Abstract

The in situ observation of geometrical and electronic structural dynamics of a single molecule junction is important in molecular electronics. Observations of single molecular junctions are difficult, however, because of sensitivity limits. In this seminar, we report surface-enhanced Raman scattering (SERS) of a single 4,4'-bipyridine molecule in a nano-gap. Significant changes in SERS intensity, energy (wavenumber), and selectivity of Raman vibrational bands that are coincident with current fluctuations provide information on distinct states of electronic and geometrical structure of the single molecule junction in solution at room temperature.