We have a great passion for the development of new catalytic procedures and the design of hetero-sequenced functionalized cavities. Our current research focuses in particular on the development of organic or metal-organic cage compounds that are suitable ligands for first row transition metals. The cage design aims thereby to mimic the ligand sphere of active sites of prominent enzymes. Those bio-inspired transition metal-complexes are investigated for their abilities to activate and transform small molecules such as H2, CO2 and N2. In addition, cage complexes are also investigated for their potential to catalytically oxidize organic substrates in a size-selective manner.