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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.
111

Síntese e caracterização de complexos de Cu(I), Cu(II) E Au(I) com ligantes triazenidos contendo substituintes triazóis / Synthesis and characterization of Cu(I), Cu(II) AND Au(I) complexes with triazenido ligands containing triazole substituents

Morgan, Dieisson 29 November 2013 (has links)
Triazenido ions are isoelectronic to amidinato anions,[R'N C(R)=NR']- and have a broad versatility in coordination chemistry. Metal complexes including triazenido ligands find applications in various areas of chemistry. Triazenes and complexes including triazole derivatives show extensive applicability as for example in supramolecular chemistry and pharmacological compounds. This work presents deals with the study of new triazene derivatives with triazole substituents resulting from the click reactions, acting as ligands in complexes with Cu(I), Cu(II) and Au(I). The following ligands 1,3-bis(2-azidophenyl)triazene (2), 1-(methyl)-3-(2-(4-phenyl-1,2,3-triazole)triazene-N-oxide (4), 1-(phenyl)-3-(2-(4-phenyl-1,2,3-triazole)triazene (5), 1,3-bis(2-(4-phenyl-1,2,3-triazole)triazene (6) and, complexes 1,3-bis(2-azidophenyl)triazenide-κN11- triphenylphosphine-gold(I) (2a), bis-{1-(methyl)-3-[2-(4-phenyl-1,2,3-triazole-κN2)]triazenide-1-oxide-κ2N3,O}copper(II) (4b), 1-(phenyl)-3-(2-(4-phenyl-1,2,3-triazole)triazenide-κN- triphenylphosphine-κP-gold(I) (5a), 1,3-bis(2-(4-phenyl-1,2,3-triazole)triazenide-κN- triphenylphosphine-κP-gold(I) (6a), bis[1,3-bis(2-(4-phenyl-1,2,3-triazole-κN2)-μ-N3-triazenide]-κN11,κN13 copper(I)κN13,κN11´copper(I) (Cu Cu) (6b) were investigated. The compounds were characterized by IR, UV-Vis and NMR (1H e 13C) spectroscopy, low or high resolution mass spectrometry (EI, ESI, ESI(+)-TOF and ESI(-)-TOF) and X-ray diffraction on single crystal. Triazene (2) and complex (2a) exhibit intramolecular assembling through classical and non-classical hydrogen bonding. Complexes with Au(I), (2a), (5a) e (6a), the metal atom show linear coordination geometry. The metal atom in complex (6b) shows a T distorted coordination geometry, which is extended to a quadratic coordination resulting from d10 d10 interactions between Cu(I) ions. Triazene (6) and its respective complexes (6a) e (6b) exhibit intermolecular interactions of the type C−H···M. Antibacterial activity of triazene (5) and complex (5a) were assayed resulting to be inactive against the bacteria tested. / Os compostos triazenidos são isoeletrônicos a íons amidinatos [R'NH C(R)=NR'], e têm sido usados com sucesso na química de coordenação. A complexação a íons metálicos possibilita a sua aplicação em diversas áreas da química. Assim como os triazenos, os triazóis possuem vasta aplicabilidade, desde a química supramolecular até a área farmacológica. Este trabalho apresenta o estudo inédito de pré-ligantes triazenos contendo substituintes triazóis os quais foram obtidos a partir de reações de Click, e seus respectivos complexos de Cu(I), Cu(II) e Au(I). Foram sintetizados os pré-ligantes 1,3-bis(2-azidofenil)triazeno (2), 1-(metil)-3-(2-(4-fenil-1,2,3-triazol)triazeno-N-óxido (4), 1-(fenil)-3-(2-(4-fenil-1,2,3-triazol)triazeno (5), 1,3-bis(2-(4-fenil-1,2,3-triazol)triazeno (6) e os complexos 1,3-bis(2-azidofenil)triazenido-κN11-trifenilfosfina-ouro(I) (2a), bis-{1-(metil)-3-[2-(4-fenil-1,2,3-triazol-κN2)]triazenido-1-óxido-κ2N3,O}cobre(II) (4b), 1-(fenil)-3-(2-(4-fenil-1,2,3-triazol)triazenido-κN-trifenilfosfina-κP-ouro(I) (5a), 1,3-bis(2-(4-fenil-1,2,3-triazol)triazenido-κN-trifenilfosfina-κP-ouro(I) (6a), bis[1,3-bis(2-(4-fenil-1,2,3-triazol-κN2)-μ-N3-triazenido]-κN11,κN13 - cobre(I)κN13,κN11´cobre(I) (Cu Cu) (6b). Estes foram caracterizados por espectroscopia de IV, UV-Vis e RMN (1H e 13C), espectrometria de massas de baixa ou alta resolução (EI, ESI, ESI(+)-TOF e ESI(-)-TOF) e difração de raios X em monocristal. O triazeno (2) e complexo (2a) apresentam ligações de hidrogênio intermoleculares e intramoleculares do tipo clássica e não-clássica. Os complexos de Au(I), (2a), (5a) e (6a) possuem geometria de coordenação linear. O complexo (6b) apresenta uma geometria T distorcida, a qual é estendida para quadrática pela interação d10 d10 entre os átomos de Cu(I), o triazeno (6) e seus complexos (6a) e (6b) apresentam ainda ligações intermoleculares do tipo C−H···M. Foi testada a atividade antibacteriana do triazeno (5) e o complexo (5a), os quais mostraram-se inativos frente às bactérias testadas.
112

Avaliação dos efeitos anticancerígenos dos 1,2,3-triazóis derivados do núcleo 1,4-naftoquinona em linhagens leucêmicas humanas / Evaluation of anticancer effects of 1,2,3-triazoles derivates to the nucleus 1,4-naphthoquinone in human leukemic cell lines.

Coulidiati, Tangbadioa Herve 18 September 2014 (has links)
Made available in DSpace on 2015-05-14T13:00:01Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 12194499 bytes, checksum: cf6dad6e7629970dd8e06f4179a17141 (MD5) Previous issue date: 2014-09-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The triazole nucleus and its derivatives have attracted considerable attention in recent decades for their chemotherapeutic potentials. Specifically, the interest in molecules containing the 1,2,3-triazole as chemotherapeutic agents for various diseases has increased, because they are known to exhibit a wide range of biological activities, such as anti-proliferative and anti-neoplastic. The aim of this study was to evaluate the potencial anti-cancer effect of new triazole derivatives from 1,4-naphthoquinone, elucidating their cytotoxicity and cell death mechanisms involved. From five cancer cell lines tested, leukemic cells (HL-60 and K562) were the most sensitive, and between the eight triazole compounds tested (called C1 to C8), compounds C2 and C3 showed the best IC50 of 14 μM and 41 μM for HL-60 cells and 24 μM and 81 μM for K562 cells, respectively. However, these two compounds showed very little cytotoxic effect towards PBMC normal cells with IC50 superior to 80 μM. Investigating the type of cell death induced by compounds C2 and C3, it was showed that compounds induced apoptosis in HL-60 cells and cell cycle arrest in the S-phase, and necrosis in K562 ones. Cell cycle arrest in S phase was related to the expression of the p21 gene in K562. Results revealed a reduced expression of Bcl-2 protein and an increased expression of BAX protein in HL-60 cells. Moreover, it was found cytochrome c release, suggesting involvement of the intrinsic pathway in apoptosis induction in these cells. Activation of this pathway may be through inhibition of ERK phosphorylation. Our results also showed that pre-treatment of HL-60 cells with N-acetyl cysteine (1 mM) for 1 hour reduced the cytotoxic effect of compounds C2 and C3 for 30,83% and 26,47% respectively; indicating that the induction of apoptosis in HL-60 is mediated by increased production of intracellular ROS. Thus, it can be concluded that C2 and C3 compounds showed cytotoxic effects on HL-60 and K562 cells, so, can be considered as prototype anti-leukemic molecules. / O núcleo triazol e seus derivados têm atraído uma atenção considerável nessas últimas décadas devido ao seu potencial quimioterápico. Mais especificamente, tem se verificado o interesse em moléculas que contêm o grupo 1,2,3-triazol, isto porque esta classe de heterocíclicos é conhecida por exibir uma vasta gama de atividades biológicas, tais como, anti-proliferativo e anti-neoplásico. O objetivo desse trabalho foi o de avaliar o potencial anticancerígeno de novos triazóis derivados do 1,4-naftoquinona, elucidando as suas citotoxicidades e o mecanismo de morte envolvido. Os resultados obtidos revelaram que, das cinco linhagens cancerígenas testadas, as linhagens leucêmicas HL-60 e K562 foram as mais sensíveis, e dentre os oito compostos (denominados C1 a C8) testados, C2 e C3 foram os mais citotóxicos, apresentando CI50 de 14 μM e 41 μM, em HL-60 e de 24 μM e 81 μM em K562, respectivamente. Entretanto, os compostos foram menos citotóxicos nas células normais do sangue periférico humano com CI50 acima 80 μM. Investigando o tipo de morte induzido pelos compostos nas duas linhagens, foi demonstrado que os compostos C2 e C3 induziram apoptose em HL-60. Já nas células K562, este dois derivados provocaram a parada do ciclo celular na fase S e necrose. A parada do ciclo celular na fase S em K562 foi relacionada com a expressão do gene p21. Foi revelado a diminuição da expressão da proteína Bcl-2 e o aumento da expressão da proteína BAX nas células HL-60, e ainda verificou-se a liberação do citocromo c sugerindo a participação da via intrínseca na indução da apoptose em HL-60. A ativação dessa via pode ser via inibição da fosforilação da proteína ERK. Os resultados mostraram também que durante uma hora de pré-tratamento das células HL-60 com o N-acetil cisteina (1 mM), houve a redução da citotoxicidade dos compostos C2 e C3 de 30,83% e 26,47% respectivamente; indicando que a indução da apoptose em HL-60 é mediada pelo aumento da produção das espécies reativas de oxigênio intracelulares. Dessa forma, pode-se concluir que os compostos C2 e C3 apresentaram efeitos citotóxicos frente às linhagens HL-60 e K562, então, podem ser considerados como protótipo de moléculas anti-leucêmicas.
113

Organokatalyse: Theoretische Untersuchungen zur Claisen-Umlagerung und zum Einfluss von Azolen auf die Morita-Baylis-Hillman-Reaktion sowie neuartige Bis(carben)metallkomplexe auf der Basis von Triazolen

Kirsten, Martin 22 June 2011 (has links)
Ziel der Arbeit war es, Katalysatoren zu entwickeln, in Modellsystemen zu testen und Rückschlüsse auf deren Aktivität und Verbesserungspotential zu ziehen. Dabei standen sowohl theoretische Betrachtungen mittels quantenmechanischer Berechnungen, aber auch experimentelle Arbeiten im Mittelpunkt. Die Untersuchungen wurden an ausgewählten Beispielen der Claisen-Umlagerung und der Morita-Baylis-Hillmann-Reaktion sowie verbrückter Bis(NHC)metallkomplexe auf der Basis von Triazolen in der Mizoroki-Heck-Reaktion durchgeführt. Claisen-Umlagerung. Die Wechselwirkung zwischen Substrat und dem Katalysator sollte hierbei auf eine bidendate Ausbildung von Wasserstoffbrücken zum Substrat entsprechend dem Design nach Jørgensen[1-4] abzielen. Die Auswahl der „Organokatalysatoren“ erstreckte sich von den Thioharnstoffen, über L-Milchsäure, einem Phosphorsäure-Derivat bis hin zu 2,2,2-Trifluorethanol (TFE). Mit dem Allyl Vinyl Ether (AVE) 83 wurden die theoretischen Betrachtungen der Wechselwirkung und der sich daraus ergebende Einfluss auf die Umlagerungs-geschwindigkeit durchgeführt. Der Thioharnstoff 1 und dessen Wechselwirkung mit 83 standen dabei im Mittelpunkt der Betrachtungen. Es wurden zwei mögliche entscheidende Übergangszustände postuliert. Im Vergleich zum konkurrierenden Übergangszustand [s-cis-83b•1A]# war [s-trans-83b•1A]# in Summe bevorzugt. Gegenüber der thermischen Claisen-Umlagerung von 83 war [s-trans-83b•1A]# für ΔG#[3,3] um +3,1 Kcal mol-1 erniedrigt, was einer leichten Erhöhung der Umlagerungsgeschwindigkeit entsprach. Dies konnte durch experimentelle Untersuchungen bestätigt werden. Das Phosphorsäure-Derivat 94 war im Vergleich zur L-Milchsäure 91 besser in der Lage, die Barriere des sigmatropen Umlagerungsschrittes abzusenken. Es zeigte sich, dass die Kombination von 91 mit einem Wassermolekül 8 zu dem Komplex 92 zu einer verbesserten Stabilisierung des Übergangszustandes führte. Bei beiden Systemen wurde jedoch beobachtet, dass die Barrieren über den Gesamtverlauf der Reaktion nicht ausreichend stark abgesenkt werden konnten. Für die Berechnungen mit dem Lösungsmittel TFE wurde gezeigt, dass die Betrachtung der Wechselwirkung einzelner TFE-Moleküle mit dem Substrat 83 nicht ausreichte. Morita-Baylis-Hillman-Reaktion. Mit der Morita-Baylis-Hillman-Reaktion[5, 6] (MBH) kann im Sinne einer C-C-Verknüpfungs-reaktion neben der atomökonomischen Durchführung zusätzlich ein Stereozentrum erzeugt werden. Basierend auf den Ergebnissen von Cheng et al.[7] wurde ein systematischer Zusammenhang zwischen dem eingesetzen Vermittler/Katalysator und Ausbeute/Umsatz hergestellt. Die aus der Literatur bekannte pH-Wert-Abhängigkeit der Reaktion konnte auf einen Bereich zwischen 8 und 9 eingegrenzt werden. Unter Verwendung verschiedener Substitutionsmuster am Imidazol konnte gezeigt werden, dass 1H-substituierte Imidazole die Reaktion wesentlich langsamer als die in 1-Position unsubstituierten Imidazole vermittelten, was durch DFT-Rechnungen unterstrichen werden konnte. Im weiteren Verlauf der experimentellen Untersuchungen stellte sich heraus, dass TFE als Lösungsmittel ohne Zusatz einer weiteren Base für die Vermittlung der Reaktion gut geeignet ist. Verbrückte Bis(NHC)metallkomplexe auf der Basis von Triazolen. Die Synthese der Bis(NHC)metallkomplexe und deren Einsatz in der Katalyse wurde von Straßner et al.[8-15] sehr intensiv studiert. Teil dieser Arbeit war es, die Bandbreite der Katalysatoren zu erweitern und den Einfluss von einem Stickstoffatom im (NHC)-Rückgrat zu untersuchen. Die synthetische Zugänglichkeit der Konstitutionsisomere wurde bereits bei der Darstellung der aromatischen Triazole gewährleistet. Die sich anschließende Darstellung der entsprechenden Salze konnte für die Methoxy-Gruppe am Aromaten erfolgreich durchgeführt werden. Die Unterscheidung von Konstitutionsisomeren eines Komplexes wurde am Beispiel von 126 und 128 durchgeführt. Hierbei zeigten sich bereits im 1H-NMR-Spektrum feine Unterschiede in den Kopplungskonstanten und auch in den Signalen für die Methylenbrücke. Der tatsächliche Beweis wurde mit der 2D-Methode, der sogenannten „Heteronuclear Multiple Bond Correlation“ – HMBC, erbracht. Der Einsatz der dargestellten Palladium(II)komplexe zeigte für p-Bromacetophenon analoge Ergebnisse zu den Imidazol-Derivaten bei „gleicher“ Konzentration. Für die Komplexe, ausgehend von den asymmetrischen Triazolen (zum Beispiel 128), wurde eine erhöhte Reaktivität beobachtet. Weiterhin wurde ein signifikanter Unterschied in der Ausbeute bei Reaktionen mit p-Chloracetophenon beobachtet. Literatur. [1] D. L. Severance, W. L. Jorgensen, Journal of the American Chemical Society 1992, 114, 10966. [2] C. J. Cramer, D. G. Truhlar, Journal of the American Chemical Society 1992, 114, 8794. [3] W. L. Jorgensen, J. F. Blake, D. Lim, D. L. Severance, Journal of the Chemical Society, Faraday Transactions 1994, 90, 1727. [4] M. M. Davidson, I. H. Hillier, Journal of Physical Chemistry 1995, 99, 6748. [5] A. B. Baylis, M. E. D. Hillman, (Celanese Corp.). Application: DE DE, 1972, p. 16 pp. [6] K. Morita, Z. Suzuki, H. Hirose, Bulletin of the Chemical Society of Japan 1968, 41, 2815. [7] S. Luo, P. G. Wang, J.-P. Cheng, Journal of Organic Chemistry 2004, 69, 555. [8] S. Ahrens, A. Zeller, M. Taige, T. Strassner, Organometallics 2006, 25, 5409. [9] M. A. Taige, A. Zeller, S. Ahrens, S. Goutal, E. Herdtweck, T. Strassner, Journal of Organometallic Chemistry 2007, 692, 1519. [10] A. Meyer, T. Strassner, unpublished results 2010. [11] M. Taige, TU Dresden (Dresden), 2009. [12] S. Ahrens, E. Herdtweck, S. Goutal, T. Strassner, European Journal of Inorganic Chemistry 2006, 1268. [13] S. Ahrens, T. Strassner, Inorganica Chimica Acta 2006, 359, 4789. [14] T. Strassner, M. Muehlhofer, A. Zeller, E. Herdtweck, W. A. Herrmann, Journal of Organometallic Chemistry 2004, 689, 1418. [15] M. Muehlhofer, T. Strassner, W. A. Herrmann, Angewandte Chemie, International Edition 2002, 41, 1745.
114

Advances in gold-carbon bond formation: mono-, di-, and triaurated organometallics

Heckler, James E. 27 January 2016 (has links)
No description available.
115

Chemistry of Cyanoform (Tricyanomethane); and Rearrangement of 1H-1,2,3-Triazoles to the Corresponding 2H-Isomers / Die Chemie des Cyanoforms (Tricyanomethan) und Umlagerung von 1H-1,2,3-Triazolen in die entsprechenden 2H-Isomere

Chityala, Madhu 28 March 2017 (has links) (PDF)
Cyanoform (tricyanomethane) is one of the strongest carbon-based organic acids reported in text books of organic chemistry, which has evaded synthesis and isolation in its free state, since 120 years. In this dissertation, the acid-free synthesis of cyanoform by an absolutely new approach has been discussed. Generation of the elusive molecule, cyanoform from the photolysis and thermolysis of 2-(azidomethylidene)malononitrile, has been confirmed at very low temperatures by 1H NMR, 13C NMR, 15N NMR, and the relevant 2D NMR spectroscopic techniques. Moreover, it has been proved that cyanoform is relatively stable, but can be detected only below –85 oC, and not at high temperatures (at –45 oC, as has been reported in literature), because of a rapid equilibration with an another species. Furthermore, the chemistry of cyanoform in the ring enlargement reactions with various highly strained epoxides, azirines, and aziridines, via the highly reactive dicyanoketenimine intermediate, as well as its Michael addition reactions with different α,β-unsaturated carbonyl compounds has been well explored. In addition, the synthesis of N1-substituted 1,2,3-triazoles and study of their rearrangement to the corresponding N2-substituted 1,2,3-triazoles, under thermal and nucleophile-catalyzed reaction conditions, has been well investigated. / Cyanoform (Tricyanomethan) ist eine der stärksten in der Literatur beschriebenen organischen Kohlenstoffsäuren, welche sich seit 120 Jahren einer erfolgreichen Synthese und Isolierung entzogen hat. In dieser Arbeit wird die säurefreie Synthese des Cyanoforms mittels eines neuartigen Ansatzes diskutiert. Die Bildung des schwer fassbaren Moleküls durch Photolyse und Thermolyse von 2 (Azidomethyliden)malonitril ist bei tiefen Temperaturen durch 1H-NMR, 13C-NMR, 15N-NMR und relevante 2D-NMR-Methoden bestätigt worden. Es konnte bewiesen werden, dass Cyanoform relative stabil ist, aber erst unterhalb von –85 °C detektierbar ist und nicht bereits bei hӧherer Temperature (bei –45 °C, wie es in der Literatur beschrieben wurde) bedingt durch die rasche Äquilibrierung mit einer weiteren Species. Des Weiteren wurde die Reaktivität von Cyanoform in Ringerweiterungsreaktionen mit verschiedenen, stark gespannten Epoxiden, Azirinen und Aziridinen untersucht, wobei das hoch reaktive Dicyanoketenimin-Intermediat durchlaufen wird. Auch die Michael-Addition an α,β ungesättigte Carbonylverbindungen wurde ausführlich untersucht. Zusätzlich wurde die Synthese N1 substituierter 1,2,3-Triazole und deren Umlagerung in N2 substituierte 1,2,3-Triazole unter thermischen und nucleophil-katalysierten Bedingungen erforscht.
116

Development of a Phase Separation Strategy in Macrocyclization Reactions

Bédard, Anne-Catherine 04 1900 (has links)
La réaction de macrocyclisation est une transformation fondamentale en chimie organique de synthèse. Le principal défi associcé à la formation de macrocycles est la compétition inhérente avec la réaction d’oligomérisation qui mène à la formation de sousproduits indésirables. De plus, l’utilisation de conditions de dilutions élevées qui sont nécessaires afin d’obtenir une cyclisation “sélective”, sont souvent décourageantes pour les applications à l’échelle industrielle. Malgré cet intérêt pour les macrocycles, la recherche visant à développer des stratégies environnementalement bénignes, qui permettent d’utiliser des concentrations normales pour leur synthèse, sont encore rares. Cette thèse décrit le développement d’une nouvelle approche générale visant à améliorer l’efficacité des réactions de macrocyclisation en utilisant le contrôle des effets de dilution. Une stratégie de “séparation de phase” qui permet de réaliser des réactions à des concentrations plus élevées a été developpée. Elle se base sur un mélange de solvant aggrégé contrôlé par les propriétés du poly(éthylène glycol) (PEG). Des études de tension de surface, spectroscopie UV et tagging chimique ont été réalisées afin d’élucider le mécanisme de “séparation de phase”. Il est proposé que celui-ci fonctionne par diffusion lente du substrat organique vers la phase ou le catalyseur est actif. La nature du polymère co-solvant joue donc un rôle crutial dans le contrôle de l’aggrégation et de la catalyse La stratégie de “séparation de phase” a initiallement été étudiée en utilisant le couplage oxidatif d’alcynes de type Glaser-Hay co-catalysé par un complexe de cuivre et de nickel puis a été transposée à la chimie en flux continu. Elle fut ensuite appliquée à la cycloaddition d’alcynes et d’azotures catalysée par un complexe de cuivre en “batch” ainsi qu’en flux continu. / Macrocyclization is a fundamentally important transformation in organic synthetic chemistry. The main challenge associated with the synthesis of large ring compounds is the competing oligomerization processes that lead to unwanted side-products. Moreover, the high dilution conditions needed to achieved “selective” cyclization are often daunting for industrial applications. Despite the level of interest in macrocycles, research aimed at developing sustainable strategies that focus on catalysis at high concentrations in macrocyclization are still rare. The following thesis describes the development of a novel approach aimed at improving the efficiency of macrocyclization reactions through the control of dilution effects. A “phase separation” strategy that allows for macrocyclization to be conducted at higher concentrations was developped. It relies on an aggregated solvent mixture controlled by a poly(ethylene glycol) (PEG) co-solvent. Insight into the mechanism of “phase separation” was probed using surface tension measurments, UV spectroscopy and chemical tagging. It was proposed to function by allowing slow diffusion of an organic substrate to the phase where the catalyst is active. Consequently, the nature of the polymer co-solvent plays a role in controlling both aggregation and catalysis. The “phase separation” strategy was initially developed using the copper and nickel co-catalyzed Glaser-Hay oxidative coupling of terminal alkynes in batch and was also transposed to continuous flow conditions. The “phase separation” strategy was then applied to the copper-catalyzed alkyne-azide cycloaddition in both batch and continuous flow.
117

Theoretical Investigation Of Tautomeric Equilibria In Certain Explosive Materials

Celik Bayar, Caglar 01 December 2012 (has links) (PDF)
Explosive materials have always been attracting the attention of scientists. Various explosives either in pure bulk form or as admixtures are synthesized and investigated from different points of view. However, because of dangerous character of these materials, their syntheses and properties have to be forecasted by theoretical studies. The new research trends of explosive materials generally include the designs of novel derivatives of well&ndash / known explosives to improve their detonation performances (heats of explosion, detonation velocities and detonation pressures) and thermal stabilities and decrease their sensitivities towards friction, electric spark, shock and impact either experimentally or theoretically. NTO (5&ndash / nitro&ndash / 2,4&ndash / dihydro&ndash / 3H&ndash / 1,2,4&ndash / triazol&ndash / 3&ndash / one) and PATO (3&ndash / picrylamino&ndash / 1,2,4&ndash / triazole) are very important secondary explosives that take place in the literature for many years in terms of their explosive properties. In this thesis study, new species of these explosives have been designed to enhance their detonation performances (ballistic properties) and to lower their sensitivities and reactivities computationally. Additionally, aromatic nitration reactions and their mechanisms for unprotonated and protonated PATO species have been analyzed. The ab initio quantum chemistry methods, Hartree&ndash / Fock (HF) and Density Functional Theory (DFT), have been used in the calculations with Pople basis sets. Novel NTO and PATO tautomeric species have been designed and investigated to enlighten the effects of tautomerism on their quantum chemical properties and detonation performances in the gas phase. Various aromatic nitration mechanisms (carbon and nitrogen mono&ndash / nitration mechanisms) of unprotonated tautomeric PATO species as well as PATO have been designed in gas phase and the reaction states (pre&ndash / transition states, transition states, intermediates and nitration products) have been detected belonging to these mechanisms. Nitrations in solution phase have also been analyzed. The reaction states have been detected for carbon and nitrogen mono&ndash / nitrations of protonated PATO species in the gas phase. The detonation performances of unnitrated and nitrated PATO products have been presented.
118

Bildungstendenz und Reaktionen von α-Azidoalkoholen

Berndt, Christian 24 April 2013 (has links) (PDF)
Gegenstand der vorliegenden Arbeit ist die Synthese von α-Azidoalkoholen durch die Reaktion von aliphatischen sowie aromatischen Aldehyden mit Stickstoffwasserstoffsäure. Dabei stellt sich ein Gleichgewicht ein, dessen Lage durch die Ermittlung der Gleichgewichtskonstanten quantitativ bestimmt wird. In jedem Fall besteht die Möglichkeit, den α-Azidoalkohol in der Gleichgewichtsmischung zu charakterisieren und teilweise gelingt die Isolierung der reinen α-Azidoalkohole bei tiefen Temperaturen sowie deren Charakterisierung mittels Tieftemperatur-NMR-Spektroskopie. Die Ausgangsaldehyde für die Synthese der α-Azidoalkohole besitzen elektronenschiebende oder elektronenziehende Substituenten oder sind prochiral oder besitzen funktionelle Gruppe für intramolekulare Reaktionen. Die Titelverbindungen werden mit Cyclooctin im Sinne einer 1,3-dipolaren Cycloaddition abgefangen oder mit Carbonsäurechloriden in die entsprechenden Ester der α-Azidoalkohole überführt. Das nur aus theoretischen Arbeiten bekannte Formylazid wird erstmals aus den α-Azidoalkoholen durch Oxidation hergestellt und in Lösung vollständig charakterisiert. Es werden zudem zahlreiche Alternativsynthesen für Formylazid erfolgreich durchgeführt.
119

Synthesen und Reaktionen von Ethinylaziden

Wutke, Jens 02 October 2010 (has links) (PDF)
Gegenstand der vorliegenden Arbeit sind Versuche zur Synthese von 1-Azido-1 alkinen (Ethinylaziden). Diese instabilen Verbindungen zersetzen sich leicht unter Stickstoffabspaltung zu hochreaktiven Carbenen, welche mit verschiedenen Reagenzien, explizit Tolan, Cyclooctin, DMSO sowie DMF, abgefangen werden konnten. Obwohl eine direkte spektroskopische Beobachtung der Titelverbindungen mittels Tieftemperatur-NMR-Spektroskopie nicht verwirklicht werden konnte, gelang der eindeutige Nachweis von Ethinylaziden via deren 1,3-dipolarer Cycloaddition mit dem hochgespannten cyclischen Alkin Cyclooctin. Als Strategie für die Synthese der Titelverbindungen wurden sowohl Substitutionsreaktionen ausgehend von (Chlorethinyl)aromaten als auch Eliminierungsreaktionen ausgehend von substituierten Vinylaziden herangezogen. Es konnten zahlreiche Sulfoxonium-Ylide sowie alpha-Oxocarbonsäureamide als eindeutige Folgeprodukte der Titelverbindungen isoliert und vollständig – größtenteils sogar anhand von Röntgeneinkristallstrukturanalysen – charakterisiert werden.
120

Síntese e aplicação de sílica modificada na adsorção de Cu(II), Cd(II) e As(V) em meio aquoso: pré-concentração em amostras de águas naturais / Synthesis and application of modified silica in Cu (II), Cd (II) and As (V) adsorption in aqueous media: preconcentration in natural water samples.

Wondracek, Marcos Henrique Pereira [UNESP] 05 October 2017 (has links)
Submitted by MARCOS HENRIQUE PEREIRA WONDRACEK null (marcoswondracek@ufgd.edu.br) on 2017-10-29T05:42:20Z No. of bitstreams: 1 TESE - versão final.pdf: 3488966 bytes, checksum: 44030b3422f6b77b9ba441eb0905cb23 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-11-09T13:58:32Z (GMT) No. of bitstreams: 1 wondracek_mhp_dr_araiq.pdf: 3488966 bytes, checksum: 44030b3422f6b77b9ba441eb0905cb23 (MD5) / Made available in DSpace on 2017-11-09T13:58:32Z (GMT). No. of bitstreams: 1 wondracek_mhp_dr_araiq.pdf: 3488966 bytes, checksum: 44030b3422f6b77b9ba441eb0905cb23 (MD5) Previous issue date: 2017-10-05 / Item merged in doublecheck by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-12-07T17:59:08Z Item was identical to item(s): 153113, 153193 at handle(s): http://hdl.handle.net/11449/152063, http://hdl.handle.net/11449/152164 / Este trabalho relata o desenvolvido de métodos analíticos que visa à determinação de algumas espécies tóxicas e potencialmente tóxicas de metais e metalóides em níveis ultra-traço em amostra de água naturais, utilizando uma técnica analítica menos sensível, como a espectrometria de absorção atômica em chama (FAAS). Essa técnica foi escolhida por ser relativamente simples e possuir baixo custo operacional. A técnica de extração em fase sólida (EFS), utilizando um novo material sorvente, foi utilizada para separar e pré-concentrar os analitos. Este estudo demonstra o procedimento de uma nova rota sintética via co-condensação visando à produção de uma sílica mesoporosa organofuncionalizada com o ligante 4-amino-3-hidrazino-5-mercapto-1,2,4-triazole e, sua utilização como sorvente para pré-concentração/análise de especiação de íons metálicos em amostras de água. O material produzido foi caracterizado por espectroscopia na região do infravermelho (FTIR), BET, ressonância magnética nuclear (RMN) de 29Si e 13C, dentre outras. As características adsortivas desse material foram estabelecidas em estudos de batelada, onde se estudou o efeito do pH, cinética de adsorção e capacidade máxima de adsorção. A otimização multivariada foi utilizada para obtenção das melhores condições químicas e de fluxo no sistema de pré-concentração, permitindo avaliar as interações principais e secundárias entre os fatores. Por meio da análise dos espectros obtidos por FTIR foi possível observar bandas de estiramento C–H, C–Cl e (NH2) oriundos da fração orgânica do material. A área superficial foi de 369,84 m2 g-1com diâmetro médio de poros em 7,1 nm, relacionados a materiais mesoporosos. Os resultados obtidos por RMN de 29Si comprovam a formação do material híbrido, sintetizado por co-condensação, e o RMN de 13C confirma o ancoramento do ligante na matriz. O pH que favorece a adsorção dos íons foi 5,0 para Cu(II) e 3,0 para Cd(II) e As(V). O modelo cinético de pseudo segunda ordem apresentou melhor ajuste aos dados experimentais, indicando adsorção química. Os dados de sorção desses íons metálicos mostraram bom ajuste ao modelo de Langmuir, com capacidade máxima de adsorção próxima aos valores obtidos experimentalmente, 0,057, 0,018 e 0,060 mmol g-1 para Cu(II), Cd(II) e As(V), respectivamente, indicando que a sorção ocorre em monocamada. Os parâmetros analíticos encontrados para o Cu(II) foram: fator de pré-concentração de 18,1; intervalo linear de 10,0 – 200,0 µg L-1 (R = 0,999) e LD de 1,45 µg L-1. Para o Cd(II): fator de pré-concentração de 15,8; intervalo linear de 2,0 – 100,0 µg L-1 (R = 0,999) e LD de 0,38 µg L-1. Para o As(V): fator de pré-concentração de 5,0; intervalo linear de 0,25 – 2,5 µg L-1 (R = 0,999) e LD de 0,039 µg L-1. A exatidão foi checada pelo método de adição e recuperação e/ou método comparativo com GFAAS ou ICP OES. As recuperações variaram de 97 – 106% (Cu), 100 – 105% (Cd), 88 – 103% (As(V)) e 96 – 106% (As(total)). Os resultados para Cu(II) determinados com os métodos propostos foram concordantes com os obtidos com o método comparativo. Conclui-se que o material produzido apresenta bom potencial para ser aplicado na extração/pré-concentração de cobre, cádmio e análise de especiação inorgânica de arsênio. Provou-se também que baixos limites de detecção e quantificação podem ser obtidos mesmo utilizando uma técnica menos sensível como a FAAS. / This paper reports on the development of analytical methods for the determination of some toxic and potentially toxic species in ultra - trace levels in natural water samples using a less sensitive analytical technique such as flame atomic absorpti on spectrometry (FAAS). This technique was chosen because it is relatively simple and has a low operating cost. The solid phase extraction technique (SPE) using a new sorbent material was used to separate and preconcentrate the analyte. This study demonstr ates the procedure of a new synthetic route using the technique of the co - condensation for the production of a mesoporous organo - functionalised silica with the 4 - amino - 3 - hydrazino - 5 - mercapto - 1,2,4 - triazole ligant and its use as a sorbent for preconcentrati on/ analysis of metal ion s speciation in water samples. The material produced was characterized by infra - red spectroscopy (FTIR), BET, 29 Si and 13 C nuclear magnetic resonance (NMR), among others. The adsorptive characteristics of this material were establis hed in batch studies, where the effect of pH, adsorption kinetics and maximum adsorption capacity were studied. Multivariate optimization was used to obtain the best chemical and flow conditions in the preconcentration system, allowing the evaluation of th e main and secondary interactions among the factors. By means of the analysis of the spectra obtained by FTIR, it was possible to observe C - H, C - Cl and (NH 2 ) stretch bands from the organic fraction of the material. The surface area was 369.84 m 2 g - 1 with a verage pore diameter at 7.1 nm related to mesoporous materials. The results obtained by 29 Si NMR prove the formation of the hybrid material, synthesized by co - condensation, and the 13 C NMR confirms the anchoring of the ligan t in the matrix. The pH 5.0 it w as favors the adsorption of the ions Cu (II), the pH 3.0 it was favors the adsorption of the Cd (II) and As (V). The kinetic model of pseudo second order showed better adjustment to the experimental data, indicating chemical adsorption. The adsorption data of Cu (II), Cd (II), and As (V) were similar to those of the Langmuir model, with a maximum adsorption capacity of 0.057, 0.018 and 0.060 mmol g - 1 for Cu (II), Cd(III) and As(V) , respectively, indicating that the sorption occurs in monolayer. The analyt ical parameters for Cu (II) were: preconcentration factor of 18.1; linear range of 10.0 - 200.0 μg L - 1 (R = 0.999) and LD of 1.45 μg L - 1 . For Cd (II): preconcentration factor of 15.8; linear range of 2.0 - 100.0 μg L - 1 (R = 0.999) and LD of 0.38 μg L - 1 . Fo r As (V): preconcentration factor of 5.0; linear range of 0.25 - 2.5 μg L - 1 (R = 0.999) and LD of 0.039 μg L - 1 . Accuracy was checked by addi tion and recovery method of the standard and/ or comparative method with GFAAS or ICP OES. The recovery ranged from 97 - 106% Cu(II), 100 - 105% Cd (II), 88 - 103% As (V) and 96 - 106% As (total)). The results for Cu (II) determined with the proposed methods were concordant with those obtained with the comparative. It is concluded that the material produced can be successfully applied in the extraction / preconcentration of copper, cadmium and analysis of inorganic speciation of arsenic and low limits of detection and quantification can be obtained even using a less sensitive technique such as FAAS.

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