Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"Ligand framework"”.
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Dynamics and mechanism of spin-state interconversion in transition metal complexes. (Volumes I and II)
… A series of compounds having a polypyridyl-based ligand framework are described which allow for systematic modification of molecular geometry. A nanosecond time-resolved laser spectrometer was constructed to measure the kinetics of spin-state interconversion as a function of temperature in an …
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Tuning the photophysical properties of amidophosphine complexes of copper
… especially when considering the phosphine-based ligand framework used.
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Fluorescent chemosensors for exploring zinc metalloneurochemistry and detecting mercury in aqueous solution
… zinc sensors from aniline-derivatized ligands and a fluroescein carboxaldehyde platform is presented. These sensors are based on the previously reported ZP4 motif and incorporate a di(2-picolyl)amine moiety in the aniline-based ligand framework. The effects of electronic variation, …
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The Synthesis, Reactivity and Electrochemical Study of Metallocene Substituted α-Diimine Ligands
… metal complexes containing redox-active ligands or ligands with redox-active substituents have been areas of ongoing interest in chemical research. To date, only a handful of examples involving redox-active ligands containing main group centres have been reported. This thesis presents …
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Ligand Cooperative Iridium PCP Complexes for Small Molecule Activation
… presents the synthesis of a new PCP pincer ligand framework bearing benzo[b]thiophene linking groups as an alternative to the parent ortho-phenylene linkers. This ligand was installed onto an iridium center via double C-H activation at the central carbon atom, resulting in a carbene donor …
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Synthesis, Characterization And Reactivity Studies Of Nickel Complexes Supported By A Phosphinimine-Based Pincer Ligand
Tridentate pincer-type ligands offer both electronic and steric flexibility and have been used to stabilize highly reactive species, including late transition metal complexes with metal–ligand multiple bonds. Herein, we report a series of novel nickel complexes supported by a pincer-type …
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Synthesis, Characterization, and Applications of Group 13 and 14 Complexes of Chelating Formazanate Ligands
… by chelating formazanate [R1-N-N=C(R3)-N=N-R5]‒ ligands. The resulting complexes are redox-active and often luminescent. Chapters two to four describe the synthesis and characterization of boron formazanate adducts. The work in these chapters demonstrates that through structural modification of …
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Synthesis, Properties, and Reactivity of Pentafluorophenyl Substituted Cyclopentadienes and Their Transition Metal Complexes
… such complex, ferrocene. Modifications of the Cp ligand framework effect changes in the physical properties and chemical reactivity of the coordinated transition metal. This concept is useful when applied to catalysis mediated by Cp complexes, because the performance of the catalyst can be …
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Investigation Of New Ligand Architechtures Towards Proton And Water Reduction Catalysis By Cobalt Complexes
<p>We designed several redox-active ligand architectures to optimize and understand the redox, electronic, and catalytic properties of their respective cobalt complexes. Ligand design was varied from pentadentate donor phenolate to tetradentate acceptor oxime in order to reduce the overpotential of …
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Synthesis and Reactivity of Low Valent Main Group Element Complexes
… of one of the germanium lone pairs into the ligand framework. Complex IV-4 was unreactive towards H–X bond activation, the lack of reactivity ascribed to the large singlet-triplet energy gap calculated. The same bis(imino)pyridine ligand was also used to prepare reduced zinc complexes. …
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Non-heme iron C-H oxidation: tolerance of nitrogen-containing motifs with application to amino-acid and peptide oxidation
… to directly install oxygen into a hydrocarbon framework negates the need for pre-oxidized materials, and allows for quick and efficient access to more diverse and complex molecules; in some cases, access to motifs that would not otherwise be accessible is possible. Furthermore, ligation at the …
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New frontiers in allylic C––H amination via palladium/sulfoxideoxazoline catalysis
… However, all these reactions proceed via near ligandless conditions (e.g. reversibly coordinating sulfoxide ligands) and require benzoquinone oxidant to coordinate to Pd metal to promote the functionalization step (known as “serial ligand catalysis). This mechanism with sulfoxide ligands …
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Ligand design in nickel and cobalt complexes for homogeneous catalysis
… for a monoanionic, bidentate NHC-CAryl ligand framework ([H(BrCC)]Br) were developed. The metalation of this ligand precursor with nickel was achieved by both initial metalation with Ni(II) followed by reduction and direct metalation with Ni(0). The presence of a Ni-CAryl bond in the …
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Bio-inspired iron complexes featuring secondary coordination sphere interactions: Ligand design strategies and dioxygen reactivity
… in a number ways including fine-tuning metal ligand interactions, supporting reactive intermediates, and controlling the movement of protons and electrons in the active site. Interested in modeling these interactions and promoting oxygen activation with bio-inspired iron complexes, our …
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Highly Efficient Catalysts for the Dimerization of α-Olefins
… influence of the substitution pattern at the ligand framework on the product distribution. Steric demanding substituents at the ortho positions of the iminophenyl ring had positive effects on the dimer yield. The influence of triphenylphosphine as an additive was investigated and strong …
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Bio-inspired iron and cobalt complexes featuring a secondary coordination sphere: ligand design, complexation, and modeling of enzymatic processes
… and characterization of tetrapodal metal-ligand complexes containing non-covalent interactions that model biologically relevant intermediates and reactivity towards small molecules. Early work focused on the synthesis of a new tetrapodal ligand platform, Py2Py(piCy)2, which was …
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Catalytic hydrofunctionalization and small molecule reactivity at a low-valent cobalt center supported by a bis(carbene) CCC pincer ligand
… metal compounds, the presence of a weak ligand field engenders a high-spin electron configuration and one-electron events at the expense of two-electron elementary steps. Accordingly, our lab and many others have endeavored to utilize a strong ligand field approach whereby a …
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Development of Deactivation-Resistant Catalysts for Pd-Catalyzed C–N Cross-Coupling Reactions
… C–N Cross-Coupling: Rational Biarylphosphine Ligand Design Enhances the Reactivity of Difficult Substrates Transition-metal-catalyzed C−N cross-coupling reactions are an important class of transformations with applications in a variety of fields, and Pd-based catalysts are among the most …
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Small molecule activation and reduction using non-heme iron complexes
… our group designed a tripodal, tetradentate ligand featuring a secondary coordination sphere through a tautomerizable framework. Each ligand arm incorporates a pyrrole-imine, which upon anionic coordination to a metal center places a hydrogen-bond acceptor in the secondary sphere. …
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Small molecule binding to electrophilic trigonal pyramidal platinum, palladium, and nickel
… ([SiP₃R]- = [(2-R₂PC₆H₄)₃Si]-; R = Ph, iPr) ligand are prepared and shown to provide access to cationic species with divergent behavior. The less electron-rich phenyl-substituted ligand renders the platinum center extremely electrophilic, leading to structurally characterized examples of …