Regensburg 2019 – scientific programme
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O: Fachverband Oberflächenphysik
O 3: New Methods and Developments I: Scanning Probe Techniques
O 3.6: Talk
Monday, April 1, 2019, 11:45–12:00, H5
Nature of binding in planar halogenbenzene assemblies and their possible visualization in scanning probe microscopy — •Aurelio Gallardo1, Jindrich Fanfrlík2, Pavel Hobza2, and Pavel Jelínek1 — 1FZU of the CAS, Prague, Czech Republic — 2IOCB of the CAS, Prague, Czech Republic
High-resolution scanning probe imaging of molecular structures on surfaces with functionalized tips provided the unprecedented spatial resolution. However, the origin of intermolecular features in high-resolution images of molecular assemblies is still under debate. Originally, such features were considered as a direct observation of weak non-covalent bonds between molecules. Nevertheless, this interpretation was challenged and ascribed to an experimental artefact. To address this long-standing controversy, we provided theoretical analysis of intermolecular interaction and high-resolution imaging of halogen substituted benzenes assemblies deposited on metallic substrate, which was extensively studied experimentally. First, we show that formation of molecular assemblies made of C6Br6 and C6F6 on surfaces is driven by interplay between halogen and dispersive interaction. Next, for the C6Br6 and C6F6 assemblies on surface we analyze simulated high-resolution IETS and AFM images acquired with a CO-tip. Very good agreement with the experimental evidence allows us to unambiguously determine the origin of the sharp edges. We discuss, why such sharp features should not be interpreted as the direct evidence of the signature of weak non-covalent bonds.
Gallardo et al., J. Phys. Chem. C, DOI:10.1021/acs.jpcc.8b09631