Binding of deposited gold clusters to thiol self-assembled monolayers on Au(111) surfaces

We study the mechanisms involved in Au nanocluster deposition on thiol self-assembled monolayer modified Au(111) surfaces. Molecular dynamics simulations reveal a wide range of cluster-surface binding configurations within a very narrow deposition energy range (0.2-0.6 eV/atom for 2.5 nm diameter clusters). These go from noncovalent to full contact and include surprising intermediate cases in which the clusters are bound to the underlying Au(111) surface via molecular links and nanowires. Experiments show that, subsequently, the clusters are covered by thiols and slightly flattened.