Mo­ti­va­ti­on, Re­se­arch & Group Life

We have proposed and demonstrated how to tame diradicals and Moebius-cumulenes with carbenes for application in singlet-fission, alleged technology of future solar cells with unrivaled quantum efficience, and two-photon absorption, key  for biomedical imaging and signal transmission. Similarly, we explored what renders carbene-radicals (i) persistent toward disproportionation and (ii) generally thermodynamically stable.  Current work is dedicated to both areas as well as rendering organic radicals, commonly highly air-sensitive, sufficiently stable for practical applications. In a side project, we have discovered bright luminescent complexes of s-block (!) metals.  Joint-work with the Bertrand group presented the first isolable secondary C-radical.

We have a long-standing interest in the mechanistic intricacies of late transition metal catalysis.  Using a large variety of physical-organic and physical-inorganic techniques, we have shown how Pd(0) complexes may oxidatively add amines, alcohols, CC bonds, and water, previously though to be unfeasible.  Our findings suggest how to achieve additive-free and thus "green" cross-coupling catalysis. We furthermore propose anti-Dewar-Chatt-Duncanson umpolung by palladium(0) for Lewis-base activation of olefins, arenes and organic carbonyls and demonstrated catalytic CF/CH bond metathesis.

We have a long-standing interest in multiple-bonding “beyond the oxo-wall” and corresponding unusual electronic structures, which allow for the swift activation of strong bonds in redox-catalysis.  Thereby, we have proposed that charge-separation, viz. zwitterionic character in π-systems, is a general motif for bond activations.  We thereby presented the first examples for palladium imides and singlet nitrenes.  Recently, we have direct our attention toward anionic terminal imides of gold(I) and free nitrenes. Further contributions with the Meyer-group include iron- and  cobalt terminal imido complexes as well as nitrenes, and even an iron(VII) (yes, VII!) nitrido-complex.  

We presented a new approach toward synthesizing electron-precise and zerovalent nanoclusters stabilized by bridging phosphinidene ligands.  Current work aims at high-spin congeners, their embedment into metal-organic frameworks, as well as corresponding nanowires (joint work with T. Kraus @INM).

We presented for the first time a persistent (in the cold) triplet carbene stabilized by a Pb(II) substituent.  Accordingly, we contributed the first report of a  bis-oxidized singlet-carbene  together with the Bertrand group.  Currently, we are super-excited about bond activation with Lewis super-acidic Phosporus-based radicals and dications.

We have been involved in the computational analysis of various molecules with intriguing electronic properties.  This includes, among others, an iron(VII) nitride, homoleptic "chiral" uranium complexes, open-shell alkyne complexes of the 3d metals, molybdenum and tungsten silylidynes and their dimers, P₄ activation by silyl stannylenes, molybdenum imido complexes, iron cyclopentadienyl complexes in unusual oxidation states, and  aluminium(I) species for Fischer-Tropsch chemistry.