetrafluoroborate may be prepared by analogously using potassium tetrafluoroborate. : BMIM

Preparation

See also

References

Further reading