Azobenzene switches as tools to investigate molecular interactions

Hermann A. Wegner / Justus-Liebig-Universität, Giessen, Germany

March 16, 2023


The experimental investigation of molecular interactions bears a great challenge despite its importance in all areas of molecular science. Especially small interactions, such as London dispersion, the attractive part of the van der Waals forces, are difficult to quantify as they are usually low in energy.[1] Nevertheless, these forces are omnipresent in any interaction of two molecular entities and can be decisive for structure and properties especially in large molecules. In the past years we have established the azobenzene switch as a powerful tool to characterize London dispersion interactions of different molecular entities.[2] Recently, we could show, that there is a subtle interplay between intramolecular interactions, the flexibility of the attached groups as well as the interaction with solvent molecules.[3,4] The insights will serve as a basis to reliably utilize London dispersion as design element for functional materials, catalysis or other chemical processes.[5]



[1] Strauss, M. A.; Wegner, H. A. Eur. J. Org. Chem2019,  295.

[2] Schweighauser, L.; Strauss, M. A.;  Bellotto, S.; Wegner, H. A. Angew. Chem. Int. Ed2015, 54, 13436.

[3] Strauss, M. A.; Wegner, H. A. Angew. Chem. Int. Ed2019, 58,18552.

[4] Strauss, M. A.; Wegner, H. A. Angew. Chem. Int. Ed. 2021,60, 779.

[5] Di Berardino, C.; Strauss, M. A.; Schatz, D.; Wegner, H. A. Chem. Eur. J. 2022, 28, ASAP: e2021042.

Hermann A. Wegner

Hermann A. Wegner studied chemistry in Göttingen, Boston and Stanford. He received his PhD under the supervision of Prof. Dr Armin de Meijere before pursuing postdoctoral studies in the group of Sir Prof. Dr Jack Baldwin at Oxford, where he was also appointed as a stipendiary lecturer at Merton College. He started his independent career at Basel University and moved in 2013 to his current position as Professor of Organic Chemistry at the Justus-Liebig-University, Giessen, where he is currently the Executive Director of the Institute of Organic Chemistry and a member of the board of directors of the Center for Materials. His research interests are in the area of physical organic chemistry for molecular materials, including bidentate Lewis acid catalysis, novel boron–nitrogen materials, molecular switches, unusual aromatics and their supramolecular chemistry, organic on-surface synthesis and energy management with organic molecules.“[6]

[6] Kohrs, D.; Volkman, J.; Wegner, H. A. Chem. Commun., 2022, 58, 7483.