The Joshua Jortner Distinguished Lectures in Chemistry
Wilson Ho
University of California, Irvine
"SINGLE MOLECULE CHEMISTRY INDUCED BY
INELASTIC ELECTRON TUNNELING"
Chemical Physics Lecture: 30 April 2015
Electron-vibrational coupling underlies numerous chemical processes and
constitutes a pathway to the control of chemistry. This coupling provides a
mechanism to activate motions of atoms in a molecule that can result in the breaking
and making of chemical bonds. The operational basis for the scanning tunneling
microscope (STM) involves the tunneling of electrons between the tip and a substrate
that can be adsorbed with molecules. The tunneling current is spatially confined to
atomic dimensions. Furthermore, inelastic electron tunneling can occur and provide a
pathway for transferring energy to the molecule. This inelastic process can induce
elementary excitations (vibration, rotation, and spin), fluorescence and plasmonic
light emission, conformational changes, and chemical reactions of single molecules. It
is also possible to discover previously unresolved properties of molecules, such as the
spin properties for molecules without unpaired electrons, or gain nanoscale
perspectives of macroscopic processes such as mechanochemistry. Inelastic electron
tunneling STM enables the probing of chemistry that could be revealed and
understood by studying single molecules.