1-Butyl-3-methylimidazolium tetrachloroferrate explained

1-Butyl-3-methylimidazolium tetrachloroferrate is a magnetic ionic liquid. It can be obtained from 1-butyl-3-methylimidazolium chloride and ferric chloride. It has quite low water solubility.^{[1] [2]}

Due to the presence of the high spin FeCl₄ anion, the liquid is paramagnetic and a magnetic susceptibility of 40.6 × 10⁻⁶ emu g⁻¹ is reported. A simple small neodymium magnet suffices to attract the liquid in a test tube.

References

1. Discovery of a Magnetic Ionic Liquid [bmim]FeCl₄ . Satoshi Hayashi . Hiro-o Hamaguchi. Chemistry Letters. 33. 2004. 18. 1590–1591. 10.1246/cl.2004.1590.
2. A new class of magnetic fluids: bmim[FeCl₄] and nbmim[FeCl₄] ionic liquids . Satoshi Hayashi . Satyen Saha . Hiro-o Hamaguchi. IEEE Transactions on Magnetics. 42. 2006. 1. 12–14. 10.1109/TMAG.2005.854875 . 2006ITM....42...12H . 42347833 .