Monolayer Formation of Molybdenum Carbonyl on Cu(111) Revealed by Scanning Tunneling Microscopy and Density Functional Theory

International audienceMolybdenum carbonyl Mo(CO)(6) was adsorbed on the Cu(111) surface at 160 K in the monolayer coverage range and studied by scanning tunneling microscopy. A well-ordered monolayer of hexacarbonyl molecules was observed experimentally for the first time. The monolayer has a hexagonal structure compatible with a (root 7 x root 7)R19 superlattice on the copper (111) plane. The arrangement and orientation of the molecules on the surface were determined by density functional theory calculations, including van der Waals interactions. The comparison of adsorption and cohesive energies reveals that the molecule-substrate interaction is stronger than the intermolecular one, which explains the observed two-dimensional growth