A comparative study of the interaction of cyclopentene, cyclohexene, and 1,4-cyclohexadiene with the silicon (0 0 1) surface

In this work we employ the state of the art pseudopotential method, within a generalized gradient approximation to the density functional theory, to investigate the interaction process (i.e. adsorption and dissociation) of cyclic hydrocarbons (cyclopentene, cyclohexene, and 1,4-cyclohexadiene) with the silicon (0 0 1) surface. Our first-principles calculations suggest that all considered cyclic hydrocarbons are adsorbed on the Si(0 0 1) surface via a [2+2] cycloaddition reaction with adsorption energies of 35, 23, and 31 kcal/mol for cyclopentene, cyclohexene, and 1,4-cyclohexadiene, respectively. Possible reaction pathways for the dissociation of the methyl radicals and the breaking of the Si–Si dimers of the surface are considered. In addition, we present theoretical STM images of possible adsorbed systems, with a view to contribute to further experimental investigations.