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The catalytic hydrogenolysis of esters to the two corresponding alcohols is a difficult transformation, since esters are very stable compounds. Therefore, the development of suitable homogeneous catalysts is very challenging. One of the current focuses in our group is the preparation of ruthenium complexes bearing tridentate ligands which consist of N-Heterocyclic Carbenes (NHCs) functionalized with phosphines. Upon coordination to transition metals, these ligands give the resulting metal complex stability and electron density that is needed for the formation of hydride species. Hydride species are important intermediates in the catalytic cycle of hydrogenolysis and hydrogenation reactions. The aim of this project is to develop ruthenium complexes bearing bidentate NHC ligands functionalized with phosphines or amines (see Figure 1) as an extension to the tridentate ligands. The amine functionalities are chosen as donor group because this group has shown to enable bifunctional mechanisms in hydrogenation reactions. The NH-group allows ‘outer sphere’ mechanisms through metal-ligand bifunctional catalysis, where the substrate does not have to bind to the metal centre. Figure 1: ligands used in this project Ligand CNHC-PPh2 and ligand CNHC-NH2 are complexated to ruthenium successfully and characterized by NMR and mass spectroscopy. The preparation of ruthenium complexes bearing ligand CNHC-NHtBu was troublesome and not accomplished. The two complexes are applied in the hydrogenation of acetophenone of which complex CNHC-NH2 showed good results. Complex CNHC-PPh2 gave a negligible conversion to 1-phenylethanol. Moreover, catalysis with in situ prepared catalysts was performed. Some of the in situ generated catalysts gave good conversions to the alcohol but the catalysts were less active compared to similar catalysts from literature.