text: Chiral recognition implies the ability of chiral stationery phases to interact differently with mirror-image molecules, leading to their separation. The mechanism of enantiomeric resolution using CSPs is generally attributed to the “three-point" interaction model (fig.1.) between the analyte and the chiral selector in the stationary phase. Also known as the Dalgliesh model.  Under this model, for chiral recognition, and hence enantiomeric resolution to happen on a CSP one of the enantiomers of the analyte must be involved in three simultaneous interactions. This means to say the one of enantiomers is able to have a good interaction with the complimentary sites on the chiral selector attached to the CSP. While Its mirror-image partner may only interact at two or one such sites. In the figure, enantiomer (a), has the correct configuration of the ligands (X, Y and Z) for three-point interactions with the complimentary sites (X’, Y’ and Z’) on the CSP, while its mirror image (b) can only interact at one site. The dotted lines (-----) indicate interaction with complimentary sites.
  The diastereomeric complexes thus formed will have different energies of interaction. The enantiomer forming the more stable complex will have less energy and stay longer in the stationary phase compared to the less stable complex with higher energy. The success of chiral separation basically depends in manipulating the subtle energy differences between the reversibly formed non-covalent transient diastereomeric complexes. The  energy difference reflects the magnitude of enantioselectivity. Mobile phase has a major role in stabilizing the diastereomeric complex and thus in chiral separation. This simplified bimolecular interaction model is a treatment suitable for theoretical purposes. Mobile phase plays a  key role in chiral recognition mechanism. Components of  MP (such as bulk solvents, modifiers, buffer salts, additives) not only influence the conformational  flexibility of CS and CA molecules but also their degree of ionization. The types of interaction involved in the analyte-selector interaction vary depending on the nature of the CSP used. These may include hydrogen bonding, dipole-dipole, π-π, electrostatic, hydrophobic or steric interactions, and inclusion complex formation.