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 30 for “"proton-coupled electron transfer (PCET)"”.
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Proton-coupled electron transfer in molecular and material catalysis
Proton-coupled electron transfer (PCET) plays an important role in a variety of electrochemical and photo-excited reactions occurring in molecular, material, and biological systems. In this thesis, the role of PCET in hydrogen evolution molecular electrocatalysts, and iron-doped nickel-oxyhydroxide …
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Mechanistic studies of the class I ribonucleotide reductases from S. cerevisiae and E. coli.
… step in catalysis is a physical step prior to proton-coupled electron transfer (PCET), nucleotide reduction, and reverse PCET. These results provide a crucial first step in understanding radical initiation over 35 [angstroms].
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Proton-coupled electron transfer : from basic principles to small molecule activation
Proton-coupled electron transfer (PCET) is the basic mechanism for bioenergetic conversion. Hallmark examples of such reactivities include water oxidation which is coupled to photosynthesis and oxygen reduction which is coupled to ATP generation by respiration. These two complementary energy …
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Transuranic Imidophosphorane Chemistry
… work to the actinides to study the molecular and electronic structures of transuranic imidophosphorane compounds. The isolation, characterization, and redox chemistry of a large isostructural family of Ce, U, Np, and Pu complexes is presented. These compounds offer a unique opportunity to map the …
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Exploring SOD1 electron transfer, heterodimerization, and hetero-amyloid formation.
… “protein charge ladders”, to distinguish between electron transfer (ET) and proton-coupled electron transfer (PCET) in a binuclear copper center by directly measuring the change in protein net charge upon reduction/oxidation (ΔZ4ET). Chapter three explores a hyper-deamidated form of SOD1, …
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Mechanistic studies of photo-induced proton-coupled electron transfer and oxygen atom transfer reactions in model systems
… model systems designed to undergo photo-induced proton-coupled electron transfer (PCET) and oxygen atom transfer (OAT) reactions, both of which are important to energy conversion chemistry (Chapter I). The effect of coupling proton transfer (PT) to electron transfer (ET) depends on their spatial …
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Small-molecule activation chemistry catalyzed by proton-coupled electron transfer
Proton-coupled electron transfer (PCET) is the basic mechanism for bioenergetic conversion. Consummate examples include water oxidation in photosynthesis and oxygen reduction in respiration. Despite the importance of PCET in such catalytic bond-making and bond-breaking reactions, the underlying …
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Photochemical ribonucleotide reductase for the study of proton-coupled electron transfer
… transport of these radicals are synonymous with proton-coupled electron transfer (PCET), which intrinsically is a quantum mechanical effect as both the electron and proton tunnel. The caveat to PCET is that proton transfer (PT) is fundamentally limited to short distances relative to electron …
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Development of non-born-Oppenheimer methods for ground and excited state molecular properties
The nuclear-electronic orbital (NEO) method is a multicomponent approach that allows the quantum mechanical treatment of electrons and specified protons on the same quantum mechanical level. NEO does not make the Born-Oppenheimber approximation between electrons and select protons, and therefore …
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Mechanistic investigations of the radical initiation pathway of class I ribonucleotide reductase from Escherichia coli
… nucleoside reduction by a putative long-range proton-coupled electron transfer (PCET) pathway over 35 A. This pathway is thought to involve specific amino acid radical intermediates (Y22-> W48-> Y356 within R2 to Y731-> Y730-> C439 within R1). In an effort to study radical initiation, we used …
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Building model systems to understand Proton-Coupled Electron Transfer in heme : spectroscopic investigation of charge transfer to axially bound diimide acceptors
Proton-Coupled Electron Transfer (PCET) is an important mechanistic motif in chemistry, which allows for efficient charge transport in many biological systems. We seek to understand how the proton and electron motions are coupled in a bidirectional system allowing for individual turning of the …
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Harnessing Aluminum Radicals via Heterobimetallic Complexes for Small-molecule Activation
… enabling aluminum to participate in single-electron processes traditionally associated with transition metals and f-block elements. A central theme of this work is the development of multiple design strategies, including redox non-innocent ligands and strained coordination geometries, to …
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Catalytic Activity of Molybdenum-Dioxo Complexes
… dependent on the ligand environment. The smaller electronically demanding ligand environment showed readily rapid reactivity for aromatic diols, but competitive side reactions and catalyst dimerization occurred. The more sterically demanding ligand environment was observed to slow the relative …
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Towards new model systems for the study of proton-coupled electron transfer
Two new model systems for the study of orthogonal proton-coupled electron transfer (PCET) have been developed. The first model system is based on Ru"(HzO)(tpy)(bpy) (tpy = 2,2';6',2"terpyridine, bpy = 2,2'-bipyridine) where methyl viologen (MV2 ) electron acceptors were appended to the ruthenium …
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Oxidation of Tetrahydropyridines by MAO B Biomimetics: Mechanistic Studies
… for just as long. Proponents of the single electron transfer (SET) pathway of oxidation faced severe critiques in that the hypothesized radical intermediates arising from the SET pathway were never directly observed. Work performed herein provides that exact evidence using biomimetics of MAO …
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Theoretical studies of proton-coupled electron transfer in interfacial and photochemical energy conversion processes
… as those nature is the directed translocation of electrons and protons. These two fundamental chemical reagents often transfer concertedly and as such the kinetics of these reactions require special attention. In this dissertation, computational and theoretical characterizations of proton-coupled …
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Mechanistic studies of proton-coupled electron transfer in aminotyrosine- and fluorotyrosine- substituted class Ia Ribonucleotide reductase
… an unprecedented mechanism of reversible proton-coupled electron transfer (PCET) to propagate a stable tyrosyl radical (Yi22-) in P2 over a distance of >35 A to an active site cysteine (C4 3 9) in a2 on each turnover. Generation of the cysteinyl radical (C4 3 9-) initiates active site …
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Spectroscopic investigation of photo-induced proton-coupled electron transfer and Dexter energy transfer in model systems
… the mechanistic interrogation of photo-induced proton coupled electron transfer (PCET) and proton-coupled (through-bond) energy transfer (PCEnT) are presented. PCET is ubiquitous in Nature, where it is at the heart of bioenergy conversion and catalysis (Chapter I). Systems of relevance to …
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Photoinitiated proton-coupled electron transfer and radical transport kinetics in class la ribonucleotide reductase
Proton-coupled electron transfer (PCET) is a critical mechanism in biology, underpinning key processes such as radical transport, energy transduction, and enzymatic substrate activation. Ribonucleotide reductases (RNRs) rely on PCET to mediate the rate-limiting step in the synthesis of DNA …
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Kinetics and dynamics controlling proton-coupled electron transfer in ribonucleotide reductase
Proton-coupled electron transfer (PCET) reactions comprise a fundamental mechanism for energy transduction in nature. In catalyzing the conversion of ribonucleotides to deoxyribonucleotides, ribonucleotide reductase (RNR) performs reversible, long-range PCET over a pathway of redox active amino …
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