The adsorption of a new molecule constituted of a 3.7-nm long conjugated board equipped with eight lateral legs was studied with scanning tunneling microscopy on the Cu(100) and nanostructured Cu(111) surfaces. The conformation of the adsorbed molecules was extracted by comparing experimental images with calculated ones. In particular, we demonstrate that not only are the legs free to rotate, but also that the central board is distorted at doubles steps. The van der Waals interaction of the conjugated board with the metallic surface is shown to be responsible for the deformation of the molecules.

• Received 22 March 2002

DOI:https://doi.org/10.1103/PhysRevB.66.075410