The role of achiral sorbent matrix in chiral recognition of amino acid enantiomers in ligand-exchange chromatography

Summary As an alternative to the known three-point interaction model describing recognition of optical isomers by a chiral resolving agent, a new concept has been developed stating that two interaction points between the resolving agent and the enantiomers are also sufficient for achieving chiral recognition of the latter, provided that the diastereomeric adducts formed by the resolving agent with the enantiomers additionally interact with a non-chiral chromatographic sorbent. This concept is based on the results of ligand-exchange chromatography of -amino acid enantiomers with copper(II) complexes of chiral bifunctional ligands as the resolving agents in chromatographic systems.