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. Stable gold-organic hybrids can be prepared on single crystal gold surfaces via a surface assisted coupling reaction between chloro-substituted perylene-3,4,9,10-tetracarboxylic acid bisimides (PBIs) and surface gold atoms in an ultrahigh vacuum environment. Participation of surface gold atoms in the coupling reaction leads to the oriented alignment of the Au-PBI chains on reconstructed Au (100) surfaces.