It actually depends on the ionic liquid. Quarternisation reactions are usually SN2 and as such are favored by polar, non protic solvents, as such alcohols or water will just slow down your reaction. DCM is too low boiling to be of any use and toluene is the opposite and as such a pain in the neck to remove completely. What we generally use is acetonitrile
The best choice is toluene. CH2Cl2 is an out-of-date hazardous solvent. methanol is toxic and hygroscopic. In the case of toluene, in most situation the IL-toluene form biphasic mixture and the separation and purification is simple. you can increase the reaction temperature up to 110 dC (reflux of toluene).
It actually depends on the ionic liquid. Quarternisation reactions are usually SN2 and as such are favored by polar, non protic solvents, as such alcohols or water will just slow down your reaction. DCM is too low boiling to be of any use and toluene is the opposite and as such a pain in the neck to remove completely. What we generally use is acetonitrile
It depends on the type of ionic liquid you are preparing. At the same, it also depends on the step i.e. quaternization or ion exchange step. If your ionic liquid is insoluble in water, for ion exchange step, DCM-water binary mixture is commonly used.
Thank you very much Dr's and Prof's.
If my IL material is aprotic 1-Butyl-1-methylpyrrolidinium bis (trifluoromethanesulfonyl)imide, then which solvent should I use? Will there be any molar ratio which should be followed to prepare the Ionic Liquid? I do not expect a trace amount of water also. I urgently need your expert comments. Thanks!!!
One pot synthesis is possible but tricky, I would suggest to prepare your BMPyrr Br in acetonitrile, separate it, and then make the anion exchange to the final product with DCM/water
Choose of any solvent during synthesis of ionic liquids depends upon the type of ionic liquids (Hydrophobic or Hydrophilic) want to synthesis. Mostly quaternization reaction (halide salt preparation) carried out in toluene and acetonitrile solvent.
Generally metathesis reaction (Ionic liquid preparation) preferable in water (Hydrophobic ILs), dichloromethane (hydrophilic ILs).
For your case synthesis of 1-Butyl-1-methylpyrrolidinium bis (trifluoromethanesulfonyl)imide water is preferable solvent because you are synthesizing hydrophobic ionic liquid. after metathesis reaction, separate the layer of ionic liquid from water and dissolve in DCM and dry by using drying agent.
Solventf for the preparation of ionic liquid you can use water
For quaternization use ACN, for purification halides AcOEt, and for anion exchange try water, acetone or water
Dear Majid Vafaeezadeh ,
I would like to ask here that if I want to immobilize such ionic liquids onto a support such as silica-coated magnetic nanoparticles, should I use toluene?
Many researchers have reported immobilization in toluene. But as you mentioned, ionic liquids are usually insoluble in toluene. Then how can immobilization be done in toluene?
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