A New Mechanism of Atomic Manipulation: Bond-Selective Molecular Dissociation via Thermally Activated Electron Attachment
journal contributionposted on 28.12.2010, 00:00 by Sumet Sakulsermsuk, Peter A. Sloan, Richard E. Palmer
We report a new mechanism of (bond-selective) atomic manipulation in the scanning tunneling microscope (STM). We demonstrate a channel for one-electron-induced C−Cl bond dissociation in chlorobenzene molecules chemisorbed on the Si(111)-7 × 7 surface, at room temperature and above, which is thermally activated. We find an Arrhenius thermal energy barrier to one-electron dissociation of 0.8 ± 0.2 eV, which we correlate explicitly with the barrier between chemisorbed and physisorbed precursor states of the molecule. Thermal excitation promotes the target molecule from a state where one-electron dissociation is suppressed to a transient state where efficient one-electron dissociation, analogous to the gas-phase negative-ion resonance process, occurs. We expect the mechanism will be obtained in many surface systems, and not just in STM manipulation, but in photon and electron beam stimulated (selective) chemistry.
Read the peer-reviewed publication
chlorobenzene molecules chemisorbedelectron beamsurface systemsThermal excitationdissociationThermally Activated Electron AttachmentWe reportmechanismNew Mechanismphysisorbed precursor statesSTM manipulationAtomic Manipulationtarget moleculeenergy barrierroom temperaturescanning tunneling microscope