Sascha Gehrke, a PhD student of the International Max Planck Research School IMPRS-RECHARGE has recently published together with Dr. Oldamur Hollóczki (Mulliken Center for Theoretical Chemistry, University of Bonn) in the Wiley journal Chemistry-A European Journal and was invited to highlight his research by designing the front page of the issue.
In the article entitled: Hydrogen Bonding of N-Heterocyclic Carbenes in Solution: Mechanisms of Solvent Reorganization, the researchers use molecular dynamics simulations to show that the exchange of hydrogen bond partners at the active centre of N-heterocyclic carbenes can take place in two different ways. Less basic carbene therefore follow a dissociative path with a free carbene species. This means that the bond to the old partner first separates before a bond is formed with a new partner, which means that the carbene is temporarily unbound in the solution. Basic carbenes, on the other hand, prefer an associative route with a three-body arrangement in which the carbene forms two hydrogen bonds with different partners simultaneously. The results require a re-evaluation of the concept underlying the interpretation of H/D exchange experiments, i.e. experiments based on the exchange of the hydrogen atom at the active centre for a deuterium atom. The change of the hydrogen bond partner investigated in the article is assumed to be a speed-determining step. Furthermore, the results open up new perspectives for the development and optimization of organocatalyst systems.
After the recent publication (How to Harvest Grotthuss Diffusion in Protic Ionic Liquid Electrolyte Systems) of another highlighted article, in a Special Issue: Interfacing Theory and Experiment, of ChemSusChem by Sascha Gehrke in cooperation with Johannes Ingenmey and Prof. Barbara Kirchner, this article is already the second cover contribution of this student to a Wiley magazine in the last months.
More about the highlighted research can be found in the original publications:
Gehrke, S., Hollóczki, O. (2018). Hydrogen Bonding of N‐Heterocyclic Carbenes in Solution: Mechanisms of Solvent Reorganization, Chem. Eur. J. 24(45), 11594-11604. https://doi.org/10.1002/chem.201802286
Ingenmey, J., Gehrke, S., Kirchner, B. (2018). How to harvest Grotthuss diffusion in protic ionic liquid electrolyte systems. ChemSusChem 11(12), 1900-1910. https://doi.org/10.1002/cssc.201800436