Im Folgenden werden die Schwerpunkte unserer aktuellen Forschung dargestellt. (nur in Englisch verfügbar)
Our current research is directed towards the development of new N-heterocyclic carbenes (NHCs). Our special interest is focused on electron poor NHCs that are able to exert a significant degree of π-acceptor character when coordinated to transition metal centres. This propensity for π-backbonding has been neglected for a long time and is not observed for standard NHCs like N-arylimidazolylidenes.
In addition to sketching down appealing new structural motifs on a piece of paper our work usually requires multistep organic syntheses to access suitable carbene precursors which can be converted to appropriate NHC derivatives upon deprotonation and scavenging the in situ-formed NHC with trapping reagents.
The electronic properties of the new NHCs are derived from spectroscopic (NMR, IR) and structural (X-ray diffraction) data. For example, we have developed a method for the assessment of the π-acidity of NHCs by recording the 77Se NMR shifts of their selenium adducts. Increasing π-acidity is accompanied by a low-field shift of the 77Se NMR resonance.
1 M. Jonek, J. Diekmann, C. Ganter, Chem. Eur. J. 2015, 21, 15759-15768. externer Link in neuem Fenster
2 T. Hölzel, M. Otto, H. Buhl, C. Ganter, Organometallics 2017, 36, 4443-4450. externer Link in neuem Fenster
3 S. Appel, P. Brüggemann, C. Ganter, Chem. Commun. 2020, 56, 9020-9023. externer Link in neuem Fenster
4 P. Brüggemann, M. Wahl, S. Schwengers, H. Buhl, C. Ganter, Organometallics 2018, 37, 4276-4286. externer Link in neuem Fenster
5 A. Liske, K. Verlinden, H. Buhl, K. Schaper, C. Ganter, Organometallics 2013, 32, 5269-5272. externer Link in neuem Fenster
We are also interested in luminescent NHC-copper complexes, especially those with a linear coordination environment around the Cu atom. We aim at a detailed understanding of the factors determining emission wavelength, quantum efficiency and radiative lifetimes, to name but a few. A multidisciplinary and collaborative approach is followed where synthesis and the experimental determination of photophysical properties are complemented by high-level quantum theoretical calculations – which in turn stimulate the syntheses of new structures with (hopefully) improved performance.