Dissertations / Theses on the topic 'Protonation'
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Al-Rammahi, Thaer Mahdi Madlool. "Protonation of biologically relevant sulfur ligands." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3983.
Full textTardy-Delassus, Anne. "Protonation asymétrique sur phases solides chirales." Montpellier 2, 1993. http://www.theses.fr/1993MON20092.
Full textRavard, Alain. "Déracémisation par protonation et élimination énantiosélectives." Rouen, 1990. http://www.theses.fr/1990ROUES017.
Full textFisher, Stuart John. "The determination of protonation states in proteins." Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525182.
Full textWeerasooriya, Neluka Oshadie. "Probing into the mechanism of enolate protonation." Thesis, Queen Mary, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404828.
Full textJackman, Hayley. "Bifunctional organic catalysts for asymmetric protonation reactions." Thesis, University of Leeds, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432332.
Full textSwetnam, S. P. "N.M.R. studies of the protonation of pyrimidines." Thesis, Keele University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372826.
Full textSuggate, Michael James. "Studies towards the enantioselective C-protonation of enolates." Thesis, Queen Mary, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418305.
Full textKim, Meekyum Olivia. "Integrating conformational and protonation equilibria in biomolecular modeling." Thesis, University of California, San Diego, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3709257.
Full textDue to high sensitivity of biomolecular systems to the electrostatic environments, coupled treatment of conformational and protonation equilibria is required for an accurate characterization of true ensemble of a given system. The research presented in this dissertation examines the effects of conformational and protonation equilibria of varying extent on diverse aspects of computational biomolecular modeling, as introduced in Chapter 1. The effects of protonation and stereoisomerism of two histidines on virtual screening against the M. tuberculosis enzyme RmlC are presented in Chapter 2. In Chapter 3, conformational flexibility of three M. tuberculosis prenyl synthases is probed using molecular dynamics simulations, with implications for computer-aided drug discovery effort for the new generation antibacterial and antivirulence therapeutics. Chapters 4 and 5 consider the conformational and protonation equilibria simultaneously by utilizing constant pH molecular dynamics, in which fluctuations in both conformation and protonation state are possible. In Chapter 4, a computational protocol utilizing constant pH molecular dynamics to compute pH-dependent binding free energies is presented. The methodology is further applied to protein-ligand complexes in Chapter 5, where the thermodynamic linkage between protonation equilibria, conformational dynamics, and inhibitor binding is illustrated.
Autissen, Valerie. "Studies on the protonation mechanisms of nickel complexes." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420069.
Full textLEON, EMMANUELLE. "Protonation et cationisation d'amidines, approche theorique et experimentale." Paris 6, 1996. http://www.theses.fr/1996PA066246.
Full textHoang, Bang. "Protonation and Other Acid-Base Chemistry of Chlorophosphazenes." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1124822574.
Full textSenger, Moritz [Verfasser]. "Protonation and Reduction Dynamics in [FeFe]-Hydrogenases / Moritz Senger." Berlin : Freie Universität Berlin, 2018. http://d-nb.info/1155761065/34.
Full textSinha, Amritanshu. "Synthesis of molybdenum olefin metatheses catalysts through protonation reactions." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36262.
Full textVita.
Includes bibliographical references.
The attempted syntheses of molybdenum imido alkylidene complexes of the type Mo(NArc,)(CH-t-Bu)[Biphen] and Mo(N-2-CF3C6H4)(CHCMe2Ph)[Biphen] (Biphen2 = 3,3'-di-t-butyl-5,5',6,6'-tetramethyl- 1,1'-biphenyl-2,2'-diolate) from Mo(NArcl)(CH-t-Bu)(OTf)2(dme) and [Biphen]K2 have sporadically afforded mixtures containing the desired products along with the corresponding amido alkylidyne complexes, Mo(NHArcl)(C-t-Bu)[Biphen] and Mo(NH-2-CF3C6H4)(CCMe2Ph)[Biphen], respectively. The reaction of [Biphen]K2 with Mo(NArc,)(CH-t-Bu)(OTf)2(dme) and 10 equivalents of triethylamine reproducibly gave Mo(NHArc,)(C-t-Bu)[Biphen] in 40% yield. An X-ray crystal structure of a related complex, Mo(NHArc,)(CCMe2Ph)[S-Biphen] confirmed the proposed structure and also revealed that one ortho chloride approaches within 2.93 A of the metal approximately trans to the alkylidyne ligand. Attempts to prepare three other amido alkylidyne complexes in an analogous manner from Mo(NR")(CH-t-Bu)(OTf)2(dme) (NR" = N-2-CF3C6H4, N-2,6-i-Pr2C6H5, N-2,6-Me2C6H5) with [Biphen]K2 in the presence of 10-20 equivalents of triethylamine failed.
(cont.) Chapter 2 The reaction between Mo(NAr)(CH-t-Bu)(CH2-t-Bu)2 (Ar = 2,6-i-Pr2C6H3) and various alcohols (1-AdamantylOH, t-BuOH, ArOH, (CF3)2CHOH, (CF3)2MeCOH, (CF3)3COH, C6F5OH) in pentane or toluene yielded either complexes of the type Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OR) through direct addition of ROH across a Mo-C bond, or complexes of the type Mo(NAr)(CH2-t-Bu)3(OR) through direct addition of ROH across a Mo=C bond. The trineopentyl species appear to be formed when the alcohol has a relatively low pKa. The outcome also can depend upon whether the alcohol is employed neat, or in benzene, and mixtures are observed in some circumstances. The conversion of Mo(NAr)(CH2-t-Bu)3(OR) into Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OR) was shown to be unimolecular in several examples. Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OR) complexes have been found to be surprisingly active catalysts for various metathesis reactions. In contrast, M(NAr)(CH-t-Bu)(CH2-t-Bu)2 species are virtually inactive for metathesis. X-ray structures are reported for Mo(NAr)(CH2-t-Bu)3(OC6F5), Mo(NAr)(CH-t-Bu)(CH2-t-Bu)IOSi(O-t-Bu)3], [Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OC6F)12, and Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OC6F5)(PMe3).
(cont.) Chapter 3. Complexes of the type Mo(NR")(CHR')(N(R)3,5-C6H3Me2)2 (NR" = N-2,6-i-Pr2C6H, N-2,6-Me2C6Hs; R' = t-Bu, CMe2Ph; R' = i-Pr, t-Bu) and Mo(NR")(CHR')(NR2)2 (NR" = N-2,6-i-Pr2C6H,, N-2,6-Me2C6H5; R' = t-Bu, CMe2Ph; R = Me, Ph) can be isolated as orange-red solids in 30-35% yields or oils by reacting Mo(NR")(CHR')(OTf)2(dme) with LiN(R')(3,5-C6H3Me2)(ether) or with LiNR2. The synthesis of Mo(NR")(CHCMe2Ph)(NPh2)2 can be improved to 70-90% isolated yields when Mo(NR")(CHCMe2Ph)[OCMe(CF3)212 is used with LiNPh2(ether). Mo(NAr)(CHCMe2Ph)(NPh2)2 has been crystallographically characterized. Mo(NR")(CHR')(N(R)3,5-C6H3Me2)2 species reacted with t-BuOH and Me(CF3)2COH in benzene to give Mo(NR")(CHR')(OR)2 (OR = O-t-Bu, OCMe(CF3)2) in situ. However, no reactions of Mo(NR")(CHR')(N(R')3,5-C6H3Me2)2 were observed with enantiomerically pure diols such as [R-TRIP]H2 (3,3'-2,4,6-i-Pr3C6H2-binaphthol), [R-Ph]H2 (3,3'-C6H5-binaphthol), [rac-Mesitylbinap]H2 (3,3'-2,4,6-Me3C6H2-binaphthol) and [R-TMSbinapJH2 (3,3'-SiMe3-binaphthol).
(cont.) Bisamido complexes of the type Mo(NR")(CHR')(NPh2)2 were found to react with the aforementioned alcohols and diols to give Mo(NR")(CHR')(diolate) species in situ, which were further reacted in a catalytic fashion with two substrates to give the corresponding ring-closed products. Preliminary :results of the in situ catalysis demonstrated here compare fairly well with the analogous catalytic reactions reported with isolated catalysts. Appendix A. Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OC6F5) (Ar = 2,6-i-Pr2C6H3) can be reacted with 5-10 equivalents of trans-3-hexene to give a crystallographically characterized dimeric complex, [Mo(NAr)(CH2-t-Bu)(OC6F5)]2 that contains an unbridged Mo=Mo bond (2.410(8) A) in high yields. The above complex can also be prepared by treating Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OC6F5) with 0.5 equivalents of divinylbenzene. IMo(NAr)(CH2-t-Bu)(OC6F5)]2 will slowly catalyze the metathesis reactions of simple substrates, although less than 5% of the catalyst seems to be activated in such reactions.
(cont.) It was observed that catalytically active species for metathesis reactions can be generated by another Mo (d2) species, Mo(NArcl)(Biphen)(H2C=CH2)(ether) (NArc, = N-2,6-C12C6H3, Biphen2 = 3,3'-di-t-butyl-5,5',6,6'-tetramethyl-1,1'-biphenyl-2,2'-diolate) that could effect the ring-opening metathesis polymerization of norbornene. A mixture of Mo(NArcl)(Biphen)(H2C=CH2)(ether) and 20 equivalents of diallylether in benzene-d6 when treated with 10 equivalents of norbornene gives 54% conversion to dihydrofuran in 10 days.
by Amritanshu Sinha.
Ph.D.
THOREY, CLAIRE. "Catalyse au paladium : protonation enantioselective d'especes enoliques, heterocyclisations diastereoselectives." Reims, 1996. http://www.theses.fr/1996REIMS035.
Full textFETSCH, DAVID. "Acides humiques : separation, proprietes de protonation et de complexation." Université Louis Pasteur (Strasbourg) (1971-2008), 1999. http://www.theses.fr/1999STR13002.
Full textAlwaaly, Ahmed Ali Swadi. "Protonation of metal-sulfur complexes : synthetic and mechanistic studies." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/2958.
Full textAdeyinka, Adedapo Sunday. "Protonation sequence of aliphatic linear polyamines : a theoretical study." Thesis, University of Pretoria, 2016. http://hdl.handle.net/2263/60820.
Full textThesis (PhD)--University of Pretoria, 2016.
Chemistry
PhD
Unrestricted
Graton, Jerome. "Basicité des Amines et de Nicotines : Liaison Hydrogène et Protonation." Phd thesis, Université de Nantes, 2001. http://tel.archives-ouvertes.fr/tel-00090950.
Full textGarrett, Brendan. "Substitution and protonation reactions at synthetic iron-sulfur-based clusters." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437982.
Full textZaafrani, Oumaya. "Protonation, distorsions structurales et espèces protoniques dans des pérovskites lacunaires." Paris 6, 2010. http://www.theses.fr/2010PA066678.
Full textNatt, François. "Synthèse asymétrique du kétoprofène par protonation stéréosélectice du mélange racémique." Montpellier 2, 1993. http://www.theses.fr/1993MON20152.
Full textGRATON, JEROME. "Basicite des amines et de nicotines : liaison hydrogene et protonation." Nantes, 2001. http://www.theses.fr/2001NANT2014.
Full textMcDonnell, P. D. "Ring closure reactions." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378891.
Full textMayo, Dennis H. "Solvent and protonation effects on a resorcin[4]arene based cavitand." Connect to resource, 2006. http://hdl.handle.net/1811/6456.
Full textTitle from first page of PDF file. Document formatted into pages: contains 29 p.; also includes graphics. Includes bibliographical references (p. 28-29). Available online via Ohio State University's Knowledge Bank.
Resler, Tom [Verfasser]. "Time-Resolved Analysis of Protonation Dynamics in Channelrhodopsin-2 / Tom Resler." Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1135969256/34.
Full textGhilagaber, Stephanos. "Developments in the enantioselective protonation of prostereogenic enolates under kinetic control." Thesis, Queen Mary, University of London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416006.
Full textBekdemir, Yunus. "The mechanisms of hydrolysis and protonation behaviour of N-aryl sultams." Thesis, University of Essex, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387004.
Full textPeschard, Olivier. "Déconjugaison par protonation énantioselective : application à la synthèse de la vinylglycine." Rouen, 1989. http://www.theses.fr/1989ROUES017.
Full textUpasen, Settakorn. "Stabilité chimique et structurale de pérovskites céramiques de conductrice protoniques pour piles à combustible et électrolyseurs." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066270/document.
Full textThe chemical and structural stability of well-densified ceramics potentially used as H2/air fuelcell/electrolyzer (and perhaps in CO2/Hydrocabons Converter) electrolyte or electrodes vs. CO2-free/saturated pressurized water has been studied. The pressurization maximizes the efficiency of theenergy conversion systems. Four types of pervoskite-related oxide ceramics were concerned:BaCe0.4Zr0.5Y0.1Zn0.04O3-d (BCZYZ), SrZr0.9Er0.1O3-d (SZE), Ln2NiO4+d (LNO, Ln = La, Pr, Nd), andLa0.6Sr0.4Co0.2Fe0.8O3-d (LSCF6428). Dense ceramic samples were exposed at 550°C to water vaporpressure in an autoclave for days to weeks. The protonation treatments were performed in twodifferent conditions: operating condition (£20 bar of CO2-free water pressure, 550°C) and acceleratedaging conditions (³40 bar of CO2-free/CO2-saturated water pressure, 550°C). The pristine and‘protonated’ samples were characterized using various analysis techniques: Optical Microscopy,Thermogravimetry, Thermal Expansion, (micro/macro) ATR FTIR, Raman micro-spectroscopy, X-rayand Neutron Scattering. The study reveals that under the operating condition (£20 bar), the stability ofLNO/LSCF6428 electrode materials and of SZE electrolyte appears good, while the BCZYZelectrolyte exhibit significant corrosion. The superior stability of LSFC6428 exposed in extreme CO2-water vapor atmosphere was demonstrated about 5 to 30 times better than LNO and SZE homologues.The surface secondary phases form at the grain boundary. The protonation modifies more or less thestructure symmetry, the unit-cell volume/parameter and the phase transition sequence in relation withthe modification of the oxygen vacancy distribution. The proton doping level for different samples isalso discussed
HUYNH, SYLVIE. "Microcalorimetrie de la protonation : application a l'etude du metabolisme des derives nitroses." Caen, 1985. http://www.theses.fr/1985CAEN2020.
Full textPoisson, Thomas. "Nouveaux développements en organocatalyse : du dédoublement d'alcools à la protonation énantioselective organocatalysée." Rouen, 2008. http://www.theses.fr/2008ROUES051.
Full textThis work deals with the development of new organocatalysis tools for organic synthesis. First, we have performed the functionalization of the 4-(dimethylamino)pyridine scaffold. This functionalization has furnished three original organocatalysts which were evaluated in two reactions : the secondary alcohol resolution and the Steglich rearrangement. During the course of this study we have discovered a new transprotection procedure of O-silyl compounds into O-benzoyl compounds. In addition, we have performed the first organocatalytic enantioselective protonation of silyl enolates mediated by cinchona alkaloids and a latent source of HF. This process was simplified by the use of carboxylic acid and cinchona alkaloids. This two approaches leads to enantioselective proton transfer with enantioselectivities up to 92% ee. Finally this methodologies was applied to the enantioselective synthesis of homoisoflavones and isoflavones with enantioselectivities up to 81%
BUET, PIERRE. "Cryptands fluorescents : nouveaux aspects de la dynamique de complexation et de protonation." Université Louis Pasteur (Strasbourg) (1971-2008), 2000. http://www.theses.fr/2000STR13014.
Full textHopf, Ryan G. "Protonation States of Novel Therapeutics for the Resurrection of Organophosphorus-Aged Acetylcholinesterase." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595331575488179.
Full textDavid, Rolf. "Chemins de protonation et réactivité des métalloenzymes : application à la superoxide réductase." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAV087/document.
Full textObtaining targeted molecules under gentle, selective and sustainable conditions is still a major challenge. Artificial metalloenzymes are animportant line of enquiry, because by playing, for example, with the second sphere of coordination, it is possible to strongly modify thereactivity of these bio-inspired systems. The development of this chemistry presupposes a thorough knowledge of the different stages of themechanism of the reaction under study. For this reason, theoretical chemistry is essential to rationalize chemical reactivity, but it still suffersfrom many shortcomings for the systems we propose to study.In this work, we study the superoxide reductase, a detoxifying enzyme of the superoxide radical. While many experiments are available detailingsome intermediates, the precise mechanism is not well documented. The aim was to implement a complete methodology ranging from thedevelopment of specific MM parameters to the study of reactivity by QM/MM metadynamics.The development of MM parameters for the iron active site allowed its study by MM dynamics giving informations on the conformation ofthe peptide backbone as well as on the interaction with solvent molecules. Due to the nature of the iron, a QM description of the active sitewas required using hybrid DFT. QM/MM metadynamics have allowed us to explore reaction pathways and to characterize the compoundsformed to obtain the needed activation energies. This methodology made it possible to understand the native reactivity of the wild form ofthe SOR, but also to explore the new reactivity of the mutations of the SOR and thus to define the crucial role of the second coordination sphere
Gegham, Galstyan [Verfasser]. "Computation of Protonation Patterns for Organic Compounds and Transition Metal Complexes / Galstyan Gegham." Berlin : Freie Universität Berlin, 2014. http://d-nb.info/1060368153/34.
Full textFriedrich, Daniel [Verfasser]. "Establishing Advanced MAS NMR Methods to Investigate Protonation Dynamics in Proteins / Daniel Friedrich." Berlin : Freie Universität Berlin, 2018. http://d-nb.info/1176640615/34.
Full textFlinois, Karine. "Protonation énantiosélective de complexes entre énolates de cétones prochiraux et 3-aminopyrrolidines chirales." Rouen, 2000. http://www.theses.fr/2000ROUES059.
Full textPretorius, P. J. "A computer simulation of the protonation and metal complexation properties of fulvic acids." Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/18338.
Full textElectrostatic interactions between binding sites on a fulvic acid molecule are incorporated into a computer model for the simulation of fulvic acid cation equilibria. A preliminary investigation into the influence of nitrogen containing constituents on simulated metal complexation results is also reported. The metal investigated is Cu²⁺. The influence of electrostatic interactions on the complexation properties of macromolecules is evaluated by focussing on the Gibbs free energy of the complexation process. The change in Gibbs free energy, characteristic of a specific complexation reaction, is modified by the electrostatic interactions between sites. ΔG is modified by a factor dependent on the work of charging a system previously uncharged. This work is, under conditions of constant temperature and pressure, equivalent to the electrostatic contribution to ΔG. In order to evaluate the electrostatic free energy, it is necessary to evaluate the electrostatic potential on the macromolecule due to the charges present. This is accomplished using dielectric models of the macromolecules. The main points to emerge from this investigation are that the electrostatic models range from very sophisticated to very crude. Typically, the sophisticated models need detailed structural information on the macromolecule, such as atomic and charge coordinates. It is found that no such structural data are available for humic substances. This limits the choice of models to those which do not require detailed structural information. These models are however fraught with approximations, introducing uncertainty of unknown extent into the calculated results. The chosen electrostatic models are incorporated into protonation and metal complexation models of fulvic acids. Parameters which may influence simulated results to a large extent are identified. This investigation indicates that input parameters for the various modelling steps should be chosen with a great degree of circumspection. The cation complexation models are used to simulate experimental results published in the open literature. The results indicate that the incorporation of electrostatic interactions leads to some improvement between experimental and simulated results. The results further suggest that there are secondary refinements to the models which may improve the agreement between simulated and experimental results. The degree of fit between experimental and simulated results proves to be rather independent of the choice of electrostatic model. The influence of nitrogen containing ligands on the Cu²⁺ complexation capacity of fulvic acid does not turn out to be very pronounced. The assumption of neglecting these constituents as possible binding sites does not seem to be a limiting assumption. The results suggest that the predictive models developed in the course of this investigation may have some potential to simulate the cation complexation characteristics of fulvic acids. Further refinement of the models is, however, necessary.
Vagedes, Peter. "Simulation of enzyme reactions the influence of protonation on catalysis and on protein protein association /." [S.l. : s.n.], 2001. http://www.diss.fu-berlin.de/2001/49/index.html.
Full textYahya, Raïda. "Etudes thermodynamiques de la protonation et de la complexation de cryptands et d'amino-3 pyridazines." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13069.
Full textYahya, Raïda. "Etudes thermodynamiques de la protonation et de la complexation de cryptands et d'amino-3 pyridazines." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37601857s.
Full textRouanet, Mehouas Cécile. "Conception de ligands à vocation thérapeutique : combinaison d'approches multidisciplinaires pour comprendre les interactions intermoléculaires." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS145/document.
Full textProtein-ligand recognition mechanisms are essential to many fundamental biological functions such as signal transduction, gene regulation or stimulation of the immune system. Understanding the physical and chemical phenomenon upon protein-ligand binding is essential for many practical applications such as drug design, ligand based diagnostic tools and any other study based on biotechnology. In this study, we extensively explored the interaction between human macrophage metallo elastase MMP-12 and RXP470.1, a potent and selective inhibitor. By combining high resolution X-ray crystallography, FRET based enzyme assays and Isothermal Titration Calorimetry, we were able to highlight the importance of entropic contributions and to quantify the importance of a single proton transfer upon RXP470.1 binding. We show, here, how the protonation of Glu219 upon RXP470.1 binding rescues an otherwise unfavourable binding enthalpy. This protonation is made possible by the large pKa shift Glu219 undergoes as RXP470 enters MMP12h To our knowledge, this study is also the first to address the zinc binding group effect from affinity, thermodynamlc and structural data. We tested two RXP470 analogues, which only differ by their zinc-binding group. We show that this, apparently minor, change has great consequences regarding their affinity profiles and thermodynamic signatures. In addition, the analysis of the b factors, associated to the X-ray structures of these compounds in complex with MMP-12, suggests that small modifications of the zinc binding group might imply important mobility variations of the residues involved in the protein-ligand interaction. These modifications are initiated by a small shift of the zinc binding groups positioning in the active site.Taken together, these results point toward the necessity to combine several experimental approaches to describe the complexity of protein-ligand interactions. These associations should allow the evaluation of new theoretical methods able to describe complex systems
Qamar, Raheel. "Dependence of the Kinetic Mechanism of Adenosine 3',5'-Monophosphate Dependent Protein Kinase Catalytic Subunit in the Direction of Magnesium Adenosine 5'-Diphosphate Phosphorylation on pH and the Concentration of Free Magnesium Ions." Thesis, University of North Texas, 1992. https://digital.library.unt.edu/ark:/67531/metadc277956/.
Full textSounier, Rémy. "Protonation spécifique des méthyles : un outil pour l'étude structurale des assemblages moléculaires par Résonance Magnétique Nucléaires." Phd thesis, Université de Grenoble, 2008. http://tel.archives-ouvertes.fr/tel-00785223.
Full textStewart-Sloan, Charlotte (Charlotte Roberta). "Understanding the effect of protonation on the self-assembly of a model polyelectrolyte-neutral block copolymer." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/103267.
Full textCataloged from PDF version of thesis.
Includes bibliographical references.
Charge-containing polymers are used in a wide variety of commercial products including fuel cell membranes, heat sealing packages, and golf ball covers. Traditionally made as random copolymers of charged and uncharged monomers, morphological understanding and control is limited due to the lack of long range order and small length scale of the structural inhomogeneities. Moreover, the charge functionality is typically introduced in a permanent way that is not modifiable after synthesis, locking in a chemistry and structure that may not be optimal for the ultimate application. This thesis develops and studies the morphologies of a model block copolymer which is controllably charged in a novel way: by protonating a weak base. This polymer is composed of one hydrophilic but uncharged block, poly(oligoethylene glycol methyl ether methacrylate) (POEGMA), and one weak polyelectrolyte, poly(2-vinylpyridine) (P2VP) which can be controllably charged by varying the amount of acid to which it is exposed. This thesis presents the synthesis and morphological characterization of this polymer using scanning probe microscopy and small angle X-ray scattering. First, the ability of P2VP protonation to change the morphology of the diblock is demonstrated; while miscible in the absence of charge, the diblock undergoes a disorder to order transition upon protonation by a variety of acids. Thin films with varying levels of polyelectrolyte protonation are created and the efficacy of several polar aqueous and organic annealing solvents are presented. The introduction of acid in either the vapor or liquid phase is also shown to induce microphase separation. This is followed by a thorough treatment of the bulk morphologies of POEGMA-P2VP as a function of acid content, temperature, and minority block volume fraction. For all diblocks, protonation is found to increase the segregation strength between the two blocks and disorder to order transitions are observed with increasing protonation and temperature. Polymers with minority block volume fractions closest to 0.5 are the most immiscible, while those richer in majority block require more acid and higher temperatures to demix. Finally, the effect of acid type is investigated in detail by the comparison of two monoprotic with one diprotic acid. The diprotic acid is found to be more efficient at inducing microphase separation than either monoprotic acid for two diblocks of differing composition.
by Charlotte Roberta Stewart-Sloan.
Ph. D.
Martin, Juliette. "Deracemisation par protonation enantioselective d'enolates d'amides et synthese des deux enantiomeres d'un antagoniste des recepteurs m2." Caen, 1998. http://www.theses.fr/1998CAEN2037.
Full textSounier, Rémy. "Protonation specifique des methyles : un outil pour l’étude structurale des assemblages moléculaires par résonance magnétique nucléaire." Grenoble 1, 2008. http://www.theses.fr/2008GRE10020.
Full textStandard NMR methods applied to the structural analysis of proteins are based on the measurement of local geometric information between protons. The lack of long range restraints can be limiting factor for the study of the modular proteins, protein complexes and supramolecular assemblies. Perdeuteration of samples is necessary for the study of these large systems. However, the exchange of protons with deuterium limit the number of detectable structural restraints, particularly NOEs distance restraints. To resolve this problem, a strategy based on the protonation of sorne discrete sites was developed. The specific protonation of methyls in proteins constitutes an optimum choice for detection of long range restraints. Protocols for specific labelling of methyls of Isoleucines, Valines and Leucines were implemented and optimized, and a new method for specific protonation of Alanines was introduced. Ln moderate size systems, the use of this specific labelling strategy combined with the development of NMR experiments allows the detection of restraints (NOEs and RDCs) between methyls separated by more than 12 Â. A robust method was developed to extract distances with very high precision. This approach can also be applied to large proteins. NOEs have been observed between methyls separated by more than 7 Â in a 468 kDa supramolecular assembly
Claraz, Aurélie. "Nouvelles applications de paires d’ions coopératifs chirales en organocatalyse : réactions énantiosélectives de protonation, de déprotonation et d’aldolisation directes vinylogues." Thesis, Rouen, INSA, 2012. http://www.theses.fr/2012ISAM0015.
Full textThis work deals with the development of new asymetric organocatalyzed methodologies. More particularly we were focused on using "cooperative chiral ion pairs" having an ammonium moiety derived from cinchona alkaloids and an anionic moiety with nucleophilic properties able to activate a reagent.Firstly, we used an in situ generated chiral ammonium amide (from the combination of an aminosilane and a quininium aryloxide) as a Brønsted base in two distinct reactions. Initially, this strategy was applied to an organocatalyzed desymmetrization of prochiral ketones by enantioselective deprotonation. Despite modest enantiometric excesses, this report constitutes the first example of an enantioselective orgonacatalyc approach. Then, an anti-selective direct vinylogous asymmetric aldol reaction of (5H)-furan-2-ones was achieved in good yields and enantioselectivities up to 94%.Secondly, we described two new catalytic cycles for the enantioselective protonation of latent enolates. By means of cinchona alkaloids and hydrogenocarbonates, enantioenriched α-substituted ketones were obtained with good enantiometric excesses up to 93% starting from the corresponding enol trifluoacetates. Finally, the nucleophilic properties of our ammonium phenoxide catalysts prompted us to develop an enantioselective protonation reaction of silyl enol ethers in the presence of phenol as achiral proton source
Hoffmann, Felix [Verfasser]. "Structural driving forces and their spectroscopic signatures : from protonation dynamics to amyloid formation ; [kumulative Dissertation] / Felix Hoffmann." Halle, 2018. http://d-nb.info/1166140636/34.
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