Regensburg 2022 – scientific programme
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O: Fachverband Oberflächenphysik
O 74: Organic Molecules at Surfaces 5: Molecular Switches
O 74.7: Talk
Thursday, September 8, 2022, 16:30–16:45, S054
Proton Transfer in Single Asymmetric Porphycene Molecules — •Simon Jaekel1,2, Jacek Waluk3, and Leonhard Grill1 — 1Department of Physical Chemistry, University of Graz, Austria — 2Chair of Physical Chemistry II, University of Erlangen-Nürnberg (FAU), Germany — 3Polish Academy of Science, Warsaw, Poland
Studying single molecular switches is of interest for a better understanding of fundamental physical and chemical processes, but also in view of their possible use in smart materials and nanoscale applications. It has been shown that switches based on tautomerization, i.e. hydrogen transfer, are especially suited for scanning tunneling microscopy (STM) studies, because the electronic states near the Fermi level are very sensitive to the position of the hydrogen atoms. Experiments on symmetric molecules such as naphthalocyanine [1], tetraphenyl-porphyrin [2], and porphycene [3] showed that the energies of the tautomers are degenerate, barring environmental modulation. Thus, if one is interested in switching processes with preferential switching directions between multiple states, structurally asymmetric molecules are of particular interest.
Here, we report STM results of the tautomerization properties of 22-Oxahemiporphycene, a derivative of porphycene with an asymmetric macrocycle, on a metal surface.
[1] Liljeroth et al. Science, 317 (2007), 1203-1206
[2] Auwärter et al. Nature Nanotechnology, 7 (2011), 41-46
[3] Kumagai et al. Physical Review Letters 111 (2013), 246101