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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.
71

Efficient and High-Yielding Routes to Diaryliodonium Salts

Bielawski, Marcin January 2008 (has links)
<p>This thesis summarizes three novel and general reaction protocols for the synthesis of diaryliodonium salts. All protocols utilize mCPBA as oxidant and the acids used are either TfOH, to obtain triflate salts, or BF3•Et2O that gives the corresponding tetrafluoroborate salts in situ.</p><p>Chapter two describes the reaction of various arenes and aryl iodides, delivering electron-rich and electron-deficient triflates in moderate to excellent yields.</p><p>In chapter three, it is shown that the need of aryl iodides can be circumvented, as molecular iodine can be used together with arenes in a direct one-pot, three-step synthesis of symmetric diaryliodonium triflates.</p><p>The final and fourth chapter describes the development of a sequential one-pot reaction from aryl iodides and boronic acids, delivering symmetric and unsymmetric, electron-rich and electron-deficient iodonium tetrafluoroborates in moderate to excellent yields. This protocol was developed to overcome mechanistic limitations existing in the protocols described in chapter two and three.</p><p>The methodology described in this thesis is the most general, efficient and high-yielding existing up to date, making diaryliodonium salts easily available for various applications in synthesis.</p>
72

Saccharide recognition : boronic acids as receptors in polymeric networks

Schumacher, Soeren January 2011 (has links)
In this thesis entitled “Saccharide Recognition - Boronic acids as Receptors in Polymeric Networks” different aspects of boronic acid synthesis, their analysis and incorporation or attachment to different polymeric networks and characterisation thereof were investigated. The following key aspects were considered: • Provision of a variety of different characterised arylboronic acids and benzoboroxoles • Attachment of certain derivatives to nanoparticles and the characterisation of saccharide binding by means of isothermal titration calorimetry and displacement assay (ARS) to enhance the association constant to saccharides at pH 7.4 • Enhancement of selectivity in polymeric systems by means of molecular imprinting using fructose as template and a polymerisable benzoboroxole as functional monomer for the recognition at pH 7.4 (Joined by a diploma thesis of F. Grüneberger) • Development of biomimetic saccharide structures and the development of saccharide (especially glucose and fructose) binding MIPs by using these structures as template molecules. In the first part of the thesis different arylboronic acid derivatives were synthesised and their binding to glucose or fructose was investigated by means of isothermal titration calorimetry (ITC). It could be derived, which is in parallel to the literature, that derivatives bearing a methylhydroxyl-group in ortho-position to the boron (benzoboroxole) exhibit in most cases a two-fold higher association constant compared to the corresponding phenylboronic acid derivative. To gain a deeper understanding NMR spectroscopy and mass spectrometry with the benzoboroxole and glucose or fructose was performed. It could be shown that the exchange rate in terms of NMR time scale is quite slow since in titration experiments new peaks appeared. Via mass spectrometry of a mixture between benzoboroxole and glucose or fructose, different binding stoichiometries could be detected showing that the binding of saccharides is comparable with their binding to phenylboronic acid. In addition, the use of Alizarin Red S as an electrochemical reporter was described for the first time to monitor the saccharide binding to arylboronic acids not only with spectroscopy. Here, the redox behaviour and the displacement were recorded by cyclic voltammograms. In the second part different applications of boronic acids in polymeric networks were investigated. The attachment of benzoboroxoles to nanoparticles was investigated and monitored by means of isothermal titration calorimetry and a colourimetric assay with Alizarin Red S as the report dye. The investigations by isothermal titration calorimetry compared the fructose binding of arylboronic acids and benzoboroxoles coupled to these nanoparticles and “free” in solution. It could be shown that the attached derivatives showed a higher binding constant due to an increasing entropy term. This states for possible multivalent binding combined with a higher water release. Since ITC could not characterise the binding of glucose to these nanoparticles due to experimental restrictions the glucose binding at pH 7.4 was shown with ARS. Here, the displacement of ARS by fructose and also glucose could be followed and consequently these nanoparticles can be used for saccharide determination. Within this investigation also the temperature stability of these nanoparticles was examined and after normal sterilisation procedures (121°C, 20 min.) the binding behaviour was still unchanged. To target the selectivity of the used polymeric networks, molecular imprinting was used as a technique for creating artificial binding pockets on a molecular scale. As functional monomer 3-methacrylamidobenzoboroxole was introduced for the recognition of fructose. In comparison to polymers prepared with vinylphenylboronic acid the benzoboroxole containing polymer had a stronger binding at pH 7.4 which was shown for the first time. In addition, another imprinted polymer was synthesised especially for the recognition of glucose and fructose employing biomimetic saccharide analogues as template molecule. The advantage to use the saccharide analogues is the defined template-functional monomer complex during the polymerisation which is not the case, for example, for glucose-boronic acid interaction. The biomimetic character was proven through structural superimposition of crystal structures of the analogues with already described crystal structures of boronic acid esters of glucose and fructose. A molecularly imprinted polymer was synthesised with vinylphenylboronic acid as the functional monomer to show that both glucose and fructose are able to bind to the polymer which was predicted by the structural similarity of the analogues. The major scientific contributions of this thesis are • the determination of binding constants for some, not yet reported saccharide – boronic acid / benzoboroxole pairs, • the use of ARS as electrochemical reporter for saccharide detection, • the thermodynamic characterisation of a saccharide binding nanoparticle system containing benzoboroxole and functioning at pH 7.4, • the use of a polymerisable benzoboroxole as functional monomer for saccharide recognition in neutral, aqueous environments • and the synthesis and utilisation of biomimetic saccharide analogues as template molecules especially for the development of a glucose binding MIP. / Die vorliegende Arbeit beschäftigte sich mit der Synthese verschiedener Boronsäurederivate und deren Charakterisierung und Anbindung oder Einbau in polymeren Netzwerken. Die synthetisierten Polymere werden charakterisiert bezüglich ihrer Morphologie und besonders hinsichtlich ihrer Saccharidbindung. Im Wesentlichen wurden die folgenden Aspekte bearbeitet: • Bereitstellung einer Reihe von verschiedenen Arylboronsäuren und Benzoboroxolderivaten • Modifizierung von Nanopartikeln mit verschiedenen Derivaten aus der Bibliothek mit dem Ziel die Bindingkonstanten zu Monosacchariden bei pH 7.4. zu erhöhen. Dabei werden isothermale Titrationskalorimetrie und ein spektroskopischer Verdrängungsassay (Alizarin Rot S) zum Bindungsnachweis verwendet. • Erhöhung der Selektivität von Polymeren mittels molekularen Prägens von Fruktose als Matrizenmolekül. Durch den Einsatz eines polymerisierbaren Benzoboroxolderivatives konnte die Anbindung bei pH 7.4 stattfinden (Dieser Teil der Arbeit wurde durch eine Diplomarbeit von F. Grüneberger unterstützt). • Entwicklung von biomimetischen saccharidanalogen Strukturen, die als Matrizenmoleküle während des molekularen Prägens eingesetzt werden, um ein Polymer für die Anbindung von Monosacchariden wie etwa Fruktose oder Glukose zu generieren. Im ersten Teil der Arbeit wurde die Synthese und Charakterisierung von verschiedenen Boronsäurederivaten beschrieben. Die Charakterisierung der Bindungskonstanten wurde mittels isothermaler Titrationskalorimetrie durchgeführt. Dabei konnte im Einklang mit der Literatur gezeigt werden, dass Derivative, die zusätzlich mit einer Methylhydroxygruppe in ortho-Position zum Bor (Benzoboroxol) derivatisiert sind, eine meist zweifach höhere Bindungskonstante als gleich substituierte Arylboronsäurederivate aufweisen. Durch 1H-NMR-Spektroskopie und Massenspektrometrie mit Benzoboroxol und Glukose oder Fruktose konnten die Bindung weiter charakterisiert werden. Dabei zeigten die Ergebnisse der 1H-NMR-Spektroskopie, dass die Bindung bezogen auf NMR-Zeitskalen recht langsam stattfindet, da es zu einer Verbreiterung der Peaks kommt. Die Ergebnisse der Massenspektrometrie zeigen, dass hinsichtlich der Stöchiometrie der Binding verschiedene Komplexe möglich sind, was in ähnlicher Weise für Phenylboronsäure schon gezeigt wurde. Zusätzlich wurde in diesem Teil der Arbeit wurde die Elektrochemie von Alizarin Rot S untersucht, um den Farbstoff, der spektroskopisch schon für den Bindungsnachweis zwischen einem Boronsäurederivat und verschiedenen Zuckern beschrieben ist, auch elektrochemisch zu nutzen. Im zweiten Teil der Arbeit wurden verschiedene Anwendungen von den charakterisierten Boronsäuren in polymeren Netzwerken beschrieben. Dabei wurde zunächst ein Polystyrollatex mit Benzoboroxol modifiziert und die Bindung von Glukose oder Fruktose mittels isothermaler Titrationskalorimetrie und einem spektroskopischen Farbassay untersucht. Die Untersuchungen mittels isothermaler Titrationskalorimetrie (ITC) wurden vergleichend zu frei in Lösung befindlichem Benzoboroxol durchgeführt. Es wurde eine höhere Bindungskonstante für die modifizierten Nanopartikel ermittelt, was auf die Erhöhung der Entropie im System zurückzuführen ist. Dies kann durch eine mutivalente Bindung und einer einhergehenden erhöhten Wasserfreisetzung erklärt werden. Da es nicht möglich war, die Glukosebindung mittels ITC zu verfolgen, wurde zusätzlich ein spektroskopischer Assay bei pH 7.4. durchgeführt. Bei diesem wird die Bindung von Fruktose oder Glukose durch Freisetzung von Alizarin Rot S verfolgt. In diesem Zusammenhang konnte auch gezeigt werden, dass die Nanopartikel nach Sterilisation bei 121°C für 20 Minuten eine vergleichbare Bindung des Farbstoffes zeigen, was die Temperaturstabilität der Partikel unterstreicht. Da in diesem System die Bindung von Zuckern abhängig von der Affinität der Zucker zu den Boronsäuren bestimmt wird, wurden molekular geprägte Polymere synthetisiert, die eine Selektivität für bestimmte Zucker zeigen. Als Funktionsmonomer wurde 3-Methacrylamidobenzboroxol verwendet. Im Vergleich zu Polymeren, die mit 3-Vinylphenylboronsäure als literaturbekanntes Funktionsmonomer synthetisiert worden sind, zeigt sich bei pH 7.4 eine höhere Bindung von Fruktose an Benzoboroxolpolymere. In einem anderen geprägten Polymer wurden biomimetische (zuckeranaloge) Substanzen als Matrizenmolekül verwendet. Der Vorteil dieser Substanz ist die Bildung eines definierten Boronsäureesters, der als Templat-Funktionsmonomerkomplexes einpolymerisiert wird. Im Gegensatz dazu weist beispielsweise ein Boronsäureester der Glukose keine definierte Struktur auf. Der biomimetische Charakter wurde durch strukturelle Überlagerung mit schon publizierten Kristallstrukturen von Boronsäureestern von Glukose und Fruktose gezeigt. Das zugehörige molekular geprägte Polymer wurde mit Vinylphenylboronsäure synthetisiert und zeigt eine Bindung von Glukose und Fruktose, was durch die Strukturüberlagerungen vorhergesagt wurde. Zusammenfassend sind die wesentlichen wissenschaftlichen Ergebnisse: • Bindungskostanten von neuen Zucker-Benzoboroxolpaaren, • Eignung von ARS als elektrochemische Nachweissubstanz der Saccharidbindung • Die thermodynamische Charakterisierung der Bindung von Fruktose oder Glukose an Nanopartikel, die Benzoboroxol - modifziert sind und so bei pH 7.4 Zucker binden können • Einsatz von Benzoboroxol als Funktionsmonomer • die Synthese und Nutzung von biomimetischen zuckeranalogen Matrizenmolekülen für die Entwicklung von molekular geprägten Polymeren für die Glukosebindung.
73

Diagnosis and Inhibition Tools in Medicinal Chemistry

Akay, Senol 29 May 2009 (has links)
Cell surface saccharides are involved in a variety of essential biological events. Fluorescent sensors for saccharides can be used for detection, diagnosis, analysis and monitoring of pathological processes. The boronic acid functional group is known to bind strongly and reversibly to compounds with diol groups, which are commonly found on saccharides. Sensors that have been developed for the purpose of saccharide recognition have shown great potential. However, they are very hydrophobic and this lack of essential water-solubility makes them useful in biological applications. The first section of this dissertation details the process of developing water-soluble saccharide sensors that change fluorescent properties upon binding to saccharides. The second section of the dissertation focuses on the development of DNA-minor groove binders as antiparasitical agents. Parasitical diseases comprise some of the world’s largest health problems and yet current medication and treatments for these parasitical diseases are often difficult to administer, costly to the patients, and have disruptive side effects. Worse yet, these parasites are developing drug resistance, thus creating an urgent need for new treatments. Dicationic molecules constitute a class of antimicrobial drug candidates that possess high activity against various parasites. The second section details the development of a series of di-cationic agents that were then screened in in vitro activities against parasitical species.
74

Nanočástice citlivé na vnější podněty obsahující fenylboronové spojky jako potenciální nosiče léčiv / Stimuli - responsive nanoparticles with boronic ester linkages as a potential carrier for drug delivery

Hlavatovičová, Eva January 2020 (has links)
This thesis deals with the post-polymerization functionalization of a pH-responsive poly(styrene)-b-poly(4-vinyl pyridine)-b-poly(ethylene oxide) triblock terpolymer with stimuli responsive and diol-binding 2-bromomethyl-4-fluorophenylboronic acid and 2- bromomethyl-phenylboronic acid suitable for biomedical applications. A reproducible method of quaternization of poly(4-vinyl pyridine) block with prescriptible quaternization ratio was developed and the reaction yield was analyzed by 11 B, 1 H NMR and infrared spectroscopy. A reproducible self-assembly protocol for stable nanoparticles from functionalized stimuli-responsive triblock terpolymer was found, and the nanoparticles were studied by static, dynamic and electrophoretic light scattering, and cryogenic transmission electron microscopy. Fluorescence and UV-VIS spectroscopy measurements were performed for description of boron-ester linkages formation and hydrolysis with model drug Alizarin as a study of encapsulation and release reactions together with sugar sensing reactions for potential drug delivery.
75

Efficient and High-Yielding Routes to Diaryliodonium Salts

Bielawski, Marcin January 2008 (has links)
This thesis summarizes three novel and general reaction protocols for the synthesis of diaryliodonium salts. All protocols utilize mCPBA as oxidant and the acids used are either TfOH, to obtain triflate salts, or BF3•Et2O that gives the corresponding tetrafluoroborate salts in situ. Chapter two describes the reaction of various arenes and aryl iodides, delivering electron-rich and electron-deficient triflates in moderate to excellent yields. In chapter three, it is shown that the need of aryl iodides can be circumvented, as molecular iodine can be used together with arenes in a direct one-pot, three-step synthesis of symmetric diaryliodonium triflates. The final and fourth chapter describes the development of a sequential one-pot reaction from aryl iodides and boronic acids, delivering symmetric and unsymmetric, electron-rich and electron-deficient iodonium tetrafluoroborates in moderate to excellent yields. This protocol was developed to overcome mechanistic limitations existing in the protocols described in chapter two and three. The methodology described in this thesis is the most general, efficient and high-yielding existing up to date, making diaryliodonium salts easily available for various applications in synthesis.
76

Synthesis and Characterization of Novel Silicone-Boronic Acid Materials / Silicone-Boronic Acids

Zepeda-Velazquez, Laura 06 1900 (has links)
Silicone polymers and network-materials have proven extremely useful in a variety of applications owing to their superb properties when compared to carbon-based polymers. Polysiloxanes containing functional groups other than simple alkyl moieties have allowed for further manipulations of pendant groups along the polymer backbone leading to a greater range of possible chemical transformations, as well as changes in physical/interfacial properties. One aspect of functional polymers that has yet to be explored with respect to primarily silicone-based systems is that of stimuli-responsive materials. In order for this unique application to work, silicones must be functionalized with a group or groups that can influence the polymer’s properties based on that group’s response to specific external stimuli. Boronic acids represent one such group, wherein the most common stimuli used to affect changes in ionization state and solubility are pH and diol-binding. Boronic acids are also capable of forming weak hydrogen-bonded dimers with other boronic acids, and dynamic covalent bonds with Lewis bases. It is proposed that the covalent attachment of boronic acids and their derivatives onto silicones could lead to stimuli-responsive silicone materials. Herein, the synthesis of silicone-boronic acids and their protected boronic esters is described. The simple two-step method involving boronic acid protection followed by hydrosilylation has led to a variety of molecules differing in molecular weight and three-dimensional geometry through the use of commercially available hydride-functional silicones. Initial results regarding saccharide binding selectivity and the impacts on silicone solubility are provided. The unique interfacial behaviour of silicone-boronic esters and their propensity to form self-assembled, crosslinked films at an air/water interface are also reported. Using several different diol protecting groups and a variety of aqueous sub-phases, the mechanism for changes in physical properties as well as crosslinking were revealed. Finally, the production of new thermoplastic silicone elastomers from silicone-boronic esters and amine-containing molecules is discussed. The Lewis acid/Lewis base complexation that occurs between nitrogen and boron can provide enough strength to produce robust, yet recyclable, silicone elastomers without the use of catalyst or solvent. Elastomers can be easily dissolved and reformed through the introduction and removal of a mono-functional Lewis base. The impact of crosslink density, controlled by the quantities and molecular weights of each polymer component used, on physical characteristics is reported. / Thesis / Doctor of Philosophy (PhD)
77

Clusters and single atoms of Pd and Pt: Synthesis and applications in catalysis and as antitumoral agents

Greco, Rossella 02 September 2021 (has links)
[ES] En esta tesis se han estudiado la síntesis y aplicación de clústeres y átomos metálicos aislados de Pd y Pt. Clústeres y átomos aislados han sido sintetizados siguiendo nuevas metodologías en disolución, sin utilizar ligandos orgánicos, y soportándolos en materiales metal-orgánico estructurados (MOFs) o polímeros. Después de la síntesis, las pequeñas especies metálicas se han caracterizado con diferentes técnicas, como espectroscopias ultravioleta-visible, de emisión, de absorción de rayos X, análisis atómico de emisión por plasma de inducción acoplado, difracción de rayos X y microscopía. Los clústeres y los átomos aislados se han utilizado como catalizadores en reacciones de acoplamiento C-C, de oxidación de alcoholes y como agentes antitumorales. La síntesis de dímeros de PdII soportados dentro de las cavidades del MOF ha dado lugar a la formación de complejos supramoleculares de coordinación en los canales del MOF (SCCs@MOF). En los SCCs, los dímeros de PdII representan los centros de coordinación, y ligandos de piridina fluorados y no-fluorados son los conectores entre las unidades bimetálicas. Después de la caracterización, los SCCs@MOF se han empleado como catalizadores en reacciones de acoplamiento C-C de ácidos borónicos y/o alquinos y de oxidación de alcoholes alquílicos. Estos catalizadores se comparan con los respectivos homogéneos, como un complejo cíclico de paladio, previamente sintetizado, o el sistema Pd(OAc)2/ligandos. Además, se mostrarán algunos de los pocos ejemplos de reacciones de acoplamiento C-C y de oxidación catalizadas por SCCs. También se ha llevado a cabo la reacción de oxidación de alcohol bencílicos catalizada por átomos aislados de paladio. Estas pequeñas especies fueron preparadas in situ, dando lugar a uno de los primeros ejemplos de átomos aislados en disolución en ausencia de ligandos. Para averiguar la actividad real de los átomos aislados y poder estabilizarlos, se han soportado en un MOF basado en cisteína y se han utilizado en el mismo proceso de oxidación. Por último, se ha desarrollado también la aplicación de los clústeres de Pt en tratamientos antitumorales. Los clústeres se han sintetizado en disolución utilizando un polímero como agente de reducción y una metodología similar ha permitido soportarlos en el mismo polímero. Estos clústeres han presentado resultados positivos en líneas celulares usualmente resistentes al platino. / [CA] En la present tesi doctoral s'ha realitzat un estudi de la síntesi i aplicació de clústers metàl·lics i àtoms aïllats de Pd i Pt com a catalitzadors. Ambdós s'han sintetitzat seguint noves metodologies en dissolució, sense la utilització de lligams i suportant-los en materials metal-orgànic estructurats (MOFs) o polímers. Una vegada sintetitzats, s'ha dut a terme una caracterització minuciosa amb diferents tècniques, com espectroscòpia Ultraviolat-Visible (UV-Vis), d'emissió, d'absorció de raigs X (XAS), d'emissió atòmica per plasma d'acoblament inductiu (ICP-AES), difracció de raigs X i microscòpia. Aquests clústers i àtoms aïllats s'han utilitzat com a catalitzadors en reaccions d'acoblament C-C, en oxidacions d'alcohols i en tractaments antitumorals. Concretament, la síntesi dels dímers de PdII suportats dins de les cavitats del MOF ha donat lloc a la formació de complexos de coordinació supramoleculars dins dels canals del MOF (SCCs@MOF). En els SCCs, els dímers de PdII representen els centres de coordinació, i les diferents unitats bimetàl·liques estan connectades per lligams de piridina fluorats i no fluorats. Després de la seua caracterització, els SCCs@MOF s'han utilitzat com a catalitzadors de reaccions d'acoblament C-C d'àcids borònics i/o alquins i en reaccions d'oxidació d'alcohols alquílics. També s'ha dut a terme la comparació entre els corresponents catalitzadors homogenis, per exemple un complex cíclic de pal·ladi o del sistema Pd(OAc)2/lligams. D'altra banda, mostrem un dels pocs exemples de reaccions d'acoblament C-C i de reaccions d'oxidació catalitzades per SCCs. A més, també es descriu la reacció d'oxidació d'alcohol benzílic catalitzada per àtoms aïllats de Pd. Aquestes espècies menudes es preparen in situ, donant lloc a un dels primers exemples d'àtoms aïllats en dissolució sense lligams. A més a més, per a poder verificar la seua activitat i estabilitzar-los, s'han suportat en MOFs basats amb cisteïna, utilitzant-se en el mateix procés d'oxidació. Finalment, s'ha desenvolupat l'aplicació de clústers de Pt (MCs) en tractaments antitumorals. Aquests clústers s'han preparat en dissolució utilitzant un polímer com agent reductor, i de forma similar s'han suportat en el mateix polímer. Els Pt MCs han donat resultats molt positius en línies cel·lulars que normalment són resistents al Pt. / [EN] The synthesis and application of tal clusters (MCs) and single atoms catalysts (SACs) of Pd and Pt is explored in this Thesis. Both clusters and single atoms were synthesized by following novel ligand-free procedures in solution, or by supporting them on Metal-Organic Frameworks (MOFs) or on polymers. After their synthesis, these entities were deeply characterized by techniques, such as Ultraviolet-Visible (UV-Vis), emission, X-ray Absorption (XAS) spectroscopies, Induced Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), X-ray Diffraction and microscopy, among others. Finally, MCs or SACs were used as catalyst in homo- or cross-coupling reactions, in alcohol oxidation reactions, and in antitumoral treatments. Especially, the supporting of PdII dimers inside a MOF network allowed the following formation of Supramolecular Coordination Complexes (SCCs) within the MOF channels (SCCs@MOF). In the SCCs, the PdII dimers represent the pivotal centers and different pyridyl ligands, fluorinated and non-fluorinated, embody the linkers between the bimetallic units. After being characterized, the SCCs@MOF were used as catalysts in homocoupling reactions of boronic acids and alkynes, in cross-coupling reactions of alkynes and in alkyl alcohols oxidation. These catalysts were compared with its homogeneous counterparts, i.e., a pre-synthesized Pd metallacycle or the system Pd(OAc)2/ligands. Overall, we show some examples of C-C coupling and oxidation reactions catalyzed by SCCs. Moreover, benzyl alcohols oxidation reaction catalyzed by palladium single atoms is described. The small metal species were prepared in situ, leading to one of the first example of ligand-free single atoms in solution. Afterward, in order to verify the real activity of single atoms and to stabilize them, they were supported inside a cysteine-based MOF and used in the same oxidation process. Finally, the application of Pt clusters (MCs) in antitumoral treatments is portrayed. The clusters were synthesized in solution by using a polymer as reductant and in a similar procedure they were supported on the same polymer, which acted as a reducing agent, but also as a support. The Pt MCs gave also positive results in usually Pt-resistant cell lines. / Greco, R. (2021). Clusters and single atoms of Pd and Pt: Synthesis and applications in catalysis and as antitumoral agents [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/171280
78

Supramolecular studies with functionalised group 15 ligands

Sanchez-Ballester, Noelia M. January 2010 (has links)
This thesis has been divided into five sections. The first chapter introduces the main themes of this thesis, including the description of the concepts of supramolecular chemistry, crystal engineering, hydrogen bonding and graph set analysis. The final section of chapter one describes a typical X-ray experiment used to determine the structures of the compounds presented in this thesis. Chapter two describes the synthesis and single crystal structures of copper(I) complexes with pyridine- and pyrazine-carboxylic acids. A series of novel solvent inclusion compounds of copper(I) complexes with pyridine- and pyrazine-carboxylic acids and the hydrogen bonding patterns adopted are also discussed. Chapter three reports the potential uses of boronic acids as building blocks for the design of novel solid-state architectures utilising hydrogen bonds. Novel copper(I) pyridine-/pyrazine-carboxylate complexes with boronic acid co-crystals are presented in which the heterodimeric boronic carboxylate R22(8) ring motif is present in all cases. Chapter four discusses the synthesis of novel ditertiary phosphines bearing functional groups with hydrogen bonding potential either via a three-step or single step synthetic route which involves a well known method of reductive amination followed by an efficient Mannich-based condensation. Complexation studies of these P,P-bidentate ligands with various transition metal centres such as Pt(II), Mo(0), Ru(II) and Au(I) are also presented. The effect on the structural motifs observed in these series of compounds by the regioselective incorporation of functional groups with potential hydrogen bonding capability such as hydroxyl and amide is also given. Finally, chapter five contains the synthesis and coordination studies of new phosphorus donor ligands leading to ideas for further work.
79

Etude par microscopie à effet tunnel de la croissance de polymères 2D sur des surfaces métalliques

Ourdjini, Oualid 14 September 2012 (has links)
La croissance de polymères bidimensionnels a été étudiée sous ultra-haut vide sur des surfaces métalliques par microscopie à effet tunnel (STM). La première étude concerne la croissance de réseaux nanoporeux covalents bidimensionnels obtenus par réaction de déshydratation des molécules d'acide 1.4 diboronique (BDBA). Les meilleurs réseaux sont obtenus pour les dépôts à flux élevés sur des substrats d'Argent chauffés à 150°C. La deuxième étude concerne la réaction chimique entre les molécules de 1,2,4,5 tétracyanobenzène (TCNB) et les atomes de Fer. La formation de liaison covalente entre les molécules et les atomes de Fer est thermiquement activée par des recuits à 200°C et permet la formation d'octacyanophtalocyanine de Fer. Ce travail ouvre de nouvelles perspectives pour la fabrication de matériaux 2D originaux obtenus par des réactions chimiques de surface. / The growth of two dimensional polymers has been studied under ultra-high vacuum on metallic surfaces by scanning tunnelling microscopy (STM). The first study relates on the growth of two dimensional covalent nanoporous networks obtained after dehydratation reaction of the 1,4 diboronic acid benzene molecule (BDBA). The best networks have been obtained with high molecular flux on silver metallic substrates maintained at 150°C during deposition. The second study relates on chemical reaction between the 1, 2, 4, 5 tetracyanobenzene molecule (TCNB) and iron atoms. The reaction takes place after an annealing at 200°C. In that case some iron octacyanophthalocyanine have been successfully synthesised at surfaces. This work opens new perspectives for the fabrication of 2D original materials by chemical reactions on surfaces.
80

Contribution à l'évaluation et à l'optimisation des application des systèmes microbio-électrochimiques : traitement des eaux, production d'électricité, bioélectrosynthèse / Contribution to the evaluation and optimisation of microbial electrochemical systems : wastewater treatment, electricity production, microbial electrosynthesis

Lapinsonnière, Laure 22 October 2013 (has links)
Les systèmes microbioélectrochimiques exploitent le métabolisme de microorganismes particuliers afin de catalyser des réactions d'oxydoréduction. Ces microorganismes organisés en biofilms à l'anode ou à la cathode sont en général des bactéries dites électroactives et peuvent être exploités dans une multitude d'applications. Une revue bibliographique des aspects fondamentaux et applicatifs de ce domaine est présentée. La génération d'électricité couplée à l'épuration d'eaux usées à l'anode de piles à combustible microbiologiques a été étudiée. Des bioanodes développées à partir d'acétate (substrat non fermentescible) sont capables de s'adapter et de dégrader le glucose et le lactose (substrats fermentescibles). Leur adaptation et leurs performances dépendent de la maturité du biofilm, du substrat et du renouvellement régulier de l'anolyte. Les propriétés physico-chimiques de la surface des électrodes ont été modulées afin de promouvoir la connexion de biofilms. A l'anode, nous avons étudié le greffage covalent d'acides phényle boroniques susceptibles de se complexer avec des glucides de la membrane externe des bactéries. Cette fonctionnalisation permet de réduire le temps de formation des biofilms et d'en améliorer les performances électriques sur graphite et sur nanotubes de carbone à parois multiples. A la cathode, les modifications de surface connues sur les bioanodes n'ont pas démontré d'influence sur les performances des biocathodes. Les différentes phases du développement de biocathodes catalysant la réduction du dioxygène à haut potentiel ont été étudiées. Le suivi de biocathodes réduisant le CO2 en acides organiques montre une production séquentielle d'acides organiques à chaîne aliphatique de plus en plus longue. / Microbial electrochemical devices use the metabolism of particular microorganisms to catalyze redox reactions. The microorganisms organized as biofilms onto anodes and cathodes are usually bacteria defined as electroactive and can be harnessed in electrochemical devices for several applications. A review of the fundamental and practical aspects of this field is presented. The simultaneous generation of electricity coupled to pollutant removal was studied at the anode of microbial fuel cells. Bioanodes developed with acetate (non-fermentable substrate) can adapt to the degradation of fermentable substrates (glucose and lactose). Their adaptation and performances depend on biofilm age, nature of the substrate and regular replacement of anolyte. The physico-chemical properties of electrode surfaces were tuned in order to promote microbial connection. At the anode, we investigated the covalent grafting of phenylboronic acids functionalities that are expected to bind with saccharides of the external membrane of bacteria. This functionalization leads to faster biofilm connection and higher performances of bioanodes on graphite and multi-walled carbon nanotubes. At the cathode, the grafting of chemical functionalities that already proved beneficial to bioanodes did not influence the performances of biocathodes. Different development phases of biocathodes catalyzing O2 reduction at high potential were studied. The monitoring of biocathodes catalyzing CO2 reduction showed a successive generation of organic acids with increasing aliphatic chain length.

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