Entwicklung von Übergangsmetallkomplexen mit neuartigen Pyrazol-NHC- und Pyridazin-NHC-Hybridliganden (English shop)

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N-heterocyclic carbenes (NHC) constitute a widely used ligand class with many advantages. NHC complexes of various transition metals bearing additional chelating donor functions have attracted much interest in the past and have shown great potential in catalytic applications.

Following C,N-chelate complexes known from the literature, several related CNNC ligand systems were developed in this work, in which two NHC units are bridged, for example, by pyrazole or pyridazine. These pyrazole-NHC and pyridazine-NHC hybrid ligands were used to prepare novel transition metal NHC complexes, in particular with the metals palladium, silver and mercury. The focus was on the synthesis and characterisation of the compounds, experiments on their stability, and comparative investigations of solid-state and solution structures. In the case of palladium, highly preorganised bimetallic complexes were obtained which may exhibit cooperative effects during substrate conversion. Some of the palladium complexes developed here were therefore examined in exploratory experiments regarding their suitability as (pre)catalysts in various reactions.