3MET: New Collaborative Research Initiative for Excellent Research in Chemistry and Physics
Participants of this new initiative originate from the Technical University of Kaiserslautern and the Karlsruhe Institute of Technology (KIT).
The aim of the initiative is to gain knowledge on "Cooperative Effects in Homo- and Heteronuclear Complexes (3MET)". In total 19 projects will be funded by the DFG. In three major sections cooperative effects will be studied on (a) magnetism, (b) synthesis and catalysis and (c) optical properties and spectroscopy. Possible applications include switchable magnets, highly selective catalysts and functional materials for optical applications.
To gain knowledge groups of two universities will collaborate on this new and hitherto not fully understood research area. First the young and ambitious TU Kaiserslautern and seconf the approved excellent KIT. The collaboration will be performed employing multiple disciplines and departments from a broad range of research areas in experimental and theoretical chemistry which are extended by groups with expertise in experimental and theoretical physics.
The Bräse group engages in section b): synthesis and catalysis.
Find out more under http://www.uni-kl.de/3met.
One topic of our group is the synthesis of geometically fixed, chiral 3MET-complexes and the investigation of their catalytical and optical properties.
Also, we investigate the possible use of these systems in the material sciences (see „KSOP”) and in biological systems. .
Figure 1: With paracyclophane-chemistry, 3MET-systems with catalytically active metal centers can be made.
As ligands, we use functionalized paracyclophane-systems with several donor motives, enabling a defined structural relation of the complexes due to their rigid backbone.
The resulting complexes are tested as multi-metal catalysts and –cooperating with different groups- new materials for optical applications.
Paracyclophane and related Systems
From paracyclophane, it is only a small step to pyridinophane. By variation of the second donor group, many ligands sutiable for homo- and heteronuclear complexes can be made. Depending on the metal, stoichiometry and additional ligands, many 3MET-systems can be made. The catalytic properties of these systems are currently under investigation
Figure 2: From paracyclophanes to pyridinophanes: A modular system for the synthesis of 3MET-complexes has been established.
New Phosphine-ligands and their Application for 3MET-complexes
Figure 3: Complex with one and more metal centers from the d-block are suitable emitting materials for OLEDs.
In the Bräse group, compounds of d-Block-metals are investigated in terms of their suitability for OLEDs. These compounds do work without the often used, but rare and expensive metal iridium. Instead, they base on well-available metals like zinc or copper. With proper ligands, they show efficiencies comparable to the established systems.
Additionally to their optical properties, these systems are versatile catalysts for many application.
Figure 4: With simple, modular systems, nearly every color of the visible spectrum can be generated. Many of the systems also show interesting optical and/or catalytic properties.
3MET goes Chemische Biologie
The interaction of home- and heteronuclear metal complexes with biological systems has not been fully understood. By using fluorescent complexes as model systems, one can find out more about the relevant processes with the help of imaging-techniques like fluorescence microscopy.
Figure 5: A fluorescent complex with two metal centers has been attached covalently on cells with click-chemistry.
 Daniel M. Zink, Tobias Grab, Thomas Baumann, Martin N. Nieger, Ericka. C. Barnes, Wim. Klopper, Stefan. Bräse, Organometallics 2011, 30, 3275–3283.
 S. Ay, R. E. Ziegert, H. Zhang, M. Nieger, K. Rissanen, K. Fink, A. Kubas, R. M. Gschwind, S. Bräse, J. Am. Chem. Soc. 2010, 132, 12899–12905.