Lattice-gas modeling of enantioselective adsorption by template chiral substrates

Abstract

The general behavior of enantioselective adsorption by templated chiral substrates is studied inthe framework of lattice-gas and random sequential adsorption theories. The template is assumedto be formed by randomly preadsorbing a chiral species A on a square lattice of sites. A secondchiral probe species, B, thus performs a random sequential adsorption process on the templatedsubstrate and the enantioselectivity of the process with respect to one of the B enantiomersis obtained as a function of the relevant parameters of the model. All species considered inthe present study are considered as monomers, i.e., they occupy a single adsorption site. In anextension of the simple model, the possibility that the chiral probe species can themselves actas templates is taken into account.It is shown how di5erent arrangements of A molecules on the surface generate di5erent enantioselectivities as a function of coverage, some of which have been observed experimentally.