Publications by authors named "W Leibl"
Article Synopsis
- The PufX protein helps certain purple bacteria with the process of exchanging two important molecules, ubiquinol and ubiquinone, in their reaction centers where they convert light into energy.
- Scientists studied this process in a type of purple bacteria called Rhodobacter capsulatus, using a special technique to see what happens when the bacteria were illuminated with light.
- They found that in bacteria without the PufX protein, the reactions weren’t as efficient, meaning that the way the molecule structure was set up made it harder for the needed molecules to reach where they needed to be in the reaction center.
The development of functional artificial photosynthetic devices relies on the understanding of mechanistic aspects involved in specialized photocatalysts. Modified iron porphyrins have long been explored as efficient catalysts for the light-induced reduction of carbon dioxide (CO) towards solar fuels. In spite of the advancements in homogeneous catalysis, the development of the next generation of catalysts requires a complete understanding of the fundamental photoinduced processes taking place prior to and after activation of the substrate by the catalyst.
View Article and Find Full Text PDFA close mimic of P680 and the Tyrosine-Histidine pair in photosystem II (PS II) has been synthesized using a ruthenium chromophore and imidazole-phenol ligands. The intramolecular oxidation of the ligands by the photoproduced Ru(III) species is characterized by a small driving force, very similar to PS II where the complexity of kinetics was attributed to the reversibility of electron transfer steps. Laser flash photolysis revealed biphasic kinetics for ligand oxidation.
View Article and Find Full Text PDFIron porphyrins are among the most studied molecular catalysts for carbon dioxide (CO ) reduction and their reactivity is constantly being enhanced through the implementation of chemical functionalities in the second coordination sphere inspired by the active sites of enzymes. In this study, we were intrigued to observe that a multipoint hydrogen bonding scheme provided by embarked urea groups could also shift the redox activation step of CO from the well-admitted Fe(0) to the Fe(I) state. Using EPR, resonance Raman, IR and UV-Visible spectroscopies, we underpinned a two-electron activation step of CO starting from the Fe(I) oxidation state to form, after protonation, an Fe(III)-COOH species.
View Article and Find Full Text PDFArticle Synopsis
- Harvesting sunlight to convert carbon dioxide (CO2) to valuable chemicals is crucial for a sustainable, carbon-neutral economy, particularly focusing on transforming CO into carbon monoxide (CO).
- The study introduces a photocatalytic process that enables rapid CO-to-CO conversion in under 10 minutes, leading to practical applications in radiochemistry related to human health by using carbon isotopes.
- The researchers used reaction-model-based simulations to optimize the process, facilitating the direct production of C- and C-labeled pharmaceuticals from their primary isotopic sources, enhancing accessibility and potential medical uses.