As counterpart to photocatalytic proton reduction, catalytic water oxidation with molecular complexes is another part of our dedication to sustainable chemistry. We are interested here in new complexes and the structural modification of known compounds in such a way that they can be immobilized into the pores of different supports, like metal-organic frameworks. The synthetic and catalytic work is complemented by mechanistic studies to understand the working principle of these new systems. In addition we focus on the invention and determination of novel energy materials, that can be used for batteries for example. The analysis is performed by advanced X-ray spectroscopy methods.