Mechanistic analogies and differences between gold- and palladium-supported Schiff base complexes as hydrogenation catalysts: A combined kinetic and DFT study

The mechanism of olefin hydrogenation catalyzed by PdII and AuIII Schiff base complexes, both with an analog d8 electronic structure, is analyzed by means of kinetic and computational methods. The computational study is able to explain the differences experimentally observed in relation to the influence of the solvent (polarity and proton donor ability) and of the hydrogen pressure on the AuIII- and PdII-catalyzed reaction mechanisms. These considerations can guide the proper selection of solid supports for heterogenization of catalysts to significantly increase their activity.