Molecule-Driven Substrate Reconstruction in the Two-Dimensional Self-Organization of Fe-Phthalocyanines on Au(110)

The structural patterns formed by molecular self-assembly at surfaces are usually controlled by the relative strengths of the intermolecular and molecule-substrate interactions. An additional steering effect is present when the substrate can easily reconstruct upon molecular adsorption, which therefore drives a self-templating effect on the metal support. This is here demonstrated for the model case of Fephthalocyanine molecules adsorbed on the Au(110) surface. Scanning tunneling microscopy shows that molecular adsorption promotes a local (1 x 5) surface reconstruction, which drives the assembly of molecular chains along the [1 (1) over bar0] direction. The order and periodicity of the molecular assemblies are determined with low energy electron diffraction patterns. Density functional theory calculations reveal the energetic origins of the molecule-driven substrate reconstruction. Since the function of molecular overlayers at surfaces is strongly correlated to their structure, these results have implications in the design of new metal/molecular interfaces.