Highly-effective gating of single-molecule junctions: an electrochemical approach.

We report an electrochemical gating approach with ~100% efficiency to tune the conductance of single-molecule 4,40-bipyridine junctions using scanning-tunnelling-microscopy break junction technique. Density functional theory calculation suggests that electrochemical gating aligns molecular frontier orbitals relative to the electrode Fermi-level, switching the molecule from an off resonance state to ''partial'' resonance. [ABSTRACT FROM AUTHOR]