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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
601

Screening of substituted pyrazolone and pyrazole as ligands with palladium precursors in the Heck reaction

Bout, Wanda 03 1900 (has links)
M. Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology): Vaal University of Technology / The arylation and alkenylation of alkenes under the influence of a palladium catalyst, commonly referred to as the Heck reaction, has been extensively exploited by synthetic chemists since its debut in the late 1960’s. A traditional Heck coupling is based on an aryl iodide or bromide as the electrophilic partner and a terminal alkene as the nucleophilic partner. Academic and industrial interest in this reaction has increased in recent years, fueled by the development of more active catalyst systems, the discovery of waste-free versions, and the desire to put the vast empirical data on a sound mechanistic basis. In this study, we wish to report the use of commercially available substituted pyrazolones (1-(4-Sulfophenyl)-3-methyl-5-pyrazolone (L1), 1-(2,5-Dicloro-4-sulfophenyl)-3-methyl-5-pyrazolone (L2) and 5-oxo-1-phenyl-2-pyrazolin-3-carboxylic acid (L3)) and pyrazoles (α-[(2-Ethoxy-2-oxoethoxy)imino]-3-pyrazole acetic acid (L4) and 3.5 dimethyl pyrazole (L5)) as auxiliary ligands in the Heck coupling reaction. These ligands were used either with PdCl2 or Pd(OAc)2 to catalyze the Heck reaction of iodobenzene with ethyl acrylate or butyl acrylate. GC-MS was used to monitor the reaction, percentage (%) conversions were determined based on the consumption of iodobenzene. Different reaction parameters such as ligands, temperature, base, solvent and influence of time were investigated. It was observed that the lower conversion was obtained for ethyl acrylate and conversions above 80% were obtained for butyl acrylate. Ligand effect proved to be very crucial during the Heck coupling reactions of iodobenzene with butyl acrylate and ethyl acrylate. For instance in the absence of ligands with PdCl2, the conversions were 29 % and 44 % for butyl acrylate and ethyl acrylate, respectively. When Pd(OAc)2 was used in the absence of ligands the conversions were 25 % and 36 % for butyl acrylate and ethyl acrylate, respectively. In the study for the effect of temperature, 80 ◦C was observed as the best temperature since promising conversions were obtained with little or no sign of deactivation of the catalysts. On the other hand, increasing the temperature to 120 ◦C and above high percent conversions are observed; however deactivation of the catalysts occurs as observed from the precipitation of palladium black at the bottom of the vial. From the results obtained it is clear that pyrazolone and pyrazole ligands/palladium systems are important at very low catalyst loadings and mild temperatures. Based on the employed reaction conditions the influence of base suggested that the organic base triethylamine was the reagent of choice since better conversions were obtained compared to inorganic bases. The inhomogeneity of the inorganic base proved to be a disadvantage in the reaction of iodobenzene with butyl acrylate at employed reaction conditions. It was also found that parameters such as solvents and time effects were important in the Heck reaction. Polar aprotic solvents proved to be solvents of choice rather than non-polar solvents, from the investigated solvents DMF gave better conversions under the used reaction conditions giving average conversions of 78 % and 75 % for all the ligands in the presence of PdCl2 and Pd(OAc)2, respectively. During the investigation of time effect, it was noteworthy to observe that L4 had a slow initiation rate, for instance after 0.5 h conversions of 2 % and 10 % were obtained for catalytic systems, PdCl2 and Pd(OAc)2 respectively. Also it was observed that under the investigated parameters there was no need to run the reaction for 24 h because after 4 h not much of a difference in conversions was observed. In comparing the influence of these two different auxiliary ligands, pyrazolone based ligands were more efficient than pyrazole based ligands under the investigated parameters. The fully detailed information supporting this has been discussed in Chapter 4.
602

A Reinvestigation of the Kinetics and Mechanism of Ligand Exchange in Mu-(2,2,8,8-Tetramethyl-3, 7-Dithianonane)-Decacarbonylditungsten(0)

Liao, Jing-Piin 08 1900 (has links)
This student is interested in reinvestigating the kinetics and mechanism of the bridged compound in l,2-dichloroethane with triisopropyl phosphite and in finding the reasons why the values of competition ratio k₋₂ /k₃ in this reaction are so large.
603

Kinetic Study of Ligand Exchange in mu-(2,2,8,8-Tetramethyl-3,7- Dithianonane)-Decacarbonylditungsten(0)

Yang, Sang-Nin 05 1900 (has links)
The substitution reaction of (DTN)W2 (CO)10 with P(OCH(CH3 )2 )3 is a stepwise reaction. The kinetics of step 1 follow the equation: -d[substrate] /dt = kld [substrate] + k la [substrate] [ligand]. Thus the mechanism of step 1 is expected to be a competition between dissociative and associative pathways. The kinetics of step 2 follow the equation: -d[(DTN)W(CO)5]/dt = k2dk3[(DTN)W(CO)5][ligand]/k-2[DTN] + k3[ligand] The plot of kobsd versus [ligand] thus is a hyperbolic curve and the plot of 1/kobsd versus 1/[L] exhibits linear behavior. A mechanism for step 2 in which (DTN)W(CO)5 dissociates to an intermediate, W(CO) 5 , and in which DTN and P(OCH(CH3 )2 )3 compete to associate with W(CO) 5 is favored. The dissociative rate constant of the first step, kld' is about 1.2 times of that of the second step, k2d. The dissociation of (DTN)W(CO) 5 from (DTN)W2 (CO) 1 0 is favored over the dissociation of DTN from (DTN)W(CO) 5 due to a combination of the steric, stoichiometric, charge repulsion and entropy effects of the reaction.
604

Modèles fonctionnels d’hydrogénases [NiFe]

Pieri, Cyril 09 November 2012 (has links)
Les sources d'approvisionnement en énergie proviennent essentiellement des matières fossiles, qui se raréfient et dont la combustion relargue dans l'atmosphère des polluants et gaz à effet de serre.Un vecteur d'énergie apparaît comme l'avenir pour subvenir aux besoins énergétiques de la planète : l'hydrogène ; cependant, son coût de production reste très élevé.Dans la nature, des enzymes, les hydrogénases, sont capables de produire et d'oxyder l'hydrogène de manière très efficace. Les scientifiques se sont alors inspirés de ces enzymes afin de concevoir des complexes qui seraient des catalyseurs bien plus robustes pour produire de l'hydrogène.Au cours de cette thèse, nous avons pris comme source d'inspiration les hydrogénases [NiFe], dont le site actif est composé d'un coeur bimétallique Ni-Fe coordiné par quatres ligands thiolates.Nous avons synthétisé divers ligands en vue d'obtenir des complexes polymétalliques de Ni, Fe ou Ru, rassemblant ce qui semble être quelques unes des propriétés clés de l'activité des hydrogénases [NiFe] : ligands thiolate sur le nickel, dont deux pontants avec le second métal, géométrie tétraédrique du nickel. Pour cela, de nouvelles familles de ligands polythiolates ont été conçues et préparées.Les complexes ainsi préparés ont été caractérisés et leur activité évaluée par différentes techniques, dont la voltammétrie cyclique et l'électrolyse couplé à une GC, qui nous ont permis d'évaluer l'activité de nos catalyseurs (TON, TOF, surtension). Un des catalyseurs actifs a été utilisé comme support pour des simulations en DFT qui nous ont aidés à mieux comprendre le mécanisme catalytique de production d'hydrogène. / The energy supply sources are mainly based on fossil materials which are growing scarce and release pollutants and greenhouse gases.In this context, an energy vector appears as the future to feed the energetic needs of the planet: the Hydrogen; but its current production costs remain very high.Nature has deviced enzymes, hydrogenases, able to produce and oxidize hydrogen very efficiently. Nevertheless, the manipulation of these organisms is not easy, notably because of their susceptibility (oxygen inhibition, organic solvents, high temperatures), and their production costs are high.So, scientists have taken this inspiration source in order to design biomimetic and bioinspired models, which would much more robust and cheap catalysts to produce hydrogen.During this thesis, we have drawn our inspiration from [NiFe] hydrogenases, where the active site is a Ni-Fe core coordinated by four thiolate ligands. Our goal has been to design new polythiolate ligands, that gather some of the key hydrogenases [NiFe] properties responsible for their activity: thiolate ligands on the nickel, among them two brinding with the second metal, nickel tetraedric geometry.The synthesised complexes have been characterized and their activity tested (TON, TOF, overvoltage) by different techniques, among them cyclic voltammetry and electrolysis coupled to a GC.Finally, the bests have been tested further, thank to bulk electrolysis, which, coupled to a GC system, has enabled us to qualify and quantify the hydrogen production.One of our most active catalysts has been used as a support for DFT calculations, helping us to better undersand the catalytic hydrogen evolving mechanism.
605

Synthesis and application of new bipyridine ligands / Synthèse et applications de nouveaux ligands bipyridine

Bednarova, Eva 26 November 2018 (has links)
Les 2,2´-bipyridines et leurs homologues, les N,N´-dioxydes, appartiennent à une classe de composés hétéroaromatiques très importante ayant montré de nombreuses applications dans le domaine de la chimie et principalement en synthèse asymétrique. Une des méthodes les plus performantes pour leurs synthèses s´est révélée être une réaction de cocyclotrimérisation d´alcynes en présence de dérivés nitriles.Une nouvelle variante de la réaction de cyclotrimérisation – cocyclotrimérisation de diynes halogénés avec des dérivés nitriles – permettant la formation de composés 2- et3-halogéno-pyridines a ainsi été développée. La réaction a été étudiée sur une large gamme de substrats permettant l´accès à une librairie de pyridines avec de bons rendements. La formation d´un sous-produit, issu d´un échange d´halogène, a été approfondie au cours de l´étude et son origine a été élucidée grâce à différentes expériences.Les 2-halogéno-pyridines ont été utilisées comme réactifs de départ pour la synthèse de ligands chiraux de type 2,2´-bipyridines. L´étape problématique s´est avérée être la réaction de dimérisation réductrice des 2-halogéno-pyridines donnant accès aux2,2-bipyridines correspondantes. L´efficacité de ces ligands chiraux de type 2,2´-bipyridinea été évaluée dans différentes réactions asymétriques catalysées par des métaux de transition telles que l´aldolisation de Mukaiyama, l´hydroxyméthylation, l´addition conjuguée, l´activation C–H d´indoles mais aussi la désymmétrisation d´époxydes meso, dans laquelle un des ligands bipyridines a montré une extraordinaire activité et robustesse. Ensuite, basées sur des analyses RMN, des calculs DFT et des analyses par diffraction des rayons X, les propriétés structurales de ce ligand ont été étudiées.De plus, une nouvelle famille de catalyseurs à chiralité axiale de type 2,2´-bipyridines N,N´-dioxydes a pu être synthétisée via 2 différentes approches, où seule l´étape clé de dimérisation diffère. La première approche, basée sur la réaction de dimérisation réductrice des 2-halogéno-pyridines, permet l´obtention d´un seul atropoisomère du N,N´-dioxydes cible après une séquence réactionnelle de 8 étapes tandis que la seconde approche, basée sur la réaction de dimérisation oxydante de pyridines N-oxydes, donne l´accès aux 2 atropoisomères en seulement 5 étapes. Le champs d´application de ces nouveaux catalyseurs de typeN,N´-dioxydes, en tant que base de Lewis, a été examiné dans l´allylation énantiosélective du benzaldéhyde ainsi que dans l´aldolisation de l´acétal de cétène trichlorosilylé en présence de l´acétophénone. / 2,2'-Bipyridines and their appropriate N,N'-dioxides form a significant class of heteroaromatic compounds, which has found application in various fields of chemistry and predominantly in asymmetric catalysis. One of the most powerful methods for their synthesis is cocyclotrimerization of alkynes with nitriles.A new variant of cyclotrimerization reaction – cocyclotrimerization of halodiynes with nitriles, which results in the formation of 2- and 3-halopyridines, has been developed. The reaction was studied on a wide range of substrates providing the pyridine products in good isolated yields. Formation of an unexpected product of halogen exchange reaction was observed during the course of the study and its origin was elucidated by experimental studies.The prepared 2-halopyridines were used as starting materials for syntheses of new chiral 2,2'-bipyridine ligands. The crucial step of their synthesis turned out to be the reductive dimerization of 2-halopyridines to the corresponding 2,2'-bipyridines. Application of the formed bipyridine ligands was then tested in various metal-catalyzed asymmetric reactions, namely Mukaiyama aldol reaction, hydroxymethylation, conjugate addition, C–H activation of indole and desymmetrization of meso-epoxides, in which one of the bipyridine ligands showed extraordinary activity and robustness. The structural properties of this ligand were then studied based on the NMR analyses, DFT calculations and single crystal X-ray analyses.New axially chiral 2,2'-bipyridine N,N'-dioxides were synthesized via two approaches, which differed in the type of the key dimerization step. While the first approach, based on the reductive dimerization of 2-halopyridines, furnished only one atropoisomer of the target N,N'-dioxide by an eight-step reaction sequence, the second approach, based on oxidative dimerization of pyridine-N-oxides, provided both atropoisomers in only five steps. The applicability of these novel N,N'-dioxides as Lewis base catalysts were then examined in the enantioselective allylation of benzaldehyde and aldol reaction of trichlorosilyl ketene acetal with acetophenone.
606

Mise au point d'une méthode de mesure d'interaction ligand-ARN par électrochimie / Development of an electrochemical method for the detection of RNA/ligands interactions

Guyon, Hélène 24 October 2016 (has links)
Etant donné leur implication dans de nombreux processus biochimiques, les ARN sont maintenant considérés comme des cibles thérapeutiques très prometteuses. Cependant, nos connaissances limitées concernant les phénomènes d'interaction entre les ARN et de petites molécules, compliquent l'élaboration de nouveaux ligands (ou médicaments), capables de reconnaître sélectivement une structure complexe d'ARN. En absence de toute approche rationnelle, une stratégie de criblage pourrait permettre de mieux comprendre ces phénomènes de reconnaissance. Cette thèse porte sur la mise au point d'une méthode électrochimique, simple, adaptée pour du criblage haut-débit et permettant de détecter et de quantifier les interactions ARN/ligands. Le principe de la méthode repose sur la différence de coefficient de diffusion qui existe entre la forme libre d'un ligand possédant des propriétés redox et sa forme complexée à l'ARN. Cette stratégie de détection par voie électrochimique présente comme avantages d'être peu coûteuse, rapide, simple d'utilisation, adaptée pour du criblage haut-débit de molécules et utilisable dans de faibles volumes. Cette méthodologie a été utilisée pour caractériser la formation d'un complexe entre un analogue d'aminoglycoside porteur d'un groupe ferocene et une séquence d'ARNr 16S23. De plus, des expériences de compétition entre le complexe ARN/ligand redox et des aminoglycosides non modifiées permettent d'étendre la méthode à la détermination de constantes de dissociation (KD) pour des molécules non marquées en phase homogène. Ces expériences de compétition pourront être généralisées pour mesurer le KD de librairies de molécules, permettant ainsi de trouver de meilleurs ligands d'ARN. / RNA molecules play a major role in various biochemical processes and they are now considered as an important drug target. However, our limited understanding of the interactions occurring between small molecules and RNA complicate the search for new ligands (or drugs) with improved specific interaction and binding to elaborated RNA structures. In the absence of any rational approach, a screening strategy could shed light on the ligand/RNA interactions. In this thesis, we describe a simple electrochemical approach allowing for high-throughput detection and quantification of small molecule/RNA interactions. The principle of the method relies on the difference of diffusion rates between a redoxmolecular probe free or bound to its RNA target and thus to the ability to more easily electrochemically detect the forme rover the latter in a homogenous solution. This electrochemical detection strategy has the advantages of being affordable,fast, easy to use, sensitive and well-adapted to a high-throughput screening strategy in small volume samples. This methodology was used to characterize the binding of an aminoglycoside analog bearing a ferocenyl group to the ribosomal RNA fragment (rRNA 16S23). Furthermore, competitive binding of unlabelled aminoglycosides on theRNA/electrochemical probe complex allowed us to evaluate their dissociation constants (KD). These competitive experiments could further be generalized to measure KD values for libraries of molecules, which could help to find better RNA ligands.
607

Synthesis, structures and properties of copper and nickel complexes containing some pyridyl ligands with potential N,O-donor sites. / Synthesis, structures & properties of copper & nickel complexes containing some pyridyl ligands with potential N,O-donor sites

January 2005 (has links)
To Hing-lun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.ii / ACKNOWLEDGMENT --- p.iii / CONTENTS --- p.iv / ABBREVIATIONS --- p.vi / Chapter CHAPTER 1 --- Synthesis and Reactivity Studies of Copper Complexes Supported by a Pyridine-Containing Ligand / Chapter 1.A. --- General Introduction / Chapter 1.A.I. --- Introduction --- p.1 / Chapter 1.A.II. --- Dioxygen Activation by Copper-Containing Species --- p.2 / Chapter 1 A.III. --- Reactivity of Copper(I) Complexes Towards Dioxygen Binding --- p.11 / Chapter 1.A.IV. --- Synthetic Models for Copper-Containing Proteins --- p.12 / Chapter 1.A.V. --- Objective of This Work --- p.27 / Results and Discussion / Chapter 1.B. --- Synthesis and Characterization / Chapter 1.B.I. --- Synthesis / Chapter 1.B.I.a. --- Ligand Synthesis --- p.28 / Chapter 1.B.I.b. --- Synthesis of Copper(I) Complexes --- p.31 / Chapter 1.B.II. --- Characterization / Chapter 1.B.II.a. --- Physical Characterization of Complex25 --- p.33 / Chapter 1.B.II.b. --- Structural Studies / Chapter 1.B.II.b.i. --- Molecular Structure of Complex25 --- p.34 / Chapter 1.B.II.b.ii. --- Comparisons of The Structural Parameters of 25 with Those of 24 and Other [Cu1(u-Br)]2 Complexes --- p.37 / Chapter 1.B.II.c. --- Electrochemical Studies --- p.38 / Chapter 1.C. --- Reactivity Studies --- p.40 / Chapter 1.D. --- Summary --- p.44 / Chapter 1.E. --- Experimental Procedures --- p.45 / Chapter 1.F. --- References --- p.54 / Chapter CHAPTER 2 --- Synthesis and Reactivity Studies of Nickel Complexes With a N3O-Donor Ligand / Chapter 2.A. --- General Introduction / Chapter 2.A.I. --- Introduction --- p.61 / Chapter 2.A.II. --- Studies of Metal-Phenoxyl Radical Arrays --- p.67 / Chapter 2.A.III. --- Objective of This Work --- p.72 / Results and Discussion / Chapter 2.B. --- Synthesis and Characterization / Chapter 2.B.I. --- Synthesis of Nickel(II) Complexes --- p.73 / Chapter 2.B.II. --- Characterization / Chapter 2.B.II.a. --- Physical Characterization of Complexes 34 and 35 --- p.75 / Chapter 2.B.II.b. --- Structural Studies / Chapter 2.B.II.b.i. --- Molecular Structure of Complex 34 --- p.75 / Chapter 2.B.II.b.ii. --- Molecular Structure of Complex 35 --- p.78 / Chapter 2.B.II.b.iii. --- Structural Comparisons --- p.81 / Chapter 2.B.II.c. --- Electrochemical Studies --- p.82 / Chapter 2.C. --- Reactivity Studies --- p.84 / Chapter 2.D. --- Summary --- p.90 / Chapter 2.E. --- Experimental Procedures --- p.91 / Chapter 2.F. --- References --- p.94 / APPENDIX A General Procedure and Physical Measurements / Chapter A.I. --- General Procedures --- p.99 / Chapter A.II. --- Physical Measurements --- p.100 / APPENDIX B Crystallographic Data / Chapter B.I. --- Selected Crystallographic Data for Compounds 25,34 and 35 --- p.102
608

Syntheses and structures of copper and zinc complexes with N₃O donor ligands.

January 2001 (has links)
by Chan Sau Han. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references. / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.ii / ACKNOWLEDGMENT --- p.iii / CONTENTS --- p.iv / ABBREVIATIONS --- p.vi / Chapter CHAPTER 1 --- General Introduction / Chapter 1-A. --- Role of Copper in Biology --- p.1 / Chapter 1-B. --- A Brief Review on Radical Copper Proteins --- p.4 / Chapter 1-C. --- Objectives of This Work --- p.12 / Chapter 1-D. --- References --- p.13 / Chapter CHAPTER 2 --- Copper(II) and Zinc(II) Complexes containing N3O Tetradentate Ligands / Chapter 2-A. --- Introduction Results and Discussion --- p.14 / Chapter 2-B. --- Preparation of Tetradentate Ligands and Complexes --- p.27 / Chapter 2-C. --- Characterization --- p.36 / Chapter 2-D. --- Generation of Metal Phenoxyl Radical Species --- p.51 / Chapter 2-E. --- Summary --- p.57 / Chapter 2-F. --- References --- p.59 / Chapter CHAPTER 3 --- Copper(I) Complexes with N30 Tetradentate Ligands / Chapter 3-A. --- Introduction Results and Discussion --- p.62 / Chapter 3-B. --- Preparation of Copper(I) Complexes with N30 Tetradentate Ligands --- p.75 / Chapter 3-C. --- Characterization --- p.79 / Chapter 3-D. --- Reactivities of 86,87 and 88 toward Dioxygen --- p.88 / Chapter 3-E. --- Summary --- p.93 / Chapter 3-F. --- References --- p.94 / Chapter CHAPTER 4 --- Experimental Sections / Chapter 4-A. --- General Preparations and Physical Measurements --- p.97 / Chapter 4-B. --- Compounds Described in Chapter2 --- p.99 / Chapter 4-C. --- Compounds Described in Chapter3 --- p.113 / Chapter 4-D. --- Oxo-Transfer to Triphenylphosphine as Described in Chapter3 --- p.117 / Chapter 4-E. --- References --- p.119 / Chapter APPENDIX A --- 1H and13 C̐ưث1H ̐ưحNMR Spectra / Chapter A-1. --- Compounds Described in Chapter2 --- p.120 / Chapter A-2. --- Compounds Described in Chapter3 --- p.127 / Chapter APPENDIX B --- Crystallographic Data / Chapter B-1. --- X-ray Crystal Structure Data for Complexes in Chapter2 --- p.131 / Chapter B-2. --- X-ray Crystal Structure Data for Complexes in Chapter3 --- p.133 / Chapter APPENDIX C --- GC-MS Spectra / Chapter C-1. --- GC-MS Spectra for Standard Samples --- p.134 / Chapter C-2. --- GC-MS Spectra for the Reactions with Triphenylphosphine Described in Chapter3 --- p.136
609

Développement de nouveaux ligands et azotures chélatants pour la cycloaddition alcyne-azoture catalysée au cuivre / Development of copper ligands and chelating azides for the copper-catalysed alkyne-azide cycloaddition

Bevilacqua, Valentina 20 December 2012 (has links)
Le développement de nouvelles réactions de ligation sélectives, capables de former des liens covalents dans des milieux complexes, est en plein essor depuis une dizaine d’années. Malgré de nombreux efforts, peu de réactions chimiques répondent aux critères de bioorthogonalité et la cycloaddition alcyne-azoture est devenue une réaction bioorthogonale essentielle à la fois pour les chimistes mais aussi pour les biochimistes.Le but de ce travail a été d’améliorer la cinétique de la réaction de cycloaddition alcyne-azoture catalysée par le cuivre, de façon à pouvoir réduire au maximum la quantité de cuivre nécessaire à la réaction et donc son éventuelle toxicité, notamment sur les cellules. Les efforts de recherche menés par de nombreux groupes dans le monde ont porté sur l’augmentation des capacités catalytiques du cuivre (I) par complexation avec des ligands appropriés. Dans un premier temps, à partir de ces résultats, une nouvelle série des ligands du cuivre a été développée au laboratoire et testée dans des milieux aqueux et biologiques. Dans un second temps, nous nous sommes intéressés à une nouvelle stratégie qui consiste à concevoir et synthétiser des azotures chélatants du cuivre. Ces azotures servent à la fois de ligands et de réactifs, et permettent d’accélérer considérablement les vitesses de réaction de la cycloaddition alcyne-azoture en milieu aqueux et en milieu complexe. Ces azotures ont été évalués pour des applications de « fishing » dans lysats cellulaires et sur cellules vivantes. / To improve the kinetic of the CuAAC (Copper Catalyzed Azide-Alkyne Cycloaddition) reaction and to overcome the problems of cytotoxicity of copper which preclude many applications in bioconjugation, recent research efforts have focused on the use of appropriate ligands in combination with copper. Indeed, certain ligands can be added to the reaction solution to bind copper, accelerate reaction, prevent the disproportion and slow down the oxygen reaction. During the first part of my PhD, we have synthesized a new library of ligands bearing amines as specific complexing sites for copper. These libraries of ligands were tested on the CuAAC reaction in diluted aqueous media and in complex media through the use of a fluorogenic assays. Ligands developed in the laboratory were compared with known ligands for the CuAAC, described in the literature. In a second part, we envisioned another strategy to accelerate the kinetics of the CuAAC. For that purpose, we synthesized new azides bearing copper complexation sites by introducing in their structure a copper chelating moiety. Those different azides have been tested in the CuAAC reaction with the help of fluorogenic assays, in diluted aqueous media and in cell lysate. Best chelating azides were tested also in “fishing” experiments of proteins in cell lysate and in cells.
610

Homo- and heterometallic 3d-metal complexes with N- and N,O-donor ligands : synthesis, structure and properties / Complexes homo- et hétero- métallique 3d avec des ligands N- et N,O donneurs : Synthèse, structure et propriétés

Stetsiuk, Oleh 10 December 2018 (has links)
Cette thèse est consacrée à la synthèse de complexes 3d homo et hétérométalliques avec des ligands bases de Schiff ou dérivés de la 1,2,4,5-tétrazine, à l’investigation de leur structure et de leurs propriétés physico-chimiques. Ce travail peut être divisé en trois parties. Dans la première partie, nous nous sommes principalement concentrés sur les ligands bases de Schiff, dérivés du salicylaldéhyde et des aminoalcools, formés in situ. Treize complexes hétérométalliques ont été obtenus et entièrement caractérisés. Il a été montré que les composés synthétisés possèdent une activité catalytique dans la réaction de l’oxydation photochimique de l’eau, présentent des propriétés de photoconductive dans les polymères composites et peuvent être utilisés pour le développement de matériaux multifonctionnels. La deuxième partie décrit la fonctionnalisation des ligands base de Schiff par l’introduction dans leur structure des unités tétrathiafulvalène et métaux dithiolènes électroactives. Deux nouvelles familles de ligands ont été synthétisées et caractérisées. La série de sels de radicaux cations et de complexes dithiolènes homo et hétérométalliques ainsi que leurs propriétés physiques ont été discutées. La dernière partie est consacrée aux ligands à base de tétrazine. Les principaux avantages du noyau tétrazine ont été discutés. Deux nouveaux ligands dérivés de la picolylamine et leurs complexes 3d mono- et binucléaires ont été décrits. / The thesis is devoted to the synthesis of homo- and heterometallic 3d-metal complexes with Schiff base ligands or derivatives of 1,2,4,5- tetrazine, together with the investigation of their structural and physico-chemical properties. This work can be divided in three parts. In the first part we have been mainly focused on the Schiff base ligands, derivatives of the salicylaldehyde and aminoalcohols. Thirteen heterometallic complexes were obtained and fully characterized. It has been shown that the synthesized compounds possess catalytic activity in the photochemical water oxidation, exhibit photoconducting properties in polymeric composites and can be used for the development of multifunctional materials of wide use. The second part describes the functionalization of Schiff base ligands by the introduction into their structure of electroactive tetrathiafulvalene and dithiolate moieties. Two new families of ligands were synthesized and characterized. The series of radicalcation salts and homo- and heterometallic dithiolene complexes together with the investigation of their physical properties have been described. The last part is devoted to the tetrazine based ligands. The main advantages of the tetrazine ring have been discussed. Two new ligands, derivative of picolylamine and their mono- and binuclear 3d-metal complexes are reported. In conclusion, perspectives of further research related to the described results were highlighted.

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