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Electronic data accompanying the publication in ChemPhotoChem 2022, e202200052; doi: 10.1002/cptc.202200052.

At the current rate, global warming will render large portions of our planet uninhabitable in the foreseeable future. Therefore, finding a clean and renewable energy source that can replace the current fossil reserve-based industry will be one of the major challenges of the 21st century. A worldwide industry based on solar power seems to be the obvious solution to this problem. The sun provides more than enough energy for our current needs and harnessing that power does not produce any pollutants, in stark contrast to fossil sources. However, current technology is not advanced enough to fully replace conventional energy sources. In the energy sector, solar cells are used to produce electricity, but they are still expensive and lack the required high efficiencies. In other important industries, the required solar powered technologies are still underdeveloped. Among these are important fields such as CO2 reduction, water splitting, or chemical reactions powered by light in general. The products of all these reactions are energy enriched substrates, so-called solar fuels, that can be used in the transport sector or at times when no sunlight is available. Main investigations in these research fields are focusing on precious metal complexes. However, for a global scale application of photocatalyzed reactions, systems based on abundant, inexpensive elements are required. The research presented in this thesis focuses on photoactive metal complexes based on inexpensive first- and second-row transition metal complexes of manganese and molybdenum. The underlying photophysical properties as well as current progress on photoactive first-row transition metal complexes will be discussed in chapter 2 of this thesis. In chapter 3, two new isocyanide complexes of Mn(I) are presented. Both of these air-stable complexes exhibit MLCT luminescence in solution at room temperature. This represents not only the first report on MLCT luminescence from Mn(I) compounds, but these are also among the first examples of any first-row transition metal complex exhibiting MLCT luminescence (apart from Cu(I) complexes, whose electronic structure makes MLCT luminescence easier accessible). Both complexes were successfully employed as photosensitizers in energy and electron transfer reactions. Further interesting photophysical properties of these complexes, as well as their synthesis, will be discussed in this chapter. The two publications presented in chapter 4 provide new insights into the properties and photocatalytic applications of Mo(0) isocyanide complexes. The introduction of bulky groups on the ligands leads to rigidification of the complex and more efficient shielding of the active metal centre from the chemical surrounding. This structural change increases the excitedstate lifetime and the photoluminescence quantum yield by one order of magnitude compared to a previously reported analogue. These enhanced properties, in combination with the high exited state oxidation potential, enable the application of this complex in challenging photoreactions. Chapter 5 provides a brief conclusion on low-valent isocyanide complexes of earth-abundant metals as well as possible future research and improvements in this area. Finally, photoinduced electron transfer in oligo-1,2-naphthylene linked donor-acceptor compounds was investigated. Unusual distance dependencies of the electron transfer rate were found for different lengths of the helical 1,2-naphthylene linker units which can be explained by “shortcuts” through close noncovalent intramolecular contacts (appendix, chapter 6).

Diese Arbeit untersucht einen innovativen Ansatz der Phosphorrückgewinnung aus Klärschlammasche. Dieser besteht darin, den phosphorhaltigen Verbrennungsrückstand bei der industriellen Phosphorsäureherstellung aus Phosphatgestein als Teilsubstitut für den Primärrohstoff einzusetzen (Mitverwertung). Im Fokus steht die Untersuchung der Auswirkungen der Mitverwertung auf die Verfahrensstufe der Calciumsulfat-Filtration. Zentrales Ergebnis der Arbeit ist ein neuartiges verfahrenstechnisches Konzept zur Integration der Aschenmitverwertung in eine industrielle Produktionsanlage, welches die verschiedenen in der Arbeit gewonnenen Erkenntnisse nutzt und Vorteile gegenüber dem Stand der Technik bietet. In this thesis a novel route for phosphorus recycling from sewage sludge ashes is investigated. The approach is to partially substitute phosphate ore with the phosphorus rich incineration residue in the industrial production process for phosphoric acid (co-processing). The implications of the ash co-processing on the process step of gypsum filtration are in the center of the investigation. A central result of this thesis is a novel process concept for implementation of co-processing of sewage sludge in an industrial phosphoric acid plant. The concept utilizes the thesis‘ findings and shows clear advantages over the state of the art.

Diisocyanide ligands with a m-terphenyl backbone provide access to Mo0 complexes exhibiting the same type of metal-to-ligand charge transfer (MLCT) luminescence as the well-known class of isoelectronic RuII polypyridines. The luminescence quantum yields and lifetimes of the homoleptic tris(diisocyanide) Mo0 complexes depend strongly on whether methyl- or tert-butyl substituents are placed in &alpha, position to the isocyanide groups. The bulkier tert-butyl substituents lead to a molecular structure in which the three individual diisocyanides ligated to one Mo0 center are interlocked more strongly into one another than the ligands with the sterically less demanding methyl substituents. This rigidification limits the distortion of the complex in the emissive excited-state, causing a decrease of the nonradiative relaxation rate by one order of magnitude. Compared to RuII polypyridines, the molecular distortions in the luminescent 3MLCT state relative to the electronic ground state seem to be smaller in the Mo0 complexes, presumably due to delocalization of the MLCT-excited electron over greater portions of the ligands. Temperature-dependent studies indicate that thermally activated nonradiative relaxation via metal-centered excited states is more significant in these homoleptic Mo0 tris(diisocyanide) complexes than in [Ru(2,2&prime, bipyridine)3]2+.

Altered oncogene expression in cancer cells causes loss of redox homeostasis resulting in oxidative DNA damage, e.g. 8-oxoguanine (8-oxoG), repaired by base excision repair (BER). PARP1 coordinates BER and relies on the upstream 8-oxoguanine-DNA glycosylase (OGG1) to recognise and excise 8-oxoG. Here we hypothesize that OGG1 may represent an attractive target to exploit reactive oxygen species (ROS) elevation in cancer. Although OGG1 depletion is well tolerated in non-transformed cells, we report here that OGG1 depletion obstructs A3 T-cell lymphoblastic acute leukemia growth in vitro and in vivo, validating OGG1 as a potential anti-cancer target. In line with this hypothesis, we show that OGG1 inhibitors (OGG1i) target a wide range of cancer cells, with a favourable therapeutic index compared to non-transformed cells. Mechanistically, OGG1i and shRNA depletion cause S-phase DNA damage, replication stress and proliferation arrest or cell death, representing a novel mechanistic approach to target cancer. This study adds OGG1 to the list of BER factors, e.g. PARP1, as potential targets for cancer treatment. S.R.P.'s laboratory is partially funded by funds from the Spanish National Research and Development Plan, Instituto de Salud Carlos III and FEDER [PI17/02303 to S.R.P]; R.T.R. is supported by a fellowship from the AECC scientific foundation; J.M.B. is supported by Spanish Ministry of Education, Culture and Sport [FPU15/01978]; J.B.'s laboratory is partially funded by FEDER funds, H2020 BRIDGES project and the Spanish Network on Rare Diseases (CIBERER) [FIS PI16/00440]; Faculty of Medicine at the Norwegian University of Science and Technology and the Central Norway Regional Health Authority supports [46056921 to A.S. and H.E.K.]; Svanhild and Arne Must's Fund for Medical Research (to A.S. and H.E.K.); Norwegian Research Council (to T.V.); SIN-TEF SEP project 102020885 (to T.V.); Vinnova (to A.C.K and P.S.); the Torsten and Ragnar Soderberg Foundation (to T.H.) and the Helleday Foundation (to C.B.). Funding for open access charge and project support: European Union's Horizon 2020 research and innovation programunder the Marie Sklodowska-Curie grant agreement [722729 to A.P., B.M.F.H., T.H.]; European Research Council [ERC TAROX-695376 to T.H.]; Swedish Research Council (to T.H. and P.S.); Swedish Cancer Society (to T.H. and P.S.); Swedish Children's Cancer Foundation (to T.H.); Swedish Pain Relief Foundation (to T.H.). Sí

By adopting a Circular Economy Package in 2015, European Commission aimed at stimulating transition towards a stronger and more circular economy where waste (including sewage) is no longer recognized as waste, but as a valuable resource of raw materials. This review study assesses the existing methodologies to produce biodiesel from wastewater-derived lipids. Depending on the stage of wastewater treatment where biodiesel would be extracted, it may cover up to 20% of the current European biodiesel demand. Further studies in regards to the biodiesel quality, legislative conditions and techno-economic assessment towards respective transition are needed.

Targeting of Wnt signaling represents a promising anti-cancer therapy. However, the consequences of systemically attenuating the Wnt pathway in an adult organism are unknown. Here, we globally prevent Wnt secretion by genetically ablating Wntless. We find that preventing Wnt signaling in the entire body causes mortality due to impaired intestinal homeostasis. This is caused by the loss of intestinal stem cells. Reconstitution of Wnt/β-catenin signaling via delivery of external Wnt ligands prolongs the survival of intestinal stem cells and reveals the essential role of extra-epithelial Wnt ligands for the renewal of the intestinal epithelium. Wnt2b is a key extra-epithelial Wnt ligand capable of promoting Wnt/β-catenin signaling and intestinal homeostasis. Wnt2b is secreted by subepithelial mesenchymal cells that co-express either Gli1 or Acta2. Subepithelial mesenchymal cells expressing high levels of Wnt2b are predominantly Gli1 positive.