Low temperature scanning tunneling microscopy (LT-STM) experiments on molecules permit a deeper insight into the quantum electronics of molecular systems and provide important information on the conformational and mechanical properties of single complex molecules.

Several methods have been developed in the last years to manipulate molecules using STM, including lateral, vertical, and electrical induced manipulation. In this talk, experiments will be reviewed, where the manipulation process can be controlled by varying one of three main parameters: the electric field, the tunneling current and the forces between tip and surface. In this way, molecules can be exactly positioned on a metal surface and conformational changes can be induced.

Moreover, the electrically controlled manipulation of supramolecular structures will be presented, showing that a structure can be moved collectively in a controlled way. Depending on the applied voltage, several types of movements (translation, rotation, reorganization) of a structure comprised of four 4-Acetylbiphenyl molecules on Au(111) are achieved. By applying consecutive pulses, the structure can be manipulated over larger distances in defined directions. The experiments show a novel possibility to softly and purely electrically manipulate nanostructures on metal surfaces in view of assembly nanoscale devices.