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
3D model (JSmol)	Interactive image Interactive image
ChemSpider	2015930
ECHA InfoCard	100.203.179
PubChem CID	2734174
UNII	ZGE3N4O8Q9
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 Key: IXQYBUDWDLYNMA-UHFFFAOYSA-N 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).
verify (what is  ?)
Infobox references

Preparation

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]

See also

• 1-Butyl-3-methylimidazolium tetrachloroferrate

References

1. Mihkel Koel (2008). Ionic Liquids in Chemical Analysis. CRC Press. p. xxvii. ISBN 1-4200-4646-2.
2. R.P. Swatloski; J.D. Holbrey & R.D. Rogers (2003). "Ionic liquids are not always green: hydrolysis of 1-butyl-3-methylimidazolium hexafluorophosphate". Green Chem. 5 (4): 361–363. doi:10.1039/b304400a.
3. Dupont J, Consorti C, Suarez P, de Souza R (2004). "Preparation of 1-Butyl-3-methyl imidazolium-based Room Temperature Ionic Liquids". Organic Syntheses.; Collective Volume, 10, p. 184

Further reading

• S. Carda-Broch; A. Berthod; D.W. Armstrong (2003). "Solvent properties of the 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid". Analytical and Bioanalytical Chemistry. 375 (2): 191–199. doi:10.1007/s00216-002-1684-1. PMID 12560962.