Inhaltspezifische Aktionen

AG Prof. Dr. Schirmeisen


    LOEWE Schwerpunkt "Principles of On-Surface Synthesis"

AG Prof. Dr. Schirmeisen - Neu



03/2022 "Bond imaging by torsional Eigenmode Force Microscopy"

We analyzed the suitability of qPlus sensors, which are commonly used for such studies, for the application of modern multifrequency AFM techniques. Two different qPlus sensors were tested for submolecular resolution imaging via actuating torsional and flexural higher eigenmodes and via bimodal AFM. The torsional eigenmode of one of our sensors is perfectly suited for performing lateral force microscopy (LFM) with single bond resolution.
Artistic image was chosen to be cover image of the journal Nanoscale 14 (2022): D. Martin Jimenez et al., Nanoscale 14 (2022) 5329 (link to article)

Blick ins Labor:
Neugierig wie es in den Laboren aussieht? Einen virtuellen Blick in die Labore der Arbeitsgruppe findet ihr hier:

09/2021 "Handmade Nanoarchitectures":

In a recent paper in Nature Chemistry we show how to build nanostructures using individual organic molecules one by one with an atomic force microscope. This opens the path to prototyping of new molecules structures, otherwise impossible to fabricate.

Q. Zhong, A. Ihle, S. Ahlers, H.A. Wegner, A. Schirmeisen, D. Ebeling "Constructing covalent organic nanoarchitectures molecule by molecule via scanning probe manipulation" Nature Chemistry (2021) (link to article)

In a recent article in Physical Review Letters we investigated atomic wear processes with the diamond tip of a friction force microscope. Depending on the temperature, wear tracks will simply obey arrhenius kinetics, or form regular ripples, as a results of complex interplay of bond breaking, surface diffusion and atomic rearrangement.
More details in W. Wang, D. Dietzel and A. Schirmeisen "Thermal Activation of Nanoscale Wear", Physical Review Letters 126 (2021) 196101 (link to article)

12/2020 "PriOSS":

LOEWE Focus project "PriOSS - principles of on-surface synthesis" is funded by the state of Hesse from 2021 to 2024 with 4.2 Mio EUR, with 8 partners from the universities of Giessen and Marburg. Goal is the decryption of molecular mechanisms that underly on-surface reaction processes of organic molecules.         

03/2020 "Superconductivity meets Nanofriction": Superconductivity is well-known to change electric resistance to zero, but why shoud it have any influence on friction? Our recent work in Science Advances shows that the sliding friction of a nanocontact on a BSCCO is reduced by 20% when crossing the superconductivity transition temperature. Friction is a complex superposition of different contribution, here we can pinpoint electronic friction to play a sizeable role.
W. Wang, D. Dietzel and A. Schirmeisen "Single-asperity sliding friction across the superconducting phase transition", Science Advances 6 (2020) eaay0165 (link to article)

10/2019 "Elusive cousins of graphene": In a cooperation with the Universities of Marburg, Oldenburg and Erlangen-Nürnberg a new 2D graphene allotrope was created by on-surface synthesis techniques. This material contains odd-numbered rings, and is predicted to possess unusual (opto)electronic properties. See also feature article in Nature Research Highlights.

Q. Fan, D. Martin-Jiminez, D. Ebeling, C.K. Krug, L. Brechmann, C. Kohlmeyer, G. Hilt, W. Hieringer, A. Schirmeisen, and J. M. Gottfried "Nanoribbons with Non-Alternant Topology from Fusionof Polyazulene: Carbon Allotropes Beyond Graphene", JACS 141 (2019) 17713 (link to article)

5/2019 "3D Imaging of Molecular Bonds": Our group has expanded the chemical bond imaging method to assess the 3D structure of organic molecules. In D. Martin-Jimenez et al., Physical Review Letters 122 (2019) 196101 (link to article) we report the successful combination of tunneling current feedback with CO-tip force sensing to determine the chemical structure and orientation of 2-iodotriphenylene.
News coverage: APS Physics viewpoint, Nature Research Highlights, Physics World

2/2019: Selectivity is a key parameter for building customized organic nanostructures via bottom-up approaches. Therefore, strategies are needed, which allow connecting molecular entities at a specific stage of the assembly process in a chemoselective manner. Studying the mechanisms of such reactions is the key to apply these transformations for the build-up of organic nanostructures. In a collaboration with Prof. Wegner (JLU), Prof. Mollenhauer (JLU) and Prof. Chi (Soochow University, China) we show the selective dehalogenation of 4-bromo-3-iodo-p-terphenyl on the Cu(111) surface using bond imaging atomic force microscopy.
D. Ebeling et al. "Adsorption Structure of Mono- and Diradicals on a Cu(111) Surface: Chemoselective Dehalogenation of 4-Bromo-3''-iodo-p-terphenyl", ACS Nano 13 (2019) 324


12/2018: New 3-year DFG project granted, which aims to unravel the "Molecular mechanisms of C-C coupling: A microscopic view into the on-surface chemical bonding processes". This is an interdisciplinary joint project together with Prof. Herman Wegner (organic chemistry, JLU) and Prof. Doreen Mollenhauer (physical chemistry, JLU).

8/2018: Site-selective functionalization of only one of two identical chemical groups within one molecule is highly challenging, which hinders the production of complex organic macromolecules. In cooperation with Prof. Lifeng Chi's group at Soochow University, China, we demonstrate that adsorption of 4,4″-diamino-p-terphenyl on a metal surface leads to a dissymmetric binding affinity. With low temperature atomic force microscopy, using CO-tip functionalization, we reveal the asymmetric adsorption geometries of 4,4″-diamino-p-terphenyl on Cu(111), while on Au(111) the symmetry is retained. For details see article: Q. Zhong, D. Ebeling, J. Tschakert, Y. Gao, D. Bao, S. Du, C. Li, L. Chi, A. Schirmeisen, "Symmetry breakdown of 4,4″-diamino-p-terphenyl on a Cu(111) surface by lattice mismatch" Nature Communications 9 (2018) 3277 (link to article)

6/2018: Ever since Louis Pasteur’s ground-breaking research we know today that molecular chirality plays an important role in our everyday life because enantiomers (i.e., mirror images) of the same molecules can interact with living organisms in completely different ways. Many chirality related phenomena, in particular, the underlying molecular recognition mechanisms, are still not well understood. This is because it is difficult to study chirality at the level of individual molecules.  In our study together with Prof. Schreiner’s group at JLU we are using low temperature atomic force microscopy (AFM) to image individual [123]tetramantane molecules on a copper surface. Our approach represents a new toolset for studying molecular recognition that can enlighten ourunderstanding about the role of chirality in nature. Ebeling, Sekutor, Stiefermann, Tschakert, Dahl, Carlson, Schirmeisen, Schreiner,
Assigning the absolute configuration of single aliphatic molecules by visual inspection"
Nature Communications 9 (2018) 2420 (link to article) see also this blog