@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}
}
@article{NollKrauseBeuerleetal.2022,
  author    = {Noll, Niklas and Krause, Ana-Maria and Beuerle, Florian and W{\"u}rthner, Frank},
  title     = {Enzyme-like water preorganization in a synthetic molecular cleft for homogeneous water oxidation catalysis},
  series = {Nature Catalysis},
  journal   = {Nature Catalysis},
  edition   = {accepted version},
  doi       = {10.1038/s41929-022-00843-x},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302897},
  year      = {2022},
  abstract  = {Inspired by the proficiency of natural enzymes, mimicking of nanoenvironments for precise substrate preorganisation is a promising strategy in catalyst design. However, artificial examples of enzyme-like activation of H\(_2\)O molecules for the challenging oxidative water splitting reaction are hardly explored. Here, we introduce a mononuclear Ru(bda) complex (M1, bda: 2,2'-bipyridine-6,6'-dicarboxylate) equipped with a bipyridine-functionalized ligand to preorganize H\(_2\)O molecules in front of the metal center as in enzymatic clefts. The confined pocket of M1 accelerates chemically driven water oxidation at pH 1 by facilitating a water nucleophilic attack pathway with a remarkable turnover frequency of 140 s\(^{-1}\) that is comparable to the oxygen-evolving complex of photosystem II. Single crystal X-ray analysis of M1 under catalytic conditions allowed the observation of a 7th H\(_2\)O ligand directly coordinated to a RuIII center. Via a well-defined hydrogen-bonding network, another H\(_2\)O substrate is preorganized for the crucial O-O bond formation via nucleophilic attack.},
  language  = {en}
}
@article{RamlerKrummenacherLichtenberg2020,
  author    = {Ramler, Jacqueline and Krummenacher, Ivo and Lichtenberg, Crispin},
  title     = {Well-Defined, Molecular Bismuth Compounds: Catalysts in Photochemically Induced Radical Dehydrocoupling Reactions},
  series = {Chemistry - A European Journal},
  volume    = {26},
  journal   = {Chemistry - A European Journal},
  number    = {64},
  doi       = {10.1002/chem.202002219},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224577},
  pages     = {14551 -- 14555},
  year      = {2020},
  abstract  = {A series of diorgano(bismuth)chalcogenides, [Bi(di-aryl)EPh], has been synthesised and fully characterised (E=S, Se, Te). These molecular bismuth complexes have been exploited in homogeneous photochemically-induced radical catalysis, using the coupling of silanes with TEMPO as a model reaction (TEMPO=(tetramethyl-piperidin-1-yl)-oxyl). Their catalytic properties are complementary or superior to those of known catalysts for these coupling reactions. Catalytically competent intermediates of the reaction have been identified. Applied analytical techniques include NMR, UV/Vis, and EPR spectroscopy, mass spectrometry, single-crystal X-ray diffraction analysis, and (TD)-DFT calculations.},
  language  = {en}
}
@article{SchlosserCibulkaGrossetal.2020,
  author    = {Schlosser, Julika and Cibulka, Radek and Groß, Philipp and Ihmels, Heiko and Mohrschladt, Christian J.},
  title     = {Visible-Light-Induced Di-\(\pi\)-Methane Rearrangement of Dibenzobarrelene Derivatives},
  series = {ChemPhotoChem},
  volume    = {4},
  journal   = {ChemPhotoChem},
  number    = {2},
  doi       = {10.1002/cptc.201900221},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-212633},
  pages     = {132 -- 137},
  year      = {2020},
  abstract  = {It is demonstrated that the di-\(\pi\)-methane (DPM) rearrangement of carbonyl-substituted dibenzobarrelene (9,10-dihydro-9,10-ethenoanthracene) derivatives is induced by visible-light-induced triplet photosensitization with Ir(ppy)\(_{3}\), Ir(dFppy)\(_{3}\) or 1-butyl-7,8-dimethoxy-3-methylalloxazine as catalysts, whereas derivatives that lack carbonyl substituents are photoinert under these conditions. Notably, the products are formed almost quantitatively.},
  language  = {en}
}
@article{WuerthnerNoll2021,
  author    = {W{\"u}rthner, Frank and Noll, Niklas},
  title     = {A Calix[4]arene-Based Cyclic Dinuclear Ruthenium Complex for Light-Driven Catalytic Water Oxidation},
  series = {Chemistry - A European Journal},
  volume    = {27},
  journal   = {Chemistry - A European Journal},
  number    = {1},
  doi       = {10.1002/chem.202004486},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230030},
  pages     = {444-450},
  year      = {2021},
  abstract  = {A cyclic dinuclear ruthenium(bda) (bda: 2,2'-bipyridine-6,6'-dicarboxylate) complex equipped with oligo(ethylene glycol)-functionalized axial calix[4]arene ligands has been synthesized for homogenous catalytic water oxidation. This novel Ru(bda) macrocycle showed significantly increased catalytic activity in chemical and photocatalytic water oxidation compared to the archetype mononuclear reference [Ru(bda)(pic)\(_2\)]. Kinetic investigations, including kinetic isotope effect studies, disclosed a unimolecular water nucleophilic attack mechanism of this novel dinuclear water oxidation catalyst (WOC) under the involvement of the second coordination sphere. Photocatalytic water oxidation with this cyclic dinuclear Ru complex using [Ru(bpy)\(_3\)]Cl\(_2\) as a standard photosensitizer revealed a turnover frequency of 15.5 s\(^{-1}\) and a turnover number of 460. This so far highest photocatalytic performance reported for a Ru(bda) complex underlines the potential of this water-soluble WOC for artificial photosynthesis.},
  language  = {en}
}
@article{WuerthnerMezaChinchaSchindleretal.2021,
  author    = {W{\"u}rthner, Frank and Meza-Chincha, Ana-Lucia and Schindler, Dorothee and Natali, Mirco},
  title     = {Effects of Photosensitizers and Reaction Media on Light-Driven Water Oxidation with Trinuclear Ruthenium Macrocycles},
  series = {ChemPhotoChem},
  volume    = {5},
  journal   = {ChemPhotoChem},
  number    = {2},
  doi       = {10.1002/cptc.202000133},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230116},
  pages     = {173-183},
  year      = {2021},
  abstract  = {Photocatalytic water oxidation is a promising process for the production of solar fuels and the elucidation of factors that influence this process is of high significance. Thus, we have studied in detail light-driven water oxidation with a trinuclear Ru(bda) (bda: 2,2'-bipyridine-6,6'-dicarboxylate) macrocycle MC3 and its highly water soluble derivative m-CH\(_2\)NMe\(_2\)-MC3 using a series of ruthenium tris(bipyridine) complexes as photosensitizers under varied reaction conditions. Our investigations showed that the catalytic activities of these Ru macrocycles are significantly affected by the choice of photosensitizer (PS) and reaction media, in addition to buffer concentration, light intensity and concentration of the sensitizer. Our steady-state and transient spectroscopic studies revealed that the photocatalytic performance of trinuclear Ru(bda) macrocycles is not limited by their intrinsic catalytic activities but rather by the efficiency of photogeneration of oxidant PS\(^+\) and its ability to act as an oxidizing agent to the catalysts as both are strongly dependent on the choice of photosensitizer and the amount of employed organic co-solvent.},
  language  = {en}
}
@phdthesis{Kiendl2020,
  author    = {Kiendl, Benjamin},
  title     = {Application of diamond nanomaterials in catalysis},
  doi       = {10.25972/OPUS-17941},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179415},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2020},
  abstract  = {In this work the catalytic activity of nanodiamond particles with different dopants and surface terminations and of diamond nanomaterials funtionalized with ruthenium-based photocatalysts was investigated, illustrating materials application in photoredox chemistry and the photo(electro)catalytic reduction of CO2. Regarding the application of diamond nanomaterials in photocatalysis, methods to fabricate and characterize several (un)doped nanoparticles with different surface termination were successfully developed. Various photocatalysts, attached to nanodiamond particles via linker systems, were tested in photoredox catalysis and the photo(electro)catalytic reduction of CO2.},
  subject      = {Fotokatalyse},
  language  = {en}
}