@article{NollGrossShoyamaetal.2023,
  author    = {Noll, Niklas and Groß, Tobias and Shoyama, Kazutaka and Beuerle, Florian and W{\"u}rthner, Frank},
  title     = {Folding-Induced Promotion of Proton-Coupled Electron Transfers via Proximal Base for Light-Driven Water Oxidation},
  series = {Angewandte Chemie International Edition},
  volume    = {62},
  journal   = {Angewandte Chemie International Edition},
  number    = {7},
  doi       = {10.1002/anie.202217745},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312020},
  year      = {2023},
  abstract  = {Proton-coupled electron-transfer (PCET) processes play a key role in biocatalytic energy conversion and storage, for example, photosynthesis or nitrogen fixation. Here, we report a series of bipyridine-containing di- to tetranuclear Ru(bda) macrocycles 2 C-4 C (bda: 2,2′-bipyridine-6,6′-dicarboxylate) to promote O-O bond formation. In photocatalytic water oxidation under neutral conditions, all complexes 2 C-4 C prevail in a folded conformation that support the water nucleophilic attack (WNA) pathway with remarkable turnover frequencies of up to 15.5 s\(^{-1}\) per Ru unit respectively. Single-crystal X-ray analysis revealed an increased tendency for intramolecular π-π stacking and preorganization of the proximal bases close to the active centers for the larger macrocycles. H/D kinetic isotope effect studies and electrochemical data demonstrate the key role of the proximal bipyridines as proton acceptors in lowering the activation barrier for the crucial nucleophilic attack of H\(_{2}\)O in the WNA mechanism.},
  language  = {en}
}
@article{SchlossarekStepanenkoBeuerleetal.2022,
  author    = {Schlossarek, Tim and Stepanenko, Vladimir and Beuerle, Florian and W{\"u}rthner, Frank},
  title     = {Self-assembled Ru(bda) Coordination Oligomers as Efficient Catalysts for Visible Light-Driven Water Oxidation in Pure Water},
  series = {Angewandte Chemie International Edition},
  volume    = {61},
  journal   = {Angewandte Chemie International Edition},
  number    = {52},
  doi       = {10.1002/anie.202211445},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312184},
  year      = {2022},
  abstract  = {Water-soluble multinuclear complexes based on ruthenium 2,2′-bipyridine-6,6′-dicarboxylate (bda) and ditopic bipyridine linker units are investigated in three-component visible light-driven water oxidation catalysis. Systematic studies revealed a strong enhancement of the catalytic efficiency in the absence of organic co-solvents and with increasing oligomer length. In-depth kinetic and morphological investigations suggest that the enhanced performance is induced by the self-assembly of linear Ru(bda) oligomers into aggregated superstructures. The obtained turnover frequencies (up to 14.9 s\(^{-1}\)) and turnover numbers (more than 1000) per ruthenium center are the highest reported so far for Ru(bda)-based photocatalytic water oxidation systems.},
  language  = {en}
}
@phdthesis{Noll2023,
  author    = {Noll, Niklas},
  title     = {Second Coordination Sphere Engineering in Macrocyclic Ruthenium Water Oxidation Catalysts},
  doi       = {10.25972/OPUS-30533},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-305332},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {About 2.4 billion years ago, nature has fundamentally revolutionized life on earth by inventing the multi-subunit protein complex photosystem II, the only molecular machine in nature that catalyzes the thermodynamically demanding photosynthetic splitting of water into oxygen and reducing equivalents. Nature chose a distorted Mn4CaO5 cluster as catalyst, better known as oxygen-evolving complex (OEC), thus recognizing the need for transition metals to achieve high-performance catalysts. The curiosity has always driven mankind to mimic nature's achievements, but the performance of natural enzymes such as the oxygen-evolving complex in photosystem II remain commonly unmatched. An important role in fine-tuning and regulating the activity of natural enzymes is attributed to the surrounding protein domain, which facilitates substrate preorganization within well-defined nanoenvironments. In light of growing energy demands and the depletion of fossil fuels, the unparalleled efficiency of natural photosynthesis inspires chemists to artificially mimic its natural counterpart to generate hydrogen as a 'solar fuel' through the light-driven splitting of water. As a result, significant efforts have been devoted in recent decades to develop molecular water oxidation catalysts based on earth-abundant transition metals and the discovery of the Ru(bda) (bda: 2,2' bipyridine-6,6'-dicarboxylate) catalyst family enabled activities comparable to the natural OEC. Similar to the natural archetypes, the design of homogeneous catalysts that interplay judiciously with the second coordination sphere of the outer ligand framework proved to be a promising concept for catalyst design. In this present thesis, novel supramolecular design approaches for enzyme like activation of substrate water molecules for the challenging oxidative water splitting reaction were established via tailor-made engineering of the secondary ligand environment of macrocyclic Ru(bda) catalysts.},
  subject      = {Katalyse},
  language  = {en}
}
@phdthesis{MezaChincha2021,
  author    = {Meza Chincha, Ana Lucia},
  title     = {Catalytic Water Oxidation with Functionalized Ruthenium Macrocycles},
  doi       = {10.25972/OPUS-20962},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-209620},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {In light of the rapidly increasing global demand of energy and the negative effects of climate change, innovative solutions that allow an efficient transition to a carbon-neutral economy are urgently needed. In this context, artificial photosynthesis is emerging as a promising technology to enable the storage of the fluctuating energy of sunlight in chemical bonds of transportable "solar fuels". Thus, in recent years much efforts have been devoted to the development of robust water oxidation catalysts (WOCs) leading to the discovery of the highly reactive Ru(bda) (bda: 2,2'-bipyridine-6,6'-dicarboxylic acid) catalyst family. The aim of this thesis was the study of chemical and photocatalytic water oxidation with functionalized Ruthenium macrocycles to explore the impact of substituents on molecular properties and catalytic activities of trinuclear macrocyclic Ru(bda) catalysts. A further objective of this thesis comprises the elucidation of factors that influence the light-driven water oxidation process with this novel class of supramolecular WOCs.},
  subject      = {Rutheniumkomplexe},
  language  = {en}
}