  On a gold surface, supramolecules composed of 4-acetylbiphenyl molecules show
structural directionality, reproducibility and robustness to external
perturbations. We investigate the assembly of those molecules on the Au(111)
surface and analyze how the observed supramolecular structures are the result
of weak long-range dispersive forces stabilizing the 4-acetylbiphenyl molecules
together. Metallic adatoms serve as stabilizing agents. Our analysis suggests
new ways of creating complex molecular nano-objects that can eventually be used
as devices or as seeds for extended hierarchical structures.
