Chemistry of single molecules at surfaces

Vibrational excitation of single molecules at surfaces will open an ultimate way of the reaction control in nano-meter scale. Direct excitation along the reaction coordinate coupled with the multiple excitations will lead to molecule-to-molecule chemistry. For the indirect process, anharmonic coupling between the excited vibrational state and the reaction coordinate plays an important role. Action spectrum for cic-2-butene on Pd(110) exhibits low frequency vibrational modes are excited by inelastic tunneling but are not clearly visible in STM-IETS.