Journal of Physical Chemistry B, Vol.112, No.41, 13022-13037, 2008
Solvation of Phenylglycine- and Leucine-Derived Chiral Stationary Phases: Molecular Dynamics Simulation Study
A theoretical study of the solvation of (R)-N-(3,5-dinitrobenzoyl)phenylglycine- and (R)-N-(3,5-dinitrobenzoyl)leucine-derived chiral stationary phases (CSPs) is presented. Semiflexible models of the chiral selectors are prepared from B3LYP/6-311G** calculations, and these are used in the molecular dynamics simulations of the corresponding interface. The chiral interface is examined for four solvents: 100% hexane, 90:10 hexane: 2-propanol, 80:20 hexane:2-propanol, and 100% 2-propanol. Despite the similarities between phenylglycine and leucine, the interfaces are distinct both in terms of the selector orientations at the surface and in the number of hydrogen bonds formed with 2-propanol. We also find that an increase in alcohol concentration alters the preferred orientations of the selectors.