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 129 for “"heteroatom"”.
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Arsacarboranes: A New Series of Heteroatom Carboranes
Made available in DSpace on 2014-12-09T17:36:30Z (GMT). No. of bitstreams: 1 7013259.pdf: 2030856 bytes, checksum: 03e8b0265fd70ce49926e11be4c2276a (MD5) Previous issue date: 1969
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Heteroatom-Doped Graphitic Materials for Energy Storage
… whilst retaining a high level of stability. Heteroatom substitution of carbon in a graphite lattice has been shown to produce high-capacity anode materials suitable for Li- and Na-ion batteries. This thesis develops an understanding of the structure and function of element-doped graphite …
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Heteroatom-containing carbons for high energy density supercapacitor
… can be comparable to those for batteries, new heteroatom-containing carbons in the form of particles and three-dimensional films were investigated. A nitrogen-containing material, acrodam, was chosen as the carbon precursor due to the inexpensiveness, high carbonization yield, …
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Entwicklung neuer Methoden zur Eisen-katalysierten Kohlenstoff-Heteroatom-Bindungsknüpfung
… bond forming reactions between carbon and heteroatoms were developed. The first part of the thesis was dedicated to the aziridination reaction of olefins by nitrene group transfer. Commercial Fe(acac)3 served as the iron source. The nitrene was formed in situ from an aromatic sulfonamide …
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Alkyl-heteroatom Bond Forming Reactions from the Late Transition Metals
C(sp3)-N bond formation is a potential high value reaction in transition metal catalysis, however, only a handful of examples of this fundamental coupling reaction step have been reported. Presented in this thesis are new efforts to promote this challenging reaction. Group 9 and 10 metals bound by …
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New Pd and Cu-based catalysts for carbon-heteroatom bond formation
… development of novel methodologies for carbon-heteroatom cross-coupling reactions catalyzed by late-transition metals. Both palladium and copper are central to the field of transition metal-catalysis and are integral to the catalyst systems developed as part of our continual advancement in …
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Automated reaction mechanism generation : data collaboration, Heteroatom implementation, and model validation
Nearly two-thirds of the United States' transportation fuels are derived from non-renewable fossil fuels. This demand of fossil fuels requires the United States to import ~ 60% of its total fuel consumption. Relying so heavily on foreign oil is a threat to national security, not to mention that …
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Functional nanostructured hydrothermal carbons for sustainable technologies : heteroatom doping and superheated vapor
… The first approach was the introduction of heteroatoms, or “doping” of the carbon framework. Sulfur was for the first time introduced as a dopant in hydrothermal carbon. The synthesis of sulfur and sulfur/nitrogen doped microspheres was presented whereby it was shown that the binding state …
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Studies on the Zinc-mediated Phenyl and Alkynyl addition to Carbon-heteroatom double bonds
… of C(sp2) and C(sp) nucleophiles to carbon-heteroatom double bonds was the subject of this research. In the first part of the thesis, the synthesis of new chiral compounds to be used as ligands for the enantioselective phenyl addition to aldehydes is described. Novel alfa-hydroxy oxazolines …
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ARYL-HETEROATOM CROSS-COUPLING WITH DUAL NICKEL/PHOTOCATALYST PROTOCOLS : THEORY, APPLICATIONS AND RECENT DEVELOPMENTS
… nickel/photocatalyst protocols to conduct aryl-heteroatom cross-coupling reactions is presented. Basic concepts of photocatalysis, including different relaxation pathways, the difference of singlet and triplet states, and parameters used to predict reactivity are first disclosed. The general …
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Recent advances in copper- and palladium-catalyzed carbon-heteroatom and carbon-carbon bond-formation
… and copper-catalyzed reactions, which employ heteroatom-based nucleophiles. Herein, newly designed catalyst systems are presented for the palladium- and/or copper-catalyzed nucleophilic substitution reactions of aryl halides with a variety of nucleophiles, including (benz)imidazoles, …
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The development and synthetic application of titanium-mediated carbon-heteroatom double bond hydrosilylation methodologies
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1997.
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Copper-catalyzed carbon-heteroatom bond formations : asymmetric hydroamination and continuous-flow aromatic Finkelstein reaction
… of new methods for copper-catalyzed carbon-heteroatom bond formations, including asymmetric hydroamination and continuous-flow aromatic Finkelstein reaction. The first part of this dissertation focuses on the development of copper-catalyzed asymmetric hydroamination reactions to access …
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Reactivity of rhodium-heteroatom bonds: from catalytic bond activation to new strategies for olefin functionalization
… is comprised of two projects in which rhodium-heteroatom 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 …
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EXPLORATIONS IN MEDIUM-RING ETHER SYNTHESIS VIA UMPOLUNG HETEROATOM ACTIVATION: TOTAL SYNTHESIS, METHODS DEVELOPMENT, AND REAGENT SYNTHESIS
… new discoveries regarding the key electrophilic heteroatom rearrangement step which prompted a full study, resulting in improved yields, one-pot derivatization protocols, expanded scope, and a better understanding of substrate effects on reactivity. Finally, armed with improved access to …
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Influence of presence of a heteroatom source on the synthesis of layered silicates - ilerite, magadiite and kenyaite
… Magadiit und Kenyait - in Anwesenheit einer Heteroatomquelle behandelt. Das Hauptziel der Studie war den Einfluss der oben genannten Verbindungen auf das entstehende Material und auch die Möglichkeit des isomorphen Ersatzes von Silizium durch Zinn-Atomen zu untersuchen. Die Eigenschaften der …
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Synthetic Molecular Models for the Oxygen Reduction Active Sites in Heteroatom-Doped Graphitic Electrocatalysts: Linking Heterogeneous and Homogeneous Electrocatalysis
The development and deployment of low-temperature fuel cell technologies require that low-cost platinum-free catalysts for the oxygen reduction reaction (ORR) that are highly active, selective, and durable be created. To this point, the advancement of potential replacement catalysts such as metal- …
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Stereochemistry, isotope effects, and inhibition of terpene biosynthesis: I. Stereospecificity and mechanism of monoterpene cyclases. II. Inhibition by heteroatom analogs of carbocation intermediates
Stereospecificity and mechanism of monoterpene cyclases have been investigated by use of deuterium and tritium labeled substrates. The stereochemistry of the terminating deprotonation in limonene biosynthesis was elucidated by radiochemical degradation of ($\sp3$H) carvoximes. Limonene cyclases …
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A valence bond for several perturbations
… energy of the parent hydrocarbon as a result of heteroatom replacement of one or more carbon atoms or introducing substituents. Such spectral perturbations may be correlated with inductive and mesomeric heteroatom or substituent effects. Preliminary studies involve a comparison of semi-empirical …
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