TY - JOUR A1 - Mielke, Johannes A1 - Martınez-Blanco, J. A1 - Peters, M. V. A1 - Hecht, S. A1 - Grill, L. T1 - Observing single-atom diffusion at a molecule-metal interface JF - Physical Review B N2 - The dynamics at the interface between a close-packed porphyrin monolayer and Au(111) is investigated by time-dependent scanning tunneling microscopy, detecting the motion of single-interface adatoms in real space. Imaging sequences reveal predominant switching of the molecular appearance in adjacent molecules, pointing to a spatial correlation that is consistent with adatom diffusion from one molecule to the next. In some cases, the number of switching molecules is drastically increased, indicating collective switching events. In addition to the thermally induced motion of adatoms at the interface, also voltage pulses from the microscope tip can induce the process—revealing different yields in agreement with the model of adatom hopping. KW - STM KW - molecular switch KW - single molecule KW - switching dynamics KW - porphyrin KW - Au(111) PY - 2016 UR - http://journals.aps.org/prb/abstract/10.1103/PhysRevB.94.035416 DO - https://doi.org/10.1103/PhysRevB.94.035416 VL - 94 IS - 3 SP - 035416-1 EP - 035416-7 PB - American Physical Society AN - OPUS4-37177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mielke, Johannes A1 - Hanke, F. A1 - Peters, M.V. A1 - Hecht, S. A1 - Persson, M. A1 - Grill, L. T1 - Adatoms underneath single porphyrin molecules on Au(111) JF - Journal of the American chemical society N2 - The adsorption of porphyrin derivatives on a Au(111) surface was studied by scanning tunneling microscopy and spectroscopy at low temperatures in combination with density functional theory calculations. Different molecular appearances were found and could be assigned to the presence of single gold adatoms bonded by a coordination bond underneath the molecular monolayer, causing a characteristic change of the electronic structure of the molecules. Moreover, this interpretation could be confirmed by manipulation experiments of individual molecules on and off a single gold atom. This study provides a detailed understanding of the role of metal adatoms in surface–molecule bonding and anchoring and of the appearance of single molecules, and it should prove relevant for the imaging of related molecule–metal systems. PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-324144 UR - http://pubs.acs.org/doi/pdf/10.1021/ja510528x DO - https://doi.org/10.1021/ja510528x SN - 0002-7863 SN - 1520-5126 VL - 137 IS - 5 SP - 1844 EP - 1849 PB - American Chemical Society CY - Washington, DC AN - OPUS4-32414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -