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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.
1

Les bambusurils : molécules-cages pour l'encapsulation d'anions et utilisation comme nouvelles plateformes multivalentes d'intérêt biologique / Bambusurils : Cage Molecules for Encapsulating Anions and their Uses as New Multivalent platforms of Biological Interest

Azazna, Djamille 23 November 2017 (has links)
Les bambusurils, BU[4] et BU[6], sont des oligomères cycliques apparentés aux cucurbiturils, CBs, constitués respectivement de 4 et 6 motifs glycolurils. Les bambusurils diffèrent des CBs par la présence de glycolurils difonctionnalisés.Les BU[6] ont la capacité d'encapsuler des anions dans leur cavité, propriété intéressante pour la décontamination d'effluents, par exemple.Une nouvelle famille de bambusurils, les allylbambusurils, qui possèdent des groupements allyles sur leur portail macrocyclique, a été développée. Leur post-fonctionnalisation par oxydation, métathèse croisée ou réaction thiol-ène a été étudiée. Par réaction thiol-ène, des BU[4] et BU[6], fonctionnalisés respectivement par 8 ou 12 thiols d'intérèt, ont été obtenus. Les BU[6] sont toujours isolés avec un halogènure à l’intérieur de leur cavité. Une méthode utilisant l’hexafluoroantimonate d’argent a été mise au point pour les décomplexer. L'affinité de ces nouveaux BU[6] exempts d'anion, pour différents halogénures, a été évaluée par RMN 1H.Des glycobambusurils ont été synthétisés par réaction thiol-ène en présence de sucres fonctionnalisés par des thiols. Ces glycoBUs donnent accès à des plateformes multivalentes de valence 8 pour les BU[4] et 12 pour les BU[6]. Le pouvoir inhibiteur de ces nouvelles plateformes a été testé sur l'enzyme WaaC, une heptosyltransferase présente dans la paroi bactérienne. Les tests enzymatiques montrent que ces glycobambusurils sont des plateformes multivalentes prometteuses. / Bambusurils, BU[4] and BU[6] are cyclic oligomers that belong to the cucurbiturils family, CBs, assembled respectively by 4 and 6 glycoluril units. Bambusurils are different from cucurbiturils because of their difunctionalized glycolurils. BU[6] are able to encapsulate anions inside their cavity and this property can be useful for the treatment of effluents.A new family of BUs, the allylbambusurils having allyls groups on their macrocyclic portal, has been developed. Their postfunctionalization by oxidation, cross metathesis and thiol-ene coupling has been studied. BU[4] and BU[6] functionalized by respectively 8 and 12 thiols of interest have been prepared.BU[6] are always obtained with an halide inside the cavity. A method using silver hexafluoroantimonate has been developed to remove this halide. Binding constants of these new empty bambusurils have been determined towards severals halide by 1H NMR.Glycobambusurils have been synthesized by thiol- ene coupling with thiosugars. These glycoBUs can lead to multivalent platforms of valency up to 8 for BU[4] and 12 for BU[6]. Inhibition activity of these new platforms has been tested on WaaC enzyme, an heptosyltransferase found in bacterial cell wall. Enzymatic tests show that these glycobambusurils are promising multivalent platforms.
2

Immobilization of Ethylene Bis-Indenyl Ligands on Functionalized Silica Gel

Simerly, Thomas, Milligan, Tyson, Mohseni, Ray, Vasiliev, Aleksey 26 September 2012 (has links)
Four ethylene bis-indenyl ligands containing tethers of various lengths were successfully immobilized on the surface of functionalized silica gel. The strategy of immobilization was based on catalytic thiol-ene coupling of terminal alkene groups in the tethers with surface thiol groups. Obtained materials have high BET surface area and pore volume. The method developed can be used for immobilization of catalytically active bis-indenyl metallocene complexes, thus preventing their dimerization and deactivation.
3

Multifunctional Dendritic Scaffolds: Synthesis, Characterization and Potential applications

Hed, Yvonne January 2013 (has links)
The development of materials for advanced applications requires innovative macromolecules with well-defined structures and the inherent ability to be tailored in a straightforward manner. Dendrimers, being a subgroup of the dendritic polymer family, possess properties which fulfill such demands. They have a highly branched architecture with a high number of functional groups and are one of the most well-defined types of macromolecules ever synthesized. However, despite their well-defined nature and high functional density, traditional dendrimers commonly lack diverse chemical functionalities. Therefore, this thesis focuses on the synthesis of more complex dendritic materials to extend their tailoring capacity by introduction of dualfunctionalities for multipurpose actions. It covers the synthesis of dualfunctional dendrimers, dendritic modification of linear poly(ethylene glycol) polymers and cellulose surfaces, and the synthesis of linear dendritic hybrids. The building blocks enabling this synthesis, AB2C monomers, were also developed during this work. The orthogonal nature between click groups (azide, alkyne and alkene) and hydroxyl groups have efficiently been utilized for postfunctionalization by robust click chemistry and traditional esterification reactions. Furthermore, linear dendritic hybrids were synthesized, merging the properties of linear and dendritic macromolecules. The dendritic frameworks were tailored towards the production of bone fracture adhesives, novel biofunctional dendritic hydrogels, biosensors and micellar drug delivery vehicles. / Utveckling av material för avancerade applikationer kräver innovativa makromolekyler med väldefinierade strukturer och som kan skräddarsys på ett enkelt sätt. Dendrimerer är en undergrupp av dendritiska polymerer vars egenskaper uppfyller dessa krav. De har en mycket förgrenad arkitektur med många funktionella grupper och är en av de mest väldefinierade befintliga syntetiska makromolekylerna. Trots dess väldefinierade karaktär och höga funktionalitet saknar ofta traditionella dendrimerer multipla kemiska funktionaliteter. Denna avhandling fokuserar därför på syntesen av mer komplexa dendritiska material för att förbättra deras kapacitet att skräddarsys, detta görs genom att introducera fler funktionaliteter som kan utnyttjas för multipla ändamål . Avhandlingen redogör för syntesen av difunktionella dendrimerer, dendritiska modifikationer av polyetylenglykol och cellulosaytor samt syntes av traditionella dendritiska hybrider. Byggstenarna som möjliggör syntesen, AB2C monomerer, framställdes också under detta arbete. Den ortogonala karaktären mellan klick grupper (azid, alkyn och alkene) och hydroxylgrupper har utnyttjats effektivt för funktionaliseringar genom användande av robust ”Click”-kemi och traditionella esterifikationsreaktioner. Vidare tillverkades de linjära dendritiska hybrider för att kombinera egenskaperna hos både linjära och traditionella dendritiska polymerer i en och samma makromolekyl. Samtliga dendritiska strukturer skräddarsyddes för applikationer så som benlimmer, biofunktionella dendritiska hydrogeler, biosensorer och läkemedels-bärande miceller. / <p>QC 20130830</p>
4

Immobilized Bis-Indenyl Ligands for Stable and Cost-Effective Metallocene Catalysts of Hydrogenation and Polymerization Reactions

Simerly, Thomas Max 15 August 2012 (has links) (PDF)
Reactions of catalytic hydrogenations and polymerizations are widely used in industry for manufacture of fine chemicals, pharmaceuticals, and plastics. Homogeneous catalysts for the processes that have low stability and their separation is difficult. Therefore, the development of new highly active and stable catalysts for hydrogenations and polymerizations is a necessity. The objective of this research was the development of a strategy for immobilization of heterogeneous metallocene catalysts. First, a methodology of immobilization of bis-indenyl ligands on the surface of mesoporous silica gel was designed. Four bis-indenyl ligands containing functionalized tethers of various lengths with terminal alkene groups were synthesized. All bis-indenyl ligands were immobilized on the surface of mesoporous functionalized silica gel by two methods: hydrosilylation and thiol-ene coupling of the double bond. After comparing the results, the second strategy was chosen as more efficient. The materials can be used further as intermediates for synthesis of supported metallocene catalysts.

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