In the context of the ecological transformation of the today's economy, the concept of catalysis plays a pivotal role. It is considered to be a "key technology for rapid introduction of renewable energy" , a "workhorse" for the defossilization of the energy system, a "primary tool for achieving all of the 12 principles of green chemistry" and a "pillar of chemical industry to reach the sustainability of the society" . Apart from the customary classification between heterogeneous and homogenous catalysts, there has been a growing recognition of the vital link between both research fields. The evolvement of the latter one, the catalytic application of transition metal complexes, is strongly accompanied by the evolution of diverse ligand types and structures.