Halogenated aromatic molecules assemble on surfaces forming both hydrogen andhalogen bonds. Even though these systems have been intensively studied on flatmetal surfaces, high-index vicinal surfaces remain challenging, as they mayinduce complex adsorbate structures. The adsorption of 2,6-dibromoanthraquinone(2,6-DBAQ) on flat and stepped gold surfaces is studied by means of van derWaals corrected density functional theory. Equilibrium geometries andcorresponding adsorption energies are systematically investigated for variousdifferent adsorption configurations.~It is shown that bridge sites and stepedges are the preferred adsorption sites for single molecules on flat andstepped surfaces, respectively. The role of van der Waals interactions, halogenbonds and hydrogen bonds are explored for a monolayer coverage of 2,6-DBAQmolecules, revealing that molecular flexibility and intermolecular interactionsstabilize two-dimensional networks on both flat and stepped surfaces. Ourresults provide a rationale for experimental observation of molecular carpetingon high-index vicinal surfaces of transition metals.
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