New Oxidation Catalysts Comprising Mesoionic Carbenes as Potentially Cooperative Ligands

• Applicant: Dr. Monika Lindner
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2011 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 202054744

In this research project I aim at developing new methods for the mild oxidation of organic compounds such as alcohols and alkanes, in particular of CO and CH bonds. For this purpose, new catalytic systems will be synthesized comprising redox-active ruthenium, iridium, and rhodium centers coordinated by new N-heterocyclic carbene ligands. These so-called abnormal carbenes show unique bonding properties due to a pronounced mesoionic character of the ligand which means that positive and negative partial charges are accommodated in the same heterocycle. This mesoionic character enables the ligand to respond to the electronic demand of the metal center important for oxidation catalysis. The new compounds will be investigated with respect to the potentially cooperative participation of the ligand in the catalyzed reaction. In this so-called bifunctional catalysis the ligands interact cooperatively with the metal center to facilitate the reaction which will be studied by mechanistic investigations. The ruthenium complexes will be examined as catalysts for the oxidation of alcohols, the iridium and rhodium complexes as catalysts for the functionalization of alkanes. Previous work in the group of Prof. Albrecht showed that complexes comprising abnormal carbenes as a class of mesoionic ligands feature remarkable properties, which are particularly powerful for oxidation catalysis, allowing for example to oxidize water to oxygen. Catalytic methods for the oxidation of alcohols and hydrocarbons under mild conditions are of great relevance for the pharmaceutical industry as well as for a better utilization of fossil fuel feedstocks (energy production) in terms of higher (atom-)economy and lower waste generation through an improved use of current resources.

• DFG Programme: Research Fellowships
• International Connection: Ireland
• Host: Professor Dr. Martin Albrecht