Preparation and chiral recognition of a mono[6^A-N-1-(2-hydroxy)- phenylethylimino-6^A-deoxy]-β-cyclodextrin HPLC stationary phase

A novel chiral stationary phase (CSP) is obtained by linking the β-CD to a chiral block (commercially available phenylglycinol) by rigid C=N bond. This chiral stationary phase exhibites good enantioselectivity for several alkylaromatic alcohols and a variety of ferrocene derivatives under reversed-phase conditions, with the best Rs value achieve up to 6.19. The hydrogen bonding interaction may be the primary factor, also π-π interaction or dipole-dipole interaction has some effect on chiral separation. The dependence of the natural logarithms of retention and selectivity factors (lnk' and lnα) on the inverse of temperature 1/T (van't Hoff plots) is used to determine thermodynamic data referring to the separation of the enantiomers. Calculated thermodynamic constants Δ(ΔH°), Δ (ΔS°), and Δ (ΔG°) are applied to help understand of the thermodynamic driving forces for retention and enantiorecognition for this chromatographic system. It can be concluded that the separations for all the investigated analytes on this CSP are enthalpically favored.