Lattice-gas modeling of enantioselective adsorption by template chiral substrates

The general behavior of enantioselective adsorption by templated chiral substrates is studied in the framework of lattice-gas and random sequential adsorption theories. The template is assumed to be formed by randomly preadsorbing a chiral species A on a square lattice of sites. A second chiral probe species, B, thus performs a random sequential adsorption process on the templated substrate and the enantioselectivity of the process with respect to one of the B enantiomers is obtained as a function of the relevant parameters of the model. All species considered in the present study are considered as monomers, i.e., they occupy a single adsorption site. In an extension of the simple model, the possibility that the chiral probe species can themselves act as templates is taken into account.