Room temperature manipulation of self-organised supramolecular nanostructures with a scanning tunnelling microscope

We have investigated the controlled manipulation of molecules located within self-organised supramolecular nanostructures on a surface with the scanning tunnelling microscope (STM). Self-assembled strips of zinc porphyrin molecules ∼10 nm wide and hundreds of nanometers long are formed by deposition from solution onto the surface of graphite. The STM tip is used to clear a break in such a strip by sliding the molecules laterally across the surface. We find that the direction of molecular translation is constrained by the intermolecular forces within the supramolecular array, which define preferred directions for molecular slip, and not simply by the direction of tip scanning.