Chiral ionic liquids (CILs) are a subcategory of ionic liquids that possess a
chiral moiety. The need for chiral separations in several industries, including
pharmaceutical, food, and chemical industries, has led to an increasing search for
materials capable of performing such separations. CILs have emerged as effective
candidates for the separation of enantiomers because of their advantageous properties
like low melting point, little vapor pressure, high thermal stability, good electrical
conductivity, and low cost. They are being employed in chromatographic methods as
chiral ligands, stationary phases, and chiral selectors for the separation of chiral
compounds. As compared to other chiral selectors (cyclodextrins, polysaccharides,
surfactants, and crown ethers), CILs show better solubility, easy synthesis, and low
cost. They represent an intriguing opportunity for use in chromatography because of
their wide range of solubility in organic and inorganic solvents, as well as their
miscibility with common solvents (methanol and acetonitrile). Considering the
flourishing research in the field, the present chapter summarizes the advancement in the
application of CILs as chiral ligands, stationary phases, and chiral selectors in liquid
and gas chromatographic techniques. Furthermore, the chiral recognition mechanism
and prospects for the use of CILs in enantioseparations have been examined.
Keywords: Amino acids, Chiral mechanism, Chiral ionic liquids, Chiral molecules, Chiral cation, Chiral anion, Chiral ligands, Chiral selectivity, Diastereomers, Enantiomers, Gas chromatography, Green precursors, Liquid chromatography, Mobile phase additives, Racemic drugs, Stereoselective, Stationary phases.
