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 61 for “"Bond activation"”.
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Meeting the challenges: carbon-hydrogen bond activation and cancer treatment
… in oxidative addition mediated C-C, and C-O bond formation processes as well as in C-Cl bond forming reactions via a reductive elimination process. Bis-NHC-Pd(II) complexes have been reported as effective catalysts to mediate direct conversion of methane into methanol. However, a H-D exchange …
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Bond activation and catalysis by nontrigonal tricoordinate and tetracoordinate phosphorus compounds
… This dissertation describes studies on E-H bond activation and catalytic reactivity of [sigma]³- and [sigma]⁴ -phosphorus compounds with distorted nontrigonal structures. Specifically, a rare example of N-H oxidative addition to a planar, C2v-symmetric P(III) center is described in Chapter …
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Characterizations of Gold Complexes and Mechanism of its Usage in π-bond Activation Reactions
… chemical transformations, especially in π-bond activation reactions to initiate nucleophilic addition. But experimental studies focused on gold heteroatom π-complexes were still limited. It is significant to research on the intermediates involved in gold-catalyzed reactions. Many groups …
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Studies of carbon-hydrogen and silicon-hydrogen bond activation by early transition metal complexes
Compounds that contain early transition metals particularly titanium, vanadium, and chromium, are used as catalysts for olefin polymerization in the Ziegler-Natta and Phillips processes. The key intermediates in these catalysts are thought to be six-coordinate metal alkyl/olefin complexes. The …
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Spectroscopic and kinetic evidence for origins of selective bond activation over transition metal catalysts
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-05-01
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Reactivity of rhodium-heteroatom bonds: from catalytic bond activation to new strategies for olefin functionalization
… reactivity is investigated: P-H bond activation reactions and olefin functionalizations via rhodaoxetane intermediates. [Tp*Rh(PPh3)2] [Tp* = hydrotris(3,5-dimethylpyrazolyl)borate] and [Tp*Rh(cod)]2 (cod = cyclooctadiene) were evaluated for their activity in alkyne …
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FRUSTRATED LEWIS PAIR-MEDIATED SELECTIVE C–F BOND ACTIVATION AND SUBSEQUENT POST-FUNCTIONALIZATION OF POLYFLUOROALKANES
… suffer from ‘over-reaction’, where multiple C-F bonds are uncontrollably functionalized. We have developed a Frustrated Lewis Pair (FLP) mediated C-F bond activation which allows selective monodefluorination of polyfluoroalkanes via base capture of intermediate fluorocarbocations. This …
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Late transition metal bimetallics for photocatalytic hydrogen production, M-X and C-H bond activation
… efficiency for challenging M-X (X = CI, Br-) bond photoactivations were undertaken by incorporating gold into a heterobimetallic rhodium-gold construct. Additionally the organometallic reactivity of two-electron mixed valence diiridium cores was explored with a specific emphasis on C-H bond …
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Mono- and Dinuclear Nonheme Iron Model Complexes: O-O Bond Activation, Structural Characterization and Reactivity Study
… were investigated. In Chapters 2 and 3, O-O bond activation of H2O2 by the dinuclear complexes [(FeIII2(μ-O)(μ-OH)L2]3+ (1A) and [(FeIII2(μ-OH)2L2]4+ (2A), L = tris(3,5-di-methyl-4-methoxypyridyl-2-methyl)amine, to form the high-valent [(FeIV2(μ-O)(OH)(O)L2]3+ (3A) and [(FeIV2(μ-O)2L2]4+ (4A) …
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Mechanistic studies of electron transfer, complex formation, C-H bond activation, and product binding in soluble methane monooxygenase
Chapter 1. Soluble Methane Monooxygenase: Activation of Dioxygen and Methane The mechanisms by which soluble methane monooxygenase uses dioxygen to convert methane selectively to methanol have come into sharp focus. Diverse techniques have clarified subtle details about each step in the reaction, …
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Solvent-Controlled Switch of Selectivity between sp[superscript]2 and s[superscript]p3 C-H Bond Activation by Platinum (II)
… The factors that control the process of the C-H bond activation, however, are not yet completely understood. C-H bonds are ever-present in organic molecules, but the vast majority of them cannot be exploited for chemical reactions due to their inert and stable nature. Early attempts to activate …
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Synthesis and Optical Properties of Four Oligothiophene-Ruthenium Complexes and Synthesis of a Bidentate Ligand for C-F Bond Activation
… but fluorescence is quenched when connected. Bonds of carbon to fluorine are among the strongest single bonds. Single bonds between carbon and hydrogen are also very strong and are ubiquitous. The ability to manipulate these bonds is of great interest to chemists. Two tungsten metal complexes, …
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Sigma bond activation of the hydrogen molecule by cooperative interaction with a boron cation, a lithium anion, and a beryllium atom
Sigma bond activation, making a sigma bond more reactive, has been one of tht' most extensively studied areas of chemistry for the past decade. Sigma bonds are the strongest bonds and therefore reactions that involve the breaking of such bonds have large activation energies. Without a doubt, the …
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Sharing the Burden of Reactivity: Synthesis, Characterization, and Reactivity of Phosphino-Alkoxide First-Row Transition Metal Complexes
Bond activation is both central in many reaction mechanisms and essential to industrial production of chemicals. Many industries, such as pharmaceutical and petrochemical production, use precious metals to perform critical synthetic transformations that rely on bond activation. Due to the scarce …
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Methods for Directed C–O Bond Functionalization of Esters and Acyl Equivalents
… arene acylation via sequential C–O/C–H bond activation and a Suzuki-Miyaura cross coupling using N-pyridylimidates as acyl equivalents.
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Unimolecular decomposition kinetics at resolved internal energies.
… utilized by our group to determine the reaction activation energies. This dissertation will focus on the unimolecular decomposition of Ni+propanal and Ni+acetic acid. The two reactions involve competition between C-C bond activation and either C-H or C-O bond activation.
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Photochemical reductive elimination of halogen from transition metal complexes
… X2 in thermodynamically uphill photocycles. The activation of strong M-X bonds is a key requirement for efficient photocatalysts and represents the most challenging step of HX splitting schemes. Studies have focused on the design and characterization of late-metal phosphine complexes with an …
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