Magnetic ionic liquid
The ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate was identified by Satoshi Hayashi and Hiro-o Hamaguchi of the University of Tokyo in 2004 as magnetic ionic liquid. It can be obtained from 1-butyl-3-methylimidazolium chloride and ferric chloride. It has quite low water solubility an thus can be considered as hydrophobic ionic liquid.  
- Satoshi Hayashi; Hiro-o Hamaguchi (2004). "Discovery of a Magnetic Ionic Liquid [bmim]FeCl4". Chemistry Letters 33 (18): 1590–1591. doi:10.1002/chin.200518200.
- Satoshi Hayashi; Satyen Saha; Hiro-o Hamaguchi (2006). "A new class of magnetic fluids: bmim[FeCl4] and nbmim[FeCl4] ionic liquids D". IEEE Transactions on Magnetics 42 (1): 12–14. Bibcode:2006ITM....42...12H. doi:10.1109/TMAG.2005.854875.