HYP*MOL colloquium with Johannes F. Teichert + network barbecue afterwards

On July 5, 2024, the HYP*MOL Colloquium will take place in Chemnitz (Reichenhainer Straße 90, room N113) at noon. Prof. Dr. Johannes F. Teichert (Chemistry University of Technology, Organic Chemistry) will talk about Neutral homoaromatic hydrocarbons as potential chiroptical switches. Coffee and sandwiches will be available before. Everyone is welcome!

The lecture and discussion will be followed by the HYP*MOL network barbecue. Before the height of summer really gets going, it offers another opportunity to discuss upcoming collaborations. A selection of barbecue food will be available until 15:30.

Homoaromatic molecules show characteristics of aromatic stabilization even though the cyclic conjugated π-system is interrupted by an sp³-carbon- or heteroatom. The concept of homoaromaticity hinges on the interaction between the disconnected π-system via through-bond or through-space homoconjugation. This has been highly controversial in the past due to the difficulty to identify clear criteria for the assignment of molecules as homoaromatic. Homoconjugation and homoaromaticity have mainly been observed and studied in anionic or cationic molecules, whereas examples for neutral homoaromatics have remained rare. [1] We recently reported the synthesis and characterization of a new class of neutral and stable homoaromatic compounds, homoannulenes such as 1 and have provided compelling evidence for their unusual electronic structure. [2,3] Furthermore, we showed that the 6π homoannulene 1 is photoswitchable to a 10π homoaromatic compound 2 through a reversible photochemical [1,11]-sigmatropic rearrangement, introducing a novel structural scaffold for molecular switches. [2,4] In this presentation, I will discuss possible applications of chiral homoannulenes as potential multi-state chiroptical switches. [5] This would allow for a light-controlled editing of chirality in the homoannulene scaffold. Additionally, we believe that this research could have implications for potential data storage on a molecular level.

[1] R. V. Williams, Chem. Rev. 2001, 101, 1185.
[2] T. Tran Ngoc, N. Grabicki, E. Irran, O. Dumele, J.F. Teichert, Nat. Chem. 2023, 15, 377.
[3] T. Tran Ngoc, J. van der Welle, T. Rüffer, J.F. Teichert, Synthesis 2023, 55, 2658.
[4] a) B.L. Feringa, W.R. Browne (Eds.), Molecular switches, 2nd Ed., Wiley-VCH, Weinheim, 2011;
b) Z.L. Pianowski (Ed.), Molecular Photoswitches, Wiley-VCH, Weinheim, 2022.
[5] B.L. Feringa, R.A. van Delden, N. Koumura, E.M. Geertsema, Chem. Rev. 2000, 100, 1789.