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Dissertations / Theses on the topic 'NMR theory][High resolution NMR'

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Published: 4 June 2021
Last updated: 14 February 2022

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1

Davies, S. J. "Frequency-selective excitation and non-linear data processing in nuclear magnetic resonance." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233510.

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2

McManus, Jamie. "Residual broadening in high-resolution NMR of quadrupolar nuclei in solids." Thesis, University of Exeter, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367404.

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3

Vlassenbroek, Alain. "Radiation damping in High Resolution NMR." Doctoral thesis, Universite Libre de Bruxelles, 1993. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212811.

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4

Laage, Ségolène. "High-resolution solid-state NMR for proteins." Lyon, Ecole normale supérieure, 2010. http://www.theses.fr/2010ENSL0583.

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La RMN a récemment prouvé son potentiel en biologie structurale. Cette thèse décrit les méthodes que nous avons développées pour l’étude de protéines par RMN du solide à haute résolution. Après une présentation des récents progrès du domaine, nous présentons les améliorations liées à l’utilisation de la rotation à l’angle magique à très haute vitesse, notamment les techniques de découplage hétéronucléaire et de polarisation croisée à basse puissance, appliquées aux cas de la Superoxide Dismutase (SOD) et de la protéine GB1. Nous détaillons ensuite les perspectives émergeant dans l’utilisation des couplages J, avec trois nouvelles séquences. La J-CHHC renseigne sur les distances entre protons, le bloc S3E améliore résolution et sensibilité en effectuant du découplage J, et l’INADEQUATE-S3E combine transfert de polarisation par couplage J et découplage J. Nous donnons enfin des perspectives de mesure de longues distances par l’exploitation des propriétés paramagnétiques de la Cu(II) SOD
Solid-state NMR recently proved its potential for structural biology. This thesis details metods we developed for high resolution NMR of nanocrystalline proteins. After an introductory presentation of the recent advances in solid-state NMR of bio-systems, we present the improvements we proposed in the ultra-fast magic-angle spinning regime, notably low-field heteronuclear decoupling and low-field cross-polarization. We demonstrate them with the study of the Superoxide Dismutase (SOD) and the protein GB1. We then focus on the perspectives arising for J-couplings in proteins by presenting three new sequences. The J-CHHC sequence probes 1H-1H distances encoded in 13C-13C correlation experiments. The S3E block improves resolution and sensitivity by performing J-decoupling, and the INADEQUATE-S3E combines J-based transfer of polarization and J-decoupling. We finally give perspectives to probe long-range structural constraints with data exploiting the paramagnetic properties of Cu(II)-SOD
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5

Cookson, Nikki Jade. "High-resolution NMR studies of nano-cages." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/13745/.

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This thesis concerns the NMR investigations of supramolecular metallo-nanocages as hosts for host-guest chemistry. The research is based on metallo-nanocages constructed from cyclotriveratrylene (CTV)-derivatives The host-guest interaction between the [Pd6(L1)8]⋅12(BF4) stella octangula cage and sodium alkyl sulfate guests have been characterised by 1H 1 D, DOSY and 2-D ROESY NMR and ESI-MS. The host-guest stoichiometry was determined at 1:2 by Job’s plot analysis. The shorter the length of the guest’s alkyl tail, the more tightly bound it was to the host cage. The self-assembly and self-sorting of the [Pd6(L1)8]⋅12(BF4) stella octangula cage were also investigated. d6-DMSO competed with the L1 ligand for the palladium(II) cation. The rate of self-sorting of the [Pd6(L1)8]⋅12(BF4) stella octangula cage was found to be affected by concentration, with lower concentrations resulting in cage systems that self-sorted in to homochiral cages at a faster rate. The novel FL1 ligand was characterised by 1H and 19F NMR spectroscopy in d6 DMSO and d3 MeCN and was used to produce stella octangula cage assemblies. The self-assembly of this system in d6 DMSO was observed and found to require an excess of palladium to form. This FL1 system was also investigated for host-guest interactions with sodium dodecyl sulfate (SDS). It formed a system that exhibited weaker binding than L1. The FL1 ligand formed quantitative cages in d3 MeCN. This system was characterised by 1H and 19F NMR spectroscopy, 2-D ROESY NMR, ESI-MS and X-ray crystallography. The L1 and FL1 ligands were used to form cryptophanes with [1,3 bis(diphenylphosphino)propane] in d6 DMSO, d3 MeCN and d3 MeNO2. These were characterised by 1H, 19F, 31P NMR spectroscopy, 2-D ROESY NMR, ESI-MS and X-ray crystallography. Both ligands showed a strong preference for anti cryptophane isomers in solution, although a small amount of syn isomer was observed in the L1 systems. The syn isomer was predominant species in the solid state.
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6

Thornton, John Stephen. "Instrumentation for low cost, high resolution NMR imaging." Thesis, University of Manchester, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358563.

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7

Dowell, Nicholas G. "Further developments in high-resolution quadrupolar NMR spectroscopy." Thesis, University of Exeter, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407274.

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8

Salager, Elodie. "High-resolution solid-state NMR for powder crystallography." Lyon, Ecole normale supérieure, 2010. http://www.theses.fr/2010ENSL0592.

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La connaissance de la structure tridimensionnelle d’un composé solide est essentielle pour la compréhension de ses propriétés et le développement de nouveaux matériaux. La diffraction des rayons X est communément utilisée pour déterminer la structure des composés monocristallins. La caractérisation structurale de composés sous forme de poudre présente plus de difficulté. En particulier, beaucoup de composés ne peuvent pas être obtenus sous forme de monocristaux ; et les composés hautement polymorphiques (tels que la plupart des médicaments) doivent être caractérisés « tels quels » afin de limiter les risques de modification structurale. Cette thèse présente de nouvelles méthodes de cristallographie de poudre par résonance magnétique nucléaire (RMN) du solide à haute résolution, i. E. La détermination de la structure, en abondance isotopique naturelle, de composés en poudre par RMN. Dans une première partie, le cas complexe de la résolution des spectres proton est abordé. Les possibilités offertes par la dernière génération de sondes RMN sont explorées et de nouvelles méthodes de découplage sont proposées. Dans la deuxième partie, des protocoles de détermination structurale sont développés. Ces derniers s’appuient sur la forte dépendance des paramètres RMN avec les détails de la structure cristalline, et profitent de la haute résolution accessible en RMN du solide pour les protons et les carbones. Ces techniques sont appliquées à un composé test, le thymol, et démontrent le potentiel de la RMN du solide pour la résolution de la structure cristalline de composés en poudre
Knowledge of the three-dimensional structure is an invaluable element for the understanding of the properties of solid materials and towards the development of new materials. While single-crystal X-ray diffraction is established as the best tool to characterise monocrystalline samples, the experimental determination of the structure of polycrystalline powders remains a challenging domain. Many crystalline solids cannot be prepared as single crystals and must be characterized in the powder form. Other compounds are highly subject to polymorphism, and there is a need for structural determination techniques that minimize the risk of structural change during the characterisation. The problem is particularly relevant in the case of drug powders, which need to be accurately characterized in their active pharmaceutical form. This thesis presents new developments relating to powder nuclear magnetic resonance (NMR) crystallography, i. E. Structure determination of powdered samples using high-resolution solid-state NMR at natural isotopic abundance. The first part of the thesis concentrates on the challenging case of protons and illustrates the opportunities offered by the latest generation of commercial NMR probes and new decoupling methods. Protocols are proposed in the second part, which benefit of the high-resolution solid-state NMR spectra accessible for protons and carbons and which make use of the strong dependence of the NMR parameters on crystalline structure details. These techniques are successfully applied to a model compound, thymol, and demonstrate the potential of solid-state NMR for structural determination of powdered compounds
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9

Kervern, Gwendal. "High-resolution solid-state NMR of paramagnetic molecules." Lyon, École normale supérieure (sciences), 2008. http://www.theses.fr/2008ENSL0483.

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Cette thèse porte sur la RMN haute résolution de composés paramagnétiques solides. Elle présente de nouvelles méthodes permettant d'obtenir de tels spectres, ainsi que l'exploitation des spectres ainsi obtenus pour la caractérisation structurale de complexes paramagnétiques. Nous avons dans un premier temps développé des méthodes qui permettent de surmonter les difficultés liées au paramagnétisme. Ces méthodes inclues du transfert d'aimantation par recouplage dipolaire, l'adaptation d'impulsions adiabatiques pour les solides en rotation à très haute vitesse et la compréhension des phénomènes mis en cause dans leur efficacité. Nous présentons ensuite l'exploitation des données ainsi obtenues. Notamment pour la caractérisation de la structure électronique d'un catalyseur à base de fer à haut spin, la démonstration de l'absence de relaxation dite "de Curie" dans les solides ainsi que le développement d'un nouvel outil de cristallographie par RMN de poudres
This thesis is about high-resolution solid-state NMR of paramagnetic molecules. It exposes new methods to obtain high-resolution NMR spectra of paramagnetic solids. These methods gave us access to the structural information born by the electronic paramagnetism. In the first part, we propose new tools to overcome the difficulties associated with NMR of paramagnetic solids. These methods include proton to carbon magnetization transfer via dipolar recoupling, the use of adiabatic pulses with paramagnetic solids rotating at high MAS speeds, the development of a theory for a better understanding of the physics of such pulses. The second part exposes the interpretation of the high quality spectra obtained throught those methods. We characterized the electronic structure of high-spin iron (II) catalyst, we tackled the absence of the so-called "Curie relaxation" mechanism in the solid-state an we developed a new tool for crystallography thanks to proton NMR of paramagnetic powedrs
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10

Odedra, Smita. "Some novel developments in high-resolution NMR spectroscopy." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5772/.

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The radiofrequency (rf) pulses used in NMR are subject to a number of imperfections, such as those resulting from the inhomogeneity of the rf field or an offset of the transmitter frequency from exact resonance. In spin-echo experiments, these imperfections yield spectra with reduced signal intensity and distorted phase. Composite pulses, which have tailored bandwidth properties with respect to experimental frequency parameters such as the rf field strength or resonance offset, offer a route to improving the amplitude of the spin-echo signal. However, the symmetry of the pulse sequence must be carefully considered to prevent the introduction of phase errors into the spin-echo signal. Here, composite pulses will be studied as a means to improving one of the most common techniques for 1H background suppression in MAS NMR, the ”Depth” sequence. Novel composite 180° pulses will be presented for this application and verified experimentally. The composite pulse Depth experiment yields spectra with improved amplitude of the 1H signals of interest, while successfully maintaining good suppression of background signals. Novel families of dual-compensated 180° composite pulses for I = 1/2 will also be designed for use in NMR spin-echo experiments. These pulses are capable of simultaneously compensating for resonance offset and rf inhomogeneity problems. Crucially, unlike many composite pulses that have been presented before, these new pulses have the correct symmetry properties to form a spin echo without phase distortion. Composite pulses have found wide usage in solution-state NMR, and although in principle the same pulses can be applied in solid-state NMR experiments, complications can arise under magic angle spinning (MAS). The effects of MAS on composite pulse performance will be explored both through computer simulations and 31P experiments. Finally, on a different theme, we will investigate spin-locking of half-integer quadrupolar nuclei in solids. Spin-locking is an important feature of many NMR experiments, yet the complex behaviour observed for quadrupolar nuclei is not fully understood. Using the theoretical model introduced by Ashbrook and Wimperis, we will investigate the far off-resonance case of spinlocking for I = 3/2 and I = 5/2 nuclei.
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11

Foxall, Peta Jane Dunckley. "High resolution NMR spectroscopic investigations into renal allograft function." Thesis, Birkbeck (University of London), 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488683.

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12

Searle, M. S. "High resolution NMR studies of antifolate drug-receptor complexes." Thesis, Open University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484411.

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13

Carss, Steven Andrew. "High-resolution NMR studies of solid halogenated organic compounds." Thesis, Durham University, 1995. http://etheses.dur.ac.uk/5208/.

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This thesis is a study of solid halogenated organic compounds by Nuclear Magnetic Resonance Spectroscopy (NMR) in an attempt to extract previously inaccessible information. The first part of the thesis is concerned with three fluorinated steroids, studied by observing (^1)H, (^13)C and (^19)F nuclei. A number of experimental techniques are employed to verify solution-state and solid-state spectral assignments, and spectral anomalies are discussed. Both proton-coupled and proton-decoupled (^19)F solid-state spectra, recorded using specially designed spectrometer hardware, are presented. The huge gain in resolution afforded by the implementation of proton decoupling allows static and MAS spectra to yield previously inaccessible information pertaining to various NMR parameters of the fluorine nuclei. Advantages of (^1)H→(^19)F cross-polarisation experiments over single-pulse experiments are explained and rotational resonance, dipolar dephasing, T(_1), measurement and spin-exchange experiments are presented from which information regarding phenomena such as spin diffusion and polymorphism is gleaned. The second part of the thesis focusses on the topic of residual dipolar coupling, the transfer of quadrupolar effects to spin-1/2 nuclei via dipolar coupling and/or anisotropy m indhect coupling. Unexpected, field-dependent, multiplicities for signals in spectra of spin-1/2 nuclei are observed, which can be used to evaluate certain fundamental NMR parameters including the quadrupolar coupling constant and, m favourable cases, anisotropy in indirect coupling. The phenomenon is comprehensively studied for the (^13)C, (^35,37)Cl and (^13)C, (^79,81)Br spin-pairs in a range of solid halogenated compounds. Coupling to more than one halogen nucleus and long- range (non-bonded) coupling are considered. First-order perturbation, inverse first- order and "exact" theories, that allow the multiplet line positions to be predicted, are introduced and their results are subsequently compared to the experimentally observed the positions. Rapid molecular motion is shown to negate the effects of residual dipolar coupling and the phenomenon is analysed with the aid of NQR measurements.
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14

Mattila, S. (Sampo). "Measurement and minimization of field inhomogeneities in high resolution NMR." Doctoral thesis, University of Oulu, 2001. http://urn.fi/urn:isbn:9514264762.

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Abstract In this work, the homogeneity of both the B0 and B1 fields was studied. Both B0 and B1 field homogeneities are the basic assumptions of high resolution liquid state NMR. Although some inhomogeneity of both of the fields is always present, the spectrometers can be operated, with the help of the developed spectral purging techniques, without giving any thought to the field inhomogeneities or the necessary actions to minimize their adverse effects. Although the effect of B0 inhomogeneity can occasionally be seen, the B1 fieldin a modern probe head is often assumed to be sufficiently homogenous for any practical purpose. By using the method used in this study the B1 field strength along one axis, typically the z-axis, can be easily mapped. Based on the information gathered from a single experiment, one can obtain reliable and valuable information about the B1 field distribution, e.g. homogeneity of the coil. From such information, the degree of required artifact suppressing methods for successful NMR experiments can be determined. Since normal pulse length calibration also requires the acquisition of several 1-D spectra, the required experimentation time is not increased. Although the maximum amount of signal from an NMR experiment is obtained when the signal is acquired from a maximum number of resonating spins, the results presented show that significantly more homogenous B1 field along the active sample volume is achieved by rejection of the signal originating from the outer parts of the coil length. Although the total amount of signal obtained from the outer parts of the RF-coil is not very high, some loss of signal is associated with the spatially selective acquisition. The rejected signal, however, is a significant source of artifacts, and if no precautions were taken, the artifacts would severely decrease the quality of the acquired data. If the sample concentration can be increased, it would be advantageous to dissolve the amount of sample available in as small an amount of solvent as is possible and place the sample in the most B1 homogenous part of the probe-head RF-coil. With the same amount of nuclear spins concentrated into a smaller volume, the sensitivity of an NMR experiment can be increased manifold. As an application of a spatially selective data acquisition, a versatile method capable of producing a map of the B0 field strength and its variation along the sample volume is presented.
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15

Barnes, Alexander B. (Alexander Benjamin). "High-resolution high-frequency dynamic nuclear polarization for biomolecular solid state NMR." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/65263.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, June 2011.
Vita. Cataloged from PDF version of thesis.
Includes bibliographical references.
Dynamic Nuclear Polarization (DNP) has exploded in popularity over the last few years, finally realizing its potential to overcome the detrimental lack of sensitivity that has plagued performing NMR experiments. Applied to magic angle spinning (MAS) experiments, this renaissance of DNP has been primarily driven by the development of instrumentation; namely gyrotron oscillators as high-power stable microwave power sources and the NMR probes and associated equipment required to spin samples routinely below 100 Kelvin. The first three chapters of this thesis provide an overview of the theory, instrumentation, and applications of DNP. Chapter 1 introduces the magnetic resonance Hamiltonian with a focus on interactions that are necessary to control in order to obtain high-resolution DNP spectra. Chapters 2 and 3 are published reviews of DNP. Whereas Chapter 2 targets magnetic resonance spectroscopists, Chapter 3 is intended for an electric engineering audience. Both reviews are included as the associated depth and coverage of the topics are complementary and lead to a better understanding of DNP. The later chapters describe in detail advancements in probe, cryogenics, and gyrotron technology required to perform DNP MAS experiments, as well as the gains in sensitivity and resolution such instrumentation has permitted. Of particular importance is the development of a cryogenic sample ejection system that resulted in exquisite resolution of spectra recorded <100 K, both of crystalline peptide and the active site of membrane proteins. Such developments in instrumentation and demonstrations of resolution go towards overturning a long-held stance in the field that DNP would always suffer from broadened, unresolved spectra. Such techniques also allow us to investigate site specific dynamics of a crystalline peptide, the high resolution SSNMR structure of which is discussed in Chapter 3. DNP and the developed instrumentation is also leveraged to measure inter-atomic distances in the active site of a membrane protein with sub-angstrom precision. Chapters 7 describes the calculation of the microwave field strength across the sample in a MAS DNP probe and introduces strategies to increase it. Finally Chapter 8 introduces a major advance in the microwave source technology associated with DNP experiments. Detailed designs of a novel 250 GHz gyrotron oscillator are shown and experiments demonstrate a continuous broad 3 GHz bandwidth with >10 W across the band, which results in substantially improved DNP performance.
by Alexander B. Barnes.
Ph.D.
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16

Krajewski, Marcin. "NMR high resolution spectroscopy of medically relevant proteins and their antagonists." [S.l.] : [s.n.], 2006. http://mediatum2.ub.tum.de/doc/601476/document.pdf.

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17

Aslimovska, Lubica. "High resolution structural studies of membrane proteins using solid state NMR." Thesis, University of Oxford, 2008. http://ora.ox.ac.uk/objects/uuid:6b72463e-92cf-4ecd-bdc3-26b2f900e813.

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NMR crystallography is a new and developing area. Unlike solution state NMR, solid state NMR has the potential for structural studies of large, motionally restricted biological macromolecules, such as proteins in crystals which may, or may not, diffract. However, finding the best and the most useful sample form and geometry is still a major obstacle to rapid progress. Little has been reported about protein sample preparation for any class of protein for NMR crystallography, mainly since the availability of NMR labelled proteins is still not routine, especially for eukaryotic membrane proteins. The amino acid L-glutamate is the major excitatory neurotransmitter in the brain. Details of glutamate binding to any of its main brain or sensory receptors are not well resolved at the atomic level. In an effort to resolve the glutamate binding mechanism by solid state NMR methods, full-length taste and brain mGluR4 were expressed in E. coli, but proved to be toxic for the cells. The ligand-binding domains (LBD) of mGluR4, with various fusions for the periplasmic expression and with various fusions for expression in the cytoplasm therefore, were used. Solubilisation and then purification of the LBD from inclusion bodies is still under way, no crystals of mGluR4 for NMR were, therefore, grown. Initial NMR spectra of labelled 13C, 15N and 17O glutamate have been recorded to verify sensitivity requirements. Using homology modelling, a model for the truncated version of the ligand binding domain of mGluR4 has been constructed as a basis for designing solid state NMR experiments to probe the ligand binding site in the receptor. Bacteriorhodopsin is a large membrane protein and a model for G-protein coupled receptors (GPCRs). Spectra of bacteriorhodopsin produced in H. salinarium in purple membrane are reported here and compared to spectra of the protein crystallised from bicelles. Optimal conditions for producing spectra suitable for spectral assignment are reported as an initial step towards spectral resolution. Three differently labelled samples of bacteriorhodopsin were prepared to test the applicability of the various assignment strategies and the effects of deuteration on quality of solid state NMR spectra of a large, crystalline membrane protein.
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18

Lange, Adam. "Three-dimensional protein structure determination by high-resolution solid-state NMR spectroscopy." Doctoral thesis, [S.l.] : [s.n.], 2006. http://webdoc.sub.gwdg.de/diss/2006/lange.

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19

Carson, Paul Jonathan Weitekamp Daniel P. "I. Ultrasensitive surface NMR using parahydrogen spin labeling. : II. High-resolution optical NMR of semiconductor heterostructures using larmor beat detection /." Diss., Pasadena, Calif. : California Institute of Technology, 1997. http://resolver.caltech.edu/CaltechETD:etd-12022003-155839.

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20

Risa, Øystein. "Application of high-resolution NMR spectroscopy in metabolic studies of the eye." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Natural Sciences and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-889.

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High-resolution NMR spectroscopy has, during the last two decades, had an increasing impact in biological and biochemical research. Rapid advances have led to improvements in sensitivity and dispersion of the spectra and have allowed more detailed assignment and monitoring of endogenous biochemical molecules. One of the latest implementations has been a technique known as high-resolution magic angle spinning (HR-MAS) NMR spectroscopy which has made it possible to obtain high-resolution proton spectra of intact tissue and cells. Simultaneous detection of a large number of metabolites by NMR spectroscopy has been successfully applied to investigate disordered metabolism for a numerous of diseases and toxic processes.

The objectives in the present work have been to evaluate different 1H NMR spectroscopy protocols as analytical tools in eye research, and further use these protocols to extract and interpret information on metabolic changes in the eye induced by external pathological stimuli. Special focus has been paid to changes in the lens and the development of cataracts.

The 1H NMR spectra of intact lenses and eye tissue extracts in present thesis showed an extensive picture of NMR detectable metabolites. In addition to the detailed analysis of extracts from cornea, lens and aqueous humour, this work has created a basis for implementation and interpretation of HR-MAS 1H NMR spectroscopy on intact lens tissue. Several significant changes in the metabolic content in cornea, aqueous humour, and lens after alkali-burns to the eye were detected and showed how careful 1H NMR spectroscopy analysis of tissue extracts provided new information (quantitative and qualitative) on the metabolic reaction pattern in the anterior eye segment in relation to eye alkali-burn injuries.

HR-MAS studies on lenses exposed in vivo to different ultraviolet-B doses did not reveal any dose-response relationship for the metabolic changes. However, significant concentration changes for most of the observed metabolites seven days post exposure demonstrated that closeto- threshold UVB radiation had great impact on the metabolites in the lens. Further time dependency studies of metabolic changes in rat lens after UVB radiation showed that significant changes in metabolite concentrations were subsequent to lens opacity development. Long-term steroid treatment (36 days) seemed to have greater impact on the metabolic changes compared to the UVB-induced changes 24 hours after UVB radiation. Even though no obvious cataract was detected after the combined treatment of steroids and UVB radiation, significant changes were observed for several metabolites.


Paper III is reprinted with kind permission from Elsevier, sciencedirect.com
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21

Bonzom, Pascale Marie Andree. "High resolution NMR applied to lipid analysis and lipid based drug design." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300537.

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22

Davies, Gareth Reynold. "Enhanced high resolution '1'2'9Xe NMR via spin exchange with optically pumped Rb." Thesis, University of York, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358240.

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23

Ruhl, Isaiah Daniel. "High Resolution Magic Angle Spinning NMR Studies of Botryococcus Braunii." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1244008200.

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24

Robertson, Aiden James. "Characterising molecular self-assembly using high-resolution 1H solid-state NMR spectroscopy." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/87431/.

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Supramolecular chemistry, the domain of chemistry ‘beyond the molecule’, is finding increasing application in a diverse range of scientific fields. A key concept in this field, termed molecular self-assembly, has important applications ranging from nanotechnology to medicine, and refers to the intermolecular assembly of individual molecules via non-covalent forces, most importantly hydrogen bonding and π-π stacking interactions. Specifically, this thesis considers the self-assembling arrangements of synthetic pyrimidine-based heterocyclic systems, which present guanine/cytosine DDA/AAD hydrogen bonding motifs. Characterisation of such systems is well documented in the liquid phase, but there exists a general paucity of solid-state analytical data for such materials. Owing to the inherent difficulty in crystallising these systems, typically due to disordered alkyl and aryl sidechains, high-resolution 1H MAS NMR is uniquely placed to elucidate hydrogen bonding arrangements in these systems, given the sensitivity of the 1H chemical shift to its local atomic environment. For cases where single-crystal X-ray structures can be obtained, a so-called NMR crystallographic approach can be used to complement the existing single-crystal X-ray data. By comparison of GIPAW calculated 1H chemical shielding parameters to experimentally observed chemical shifts and, more specifically, through comparison of calculated shielding values for the full crystal versus the isolated molecule, an analysis of the strength of non-covalent phenomenon present in a given system can be presented. This thesis applies fast MAS 1H detected 2D NMR methods to a range of structural problems concerning pyrimidine-based synthetic organic molecules. Specifically,1H – 1H DQ/SQ MAS, 14N – 1H HMQC and 1H – 13C techniques, such as the refocused INEPT and well-known CP MAS methods, are used, where applicable, in conjunction with GIPAW calculated NMR parameters to provide a comprehensive study of the solid-state packing arrangements of a series of guanine/cytosine synthetic derivatives which exhibit a diverse range of self-assembling architectures, including helical and stacking trimeric motifs. It is shown that, for crystalline compounds, confirmation of chemical shift assignments via the GIPAW method can be used to infer the structure of related systems for which diffraction data is not available, through comparison of the observed experimental NMR data. In addition, it is demonstrated that, for a series of pyrimidine and pyridopyrimidine intermediates which form non-crystalline powdered solids, high-resolution 1H MAS NMR methods can be applied alone to elucidate likely hydrogen bonding motifs in the absence of crystallographic data, thereby allowing the observer to speculate on likely modes of self-assembly in the solid state. Interestingly, this study involves the relatively novel investigation (by means of solid-state NMR) of aldehyde and, in particular, oxime containing organic molecules, for which (in the case of the latter functional group) no published 1H MAS NMR studies have been presented at the time of writing. Finally, in collaboration with the spectrometer company JEOL, it is shown that a selective saturation pulse can be employed to supress excessive t1 noise in two-dimensional 1 H MAS NMR spectra, at fast MAS frequencies. To demonstrate this effect, the intense methyl resonance of a synthetic nucleoside derivative is suppressed, whilst reduced spin diffusion rates at higher MAS frequencies ensure that the effect on nearby spins is minimised.
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25

Mifsud, Nicolas. "Structure determination in ordered and disordered solids by high-resolution NMR spectroscopy." Lyon, École normale supérieure (sciences), 2007. http://www.theses.fr/2007ENSL0418.

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Nuclear Magnetic Resonance is a potential powerful probe of structure and dynamics for a large range of materials in the solid-state. In this thesis, we show how powder samples at natural isotopic abundance can be assigned to crystal structures by using high-resolution proton and carbon-13 solid-state NMR spectra in combination with first principles calculations. Similarly, the determination of the three-dimensional structure of an organic compound in powder form and at natural isotopic abundance is presented. It is obtained by an approach that combines molecular modeling with experimental spin diffusion data of protons. Finally, temperature dependent 29Si NMR studies of the order and disorder in silicate framework materials are presented. Notably, we introduce and demonstrate the idea that Silicon-29 NMR transverse dephasing times can be used to probe dynamic processes independently of static disorder
La résonance magnétique nucléaire du solide est un outil potentiellement puissant pour déterminer la structure et la dynamique d’une large variété de composés. Dans cette thèse, nous montrons tout d’abord comment assigner un échantillon en poudre et en abondance isotopique naturelle à une structure cristalline en utilisant la RMN du solide haute résolution proton et carbone associée à des calculs théoriques. De même, la détermination de la structure tridimensionnelle d’un composé organique en poudre et en abondance isotopique naturelle est présentée. Elle est obtenue par une méthode qui combine modélisation moléculaire et données expérimentales de diffusion de spin proton. Enfin, une étude de la dynamique et du désordre structural a été réalisée sur des matériaux composés de silice par l’intermédiaire de la RMN du silicium. Ainsi, on montre que le temps de déphasage transverse T2’ du silicium peut être utilisé comme une sonde de la dynamique indépendamment du désordre statique
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26

Wang, Guangshun. "Conformations of important human serum apolipoprotein segments, high resolution NMR of apoA-I." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24363.pdf.

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27

Barkhuysen, Shani. "High resolution 195Pt and 119Sn NMR characterization of platinum(II)-tin(II) complexes." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17841.

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28

Feng, Yi. "One- and two-dimensional high-resolution solid-state NMR investigation of zeolite structures." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30806.

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The work reported in this thesis describes for the first time the application of two-dimensional ²⁹Si high-resolution solid state NMR experiments to the investigation of the three-dimensional Si-O-Si bonding connectivities in zeolites. 2D COSY type, INADEQUATE type and spin-diffusion experiments are discussed and evaluated, the INADEQUATE experiments being particularly successful in this work. By preparing highly crystalline, highly siliceous samples of zeolites and careful optimization of all experimental parameters, it is possible to directly observe ²⁹Si-O-²⁹Si J couplings in these experiments. The three-dimensional lattice connectivities obtained from this work for ²⁹Si enriched zeolite ZSM-39 and natural abundance ZSM-12 and ZSM-22 are in excellent agreement with the lattice structures determined by XRD techniques. In the case of a ²⁹Si enriched sample of zeolite DD3R, the ²⁹Si 2D NMR results indicate that the structure is of lower symmetry than has been postulated from diffraction studies. Zeolite ZSM-5, which has the most complex three-dimensional framework of all the known zeolites, was extensively studied in its room temperature phase by 2D NMR spectroscopy. In addition, the effects of temperature and the presence of sorbed p-xylene and p-dichlorobenzene on the phase behavior of ZSM-5 were also investigated. The ²⁹Si 2D NMR data on ZSM-11 at high temperature are in good agreement with the known structure, I4m2. Low temperature 2D experiments on ZSM-11 gave the assignment of space group symmetry 14 to the structure which was previous unknown. Finally, ²⁹Si 2D NMR results on ZSM-23 reveal that there are 12 independent T-sites in the structure which is not consistent with the space groups proposed in the literature which have 7 crystallographically inequivalent T-sites.
Science, Faculty of
Chemistry, Department of
Graduate
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29

Coen, Muireann. "High-resolution magic angle spinning NMR spectroscopic studies of heterogenous chemical and biological samples." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397328.

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30

Tsang, Tsz Mon. "High resolution magic angle spinning NMR spectroscopy and pattern recognition studies on neuronal damage." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405822.

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31

West-Jordan, Julie Ann. "High resolution '3'1p NMR studies of factors influencing in vitro skeletal muscle cell viability." Thesis, University of Liverpool, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316948.

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32

Lewandowski, Józef Romuald. "Methodology and applications of high resolution solid-state NMR to structure determination of proteins." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45640.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2008.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Vita.
Includes bibliographical references.
A number of methodological developments and applications of solid-state NMR for assignment and high resolution structure determination of microcrystalline proteins and amyloid fibrils are presented. Magic angle spinning spectroscopy on uniformly and selectively "C and '5N labeled samples is performed at magnetic fields from 11.7 to 21.1 T and spinning frequencies from 9 to 65 kHz.Dynamic Nuclear Polarization on nanocrystals of amyloidogenic peptide GNNQQNY is presented demonstrating that 'H-'H spin diffusion can efficiently transfer the enhanced polarization across the solute that is not in an intimate contact with the polarizing agent.An improved theoretical treatment of Rotational Resonance Width (R2W) experiments and its application to determination of precise 13C-13C distance is presented. A general theory of second averaging in modulation frame for designing solid-state NMR experiments is introduced and discussed in the context of two methods: Cosine Modulated Rotary Resonance (CMpRR) for performing a broadband double-quantum 13C-13C recoupling without the need for additional 'H decoupling and Cosine Modulated recoupling with Chemical Shift reintroduction (COMICS) that provides a general frequency selective method for measuring precise 13C-13C distances in uniformly labeled solids. Cosine Modulated Adiabatic Recoupling (CMAR) - an adiabatic extension of the CMpRR, that is particularly robust with respect to rf inhomogeneity, is also introduced. A number of applications CMpRR at 21.1 T to proteins with varying degrees of macroscopic order are presented. A second order Third Spin Assisted Recoupling (TSAR) mechanism is introduced and discussed in detail. The heteronuclear TSAR - Proton Assisted Insensitive Nuclei Cross-Polarization (PAIN-CP) and homonuclear Proton Assisted Recoupling (PAR) yield long distance 13C_1-N, 3C-_13C and 15N- 5N restraints in uniformly labeled systems with spinning frequencies up to 65 kHz that are used for protein structure calculation. Structure, dynamics and polymorphism of amyloidogenic peptide GNNQQNY from the yeast protein sup35p are investigated. Finally, PAIN-CP and '3C-13C PAR are used for high resolution de novo structure determination of 10.4 kDa Crh protein dimer.
by Józef Romuald Lewandowski.
Ph.D.
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33

Jia, Hsi-Wei. "Selective excitation in high-resolution NMR for determination of coupling constants and internuclear distances." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627313.

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34

Shannon, Matthew D. "High Resolution Structural and Dynamic Studies of Biomacromolecular Assemblies using Solid-State NMR Spectroscopy." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534321838601796.

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35

Yamamoto, Hiroyuki. "Studies on structure of native cellulose by high-resolution solid-state 13C NMR spectroscopy." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149841.

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36

Goodsell, L. S. "High resolution structural models of ribosome nascent chain complexes restrained by experimental NMR data." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1470654/.

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As understanding of the ways in which the complex cellular environment affects the in vivo folding of proteins improves, improved methods for their study are required. It is possible to produce limited quantities of ribosome-nascent chain complexes (RNCs) and techniques for gathering data about them are improving, but no single technique provides all the information required to understand folding of nascent proteins on the ribosome and there are still significant data that cannot be obtained experimentally. In particular, while NMR chemical shift and residual dipolar couplings may be recorded, the samples are of too low concentration and stability to conduct the most informative NOESY experiments that are traditionally used for revealing atomic-resolution structure. Recently, the ability to use chemical shifts to reveal structural details and dynamic properties of small proteins has been developed. By simulating multiple molecules and predicting the average chemical shift of the ensemble, the simulation may be restrained to conform to the experimentally measured data, making testable predictions about the atomic-resolution dynamic properties of the molecule. By adapting these methods to the macromolecular RNC structures it is theorized that the limited chemical shift data available may be used to provide structural details of the protein as it emerges from a ribosome. This, however, is faced by many challenges, including the ability to simulate such large number of atoms in a suitable timescale and applying the restraints to the nascent chain alone. The thesis presented describes the development of computational techniques to characterize RNCs, including the concepts and challenges faced, the chemical-shift restrained simulation of nascent chains alone, the development of techniques to perform chemical-shift restrained molecular dynamics simulations of the RNCs and the application of these techniques to a model system.
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37

Li, Xing. "Structure and dynamics of alamethicin dimers by high-resolution proton and nitrogen-15 NMR spectroscopy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0026/MQ51741.pdf.

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38

Li, Xing. "Structure and dynamics of alamethicin dimers by high-resolution proton and nitrogen-15 NMR spectroscopy." Ottawa : National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.nlc-bnc.ca/obj/s4/f2/dsk1/tape2/PQDD%5F0026/MQ51741.pdf.

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39

Zhang, Wurong 1966. "High resolution NMR scattering : the first measurement of spin diffusion rates in a homogeneous solid." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9616.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1998.
Includes bibliographical references (leaves 88-92).
The first direct measurement of the rate of spin diffusion through a homogeneous sample was performed as an incoherent NMR scattering experiment. The experiment consists of a combination of pulsed gradient spin echo methods with multiple pulse/ pulsed gradient spatial encoding met.hods. The NMR scattering experiment involves the creation of an initial spatial magnetization grating, a period of spin evolution including the displacement of spin magnetization, followed by the detection of the residual magnetization grating. The essence of NMR scattering measurements is to record the extent of microscopic motion of spin magnetization through a sample by directly observing amplitude and phase changes of a well defined spin magnetization grating. The spin diffusion measurement records the rate of destruction of a magneti­zation grating by the random offset of spin magnetization associated with the flip-flop term of the homonuclear dipole-dipole interaction. Since the microscopic motion driven by di- polar coupling is very slow, only fine magnetization gratings are sensitive to the small spatial offsets. Strong pulsed mag­netic field gradient techniques were developed for these studies which generate switched gradients with strengths up to 103T /m (a factor of 100 stronger than those commer­cially available, and a factor of 25 stronger than the highest previously reported). These gradients are able to create a spatial magnetization grating with a pitch of from l[mu]m to 1nm for solid state NMR scattering experiments. Gradients on the order of 200T /m were applied in the spin diffusion measurement experiment. For single crystal CaF2, the measured parallel components of the spin diffusion rates are 7.1 x 10-12cm2 /s along the [0,0,1) direction and 5.3 x 10-12cm2/s along the [1,1,1) direction, in good agreement with theoretical predictions. Additional work has been done on flow measurement. A novel approach is intro­duced to measuring flow velocities using a probe with a spatially varying RF field, and without using other magnetic field gradients. The velocities of the spins are measured as a modulation of the NMR signal from the translatlation of a spatial mag­netization grating through a detection coil with a spatially periodic field profile. Since the same coil can be employed to create the initial magnetization grating, the overall measurement is as simple as recording the signal modulation frequency following a single excitation pulse. The design principles are discussed for a probe that has a spatially periodic field constructed from a series of lumped element x-circuits. Spa­tial modulation of the amplitude or the phase of the RF field can easily be achieved, and either of these may be used t.o characterize a flow field. Examples are shown of measurements of pipe flow using a probe with an amplitude modulated RF field.
by Wurong Zhang.
Ph.D.
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40

Diaz, Garcia Anix C. "Investigation of the three-dimensional structures of zeolite molecular sieves by high-resolution solid-state NMR." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0014/NQ38878.pdf.

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41

Waters, Nigel James. "High resolution magic angle spinning NMR spectroscopy and pattern recognition studies of drug induced tissue damage." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252174.

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42

Westra, Arjan Nicolaas. "High resolution NMR studies concerning the solvation/hydration and coordination chemistry of Pt (II/IV) compounds." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50362.

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Thesis (PhD)--Stellenbosch University, 2005.
ENGLISH ABSTRACT: Pt(JV) complexes with S, 0-donating aroylthioureas have been synthesized by oxidative addition of elemental halogens to the Pt(JJ) precursors, leading to the first-reported crystal structures of Pt(JV) with this class of ligand. The treatment of Pt(II) complexes of N,N-diethyi-N'-benzoylthiourea with 12, Br2 and Cl2 leads to facile oxidative addition of the halogens to the platinum center, yielding several geometric isomers, as determined by 195Pt NMR; the products cis-bis(N ,N-diethyi-N' -benzoylthioureato )diiodoplatinum(IV), 26, and cisbis( N,N-diethyl-N'-benzoylthioureato)dibromo-platinum(IV), 27, have been isolated and structurally characterized. Reaction of cis-/trans-bis(N-benzoyi-N'-propylthiourea-kS)dibromoplatinum(II) with Br2, similarly results in oxidative addition of the dihalogen, yielding the product trans-bis(N-benzoyi-N'propylthiourea- kS)tetrabromoplatinum(IV), 29. lz, however, does not undergo oxidative addition to cis! trans-bis(N-benzoyi-N' -propylthiourea-kS)diiodoplatinum(II), instead the iodine inclusion compound trans-bis(N-benzoyl-N'-propylthiourea-kS)diiodoplatinum(II) diiodine, 28, was isolated. Short intermolecular I··· I interactions in crystals of compounds 26 and 28 lead to infinite chains of weakly linked molecules in the respective solids. 195Pt NMR reveals that the 3: 3 Pt(II) metallamacrocycle of 3,3,3',3'-tetra(n-butyl)-l,l'terephthaloylbis( thiourea) undergoes stepwise oxidative addition of 12 or Br2 to each of the Pt(II) centers, upon treatment with the dihalogens. Treatment of the 2: 2 Pt(II) complex of 3,3,3',3'-tetraethyl-1,1'isophthaloylbis( thiourea) with 12 also results in the oxidative addition of the halogen, yielding a 2 : 2 trans-Pt(IV)-iodo metallamacrocycle, 35. The corresponding trans-Pt(IV)-X (X= Br, Cl) complexes were synthesized by oxidative addition in an electrolytic cell containing the 2 : 2 Pt(II) precursor and an appropriate halide salt in dichloromethane. The 2: 2 trans-Pt(IV)-X (X= I, Br, Cl) metallamacrocycles, 36 an 37, were isolated and structurally characterized. Intermolecular 1···1 interactions between molecules of 35, in crystals of the compound, result in chains of weakly connectedmolecules in the lattice. 195 Pt NMR is used as a sensitive probe for studying the hydration/solvation spheres of the PtX/ (X = Cl, Br) anions, and to investigate the occurrence of {Na + [PtCl/"]}" contact ion-pairing in non-aqueous solutions. The 195Pt NMR chemical shifts of the Pt~2 • (X = Cl, Br) anions in D20 and in various organic solvents have been determined, and are discussed with regard to solvent polarities and donor and acceptor properties. The non-linear variations of bp1•195 for the anions with changing bulk composition in aqueous binary mixtures with the organic solvents, suggest that the anions are preferentially solvated by the organic solvents relative to water. The anion solvation sphere compositions with changing bulk composition, as well as preferential solvation equilibrium constants, K11 ", are determined from the NMR data. Significant non-linear variations of the 195Pt NMR chemical shift for methanol and acetonitrile solutions of PtXt (X = Cl, Br) ·with increasing NaCI04 concentrations indicate the occurrence of {Na+[PtX6 2_]}_ contact ion-pair formation in these solutions. By contrast, the variation of Dp1•195 for aqueous solutions of the halogenoplatinate anions with increasing sodium perchlorate concentration is slight, revealing that Na+···PtXe?- ion association is not favoured in the aqueous medium. The 195Pt chemical shift variations are used to estimate conditional ion-pair formation equilibrium quotients, Q (M"\ for {Na+[Ptxi·Jr contact ion-pair formation in water, methanol and acetonitrile. The estimated Q values illustrate that the extent of {Na+[Ptxi·Jr ion-pairing increases in these solvents in the order water< methanol< acetonitrile, which is in accordance with the solvent donor and acceptor properties.
AFRIKAANSE OPSOMMING: Pt(JV) komplekse met S, 0-donerende aroi"eltioiireum ligande is deur middel van die oksidatiewe addisie van halogene aan Pt(JJ) uitgangskomplekse gesintetiseer; die kristalstrukture van die Pt(IV) komplekse met hierdie tipe ligande word vir die eerste keer gerapporteer. Die behandeling van die Pt(II) komplekse van N,N-dietiel-N'-bensoieltioiireum met 12, Br2 en Cl2 gee geredelik aanleiding tot die oksidatiewe addisie van die halogene aan die platinum sentrum, en lei, volgens bepaling met 195Pt KMR, tot die vorming van verskeie geometriese isomere; die produkte cis-bis(N,Ndietiel- N' -bensoieltioiireato )di-jodoplatinum(IV), 26, en cis-bis(N,N-dietiel-N' -bensoieltioiireato )dibromoplatinum( IV), 27, is geisoleer en kristallografies gekarakteriseer. Reaksie van cis-/trans-bis(N-bensoiel-N'propieltioiireum- IGS)dibromoplatinum(II) met Br2, lei ooreenkomstiglik tot oksidatiewe addisie van die halogeen, met trans-bis(N-bensoiel-N' -propieltioiireum-IGS)tetrabromoplatinum(IV) as produk, 29. 12 ondergaan egter nie oksidatiewe addisie aan cis-ltrans-bis(N-bensolel-N' -propieltioiireum-IGS)dijodoplatinum( II) nie; 'n verbinding waarin h ingesluit word in 'n kristalstruktuur met trans-bis(N-bensoielN'- propieltioiireum-IGS)di-jodoplatinum(II), word geisoleer, 28. Kort intermolekulere 1···1 interaksies in die kristalstrukture van verbindings 26 en 28 lei tot die ontstaan van swak-gebonde molekuul-kettings in die kristalle. 195Pt KMR dui aan dat met behandeling van die 3 : 3 Pt(II) metallomakrosikliese kompleks van die 3,3,3' ,3 '-tetra(n-butiel)-1, 1 '-tereftaloielbis(tioiireum) ligand met 12 of Br2, daar stapsgewyse oksidatiewe addisie van die halogene aan die Pt(II) ione in die kompleks plaasvind. Behandeling van die 2 : 2 Pt(II) kompleks van 3,3,3' ,3 '-tetraetiel-1, 1 '-isoftaloielbis(tioiireum) met 12 gee ook aanleiding tot oksidatiewe addisie, met 'n 2 : 2 trans-Pt(IV)-jodo metallomakrosikliese kompleks as produk, 35. Die ooreenkomstige trans-Pt(IV)-X (X = Br, Cl) komplekse is gesintetiseer deur middel van oksidatiewe addisie in 'n elektrolitiese se! wat die 2 : 2 Pt(II) uitgangskompleks bevat tesame met 'n toepaslike haliedsout in dichlorometaan. Die 2 : 2 trans-Pt(IV)-X (X = I, Br, Cl) komplekse, 36 en 37, is geisoleer en kristallografies gekarakteriseer. lntermolekulere I··· I interaksies tussen molekule in kristalle van verbinding 35, gee aanleiding tot kettings van swak-gebonde molekule in die struktuur. 195 Pt KMR word gebruik om die hidraterings-/solvaterings-sfere van die PtX/" (X = Cl, Br) anione te ondersoek, asook om die voorkoms van {Na + [PtCIX/}F kontak-ioonparing in nie-waterige oplosmiddels te bestudeer. Die195Pt KMR chemise verskuiwing van die PtXl" (X= Cl, Br) anione in D20 en in verskeie organiese oplosmiddels is bepaal, en word bespreek met verwysing na die polariteite asook die donor- en akseptoreienskappe van die oplosmiddels. Die nie-lineere variasies van Op1_195 vir die anione met veranderende oplosmiddelsamestelling in waterige binere mengsels met die organiese oplosmiddels, dui aan dat die anione by voorkeur deur die organiese oplosmiddels gesolvateer word. Die solvateringssamestelling van die anione met veranderende oplosmiddelsamestelling, asook ewewigskonstantes vir die voorkeur-solvatering deur die organiese oplosmiddels, K11 ", word met behulp van die KMR data bepaal. Beduidende nie-lineere variasies van Op1_195 in metanol en asetonitriel oplossings van PtXl" (X = Cl, Br) met toenemende NaC104 konsentrasies, dui op die voorkoms van {Na +[PtClxl-]}- kontak-ioonparing in die oplossings. Die variasies van Op1_195 in waterige oplosings van die anione met toenemende NaC104 konsentrasies is egter minder beduidend, waaruit afgelei kan word dat ioonparing nie in die waterige medium bevoordeel word nie. Die 195Pt chemiese verskuiwings word gebruik om kondisionele ioonpaarvormings-ewewigskwosiente, Q (M-1 ), vir die vorming van {Na+[PtCIXtJr in water, metanol en asetonitriel af te lei. Die Q-waardes dui in ooreenstemming met die donor- en akseptoreienskappe van die onderskeie oplosmiddels aan dat die voorkoms van kontak-ioonparing toeneem vir die oplosmiddels in die volgorde water < metanol < asetonitriel.
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43

Gutiérrez, González Luis Horacio. "Structural and dynamical studies on human epidermal-type fatty acid binding protein using high resolution NMR spectroscopy." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964395630.

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44

Marulanda, Dabeiba. "Structural studies of reassembled and intact thioredoxin by high-resolution solid-state NMR magic angle spinning spectroscopy." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 13.72 Mb., 213 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3205438.

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45

Mal, Tapas Kumar. "Studies of a deuterated protein (Fyn SH3) and of protein side chain interactions using high resolution NMR." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390484.

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46

Lee, Daniel. "Development of high-resolution two-dimensional correlation spectroscopy in solid-state NMR : applications to nanocomposites and fullerides." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/11864/.

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Two-dimensional correlation spectroscopy in solid-state NMR is an immensely important tool for the analysis of materials, such as technologically interesting nano-materials or bio-materials. After detailing one method that returns high-resolution one-dimensional solid-state proton NMR spectra, high-resolution proton-proton two-dimensional correlation experiments are described and demonstrated. Subsequently, a new two-dimensional NMR experiment is described which is suitable for obtaining a high-resolution proton dimension in heteronuclear dipolar correlation spectra of solids. This new experiment has been used to characterise the interface between the organic and inorganic components of "coreshell" colloidal nanocomposite particles. In addition, a new two-dimensional NMR experiment is described which is suitable for obtaining homonuclear scalar correlation spectra in solids. This new experiment has several advantages, including increased cross peak intensities coupled with good suppression of the diagonal. Its utility is demonstrated via carbon-13 spectra of natural abundance samples as well as the polymer phase of caesium fulleride.
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47

Bradley, Jonathan P. "Development and application of high-resolution solid-state NMR methods for probing polymorphism of active pharmaceutical ingredients." Thesis, University of Warwick, 2011. http://wrap.warwick.ac.uk/55436/.

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The objective of the work presented in this thesis is to apply advanced high-resolution solid-state NMR methods for the structural characterisation of organic crystalline systems, specifically active pharmaceutical ingredients (APIs). The determination of the crystal packing is an important stage in the development of new APIs, and solid-state magic angle spinning (MAS) NMR is well suited to complement existing techniques. Improvements in spectral resolution in recent years have led to the development of homonuclear correlation experiments capable of identifying intermolecular proximities between 1H nuclei. These experiments provide a powerful probe of the local environment of each 1H nucleus in the three-dimensional structure, and the majority of the research presented in this thesis is focussed on the development of detailed analysis methods that may be used to extract more detailed structural information from 2D solid-state NMR correlation spectra. Throughout this thesis, experimental solid-state NMR results are analysed alongside computational data, including density matrix simulations of experiments and first principles calculations of shielding tensors. The results of simulations of a 1H DQ (double-quantum) correlation experiment are compared to experiment, in order to investigate the dependence of the DQ build-up (change in peak intensity as a function of the recoupling pulse duration) on the precise nature of the dipolar coupled proton network. It is found (for a simple dipeptide) that quantitative information on the relative H{H distance may be obtained by comparison of the maximum intensity reached in the corresponding 1H DQ build-up curves. This method is then applied to pharmaceutically relevant systems. It is shown that differences between two polymorphs of an API may be identified in the 1H DQ build-up of particular peaks, and, following the analysis for the dipeptide, this difference may be ascribed to differences in specific intermolecular distances. In the study of a second API, -indomethacin, it is shown that the standard 1H DQ experiment provides insufficient resolution to identify specific DQ peaks. A recently developed 1H(DQ){13C correlation experiment is used to exploit the higher resolution in the 13C dimension, hence allowing the extraction of DQ build-up curves which may be used, in conjunction with simulations, to obtain structural data. Finally, a recently discovered polymorph of the API ibuprofen is studied using 13C CPMAS (cross polarisation) solid-state NMR. Through the use of first-principles calculations, the 13C spectra of both the well known and new polymorphs are assigned, and the conversion of an amorphous solid to the new polymorph is monitored through the use of temperature-controlled solid-state NMR experiments.
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48

Ma, Liping. "Investigation of the conformational behaviour of cembrenoids by using high resolution NMR techniques and modern computational methods /." [S.l.] : [s.n.], 1994. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.

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49

Nadaud, Philippe S. "High-Resolution Structural Studies of Paramagnetic Proteins by Multidimensional Solid-State Nuclear Magnetic Resonance Spectroscopy." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1268318234.

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50

Christou, Nina-Eleni. "Development of NMR as a tool for the structural and dynamic high-resolution characterization of phototranformable fluorescent proteins." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALY051.

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La découverte de protéines fluorescentes photo-transformables (PTFP) au cours des dernières décennies a révolutionné le domaine de la microscopie optique. Les protéines fluorescentes réversiblement commutables (RSFP), en particulier, sont couramment utilisées pour les techniques de microscopie à super-résolution comme en RESOLFT (REversible Saturable OpticaL Fluorescence Transitions) par exemple. Par photoactivation, les RSFP passent d'un état "on" - fluorescent - à un état "off" - éteint - qui, combiné à des systèmes d'illumination avancés permet d'imager des composants cellulaires préalablement marqués à une résolution nanométrique. De nombreuses études cristallographiques sur les RSFP ont apporté des informations structurelles importantes et ont permis de dresser des hypothèses quant à leur comportement photo-physique. Elles ont également guidé l'ingénierie des protéines fluorescentes afin d'améliorer leur conception et leur utilisation in vivo. Cependant, les cristaux de ces protéines qui sont étudiées à des températures cryogéniques ne permettent pas de capturer la dynamique moléculaire des RSFP dans le but de comprendre, voir d'améliorer leur propriétés photo-physique. C'est pourquoi au cours de ma thèse, j'ai majoritairement utilisé la résonance magnétique nucléaire (RMN) en solution multidimensionnelle sur une RSFP verte - appelée rsFolder - afin de compléter et améliorer nos connaissances sur ces protéines. À l'aide d'un dispositif d'éclairage laser in situ portatif couplé au spectromètre RMN, j'ai pu extraire des informations dynamiques locales quantitatives concernant les états "on" et "off" fluorescents de rsFolder qui sont respectivement caractérisés par un chromophore en conformation cis et trans. Les signatures des résidus dans l'état "off" non fluorescent ont été identifiées à l'aide d'expériences de RMN d'échange induite par LASER. L'état "off" métastable de rsFolder apparaît plus dynamique dans l'échelle de temps de la milliseconde que l'état "on" fluorescent. La RMN a également permis de mettre en lumière quatre configurations du chromophore possible qui sont pH dépendante. De plus, j'ai observé pour la première fois l'isomérisation du chromophore induite par le pH cis-trans. Les valeurs dérivées de la RMN des énergies d'activation concernant l'isomérisation et les différences d'énergie libre entre le chromophore cis et trans ont permis de cartographier le paysage d'énergie libre de l'état fondamental de rsFolder à différents pH. Enfin, la comparaison de données de RMN et des mesures optiques sur rsFolder ainsi que sur différents mutants a mis en évidence le rôle important que la RMN peut jouer dans le domaine de l'ingénierie des RSFPs.Dans l'ensemble, mes travaux de thèse ont permis non seulement d'établir un système d'illumination in situ fiable, accompagné d'expériences de RMN pertinentes dans le but d'étudier les RSFP mais aussi de souligner l'importance de la dynamique moléculaire dans la compréhension des propriétés photo-physiques des RSFPs
The discovery of Phototransformable Fluorescent proteins (PTFPs) over the last decades has revolutionized the field of microscopy. Reversibly photo-switchable fluorescent proteins (RSFPs), in particular, are currently routinely used for Super Resolution Microscopy techniques, such as RESOLFT (REversible Saturable OpticaL Fluorescence Transitions). Photo-induced switching between a fluorescent "on"- and a dark "off"-state, in combination with advanced illumination schemes has allowed for imaging nanometer sized compartments in biological cells. Crystallographic studies of such RSFPs have provided useful mechanistic explanations for their photophysical behaviour and has guided fluorescent protein engineering into designing better tags. However, the crystal forms of such proteins studied at cryogenic temperatures fail to capture dynamics present in RSFPs which could potentially play a significant role in their photophysics. So far, only a single NMR study for the RSFP Dronpa has been reported in the literature (Mizuno, 2008). During my PhD thesis, I was able to complement crystallographic studies of rsFolder, a green RSFP, with a dynamic perspective using multidimensional solution NMR spectroscopy.Using a portable in-situ laser illumination device coupled with the NMR spectrometer, I was able to extract quantitative local dynamic information for both the fluorescent "on"- and "off"-states of rsFolder, characterized by a primarily cis and trans chromophore, respectively. NMR signatures of residues in the non-fluorescent "off"-state were identified using LASER-driven Exchange NMR experiments. The metastable photo-induced "off"-state of rsFolder appears more dynamic on the millisecond timescale than the fluorescent "on"-state. NMR investigations of the chromophore resulted in the deciphering of four configurations, populated in a pH-dependent fashion. Moreover, pH-induced cis-trans isomerization of the chromophore was observed, in the absence of light. NMR-derived values of activation energies for isomerization and free energy differences between the cis and trans chromophore enabled the mapping of the ground-state free energy landscape of rsFolder at different pH values and buffer compositions. Lastly, comparing NMR observables with optical measurements on rsFolder and mutants highlights the potential role that NMR can play in the field of RSFP engineering. Altogether, my PhD work yielded in not only a reliable in-situ illumination set-up accompanied with relevant NMR experiments to study RSFPs, but also highlighted the importance of dynamics in understanding RSFPs' photophysical properties
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