Controlled electron transport through single molecules

Using a first principles approach, we study the electron transport properties of a new class of molecular wires containing fluorenone units, whose features open up new possibilities for controlling transport through a single molecule. We show that the presence of side groups attached to these units leads to Fano resonances close to the Fermi energy. As a consequence electron transport through the molecule can be controlled either by chemically modifying the side group, or by changing the conformation of the side group. This sensitivity, opens up new possibilities for novel single-molecule sensors. We also show that transport can be controlled by tilting a molecule with respect to the electrode surfaces. Our results compare favorably with recent experiments.