@phdthesis{Schindler2022,
  author    = {Schindler, Dorothee},
  title     = {Water Oxidation with Multinuclear Ruthenium Catalysts},
  doi       = {10.25972/OPUS-23309},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233093},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {In terms of the need of environmentally benign renewable and storable energy sources, splitting of water into hydrogen and oxygen by using sunlight is a promising approach. Hereby, water oxidation catalysts (WOCs) are required to perform the water oxidation comprising the transfer of four electrons to provide the reducing equivalents for producing hydrogen. The class of Ru(bda) (bda = 2,2'-bipyridine-6,6'-dicarboxylate) catalysts has proven to be efficient for this reaction. In this thesis, ligand exchange processes in Ru(bda) complexes have been analyzed and the formation of multinuclear macrocyclic WOCs was studied. Based on the knowledge acquired by these studies, new multinuclear cyclic Ru(bda) complexes have been synthesized and their catalytic efficiencies in homogeneous water oxidation have been investigated. Going one step further for setting up functional devices, molecular WOCs have been immobilized on conducting or semiconducting supporting materials. Direct anchoring on carbon nanotubes generated a promising materials for further applications.},
  subject      = {Rutheniumkomplexe},
  language  = {en}
}
@phdthesis{Wuertemberger2012,
  author    = {W{\"u}rtemberger, Max},
  title     = {Untersuchungen zur Synthese und Reaktivit{\"a}t NHC-substituierter Ruthenium- und Eisen-Komplexe},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72032},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Diese Arbeit besch{\"a}ftigt sich mit Untersuchungen zur Synthese und Reaktivit{\"a}t von Ruthenium(II)- und Eisen(II)-Komplexen welche durch Alkyl-subsituierte N-Heterozyklische-Carben Liganden stabilisiert werden. Ein besonderes Augenmerk liegt hierbei auf dem synthetischen Zugang von Rutheniumverbindungen jenseits der Metathese-Katalysatoren.},
  subject      = {Rutheniumkomplexe},
  language  = {de}
}
@phdthesis{Klueh2006,
  author    = {Kl{\"u}h, Katharina},
  title     = {Primary Phosphine Halfsandwich Complexes of Iron and Ruthenium - Synthesis and Hydrophosphination Reactions},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-18603},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2006},
  abstract  = {Die Hydrophosphinierung stellt eine wertvolle Synthesem{\"o}glichkeit zum Aufbau von prim{\"a}ren, sekund{\"a}ren und terti{\"a}ren Phosphanen dar. In dieser Arbeit wird die Synthese verschiedener Prim{\"a}r-Phosphan-Komplexes des Eisens und Ruthenium beschrieben. Untersucht wurden ihre Reaktivit{\"a}t bez{\"u}glich Hydrophosphinierungsreaktionen sowie den Einfluss verschiedener Liganden z.B. bidentate Phosphanliganden und hemilabilen Liganden.},
  subject      = {Phosphine},
  language  = {en}
}
@phdthesis{GamachegebRupp2021,
  author    = {Gamache [geb. Rupp], Mira Theresa},
  title     = {Ligand Design for Ru(II) Photosensitizers in Photocatalytic Hydrogen Evolution},
  doi       = {10.25972/OPUS-24676},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246766},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {This thesis investigates different ligand designs for Ru(II) complexes and the activity of the complexes as photosensitizer (PS) in photocatalytic hydrogen evolution. The catalytic system typically contains a catalyst, a sacrificial electron donor (SED) and a PS, which needs to exhibit strong absorption and luminescence, as well as reversible redox behavior. Electron-withdrawing pyridine substituents on the terpyridine metal ion receptor result in an increase of excited-state lifetime and quantum yield (Φ = 74*10-5; τ = 3.8 ns) and lead to complex III-C1 exhibiting activity as PS. While the turn-over frequency (TOFmax) and turn-over number (TON) are relatively low (TOFmax = 57 mmolH2 molPS-1 min-1; TON(44 h) = 134 mmolH2 molPS-1), the catalytic system is long-lived, losing only 20\% of its activity over the course of 12 days. Interestingly, the heteroleptic design in III-C1 proves to be beneficial for the performance as PS, despite III-C1 having comparable photophysical and electrochemical properties as the homoleptic complex IV-C2 (TOFmax = 35 mmolH2 molPS-1 min-1; TON(24 h) = 14 mmolH2 molPS-1). Reductive quenching of the excited PS by the SED is identified as rate-limiting step in both cases. Hence, the ligands are designed to be more electron-accepting either via N-methylation of the peripheral pyridine substituents or introduction of a pyrimidine ring in the metal ion receptor, leading to increased excited-state lifetimes (τ = 9-40 ns) and luminescence quantum yields (Φ = 40-400*10-5). However, the more electron-accepting character of the ligands also results in anodically shifted reduction potentials, leading to a lack of driving force for the electron transfer from the reduced PS to the catalyst. Hence, this electron transfer step is found to be a limiting factor to the overall performance of the PS. While higher TOFmax in hydrogen evolution experiments are observed for pyrimidine-containing PS (TOFmax = 300-715 mmolH2 molPS-1 min-1), the longevity for these systems is reduced with half-life times of 2-6 h. Expansion of the pyrimidine-containing ligands to dinuclear complexes yields a stronger absorptivity (ε = 100-135*103 L mol-1 cm-1), increased luminescence (τ = 90-125 ns, Φ = 210-350*10-5) and can also result in higher TOFmax given sufficient driving force for electron transfer to the catalyst (TOFmax = 1500 mmolH2 molPS-1 min-1). When comparing complexes with similar driving forces, stronger luminescence is reflected in a higher TOFmax. Besides thermodynamic considerations, kinetic effects and electron transfer efficiency are assumed to impact the observed activity in hydrogen evolution. In summary, this work shows that targeted ligand design can make the previously disregarded group of Ru(II) complexes with tridentate ligands attractive candidates for use as PS in photocatalytic hydrogen evolution.},
  subject      = {Fotokatalyse},
  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}
}