Chiral nanopatterned surfaces as versatile enantiospecific adsorbents: a Monte Carlo model

This paper deals with the application of the Monte Carlo simulation method for modeling of adsorption of chiral molecules on a planar surface patterned with active binding sites. The enantiomers are assumed to be rigid chains composed of four identical segments, each occupying one binding site. The energy of interaction between a segment and a binding site is characterized by epsilon(a) and epsilon(b) depending whether the site is active or it is inert. We demonstrate that epsilon(a)>epsilon(b) imposed in our previous work [J. Chem. Phys. 126, 144709 (2007)] is not a necessary condition for the separation of enantiomers form their racemate. The obtained results suggest that the major source of enantioselectivity of the surface lies in its geometrical properties. The active adsorption sites which form the chiral pattern do not have to interact stronger with the adsorbing molecules to ensure enantioseparation. In this context, the proposed chiral surface offers more flexibility in selection of the energetic properties of the binding sites. This, in practice, means wider possibilities of manipulating chemical composition of the surface.