Enthalpy-entropy compensation effect in gas chromatographic enantiomeric separation

In this paper, the enthalpy-entropy compensation effect in the enantiomeric separation by modified cyclodextrins (CD) and diamide chiral stationary ph ase (CSP) gas chromatography was investigated using the method of plotting Delta(Delta H) versus Delta(Delta G)(Thm) combined with t-test statistic an alysis. The investigated racemates cover alpha-phenylethylamine and its ana logs, 2-alkylamines, chiral acyclic alcohols, halogenated arylethanediol-1, 2-diperfluoropropionates, amino acid and its analogs, and two series of co mpounds containing chloro and bromo substituents. From the compensation ana lysis results, the effects of the diluent composition in the investigated c hiral stationary phases, the size and. the modified groups on investigated cyclodextrins, the derivatization methods and the groups attached to the st ereocenters on enantiomeric separation mechanisms were all discussed.