Understanding molecular self-assembly of a diol compound by considering competitive interactions.

With a combination of scanning tunneling microscopy and density functional theory, effects on molecular self-assembly involving two distinct chemical groups were investigated. We analyzed the influence of the individual functional units in the adsorbate and extracted the dominating contributions to the adsorption behaviour. The viability of such a systematic approach to study self-assembled structures by considering the interplay between substrate effects and molecular design is demonstrated.

On-surface reductive coupling of aldehydes on Au(111).

On-surface synthesis of a polyphenylene vinylene oligomer via reductive coupling of a terephthalaldehyde derivative on Au(111) is reported. Scanning tunneling microscopy and photoelectron spectroscopy experiments confirmed oxygen dissociation and its desorption from the surface. Density functional theory calculations provided a reasonable reaction mechanism involving reactive sites on the substrate.

Surface supported gold-organic hybrids: on-surface synthesis and surface directed orientation.

The surface-assisted synthesis of gold-organic hybrids on Au (111) and Au (100) surfaces is repotred by thermally initiated dehalogenation of chloro-substituted perylene-3,4,9,10-tetracarboxylic acid bisimides (PBIs). Structures and surface-directed alignment of the Au-PBI chains are investigated by scanning tunnelling microscopy in ultra high vacuum conditions. Using dichloro-PBI as a model system, the mechanism for the formation of Au-PBI dimer is revealed with scanning tunnelling microscopy studies and density functional theory calculations. A PBI radical generated from the homolytic C-Cl bond dissociation can covalently bind a surface gold atom and partially pull it out of the surface to form stable PBI-Au hybrid species, which also gives rise to the surface-directed alignment of the Au-PBI chains on reconstructed Au (100) surfaces.