The ideal recrystallization solvent should possess the following
characteristics:
- The compound of interest should fully dissolve in hot (boiling)
solvent.
- The compound of interest should have little or no solubility in
the solvent at room temperature.
- The boiling point of the solvent should be lower than the
melting point of the compound of interest. If it is not, you may
obtain an oil rather than crystals.
- The solvent should have a fairly low boiling point (this makes
it easier to remove by evaporation when air drying). Also allows
you to use a low temperature oven to remove any traces of
solvent.
- The solvent should be inexpensive, non-toxic, non reactive, and
have a low odor.