1-Butyl-3-methylimidazolium hexafluorophosphate

1-Butyl-3-methylimidazolium hexafluorophosphate, also known as BMIM-PF₆, is a viscous, colourless, hydrophobic and non-water-soluble ionic liquid with a melting point^[1] 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.^[2]

1-Butyl-3-methylimidazolium hexafluorophosphate

Names
IUPAC name 1-butyl-3-methylimidazol-3-ium hexafluorophosphate
Other names BMIM-PF6
Identifiers
CAS Number	174501-64-5 Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	2015930 Y
ECHA InfoCard	100.203.179
PubChem CID	2734174
UNII	ZGE3N4O8Q9 Y
CompTox Dashboard (EPA)	DTXSID4047911
InChI InChI=1S/C8H15N2.F6P/c1-3-4-5-10-7-6-9(2)8-10;1-7(2,3,4,5)6/h6-8H,3-5H2,1-2H3;/q+1;-1 Y Key: IXQYBUDWDLYNMA-UHFFFAOYSA-N Y InChI=1/C8H15N2.F6P/c1-3-4-5-10-7-6-9(2)8-10;1-7(2,3,4,5)6/h6-8H,3-5H2,1-2H3;/q+1;-1 Key: IXQYBUDWDLYNMA-UHFFFAOYAH
SMILES CCCCN1C=C[N+](=C1)C.F[P-](F)(F)(F)(F)F CCCCn1cc[n+](c1)C.F[P-](F)(F)(F)(F)F
Properties
Chemical formula	C8H15F6N2P
Molar mass	284.186 g·mol−1
Appearance	Light yellow liquid
Density	1.38 g/mL (20 °C)
Melting point	−8 °C (18 °F; 265 K)
Solubility in water	insoluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation and uses

BMIM-PF₆ is commercially available. It may be obtained in two steps: BMIM-Cl is synthesized by alkylating 1-methylimidazole with 1-chlorobutane. A metathesis reaction with potassium hexafluorophosphate gives the desired compound; the tetrafluoroborate may be prepared by analogously using potassium tetrafluoroborate.^[3]

BMIM-PF₆ has been investigated in electrochemistry where it serves both as solvent and electrolyte.^[4] and electrochemical CO₂ reduction.^[5]

See also

• 1-Butyl-3-methylimidazolium tetrachloroferrate