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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

Silver(I) and Copper(I) Complexes from Homoleptic to Heteroleptic: Synthesis, Structure and Characterization

Almotawa, Ruaa Mohammed 12 1900 (has links)
A plethora of novel scientific phenomena and practical applications, such as solid-state molecular solar cells and other optoelectronic devices for energy harvesting and lighting technologies, have catalyzed us to synthesize novel compounds with tunable properties. Synthetic routes, single crystal structures, and spectral and materials properties are described. Reactions of Ag(I) and Cu(I) precursors with various types of ligands -- including the azolates, diimines, and diiphosphines -- lead to the corresponding complexes in high yield. Varying the metal ions, ligands, synthetic methods, solvents, and/or stoichiometric ratio can change the properties including the molecular geometry or packing structure, reactivity, photophysical and photochemical properties, semiconducting behavior, and/or porosity of the functional coordination polymers obtained. For solar cells purposes, the absorption energy can be extended from the ultraviolet (UV) region, through the entire visible (Vis) region, onto a significant portion of the near-infrared (NIR) portion of the solar spectrum with high absorption coefficients due to the infinite conjugation of Cu(I) with diimine ligands. Twenty-eight crystal structures were obtained by conventional crystal growth methods from organic solvents, whereas their bulk product syntheses also included "green chemistry" approaches that precluded the use of hazardous organic solvents. The resulting products are characterized by powder x-ray diffraction (PXRD), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), UV/Vis/NIR absorption/diffuse reflectance/photoluminescence spectroscopies, and thermogravimetric analysis (TGA). Regarding the scientific phenomena investigated, the highlighting work in this dissertation is the discovery of novel bonding/photophysical/optoelectronic properties of the following materials: a black absorber with absorption from 200- 900 nm, a very stable compound with a bright green luminescence obtained by a solventless reaction, and a novel coordination polymer showing uncommon interaction of Ag(I) with three different types of diimine ligands simultaneously.
2

Estudos de compostos baseado no ligante fenilhidrazonopropanodinitrila para-substituída e seus compostos de coordenação visando sua aplicação em dispositivos ópticos não-lineares / Study of compounds based on binding phenylhydrazonepropanedinitrile para-replaced and its coordination compounds of your aiming for a non-linear optical devices

Caixeta, Bruno Pontes 07 February 2014 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-02-06T18:21:03Z No. of bitstreams: 2 Dissertação - Bruno Pontes Caixeta - 2014.pdf: 1763848 bytes, checksum: 7462015149307babdc173bd055c436f9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-02-06T18:21:16Z (GMT) No. of bitstreams: 2 Dissertação - Bruno Pontes Caixeta - 2014.pdf: 1763848 bytes, checksum: 7462015149307babdc173bd055c436f9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-02-06T18:21:16Z (GMT). No. of bitstreams: 2 Dissertação - Bruno Pontes Caixeta - 2014.pdf: 1763848 bytes, checksum: 7462015149307babdc173bd055c436f9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-02-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this study, the synthesis of five carbonylcyanidephenylhydrazone (ccp), with general formula [RC6H4NHNC(CN)2], where R (= -CH3, -H, -COOH, -CN e -NO2), and their coordination complexes with Ag(I) is presented. Subsequently, these compounds were characterized using spectroscopic methods. The analysis of the compound ccp-H by X Ray diffraction reveals that structurally this compound consists of a nearly linear and planar polymeric form. Data from infrared spectroscopy suggest the formation of hydrogen bonds between the units ccp. In the synthesized Ag(I) coordination compounds, the coordination of each Ag(I) occurs with three ccp units, forming a tridentate ligand-metal coordination with the formation of a three-dimensional structure. In the evaluation of the potential of these compounds to present expressive nonlinear optical properties (NLO), with special attention to the first hyperpolarizability (β), methods from Density Functional Theory (DFT) were employed to describe the structural and electronic characteristics of these compounds, and in the calculation of this parameter. The results show that the incorporation of a group with a strong electron acceptor character, along with the introduction of Ag(I), increases significantly the  values. On the other hand, the results suggest that the CAM-B3LYP functional provides more reliable  values, since the calculations based on this functional reproduced well experimental values of  related to compounds used to calibrate the instrumentation used in these measurements. Based on the estimated  values, it is expected that the studied coordination polymers present promising characteristics for use in photonic devices. / Neste estudo, a síntese de cinco carbonilcianetofenilhidrazonas (ccp), com fórmula geral [RC6H4NHNC(CN)2], onde R = -CH3, -H, -COOH, -CN e -NO2, e de seus compostos de coordenação com Ag(I), é apresentada. Esses compostos foram subsequentemente analisados do ponto de vista espectroscópico. A análise por difração de Raios X em monocristal do composto ccp-H revela que o mesmo é uma forma polimérica estruturalmente planar e praticamente linear. Resultados obtidos por espectroscopia no infravermelho sugerem a formação de ligações de hidrogênio entre as unidades ccp. Nos compostos de coordenação sintetizados, a coordenação de cada íon Ag(I) envolve três unidades ccp, resultando em uma coordenação tridentada entre os ligantes e o metal, resultando em uma estrutura tridimensional. Na avaliação do potencial desses compostos de apresentarem propriedades ópticas não lineares (ONL) expressivas, com atenção especial para a primeira hiperpolarizabilidade (β), foram empregados métodos da Teoria do Funcional da Densidade (DFT) na descrição estrutural e eletrônica, e no cálculo de parâmetros ópticos não-lineares. Os resultados mostram que a incorporação de um grupo com um forte caráter aceitador de elétrons e a introdução de Ag(I) aumenta significativamente os valores de . Por outro lado, os resultados sugerem que o funcional CAM-B3LYP deve fornecer os valores mais confiáveis de , já que nos cálculos com este funcional conseguiu-se reproduzir valores experimentais do  de padrões usados para aferir a instrumentação usada nessas medidas. Com base no observado, espera-se que os polímeros de coordenação apresentem características promissoras para aplicação em dispositivos fotônicos.
3

Silver(I) and Copper(I) Complexes from Homoleptic to Heteroleptic: Synthesis, Structure and Characterization

Almotawa, Ruaa Mohammed 12 1900 (has links)
A plethora of novel scientific phenomena and practical applications, such as solid-state molecular solar cells and other optoelectronic devices for energy harvesting and lighting technologies, have catalyzed us to synthesize novel compounds with tunable properties. Synthetic routes, single crystal structures, and spectral and materials properties are described. Reactions of Ag(I) and Cu(I) precursors with various types of ligands -- including the azolates, diimines, and diiphosphines -- lead to the corresponding complexes in high yield. Varying the metal ions, ligands, synthetic methods, solvents, and/or stoichiometric ratio can change the properties including the molecular geometry or packing structure, reactivity, photophysical and photochemical properties, semiconducting behavior, and/or porosity of the functional coordination polymers obtained. For solar cells purposes, the absorption energy can be extended from the ultraviolet (UV) region, through the entire visible (Vis) region, onto a significant portion of the near-infrared (NIR) portion of the solar spectrum with high absorption coefficients due to the infinite conjugation of Cu(I) with diimine ligands. Twenty-eight crystal structures were obtained by conventional crystal growth methods from organic solvents, whereas their bulk product syntheses also included "green chemistry" approaches that precluded the use of hazardous organic solvents. The resulting products are characterized by powder x-ray diffraction (PXRD), Fouriertransform infrared (FTIR), nuclear magnetic resonance (NMR), UV/Vis/NIR absorption/diffuse reflectance/photoluminescence spectroscopies, and thermogravimetric analysis (TGA). Regarding the scientific phenomena investigated, the highlighting work in this dissertation is the discovery of novel bonding/photophysical/optoelectronic properties of the following materials: a black absorber with absorption from 200- 900 nm, a very stable compound with a bright green luminescence obtained by a solventless reaction, and a novel coordination polymer showing uncommon interaction of Ag(I) with three different types of diimine ligands simultaneously.
4

Molekulare Architekturen auf Basis von oligofunktionellen Pyridinliganden

Antonioli, Bianca 03 September 2007 (has links) (PDF)
Zu den eleganten Methoden des Aufbaus supramolekularer Architekturen gehören Selbstorganisationsprozesse, die auf Übergangsmetall-Ligand-Wechselwirkungen beruhen und ganz wesentlich von dem verwendeten Metallion und der Ligandstruktur sowie den gewählten experimentellen Bedingungen (Lösungsmittel, Gegenion und pH-Wert) bestimmt werden. Gegenstand der vorliegenden Arbeit war die Synthese neuer mehrzähniger oligofunktioneller Pyridinliganden und die Charakterisierung ihrer Komplexbildungseigenschaften. Ein Schwerpunkt betraf dabei Strukturuntersuchungen an kristallinen Silber(I)-, Palladium(II)- und Kupfer(II)-Komplexen. Aussagen zum Phasentransfer und zur Selektivität wurden durch Flüssig-Flüssig-Extraktion und Membrantransportuntersuchungen erhalten. Neue Ligandmoleküle wurden durch die Anknüpfung der chelatisierenden Donorfunktionseinheiten 2,2’-Dipyridylamin bzw. Di(2-picolyl)amin an unterschiedliche strukturgebende Plattformen, Benzol, 2,6-Lutidin, 1,3,5-Triazin, Cyclohexan oder an eine tripodale Polyamineinheit realisiert. Es wurden Komplexe der 2,2’-Dipyridylamin-Liganden mit Ag(I) in Anwesenheit von Nitrat, Perchlorat, Tetrafluoroborat und Hexafluorophosphat hergestellt und strukturell charakterisiert. Dabei konnten einfache 1:1-Komplexe bzw. makrocyclische und polymere Architekturen beobachtet werden. In der Mehrzahl der Ag(I)-Komplexe wird das Metallzentrum von zwei Pyridin-N-Atomen unterschiedlicher 2,2’-Dipyridylamin-Einheiten verbrückend koordiniert, wobei Lösungsmittelmoleküle (CH3CN, CH3OH) bzw. Anionen (Nitrat, Perchlorat) die Koordinationssphäre des Ag(I) ergänzen. Die Koordinationszahlen für Ag(I) variieren dabei zwischen zwei bis vier. Intermolekulare Ag(I)–π-Wechselwirkungen (3.0-3.9Å) erweitern außerdem die Koordinationssphäre von Ag(I). Die vielseitigen Koordinationsmöglichkeiten der zweizähnigen 2,2’-Dipyridylamin-Liganden zeigen sich darüber hinaus in den Komplexen mit Pd(II) und Cu(II). Im wässrig-organischen Zweiphasensystem erwiesen sich die synthetisierten Liganden insbesondere gegenüber Silber(I) als sehr effektive Extraktionsmittel. Die Kupfer(II)-Komplexe mit Di(2-picolyl)amin demonstrieren die dirigierende Wirkung des Anions auf die Struktur. Strukturell ähnlich sind die Cu(II)-Komplexe der mono- bzw. disubstituierten Di(2-picolyl)amin-Derivate. Flüssig-Flüssig-Extraktionsergebnisse mit den Di(2-picolyl)amin-Derivaten zeigen im Zweiphasensystem insbesondere gegenüber Silber(I) hohe Extraktionsausbeuten und liegen deutlich über denen der strukturanalogen 2,2’-Dipyridylamin-Liganden.
5

Molekulare Architekturen auf Basis von oligofunktionellen Pyridinliganden

Antonioli, Bianca 20 April 2007 (has links)
Zu den eleganten Methoden des Aufbaus supramolekularer Architekturen gehören Selbstorganisationsprozesse, die auf Übergangsmetall-Ligand-Wechselwirkungen beruhen und ganz wesentlich von dem verwendeten Metallion und der Ligandstruktur sowie den gewählten experimentellen Bedingungen (Lösungsmittel, Gegenion und pH-Wert) bestimmt werden. Gegenstand der vorliegenden Arbeit war die Synthese neuer mehrzähniger oligofunktioneller Pyridinliganden und die Charakterisierung ihrer Komplexbildungseigenschaften. Ein Schwerpunkt betraf dabei Strukturuntersuchungen an kristallinen Silber(I)-, Palladium(II)- und Kupfer(II)-Komplexen. Aussagen zum Phasentransfer und zur Selektivität wurden durch Flüssig-Flüssig-Extraktion und Membrantransportuntersuchungen erhalten. Neue Ligandmoleküle wurden durch die Anknüpfung der chelatisierenden Donorfunktionseinheiten 2,2’-Dipyridylamin bzw. Di(2-picolyl)amin an unterschiedliche strukturgebende Plattformen, Benzol, 2,6-Lutidin, 1,3,5-Triazin, Cyclohexan oder an eine tripodale Polyamineinheit realisiert. Es wurden Komplexe der 2,2’-Dipyridylamin-Liganden mit Ag(I) in Anwesenheit von Nitrat, Perchlorat, Tetrafluoroborat und Hexafluorophosphat hergestellt und strukturell charakterisiert. Dabei konnten einfache 1:1-Komplexe bzw. makrocyclische und polymere Architekturen beobachtet werden. In der Mehrzahl der Ag(I)-Komplexe wird das Metallzentrum von zwei Pyridin-N-Atomen unterschiedlicher 2,2’-Dipyridylamin-Einheiten verbrückend koordiniert, wobei Lösungsmittelmoleküle (CH3CN, CH3OH) bzw. Anionen (Nitrat, Perchlorat) die Koordinationssphäre des Ag(I) ergänzen. Die Koordinationszahlen für Ag(I) variieren dabei zwischen zwei bis vier. Intermolekulare Ag(I)–π-Wechselwirkungen (3.0-3.9Å) erweitern außerdem die Koordinationssphäre von Ag(I). Die vielseitigen Koordinationsmöglichkeiten der zweizähnigen 2,2’-Dipyridylamin-Liganden zeigen sich darüber hinaus in den Komplexen mit Pd(II) und Cu(II). Im wässrig-organischen Zweiphasensystem erwiesen sich die synthetisierten Liganden insbesondere gegenüber Silber(I) als sehr effektive Extraktionsmittel. Die Kupfer(II)-Komplexe mit Di(2-picolyl)amin demonstrieren die dirigierende Wirkung des Anions auf die Struktur. Strukturell ähnlich sind die Cu(II)-Komplexe der mono- bzw. disubstituierten Di(2-picolyl)amin-Derivate. Flüssig-Flüssig-Extraktionsergebnisse mit den Di(2-picolyl)amin-Derivaten zeigen im Zweiphasensystem insbesondere gegenüber Silber(I) hohe Extraktionsausbeuten und liegen deutlich über denen der strukturanalogen 2,2’-Dipyridylamin-Liganden.
6

From Copper to Gold: Identification and Characterization of Coinage-Metal Ate Complexes by ESI Mass Spectrometry and Gas-Phase Fragmentation Experiments

Weske, Sebastian 30 January 2019 (has links)
No description available.

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