Principal Research Interests

The research interests of the Breher group centre around the synthesis, structure, bonding and reactivity of organometallic and coordination compounds of Main Group element clusters/cages and transition metal and f-element complexes. All activities are based on a strong experimental background. Spectroscopic techniques including cyclic voltammetry, EPR spectroscopy, and advanced NMR methods as well as density functional theory calculations are also of interest.

Upon contacting FB - preferably by Email - further details concerning the research projects as well as open positions (Vertiefungspraktikum, Diploma thesis, Ph.D. or postdoc) are available.

Ambidentate ligand systems

Some activities of our research group concentrate on Main Group element or d-block transition metal complexes of novel ambidentate ligand systems comprising dual functionality. These ligands are usually based on a tripodal shape and have additional Lewis-basic coordination sites in the backbone coupled with chelating donors to produce either intra- or intermolecular coordinating systems. Particular interest in this class of ligands arises from the possibility to form heterobimetallic (or multinuclear) complexes consisting of metal atoms arranged in close spatial proximity. Our main research activities in this area are focused on:

• Organometallic and coordination chemistry of tris(pyrazolyl)methanides (^RTpmd) (performed in part in collaboration with Prof. Philip Mountford, Oxford, UK).
• Group 14 element pyrazolyl compounds and their coordination chemistry
• Determining communication pathways between redox-active transition metal centres
• Molecular presursors for the synthesis of functional metallooligomers and polymers
• Tailored ligands for the stabilisation of small inorganic clusters

Main Group element chemistry

Fundamental studies of academic interest are pursued in the field of organometallic Main Group chemistry, in particular, Group 14 element cluster compounds such as [1.1.1]metallapropellanes. Although numerous quantum chemical calculations have been performed for these and related systems, synthetically accessible and structurally characterised species are very rare; experimental studies on the reactivity of metallapropellanes are still at its infancy. Our goal is to better understand fundamental aspects of the bonding within these biradicaloids and to relate this with their reactivity. Current research focuses on:

• Synthesis and reactivity of Group 14 element metallapropellanes
• Theoretical investigation of the bonding and the amount of biradicaloid character (close collaboration with our colleagues in the theoretical chemistry)
• Attempts to prove the biradicaloid behaviour and to use these and related clusters for homolytic bond activations

Development of Multidentate Ligand Systems

The recently initiated research concerning multidentate ligand systems focuses on robust and easily accessible systems consisting of diverse donor functionalities. Promising ligands are employed in various areas addressing a wide range of disciplines, from fundamental bonding concepts to technically relevant processes. Activities on the stability, reactivity, and solution behaviour of f-element coordination compounds are performed in close collaboration with the INE, FZK.