DETAILED EXPERIMENTAL AND THEORETICAL-ANALYSIS OF CHIRAL DISCRIMINATION - ENANTIOSELECTIVE BINDING OF R S METHYL MANDELATE BY BETA-CYCLODEXTRIN/

Enantiodifferentiation of methyl mandelate by beta-Cyclodextrin in the liquid phase is explored in detail. Temperature dependent studies usi ng a beta-cyclodextrin chiral stationary phase provided differential b inding enthalpies and entropies. NMR studies revealed where around the host molecule the guest tends to reside. Molecular dynamics simulatio ns correctly predict the retention order and provide an atomistic acco unt of how chiral discrimination takes place, It is found that short r ange dispersion forces rather than long range coulombic forces are res ponsible for both complexation and for enantiodiscrimination. The inte rmolecular hydrogen bonds are not discriminating and the idea that a t ight st of included species within a cyclodextrin cavity be a requirem ent for chiral discrimination is questioned. (C) 1996 Wiley-Liss, Inc.