Experimentelle und computerchemische Untersuchungen von Ruthenium-Acriphos-Komplexen in Wasserstoff-Transfer-Reaktionen

• Experimental and computerchemical investigation of ruthenium-acriphos-complexes in hydrogen-transfer-reactions

Ronge, Meria; Leitner, Walter (Thesis advisor); Liauw, Marcel (Thesis advisor)

Aachen (2020)
Dissertation / PhD Thesis

Dissertation, RWTH Aachen University, 2020

Abstract

The overriding topic of this dissertation is the correlation of computerchemical and experimental methods in homogeneous catalysis. A variety of Ru-PNP-pincer complexes are applied as pre-catalysts in three different hydrogen-transfer reactions. In addition to an experimental optimization, the aim is to uncover and understand reaction mechanisms and calculate the respective catalytic cycles. By comparison of experimental and computerchemical results, an evaluation of the computerchemical method in respect to the prediction of catalyst activities is performed. This contributes to the assessment of the reliability of the computerchemical method, which might be the foundation of further work in the field of predictive computation in homogeneous catalysis. The long-term goal is to predict the effects of electronic and steric modifications in catalysts in respect to their activity and selectivity. The reactions optimized in the course of this thesis differ from each other in the way of complexity, wherein product diversity and side reactions are the most prominent aspects: While the hydrogenation of CO2 in the presence of triethylamine to formate presents a relatively limited product variety, the complexity of the reactions in the ensuing chapters rises respectively. Already the hydrogenation of benzonitrile poses the difficulty of yielding the primary and secondary amine beside the imine and other side-products. Lastly, the hydrogen transfer reaction in the silylation of 4-methylpyridine shows a variety of products and also a more complex set of reactants, which poses a greater challenge in the computational work as well as the applied analysis of the reaction. An Evaluation of the reliability of the results of each reaction allows for an assessment of the applicability of the computerchemical method in comparable experiments.