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Dissertations / Theses on the topic 'Electron Transfer'

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Author: Grafiati

Published: 4 June 2021

Last updated: 25 May 2024

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1

Moore, Evan Guy. "A macrocyclic scaffold for electronic energy transfer and photoinduced electron transfer /." St. Lucia, Qld, 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17983.pdf.

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2

Wilson, Emma Katherine. "Electron transfer in and complex assembly of the trimethylamine dehydrogenase-electron transfer flavoprotein complex." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627132.

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3

Rasheed, Faiza. "Electron transfer reactions of tetrathiafulvalene." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294254.

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4

Kuzume, Akiyoshi. "Electron transfer at nanostructured interfaces." Thesis, University of Liverpool, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402324.

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5

Gosavi, Shachi S. Kuppermann Aron Marcus R. A. "Electron transfer at metal surfaces /." Diss., Pasadena, Calif. : California Institute of Technology, 2003. http://resolver.caltech.edu/CaltechETD:etd-03192003-095722.

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6

Robinson, Julian Neal. "Electron transfer in microheterogeneous systems." Thesis, University of St Andrews, 1990. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.751078.

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7

He, J. "Few-electron transfer devices for single-electron logic applications." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603913.

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Silicon-compatible single-electron circuit architectures may provide a promising solution for the development of very large-scale integrated circuits using nanoscale devices. In these circuits, single-electron charging effects may be used to control the transport of electrons with single-electron precision. Single-electron devices are also inherently small and have low power dissipation. This raises the possibility of very large-scale integrated circuits that combine large integration and low power dissipation. In this work, few-electron transfer devices, for use as the basic element for logic applications, are implemented using nanowire single-electron transistors, in silicon-on-insulator material. A two-way few-electron switch, based on the operation of two bi-directional electron pumps, was fabricated and characterised electrically at 4.2 K. The switch was implemented using three SETs and the circuit was driven by a sine-wave r.f. signal. It was possible to switch few-electron packets ~ 600 electrons in size, using an input gate voltage, from one entry branch into one of two exit branches. Another few-electron transfer device, the ‘universal electron switch’, similar in the general design to the two-way switch, was also fabricated and characterised at 4.2 K. This switch can switch electron packets ~ 10 electrons in size, from any one of three branches to any other branch. These switches may be used for the precise transfer and steering of few-electron packets and as the basic element in few-electron logic applications, such as binary decision diagram logic applications. A radio-frequency single-electron transistor was also developed in silicon-on-insulator material. This device incorporates an SET with an LC resonant circuit and forms a highly-sensitive fast-response electrometer. This device was characterised using 813 MHz microwave at 4.2 K, in order to investigate the high frequency response of an SOI single-electron transistor.

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8

Gardel, Emily Jeanette. "Microbe-electrode interactions: The chemico-physical environment and electron transfer." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11185.

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This thesis presents studies that examine microbial extracellular electron transfer that an emphasis characterizing how environmental conditions influence electron flux between microbes and a solid-phase electron donor or acceptor. I used bioelectrochemical systems (BESs), fluorescence and electron microscopy, chemical measurements, 16S rRNA analysis, and qRT-PCR to study these relationships among chemical, physical and biological parameters and processes.
Engineering and Applied Sciences

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9

Hassan, Md Mahamudul. "Role of biological electron mediators in microbial extracellular electron transfer." Thesis, Hassan, Md Mahamudul (2018) Role of biological electron mediators in microbial extracellular electron transfer. PhD thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/42418/.

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Electron mediators are redox active compounds capable of mediating electron transfer from a donor to acceptor. In microbial systems, electron mediators play a key role in extracellular electron transfer processes to assist the bacteria to thrive under unusual environmental conditions. Electron mediators are known to facilitate electron transfer from the bacterial cells to their electron acceptors which are insoluble (e.g. Fe3+, Mn4+) or toxic (e.g. oxygen for anaerobes). Interspecies electron transfer between different microbial species is also known to be driven by electron mediators. In this case, one species uses the oxidized mediator as electron acceptor and reduces it while the other species uses the reduced mediator as electron donor. The involvement of electron mediators in these electron transfer processes has led to extensive investigation to elucidate their contribution in microbial ecosystems. The aim of this thesis is to investigate the role of microbially produced electron mediators in facilitating microorganisms to thrive in selected environments that are of human concern. In this study, a novel electrochemical tool was developed that allows characterization of the electron mediators more effectively than the conventional techniques. The proposed method offered much better sensitivity and resolution compared to the conventional technique in detecting electron mediators. Conventional electrochemical studies use the three-electrode electrochemical cell which is equipped with only one controllable working electrode (WE). The other two electrodes serve as counter and reference electrodes. The traditional one-WE setup is based on the oxidation or reduction of the target molecule at different time interval as for example used in cyclic voltammetry. Having only one WE does not allow mimicking redox condition of the microbial systems where oxidation and reduction occur simultaneously. In order to test for the presence of redox active mediators, a new apparatus and technique was developed that consists of two independently controllable WEs which enable the generation of redox gradient between the WEs to allow simultaneous oxidation and reduction of the target redox active mediator. By using this redox gradient generating property, a new method was developed that characterizes electron mediators within a thin layer microscale (250 μm) system without the need of a bulk solution and associated mass transfer. Electrochemical properties of electron mediators were characterized by stepwise shifting a “voltage window” (maintaining 0.05 V potential difference between two WEs) within a range of potentials (between –1 V and +0.5 V vs. Ag/AgCl) and monitoring the establishment of steady equilibrium current in both WEs. The resulting current difference between two WEs was recorded for each voltage step of the “voltage window”. Results indicated that this technique enabled identification (by the distinct peak locations at the potential scale) and quantification (by the peak of current) of individual mediators as well as several mediators in an aqueous mixture. This technique enabled the precise determination of the mid-potential of hexacyanoferrate (HCF), riboflavin (RF) and two mediators from the pyocyanin-producing P. aeruginosa (WACC 91) culture. The capability of Twin-WE approach in detecting unknown electron mediators from a microbial culture confirms its suitability in studying microbial extracellular electron transfer (EET) processes. The Twin-WE electrochemical cell was used to investigate the role of the bacterial mediator PYO in electron transfer processes accomplished by its producer P. aeruginosa (PA), a high impact bacterium from human health perspective. Pyocyanin (PYO) is a redox active compound present in the biofilm of P. aeruginosa and believed to mediate an electron transfer from PA cells to oxygen for assisting PA to respire under oxygen limited condition. In contrast to widely held belief, this study shows that reduced PYO v (RedPYO) is not readily oxidized by oxygen unless catalyzed by living cells. The results are supportive to a scenario in which PYO can extract electrons from other living cells by oxidizing their NADH. The resulting RedPYO can be utilized as electron donor for oxygen or nitrate respiring PA cells. While this PYO mediated electron transfer resembles syntrophic interspecies electron transfer, it suggests, in this case, the existence of a not yet described form of energy parasitism. The discovery of this parasitic life style puts a new perspective on the role of PYO in biofilms, its natural soil environment and host infections. The existence of a similar electron extracting mechanism of PYO was also investigated in microbially influenced corrosion (MIC). MIC is a complex bio-electrochemical process where the exposure of the metal to microorganisms and their metabolic products causes dissolution of metal ions. Corrosion of steel occurs due to the existence of simultaneous anodic and cathodic reactions on the steel surface. At the cathodic site, steel loses electrons which consequently causes the dissolution of ferrous ions at the anodic site. Under aerobic condition, steel loses electrons from the cathodic site to oxygen. MIC has been described as bacteria rely on mediators to use electrons from the cathode under anaerobic conditions. The potential role of bacterial mediators to influence corrosion in the presence of oxygen has not been investigated yet. The capability of PYO to extract electrons from living cells was translated to electron extraction from corroding steel. Results showed that PYO can more efficiently harness electrons from the steel than oxygen alone. The reduced PYO thus generated (RedPYO) subsequently can transfer electrons to oxygen. The corrosion rate as determined by the release of dissolved iron was increased by two-fold when carbon steel was exposed to PYO compared to the exposure to a PYO free electrolyte under oxygen saturated environment. This increase in corrosion rate can be explained by the existence of a PYO mediated electron flow from the steel to the oxygen which accelerated the cathodic half reaction. PA cells can also benefit from this electron flow to generate cellular energy (ATP) using RedPYO as the electron donor for oxidative phosphorylation. Hence, PA and PYO containing biofilms could be described as catalyst of the cathodic reaction of corroding iron. To our knowledge, this is the first study to demonstrate the role of a biological electron mediator in influencing aerobic corrosion by cathodic stimulation. Overall, this thesis has contributed towards improving the understanding of microbial mediators, their detection and possible role in microbial consortia and in interaction of microbes with reducing surfaces such as steel constructions.

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10

Kawai, Shota. "Studies on Electron Transfer Pathway and Characterization of Direct Electron Transfer-Type Bioelectrocatalysis of Fructose Dehydrogenase." Kyoto University, 2015. http://hdl.handle.net/2433/199346.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第19022号
農博第2100号
新制||農||1030(附属図書館)
学位論文||H27||N4904(農学部図書室)
31973
京都大学大学院農学研究科応用生命科学専攻
(主査)教授加納健司, 教授阪井康能, 教授小川順
学位規則第4条第1項該当

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11

Dosche, Carsten, Wulfhard Mickler, Hans-Gerd Löhmannsröben, Nicolas Agent, and K. Peter C. Vollhardt. "Photoinduced electron transfer in [N]phenylenes." Universität Potsdam, 2007. http://opus.kobv.de/ubp/volltexte/2007/1246/.

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First studies of electron transfer in [N]phenylenes were performed in bimolecular quenching reactions of angular [3]- and triangular [4]phenylene with various electron acceptors. The relation between the quenching rate constants kq and the free energy change of the electron transfer (ΔG0CS ) could be described by the Rehm-Weller equation. From the experimental results, a reorganization energy λ of 0.7 eV was derived. Intramolecular electron transfer reactions were studied in an [N]phenylene bichomophore and a corresponding reference compound. Fluorescence lifetime and quantum yield of the bichromophor display a characteristic dependence on the solvent polarity, whereas the corresponding values of the reference compound remain constant. From the results, a nearly isoenergonic ΔG0CS can be determined. As the triplet quantum yield is nearly independent of the polarity, charge recombination leads to the population of the triplet state.

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12

Sekretaryova, Alina. "Facilitating electron transfer in bioelectrocatalytic systems." Doctoral thesis, Linköpings universitet, Kemiska och optiska sensorsystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-125242.

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Bioelectrocatalytic systems are based on biological entities, such as enzymes, whole cells, parts of cells or tissues, which catalyse electrochemical processes that involve the interaction between chemical change and electrical energy. In all cases, biocatalysis is implemented by enzymes, isolated or residing inside cells or part of cells. Electron transfer (ET) phenomena, within the protein molecules and between biological redox systems and electronics, enable the development of various bioelectrocatalytic systems, which can be used both for fundamental investigations of enzymatic biological processes by electrochemical methods and for applied purposes, such as power generation, bioremediation, chemical synthesis and biosensing. Electrical communication between the biocatalyst’s redox centre and an electrode is essential for the functioning of the system. This can be established using two main mechanisms: indirect ET and direct ET. The efficiency of the ET influences important parameters such as the turnover rate of the biocatalyst, the generated current density and partially the stability of the system, which in their turn determine response time, sensitivity, detection limit and operational stability of biosensing devices or the power densities and current output of biofuel cells, and hence should be carefully considered when designing bioelectrocatalytic systems. This thesis focuses on approaches that facilitate ET in bioelectrocatalytic systems based on indirect and direct ET mechanisms. Both fundamental aspects of ET in bioelectrocatalytic systems and applications of such systems for biosensing and power generation are considered. First, a new hydrophobic mediator for oxidases – unsubstituted phenothiazine and its improved ET properties in comparison with commonly used mediators are discussed. Application of the mediator in electrochemical biosensors is demonstrated by glucose, lactate and cholesterol sensing. Utilisation of mediated biocatalytic cholesterol oxidation, as the anodic reaction for the construction of a biofuel cell acting as a power supply and an analytical device at the same time, is investigated to deliver a selfpowered biosensor. Also the enhancement of mediated bioelectrocatalysis by employment of microelectrodes as a transducer is examined. The effect of surface roughness on the current response of the microelectrodes under conditions of convergent diffusion is considered. The applicability of the laccase-based system for total phenol analysis of weakly supported water is demonstrated. Finally, a new electrochemical approach derived from collision-based electrochemistry applicable for examination of the ET process of a single enzyme molecule is described. All together, the results presented in this thesis contribute to the solution of the ‘electronic coupling problem’, arising when interfacing biomolecules with electronics and limiting the performance of bioelectrocatalytic systems in specific applications. The developed methods to facilitate ET will hopefully promote future biosensing devices and biofuel cells. I believe the new approach for investigation of ET processes at a single enzyme molecule will complement existing single molecule techniques, giving further insights into enzymatic ET mechanisms at the molecular level and filling the gap between fundamental understanding of biocatalytic processes and their potential for bioenergy production.

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13

Lee, Lester Y. C. "Transmembrane electron transfer in artificial bilayers /." Full text open access at:, 1985. http://content.ohsu.edu/u?/etd,86.

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14

Guo, Liang-Hong. "Electrochemical studies of biological electron transfer." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.258256.

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15

Wilson, L. M. "Electron-transfer properties of polynuclear complexes." Thesis, University of East Anglia, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374277.

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16

White, R. P. "Spectroscopic probes for electron transfer phenomena." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382862.

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17

Beoku-Betts, D. F. "Electron transfer reactions of photosynthetic proteins." Thesis, University of Newcastle Upon Tyne, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353440.

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18

Garcia-Gonzalez, Monica. "Electron transfer across self-assembled monolayers." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385394.

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19

Mahesh, Mohan. "Expanding the scope of electron-transfer." Thesis, University of Strathclyde, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424298.

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20

Hilmer, Andrew J. (Andrew Joseph). "Engineering nanocarbon interfaces for electron transfer." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/83783.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 131-141).
Electron-transfer reactions at nanometer-scale interfaces, such as those presented by single-walled carbon nanotubes (SWCNTs), are important for emerging optoelectronic and photovoltaic technologies. Electron transfer also governs a primary means by which these interfaces are chemically functionalized and subsequently manipulated. This thesis explores several chemical approaches to understanding and controlling charge transfer at nanocarbon interfaces. In the first part of this thesis, we explore ground-state electron transfer via the chemical reaction of SWCNTs with selected diazonium salts as a means of controlling the number of moieties attached to a given nanotube. We initially explore this reaction theoretically using a kinetic Monte Carlo simulation, with rate parameters evaluated using Gerischer-Marcus theory, in order to examine the extent to which these reactions can be controlled stoichiometrically. These modeling results indicate that heterogeneities in SWCNT chiral population result in a large variance in the number of covalent defects, even at low conversions, thereby limiting the ability to control these reactions through stoichiometry. We then experimentally examine the ability to impart an additional degree of control over these reactions through utilization of the adsorbed surfactant layer. Surfactants are commonly employed in the processing of nanoparticles to impart colloidal stability to otherwise unstable dispersions. We find that the chemical and physical properties of adsorbed surfactants influence the diazonium reaction with SWCNT in several ways. Surfactants can impose electrostatic attraction or repulsion, steric exclusion, and direct chemical modification of the reactant. Electrostatic effects are most pronounced in the cases of anionic sodium dodecyl sulfate and cationic cetyltrimethylammonium bromide, where differences in surfactant charge can significantly affect the ability of the diazonium ion to access the SWCNT surface. For bile salt surfactants, with the exception of sodium cholate, we find that the surfactant wraps tightly enough that exclusion effects are dominant. Here, sodium taurocholate exhibits almost no reactivity under the explored reaction conditions, while for sodium deoxycholate and sodium taurodeoxycholate, we show that the greatest extent of reaction is observed among a small population of nanotube species, with diameters between 0.88 and 0.92nm. The anomalous reaction of nanotubes in this diameter range implies that the surfactant is less effective at coating these species, resulting in a reduced surface coverage on the nanotube. Contrary to the other bile salts studied, sodium cholate enables high selectivity toward metallic species and small band-gap semiconductors, which is attributed to surfactant-diazonium coupling to form highly reactive diazoesters. We subsequently move on to examine excited-state electron transfer events between SWCNTs and fullerenes. This electron transfer system is distinct from the diazonium system since it does not result in the formation of a covalent bond between the donor and acceptor species. To study this interface, we synthesized a series of methanofullerene amphiphiles, including derivatives of C60 , C70, and C84, and investigated their electron transfer with SWCNT of specific chirality, generating a structure/reactivity relationship. In the cases of lipid-C61-PEG and lipid-C 71-PEG, which are predicted to similar surfactant surface coverages, band-gap dependent, incomplete quenching was observed across all semiconducting species, indicating that the driving force for electron transfer from SWCNT is small. This is further supported by a Marcus theory model, which predicts that the energy offsets between the SWCNT conduction bands and the fullerene LUMO levels are less than the exciton binding energy of the SWCNT in these two systems. In contrast, the lipid-C 85-PEG derivative shows complete quenching of all SWCNT species utilized in this work. This enhancement in quenching efficiency is consistent with the fact that the LUMO level of C85 methanofullerene is approximately 0.35eV lower than that of the smaller fullerene adducts, resulting in energy offsets which exceed the exciton binding energy. This result, combined with the fact that C8 5 has much higher photo-stability than C61 and C71, makes this larger fullerene adduct a promising candidate for SWCNT-based sensors and photovoltaics. Finally, we design and synthesize fullerene derivatives that self-assemble into onedimensional arrays. We find that a dendritic fullerene, which possesses a Boc-L-Ser-L-Ala-OMe dipeptide sequence at its apex, selectively forms S-oriented, helical, one-dimensional nanowires upon cooling from an isotropic state in cyclohexane. These nanowires possess diameters of 3.76 ± 0.52nm, and can be several microns in length. Control molecules, which do not possess the dipeptide sequence, only produce poorly formed aggregates under identical conditions, indicating that dipeptide-dipeptide interactions are integral to assembly. These nanorods open new opportunities in the chiral assembly of novel electron acceptor materials for optoelectronic and photovoltatic applications.
by Andrew J. Hilmer.
Ph.D.

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21

Vieira, Rebecca. "Photoinduced electron transfer in ionic media." College Park, Md. : University of Maryland, 2008. http://hdl.handle.net/1903/8891.

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Thesis (Ph. D.)--University of Maryland, College Park, 2008.
Thesis research directed by: Dept. of Chemistry and Biochemistry. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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22

Ceres, Donato Marino Lewis Nathan Saul Barton Jacqueline K. "Electron transfer at DNA-modified electrodes /." Diss., Pasadena, Calif. : Caltech, 2006. http://resolver.caltech.edu/CaltechETD:etd-06202006-113417.

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23

Maulén, Jara Boris Eduardo. "Electron localization in intramolecular proton transfer." Tesis, Universidad de Chile, 2019. http://repositorio.uchile.cl/handle/2250/170285.

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Tesis para optar al grado de Magíster en Ciencias, Mención Física
The electron localization function (ELF) is a scalar field that accounts of the excess of electronic kinetic energy due to Pauli repulsion between electrons with the same spin. With this function, it is possible to divide real space in regions (basins) where electronic localization is high and Pauli repulsion is low (up-down electron pairs). From a phenomenological point of view, bifurcation points of the localization domains (points that belong to certain basins of a molecule) can be used to describe the rupture and formation of chemical bonds. Moreover, topological analysis of ELF allows us performing a statistical analysis of the electronic population of basins in a molecule. In this work, by using density functional theory with an hybrid exchange-correlation functional, we describe the electron localization along the intramolecular proton transfer in the Salicidene Methilamine molecule (SMA). First we do it in the ground state, in order to acquire physical insight of the process. Later, by means of time-dependent density functional theory (TD-DFT) in the linear response regime, we perform an equivalent analysis in the first excited state, for which we propose a way to compute ELF in excited states using TD-DFT. We show how the electronic population and other properties of interest of the basins associated with the atoms and bonds involved in the proton transfer change during the reaction. Finally, we choose this system because, after photoexcitation and proton transfer process, SMA suffers a large Stokes shift followed by a "closed" photocycle that ends with the molecule in its original ground state. This makes molecules like SMA good prospects for molecular photoswitches. The main contribution of this thesis is that this is the first time that the ELF developed and successfully used to explain chemical bonding in excited states.

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24

Maza, William Antonio. "Reaction Enthalpy and Volume Profiles for Excited State Reactions Involving Electron Transfer and Proton-Coupled Electron Transfer." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4539.

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Electron transfer, ET, and proton-coupled electron transfer, PCET, reactions are central to biological reactions involving catalysis, energy conversion and energy storage. The movement of electrons and protons in either a sequential or concerted manner are coupled in a series of elementary reaction steps in respiration and photosynthesis to harvest and convert energy consumed in foodstuffs or by absorption of light into high energy chemi-cal bonds in the form of ATP. These electron transfer processes may be modulated by conformational dynamics within the protein matrix or at the protein-protein interface, the energetics of which are still not well understood. Photoacoustic calorimetry is an estab-lished method of obtaining time-resolved reaction enthalpy and volume changes on the nanosecond to microsecond timescale. Photoacoustic calorimetry is used here to probe 1) the energetics and volume changes for ET between the self-assembled anionic uroporphy-rin:cytochrome c complex and the role of the observed volume changes in modulating ET within the complex, 2) the enthalpy and volume change for the excited state PCET reac-tion of a tyramine functionalized ruthenium(II) bis-(2,2'-bipyridine)(4-carboxy-4'-methyl-2,2'-bipyrine) meant to be a model for the tyrosine PCET chemistry carried out by cyto-chrome c oxidase and photosystem II, 3) the enthalpy and volume changes related to car-bon monoxide and tryptophan migration in heme tryptophan catabolic enzyme indoleam-ine 2,3-dioxygenase.

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25

He, Qizhi Chan Sunney I. Chan Sunney I. "Cytochrome c oxidase : studies of electron input and intramolecular electron transfer /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-10052007-085601.

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26

Armitage, Bruce Alan. "Photoinduced electron transfer, energy transfer and polymerization reactions in phospholipid membranes." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186212.

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The differential physical properties found at different depths of a phospholipid membrane permit design of systems for vectorial reactions (which are not possible in isotropic solution). In the system described in Chapter IV, a hydrophobic electron donor (triphenylbenzylborate) binds to the membrane interior while a hydrophilic electron acceptor (a cyanine dye) binds to the surface. Irradiation with red light leads to vectorial electron flow via photoinduced electron transfer (PET), as monitored by fluorescence quenching and photobleaching techniques. The PET reaction efficiency is enhanced over the case where the donor and acceptor are present in water without membranes. In that case, strong dimeric complexes are formed which reduce the efficiency of PET by enhancing nonradiative decay modes for the dye (Chapter III). Addition of a porphyrin to the membrane surface extends the sensitivity of the system to blue light (Chapter V). Excitation of the porphyrin at 417 nm and subsequent energy transfer to the cyanine trigger the same PET chemistry observed with red-light irradiation. Furthermore, the electron- and energy-transfer reactions are enhanced on polymerized, phase-separated membranes (Chapter VI). In these applications, membranes are media for chemical reactions. Membranes also make interesting substrates for chemical reactions, in this case, polymerization. A system consisting of a membrane-bound, amphiphilic cyanine dye and molecular oxygen is described in Chapter VII which effectively initiates the polymerization of vesicles upon irradiation with visible light. Potential utility in drug delivery applications is discussed.

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27

Lancaster, Kelly. "Intramolecular electron transfer in mixed-valence triarylamines." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31709.

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Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2010.
Committee Chair: Bredas, Jean-Luc; Committee Member: Kippelen, Bernard; Committee Member: Marder, Seth; Committee Member: Orlando, Thomas; Committee Member: Sherrill, David. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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28

Ernstorfer, Ralph. "Spectroscopic investigation of photoinduced heterogeneous electron transfer." [S.l. : s.n.], 2004. http://www.diss.fu-berlin.de/2004/268/index.html.

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29

Blair, Amber Dawn. "Controlling electron transfer at sensitized TiO₂ surfaces." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/52946.

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A series of three bis-tridentate ruthenium(II) complexes containing one cyclometalating ligand with terminal triphenylamine (TPA) substituents have been synthesized and characterized for insight into electron transfer reactions at TiO₂ surfaces. The structure of each complex conforms to a molecular scaffold formulated as [Ru(II)(TPA-2,5-thiophene-pbpy)(H₃tctpy)] (pbpy = 6-phenyl-2,2’-bipyridine; H₃tctpy = 4,4’,4”-tricarboxy-2,2’:6’,2”-terpyridine), where an electron-donating group (EDG) or an electron-withdrawing group (EWG) is installed about the anionic ring of the pbpy ligand and methyl groups surrounding the TPA-thiophene bridge. Modification of the anionic ring of the pbpy chelated with EDGs and EWGs enables the modulation of the Ru(III)/Ru(II) redox potential over 140 mV. This property offers the opportunity to turn on and off intramolecular hole transfer. Pulsed light laser excitation of the sensitized thin film resulted in rapid excited state injection and in some cases hole transfer to TPA [TiO₂(e⁻)/Ru(III)−TPA → TiO₂(e⁻)/Ru(II)−TPA･⁺. The rate constants for charge recombination of [TiO₂(e⁻)/Ru(III)−TPA → TiO₂/Ru(II)−TPA and TiO₂(e⁻)/Ru(II)−TPA･⁺ → TiO₂/Ru(II)−TPA] were drastically affected by modification of the bridging unit and can be modulated over 5.2 – 6.2×10⁵ s ⁻¹ and 1.7 – 5.1×10⁴ s⁻¹ respectively.
Science, Faculty of
Chemistry, Department of
Graduate

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30

Zhang, Bo. "Ferritin : mechanistic studies and electron transfer properties /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1533.pdf.

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31

Zettergren, Henning. "Electron transfer and fragmentation in fullerene collisions." Doctoral thesis, Stockholm : Department of Physics, Stockholm University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-630.

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32

Joseph, Daphne Melissa Thow. "Energy and electron transfer in Photosystem Two." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362720.

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33

Psalti, Ioanna S. M. "Microelectrodes : single and arrays in electron transfer." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302826.

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34

Salem, M. A. A. "Electron transfer activity of some oxide catalysts." Thesis, Queen's University Belfast, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374993.

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35

Mohamed-Ibrahim, M. I. "Electron transfer reactions of polynuclear complex ions." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235267.

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36

Amini, Ata. "Computational chemistry as applied to electron transfer." Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397288.

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37

Hamard, Jean-Benoit. "Investigation of electron transfer reactions in DNA." Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439590.

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38

Harrison, Robert J. "Photo-induced intramolecular proton and electron transfer." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329765.

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39

Hopper, Amanda Clare. "The electron transfer chains of Neisseria gonorrhoeae." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3280/.

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\(Neisseria gonorrhoeae\) is an obligate human pathogen that can use both oxygen and nitrite as electron acceptors, but its electron transfer chain has only been partially characterised. The gonococcus encodes one azurin, Laz, and eight c-type cytochromes. The aim of this project was to determine the functions of these redox proteins. Single mutants lacking cytochromes c2, c4 and c5 reduced oxygen at 126%, 84% and 80% of the parental rate, respectively. It was not possible to construct a double mutant defective in both cytochromes c4 and c5, unless an ectopic copy of cytochrome c5 was present, the expression of which was induced by IPTG. It was concluded that cytochromes c4 and c5 form a bifurcated electron transfer pathway between the cytochrome bc1 complex and the cytochrome cbb3 oxidase. Candidates for electron donors to the nitrite reductase, AniA, were Laz and cytochromes c2, c4 and c5. Mutants lacking various combinations of these redox proteins retained the ability to reduce nitrite, implicating the presence of further electron transfer pathways to AniA. Mutants defective in the third heme-binding domain of CcoP or the second domain of cytochrome c5 reduced nitrite at 52% and 39% of the parental rate, respectively. The double mutant still reduced nitrite, but at only 12% of the parental rate. It was concluded that the third heme group of CcoP and the second heme group of cytochrome c5 constitute the main electron transfer pathways to AniA, but a third pathway remains to be identified. Previous research failed to demonstrate the presence of cytochrome c2 on an SDS-PAGE gel stained for covalently bound heme. This was shown to be due to the low constitutive level of expression of this protein. Although a precise role for cytochrome c2 could not be determined, the data presented suggest that the protein could function either as an electron donor to AniA, an electron donor to ScoI, or as a regulator of electron flux to the terminal reductases. The combined data show that the plasticity of the gonococcal electron transfer chains allows this bacterium to respond rapidly to changes in terminal electron acceptor availability.

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40

Findlay, Neil. "The development of powerful electron-transfer reagents." Thesis, University of Strathclyde, 2010. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=22628.

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This thesis discusses the investigation into powerful electron-transfer reagents conducted in the research group of Professor John Murphy at the University of Strathclyde between October 2006 and March 2010. Chapter one discusses the principal themes and areas of chemical research that are contained within this thesis, providing useful background information. Section 1.1 introduces electrontransfer using metals and metal-based reagents, including the use of dissolving group 1 (and 2) metal reductions, transition metals and lanthanides. Section 1.2 discusses organic electron-transfer reagents, focussing on the development of more powerful reagents. Section 1.3 focuses on N-heterocyclic carbenes (NHCs), including their structure and properties, their use as organocatalysts and their employment as ligands. Finally, section 1.4 introduces the theme of electron-transfer using nickel complexes, including the formation of aldehydes using nickel(I) salen and the employment of nickel(0) and NHCs in the reduction of organic substrates. Chapters two, three and four discuss the results obtained during the development of powerful electron-transfer reagents. Chapter two reveals the surprising isolation of alcohols (e.g., 2.6) following the reduction of alkyl halides (e.g., 2.1) using a powerful organic electron-donor 1.150 (scheme i). The substrate scope is revealed, followed by mechanistic studies that investigate the mechanism that leads to alcohol formation. Several pathways were ruled out, allowing a single mechanism to be postulated as the most likely route for this transformation. Scheme i: the isolation of alcohol 2.6 from alkyl iodide 2.1 using organic electron donor 1.150. Chapter three discusses a novel, nickel(II) crown carbene complex 3.1 that, when activated, is a powerful electron-donor (figure i). The activated nickel complex, formed by treatment with sodium amalgam, is a powerful reductant that reduces carbonyl-containing compounds, both activated and non-activated sulfones and sulfonamides and the central aromatic ring of anthracene (and substituted analogues) in a Birch reduction. Extensive investigations into the active species using control experiments, cyclic voltammetry and computational analysis reveal the active species to be a nickel(II) ion bound to a di-anion ligand. Figure i: the structure of nickel(II) crown carbene complex 3.1. Chapter four describes attempts to formulate a catalytic, reductive procedure using electrochemical cycling to generate the catalytic electron-donor 1.177 (scheme ii). The screening of various proton sources is discussed, as well as the synthetic procedures used and the challenges still ahead. Scheme ii: the reduction of aryl halide 4.4 using electrochemically generated donor 1.177. Finally, Chapter five contains the experimental procedures and data for all synthesised compounds discussed within this thesis.

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41

Liu, Sidong. "Cytochrome c3 modules as electron transfer nanowires." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/12442.

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The tetraheme cytochrome c₃ from Desulfovibrio vulgaris Miyazaki F is involved in sulphate reduction. It contains four c-type hemes covalently bound to a single polypeptides of only 107 amino acids. The protein surface is highly positively charged at physiological pH with a prevalence of lysine residues. All four hemes are bis-histidine ligated and their reduction potentials are very low, ranging form -239 to -358 mV at neutral pH. With a cyclic heme arrangement and their partial exposure to solvent, cytochrome c₃ can transfer electrons in all directions. The purpose of this work is to develop novel methods of controlling the crosslinking selectivity of proteins constructing biological “nanowires” with cytochrome c₃ modules. The crosslinking functional groups are bismaleimide derivatives and the cysteine thiol. And construction strategies involve the electrostatic selection by controlling the surface charge distribution regulating the protein crosslinking, and the use of protein-peptide recognition (i.e. Calmodulin and its binding peptide) to block/protect the crosslinking sites. The electrochemical properties of cytochrome c₃ are also exploited by covalently attaching it to active centre buried redox enzymes (i.e. cytochrome P450 BM3 heme domain) and electrodes to form unique bioelectronic components, which could facilitate the electron transfer between enzymes and electrodes.

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42

Jones, Anne Katherine. "Investigations of electron transfer in redox enzymes." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393559.

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43

Venceslau, Sofia Cristina dos Santos. "Electron transfer chains in sulfate reducing bacteria." Doctoral thesis, Universidade Nova de Lisboa. Instituto de Tecnologia Química e Biológica, 2011. http://hdl.handle.net/10362/9779.

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Dissertação para a obtenção de grau de doutor em Bioquímica pelo Instituto de Tecnologia Química e Biológica. Universidade Nova de Lisboa.
The dissimilatory reduction of sulfur compounds (i.e.sulfate/sulfite reduction and sulfur disproportionation) is considered to have been one of the earliest metabolic processes on Earth able to sustain life. Dissimilatory sulfate reduction, using sulfate as an electron acceptor and organic compounds or hydrogen as electron donors, plays a significant role in the global sulfur and carbon cycles.(...)
Fundação para a Ciência e a Tecnologia (FCT)

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44

Fukui, Keijiro. "Photoinduced Electron Transfer in Acridine-Intercalated DNA." Kyoto University, 1997. http://hdl.handle.net/2433/202296.

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45

Singh, Priti. "The electron transfer chemistry of nitrosyl complexes." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-34223.

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46

Li, Debin. "Exploring electron transfer in myoglobin-based transistors." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10211.

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Thesis (Ph. D.)--West Virginia University, 2009.
Title from document title page. Document formatted into pages; contains xiii, 104 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 99-104).

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47

Shreve, Gary A. Lewis Nathan Saul. "Electron transfer at n-silicon-methanol junctions /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-10222007-110727.

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48

Langen, Ralf Warshel Arieh Gray Harry B. Richards John. "Electron transfer in proteins : theory and experiment /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-03062006-091606.

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49

Hamann, Thomas William Lewis Nathan Saul Lewis Nathan Saul. "Interfacial electron-transfer reactions at semiconductor electrodes /." Diss., Pasadena, Calif. : California Institute of Technology, 2007. http://resolver.caltech.edu/CaltechETD:etd-12272004-162841.

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50

Leigh, Brian Scott Richards John Gray Harry B. "Electron transfer through organic and biological molecules /." Diss., Pasadena, Calif. : California Institute of Technology, 2009. http://resolver.caltech.edu/CaltechETD:etd-08042008-115533.

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