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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

Investigations of Stimuli-Responsive Platinum(II) Salts

Norton, Amie E. 30 October 2017 (has links)
No description available.
2

Templated interlocked host structures for the recognition and sensing of charged substrates

Knighton, Richard C. January 2014 (has links)
This thesis describes the synthesis of acyclic, macrocyclic and, in particular, interlocked anion and ion-pair receptors and sensors. <strong>Chapter One</strong> will introduce the field of supramolecular chemistry with particular emphasis on areas which are pertinent to this thesis, including anion receptor design and templated synthesis of interlocked structures. <strong>Chapter Two</strong> focuses on the synthesis of new heteroditopic macrocycles functionalised with both cation and anion recognition sites and their incorporation into interlocked architectures. The affinity for a range of anions and ion-pairs is explored via <sup>1</sup>H NMR and UV-visible spectroscopy as well as by X-ray crystallography. <strong>Chapter Three</strong> details the incorporation of d- and f-metal luminescent reporter groups into an isophthalamide motif in order to construct acyclic, macrocyclic and [2]rotaxane receptors. <strong>Chapter Four</strong> investigates the synthesis of complex higher-order interlocked structures through post-synthetic modification of lower-order interlocked structures. <strong>Chapter Five</strong> explores the potential for fluorescent gold nanoparticle conjugates to act as luminescent and colourimetric sensors for chemical warfare agents (CWAs) by employing a fluorescent displacement assay technique.
3

Synthesis, Characterization and Anion Complexation of Cationic Main Group Lewis Acids

Kim, Youngmin 2010 August 1900 (has links)
Due to favorable Coulombic effects, cationic main group Lewis acids should be more Lewis acidic than their neutral counterparts. To investigate this idea, this dissertation has been dedicated to the synthesis, characterization and anion binding properties of new cationic Lewis acids for selective anion complexation. The cationic borane [p-(Mes2B)C6H4(PPh3)] displays an enhanced anion affinity towards fluoride due to a combination of Coulombic and hydrophobic effects, and can be used to detect fluoride at levels below 4 ppm in water. A related phosphonium borane featuring a chromophoric dansyl amide moiety has been synthesized and used for the fluorescence turn on sensing of CN−. This borane is very sensitive and can be used to measure cyanide concentration in the 20-30 ppb range in water. The bidentate borane [o-(Mes2B)C6H4(PPh2Me)] is selective for N3 − over F− in water/chloroform biphasic mixtures because of the lipophilic character of the azide anion, as well as its ability to interact with both the boron and phosphorus Lewis acidic sites of the receptor via chelation (lp(N)s*(P-C)). Sulfonium borane [o(Mes2B)C6H4(SMe2)] can detect up to 50 ppb of cyanide in water at pH 7 due to favorable Coulombic effects. The sulfonium moiety interacts with the cyanide anion through both bonding and back-bonding interactions, thus enhancing the unusual affinity of [o-(Mes2B)C6H4(SMe2)] towards cyanide. This approach can be extended to Lewis acids containing fluorosilanes such as [1-Ant2FSi-2-Me2S-(C6H4)] whose fluoride affinity exceeds that of neutral fluorosilanes by several orders of magnitude.
4

Novel Hydrogen Bonding Organocatalysts: Applications in the aza-Morita-Baylis-Hillman Reaction and Anion Sensing

Diep, Jenny 22 November 2013 (has links)
Self-assembly is an efficient method for generating large numbers of structurally diverse catalysts for screening. In this work, the method of self-assembly was explored in the construction of bifunctional catalysts, from a chiral aminophosphine, 2-formylphenylboronic acid, and a (thio)urea-containing diol. These catalysts were evaluated by their effect on the asymmetric aza-Morita-Baylis-Hillman reaction. In the second half of this thesis, the hydrogen bonding abilities of different dithiosquaramides were analyzed. As thioureas have been shown to be stronger hydrogen bond donors than ureas, it was hypothesized that dithiosquaramides may also follow a similar trend. Affinities of corresponding squaramides and dithiosquaramides to chloride, sulfate, and tosylate were compared, as well as their abilities to catalyze the Freidel-Crafts alkylation between indole and trans-β-nitrostyrene.
5

Novel Hydrogen Bonding Organocatalysts: Applications in the aza-Morita-Baylis-Hillman Reaction and Anion Sensing

Diep, Jenny 22 November 2013 (has links)
Self-assembly is an efficient method for generating large numbers of structurally diverse catalysts for screening. In this work, the method of self-assembly was explored in the construction of bifunctional catalysts, from a chiral aminophosphine, 2-formylphenylboronic acid, and a (thio)urea-containing diol. These catalysts were evaluated by their effect on the asymmetric aza-Morita-Baylis-Hillman reaction. In the second half of this thesis, the hydrogen bonding abilities of different dithiosquaramides were analyzed. As thioureas have been shown to be stronger hydrogen bond donors than ureas, it was hypothesized that dithiosquaramides may also follow a similar trend. Affinities of corresponding squaramides and dithiosquaramides to chloride, sulfate, and tosylate were compared, as well as their abilities to catalyze the Freidel-Crafts alkylation between indole and trans-β-nitrostyrene.
6

Solid-state Structures and Electronic properties of Platinum(II) Terpyridyl Complexes: Implications for Vapor and Aqueous Anion Sensing

Taylor, Stephen D. 23 September 2011 (has links)
No description available.
7

Synthesis of Macrocyclic Lanthanide Chelates for Anion Sensing and Magnetic Resonance Imaging Applications

Gulgas, Christopher George January 2007 (has links)
No description available.
8

Design, Synthesis, and application of cross-reactive fluorescent macrocyclic supramolecular sensors for detection and quantitation of phosphates and their mixtures

Radujevic, Aco 19 December 2022 (has links)
No description available.
9

Développement de nouveaux matériaux organométalliques pour des applications dans le domaine de la conversion d’énergie solaire

Yvon-Bessette, André 04 1900 (has links)
Dans un contexte où l’approvisionnement énergétique mondial du 21e siècle est un enjeu majeur, le développement de sources d’énergie renouvelables suscite l’attention croissante de la communauté scientifique et industrielle. L’énergie solaire est définitivement l’une des meilleures alternatives aux combustibles fossiles en tant que source d’énergie du monde de demain. Ce mémoire traite donc du développement de nouveaux matériaux organométalliques pour des applications de photorécoltage d’énergie en photovoltaïque et en production d’hydrogène. Le premier chapitre présente la synthèse assistée par microondes de quatre nouveaux complexes de Co(II), Ni(II), Cu(II) et Zn(II) basés sur le ligand tétra-p-méthoxyphényl-azadipyrrométhène (ADPM) avec des rendements variant de 89% à quantitatif. Ces complexes sont mis en relation avec d’autres complexes homoleptiques connus portant le tétraphényl-ADPM comme ligand ainsi qu’avec leurs chélates de BF2+ pour une meilleure compréhension des tendances engendrées par la substitution de l’agent coordonnant et/ou des substituants p-méthoxy. Pour ce faire, le comportement électrochimique et photophysique est présenté. De façon générale, la présence des quatre groupements p-méthoxy semble rendre les dérivés de cet ADPM plus susceptibles à la dégradation électrochimique en conditions d’oxydation et induire un déplacement bathochromique des propriétés optiques d’absorption et d’émission. Les structures rayons X du ligand tétra-p-méthoxyphényl-ADPM et de son complexe homoleptique de Co(II) sont aussi discutées. Cette étude a été effectuée dans l’espoir de fournir des informations utiles sur la stabilité des ADPM aux chercheurs du domaine photovoltaïque en quête de nouveaux chromophores dans le proche infrarouge (NIR). Le deuxième chapitre présente quant à lui les propriétés de senseur envers les anions F-, OAc- et H2PO4- de deux nouveaux complexes neutres de Re(I) de type mono- et dinucléaire basés sur une phénanthroline substituée en position 5 contenant un récepteur thio-urée. Ces composés ont été obtenus dans des rendements de 81% et 60%, respectivement. L’effet de la formation de ponts hydrogène lors de l’ajout d’anions versus la déprotonation du récepteur a été évalué par des titrations UV/Vis et RMN 1H et semble indiquer que la formation de la base conjuguée du récepteur est favorisée pour ce type de système. De plus, la structure rayons X d’un des précurseurs est présentée et permet une discussion sur la chiralité des complexes mono- et dinucléaire obtenus. L’obtention d’un complexe bimétallique par autoassemblage ouvre la voie à la préparation d’antennes moléculaires pour des systèmes de photosynthèse artificielle. / The world's energy supply is rapidly becoming the major issue of the 21st century. Instead of the status quo approach of finding and extracting more hydrocarbons from the ground, the development of renewable energy sources is attracting much interest from both the scientific and industrial communities. Solar energy is definitively one of the best sources to power the World of tomorrow. In such a framework, this dissertation discusses the development of new organometallic materials able to harvest solar energy for photovoltaic or H2 photoproduction applications. The first chapter presents the synthesis by a microwaves-assisted methodology of four new homoleptic complexes of Co(II), Ni(II), Cu(II) and Zn(II) based on the tetra-p-methoxyphenyl-azadipyrromethene (ADPM) ligand in yields ranging from 89% to quantitative. Those complexes are put in relation with already known ADPM homoleptic complexes of the same M(II) series and related BF2+ chelates (Aza-BODIPY) for a better understanding of trends arising from substitution of the chelate and/or electron-donating effect of the p-methoxy substituents. This is achieved by the study of electrochemical behavior of the compounds and their photophysical properties. From a general point of view, the presence of the four p-methoxy substituents leads to an electrochemical decomposition of the derivatives based on that ADPM in oxidative conditions, along with a bathochromic shift of the optical properties. X-Ray structures for the tetra-p-methoxyphenyl-ADPM ligand and related Co(II) complex are also discussed. Hopefully, this study will provide useful insights to researchers on the substituents to install for stable ADPM derivatives in their quest for NIR chromophores utilizable for photovoltaic application. The second chapter report anion sensing properties toward F-, OAc- and H2PO4- of new neutral mononuclear and dinuclear Re(I) complexes based on a 5-substituted phenanthroline moiety bearing a thiourea hydrogen-bonding receptor. Those complexes were obtained in 81% and 60% yields, respectively. The effect of hydrogen-bonding versus deprotonation of the thiourea receptor upon addition of the anions was also evaluated by UV/vis and 1H NMR titration techniques. Observations made support the hypothesis that formation of the conjugated base of the receptor is favored. In addition, an X-ray structure of the Re(I) precursor complex is reported and the chirality of the mononuclear and dinuclear complexes is discussed. Achievement of a bimetallic complex by self-assembly paves the way for the preparation of light-harvesting molecular antennae utilizable in artificial photosynthesis systems.
10

Développement de nouveaux matériaux organométalliques pour des applications dans le domaine de la conversion d’énergie solaire

Yvon-Bessette, André 04 1900 (has links)
Dans un contexte où l’approvisionnement énergétique mondial du 21e siècle est un enjeu majeur, le développement de sources d’énergie renouvelables suscite l’attention croissante de la communauté scientifique et industrielle. L’énergie solaire est définitivement l’une des meilleures alternatives aux combustibles fossiles en tant que source d’énergie du monde de demain. Ce mémoire traite donc du développement de nouveaux matériaux organométalliques pour des applications de photorécoltage d’énergie en photovoltaïque et en production d’hydrogène. Le premier chapitre présente la synthèse assistée par microondes de quatre nouveaux complexes de Co(II), Ni(II), Cu(II) et Zn(II) basés sur le ligand tétra-p-méthoxyphényl-azadipyrrométhène (ADPM) avec des rendements variant de 89% à quantitatif. Ces complexes sont mis en relation avec d’autres complexes homoleptiques connus portant le tétraphényl-ADPM comme ligand ainsi qu’avec leurs chélates de BF2+ pour une meilleure compréhension des tendances engendrées par la substitution de l’agent coordonnant et/ou des substituants p-méthoxy. Pour ce faire, le comportement électrochimique et photophysique est présenté. De façon générale, la présence des quatre groupements p-méthoxy semble rendre les dérivés de cet ADPM plus susceptibles à la dégradation électrochimique en conditions d’oxydation et induire un déplacement bathochromique des propriétés optiques d’absorption et d’émission. Les structures rayons X du ligand tétra-p-méthoxyphényl-ADPM et de son complexe homoleptique de Co(II) sont aussi discutées. Cette étude a été effectuée dans l’espoir de fournir des informations utiles sur la stabilité des ADPM aux chercheurs du domaine photovoltaïque en quête de nouveaux chromophores dans le proche infrarouge (NIR). Le deuxième chapitre présente quant à lui les propriétés de senseur envers les anions F-, OAc- et H2PO4- de deux nouveaux complexes neutres de Re(I) de type mono- et dinucléaire basés sur une phénanthroline substituée en position 5 contenant un récepteur thio-urée. Ces composés ont été obtenus dans des rendements de 81% et 60%, respectivement. L’effet de la formation de ponts hydrogène lors de l’ajout d’anions versus la déprotonation du récepteur a été évalué par des titrations UV/Vis et RMN 1H et semble indiquer que la formation de la base conjuguée du récepteur est favorisée pour ce type de système. De plus, la structure rayons X d’un des précurseurs est présentée et permet une discussion sur la chiralité des complexes mono- et dinucléaire obtenus. L’obtention d’un complexe bimétallique par autoassemblage ouvre la voie à la préparation d’antennes moléculaires pour des systèmes de photosynthèse artificielle. / The world's energy supply is rapidly becoming the major issue of the 21st century. Instead of the status quo approach of finding and extracting more hydrocarbons from the ground, the development of renewable energy sources is attracting much interest from both the scientific and industrial communities. Solar energy is definitively one of the best sources to power the World of tomorrow. In such a framework, this dissertation discusses the development of new organometallic materials able to harvest solar energy for photovoltaic or H2 photoproduction applications. The first chapter presents the synthesis by a microwaves-assisted methodology of four new homoleptic complexes of Co(II), Ni(II), Cu(II) and Zn(II) based on the tetra-p-methoxyphenyl-azadipyrromethene (ADPM) ligand in yields ranging from 89% to quantitative. Those complexes are put in relation with already known ADPM homoleptic complexes of the same M(II) series and related BF2+ chelates (Aza-BODIPY) for a better understanding of trends arising from substitution of the chelate and/or electron-donating effect of the p-methoxy substituents. This is achieved by the study of electrochemical behavior of the compounds and their photophysical properties. From a general point of view, the presence of the four p-methoxy substituents leads to an electrochemical decomposition of the derivatives based on that ADPM in oxidative conditions, along with a bathochromic shift of the optical properties. X-Ray structures for the tetra-p-methoxyphenyl-ADPM ligand and related Co(II) complex are also discussed. Hopefully, this study will provide useful insights to researchers on the substituents to install for stable ADPM derivatives in their quest for NIR chromophores utilizable for photovoltaic application. The second chapter report anion sensing properties toward F-, OAc- and H2PO4- of new neutral mononuclear and dinuclear Re(I) complexes based on a 5-substituted phenanthroline moiety bearing a thiourea hydrogen-bonding receptor. Those complexes were obtained in 81% and 60% yields, respectively. The effect of hydrogen-bonding versus deprotonation of the thiourea receptor upon addition of the anions was also evaluated by UV/vis and 1H NMR titration techniques. Observations made support the hypothesis that formation of the conjugated base of the receptor is favored. In addition, an X-ray structure of the Re(I) precursor complex is reported and the chirality of the mononuclear and dinuclear complexes is discussed. Achievement of a bimetallic complex by self-assembly paves the way for the preparation of light-harvesting molecular antennae utilizable in artificial photosynthesis systems.

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