Cyano-Functionalized Triarylamines On Coinage Metal Surfaces: Interplay Of Intermolecular And Molecule-Substrate Interactions

The self-assembly of cyano-functionalized triarylamine derivatives on Cu(111), Ag(111) and Au(111) was studied by means of scanning tunnelling microscopy, low-energy electron diffraction, X-ray photoelectron spectroscopy and density functional theory calculations. Different bonding motifs, such as antiparallel dipolar coupling, hydrogen bonding and metal coordination, were observed. Whereas on Ag(111) only one hexagonally close-packed pattern stabilized by hydrogen bonding is observed, on Au(111) two different partially porous phases are present at submonolayer coverage, stabilized by dipolar coupling, hydrogen bonding and metal coordination. In contrast to the self-assembly on Ag(111) and Au(111), for which large islands are formed, on Cu(111), only small patches of hexagonally close-packed networks stabilized by metal coordination and areas of disordered molecules are found. The significant variety in the molecular self-assembly of the cyano-functionalized triarylamine derivatives on these coinage metal surfaces is explained by differences in molecular mobility and the subtle interplay between intermolecular and molecule-substrate interactions

Cyano-Functionalized Triarylamines On Au(111): Competing Intermolecular Versus Molecule/Substrate Interactions

The self-assembly of cyano-substituted triarylamine derivatives on Au(111) is studied with scanning tunneling microscopy and density functional theory calculations. Two different phases, each stabilized by at least two different cyano bonding motifs are observed. In the first phase, each molecule is involved in dipolar coupling and hydrogen bonding, while in the second phase, dipolar coupling, hydrogen bonding and metal-ligand interactions are present. Interestingly, the metal-ligand bond is already observed for deposition of the molecules with the sample kept at room temperature leaving the herringbone reconstruction unaffected. It is proposed that for establishing this bond, the Au atoms are slightly displaced out of the surface to bind to the cyano ligands. Despite the intact herringbone reconstruction, the Au substrate is found to considerably interact with the cyano ligands affecting the conformation and adsorption geometry, as well as leading to correlation effects on the molecular orientation

Cyano-Functionalized Triarylamines on Au(111): Competing Intermolecular versus Molecule/Substrate Interactions

The self-assembly of cyano-substituted triarylamine derivatives on Au(111) is studied with scanning tunneling microscopy and density functional theory calculations. Two different phases, each stabilized by at least two different cyano bonding motifs are observed. In the fi rst phase, each molecule is involved in dipolar coupling and hydrogen bonding, while in the second phase, dipolar coupling, hydrogen bonding and metal-ligand interactions are present. Interestingly, the metal–ligand bond is already observed for deposition of the molecules with the sample kept at room temperature leaving the herringbone reconstruction unaffected. It is proposed that for establishing this bond, the Au atoms are slightly displaced out of the surface to bind to the cyano ligands. Despite the intact herringbone reconstruction, the Au substrate is found to considerably interact with the cyano ligands affecting the conformation and adsorption geometry, as well as leading to correlation effects on the molecular orientation

Cyano-Functionalized Triarylamines on Coinage Metal Surfaces: Interplay of Intermolecular and Molecule–Substrate Interactions

The self-assembly of cyano-functionalized triarylamine derivatives on Cu(111), Ag(111) and Au(111) was studied by means of scanning tunnelling microscopy, low-energy electron diffraction, X-ray photoelectron spectroscopy and density functional theory calculations. Different bonding motifs, such as antiparallel dipolar coupling, hydrogen bonding and metal coordination, were observed. Whereas on Ag(111) only one hexagonally close-packed pattern stabilized by hydrogen bonding is observed, on Au(111) two different partially porous phases are present at submonolayer coverage, stabilized by dipolar coupling, hydrogen bonding and metal coordination. In contrast to the self-assembly on Ag(111) and Au(111), for which large islands are formed, on Cu(111), only small patches of hexagonally close-packed networks stabilized by metal coordination and areas of disordered molecules are found. The significant variety in the molecular self-assembly of the cyano-functionalized triarylamine derivatives on these coinage metal surfaces is explained by differences in molecular mobility and the subtle interplay between intermolecular and molecule–substrate interactions