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Ungesättigte Dithioetherliganden : selektive Extraktionsmittel für die Gewinnung von Palladium(II) aus Sekundärrohstoffen / Unsaturated dithioether ligands : selective extractants for the recovery of Palladium(II) from secondary sourcesTraeger, Juliane January 2012 (has links)
Die Entwicklung neuer Verfahren für die Rückführung von Palladium aus Altmaterialien, wie gebrauchten Autoabgaskatalysatoren, in den Stoffstromkreislauf ist sowohl aus ökologischer als auch ökonomischer Sicht erstrebenswert. In dieser Arbeit wurden neue Flüssig-Flüssig- und Fest-Flüssig-Extraktionsmittel entwickelt, mit denen Palladium(II) aus einer oxidierenden, salzsauren Laugungslösung, die neben Palladium auch Platin und Rhodium sowie zahlreiche unedle Metalle enthält, zurückgewonnen werden kann. Die neuen Extraktionsmittel ungesättigte monomere 1,2-Dithioether und oligomere Ligandenmischungen mit vicinalen Dithioether-Einheiten – sind im Gegensatz zu vielen in der Literatur aufgeführten Extraktionsmitteln hochselektiv. Aufgrund ihrer geometrischen und elektronischen Präorganisation bilden sie mit Palladium(II) stabile quadratisch-planare Chelatkomplexe. Für die Entwicklung des Flüssig-Flüssig-Extraktionsmittels wurde eine Reihe von ungesättigten 1,2-Dithioetherliganden dargestellt, welche auf einer starren 1,2-Dithioethen-Einheit, die in ein variierendes elektronenziehendes Grundgerüst eingebettet ist, basieren und polare Seitenketten besitzen. Neben der Bestimmung der Kristallstrukturen der Liganden und ihrer Palladiumdichlorid-Komplexe wurden die elektro- und photochemischen Eigenschaften, die Komplexstabilität und das Verhalten in Lösung untersucht. In Flüssig-Flüssig-Extraktionsuntersuchungen konnte gezeigt werden, dass einige der neuen Liganden industriell genutzten Extraktionsmitteln durch eine schnellere Einstellung des Extraktionsgleichgewichts überlegen sind. Anhand von Kriterien, die für eine industrielle Nutzbarkeit entscheidend sind, wie: guter Oxidationsbeständigkeit, einer hohen Extraktionsausbeute (auch bei hohen Salzsäurekonzentrationen der Speiselösung), schneller Extraktionskinetik und einer hohen Selektivität für Palladium(II) wurde aus der Reihe der sechs Liganden ein geeignetes Flüssig-Flüssig-Extraktionsmittel ausgewählt: 1,2-Bis(2-methoxyethylthio)benzen. Mit diesem wurde ein praxisnahes Flüssig-Flüssig-Extraktionssystem entwickelt. Nach der schrittweisen Adaption der wässrigen Phase von einer Modelllösung hin zu der oxidierenden, salzsauren Laugungslösung erfolgte die Auswahl eines geeigneten großtechnisch, einsetzbaren Lösemittels (1,2-Dichlorbenzen) und eines effizienten Reextraktionsmittels (0,5 M Thioharnstoff in 0,1 M HCl). Die hohe Palladium(II)-Selektivität dieses Flüssig-Flüssig-Extraktionssystems konnte verifiziert und seine Wiederverwendbarkeit und Praxistauglichkeit unter Beweis gestellt werden. Weiterhin wurde gezeigt, dass sich beim Kontakt mit oxidierenden Medien aus dem Dithioether 1,2-Bis(2-methoxyethylthio)benzen geringe Mengen des Thioethersulfoxids 1-(2-Methoxyethylsulfinyl)-2-(2-methoxyethylthio)benzen bilden. Dieses wird im sauren Milieu protoniert und beschleunigt die Extraktion wie ein Phasentransferkatalysator, ohne jedoch die Palladium(II)-Selektivität herabzusetzen. Die Kristallstruktur des Palladiumdichlorid-Komplexes des Tioethersulfoxids zeigt, dass der unprotonierte Ligand Palladium(II), analog zum Dithioether, über die chelatisierenden Schwefelatome koordiniert. Verschiedene Mischungen von Oligo(dithioether)-Liganden und der monomere Ligand 1,2-Bis(2-methoxyethylthio)benzen dienten als Extraktionsmittel für Fest-Flüssig-Extraktionsversuche mit SIRs (solvent impregnated resins) und wurden zu diesem Zweck auf hydrophilem Kieselgel und organophilem Amberlite® XAD 2 adsorbiert. Die Oligo(dithioether)-Liganden basieren auf 1,2-Dithiobenzen oder 1,2-Dithiomaleonitril-Einheiten, welche über Tris(oxyethylen)ethylen- oder Trimethylen-Brücken miteinander verknüpft sind. Mit Hilfe von Batch-Versuchen konnte gezeigt werden, dass sich strukturelle Unterschiede - wie die Art der chelatisierenden Einheit, die Art der verbrückenden Ketten und das Trägermaterial - auf die Extraktionsausbeuten, die Extraktionskinetik und die Beladungskapazität auswirken. Die kieselgelhaltigen SIRs stellen das Extraktionsgleichgewicht viel schneller ein als die Amberlite® XAD 2-haltigen. Jedoch bleiben die Extraktionsmittel auf Amberlite® XAD 2, im Gegensatz zu Kieselgel, dauerhaft haften. Im salzsauren Milieu sind die 1,2-Dithiobenzen-derivate besser als Extraktionsmittel geeignet als die 1,2-Dithiomaleonitrilderivate. In Säulenversuchen mit der oxidierenden, salzsauren Laugungslösung und wiederverwendbaren, mit 1,2-Dithiobenzenderivaten imprägnierten, Amberlite® XAD 2-haltigen SIRs zeigte sich, dass für die Realisierung hoher Beladungskapazitäten sehr geringe Pumpraten benötigt werden. Trotzdem konnte die gute Palladium(II)-Selektivität dieser Festphasenmaterialien demonstriert werden. Allerdings wurden in den Eluaten im Gegensatz zu den Eluaten, die aus Flüssig-Flüssig-Extraktion resultierten neben dem Palladium auch geringe Mengen an Platin, Aluminium, Eisen und Blei gefunden. / The development of new processes for the recovery of palladium from recycling materials like spent automotive catalysts is of economic and ecologic interest. In this thesis new solvent and solid phase extractants have been designed, which are suitable for the recovery of palladium(II) from an oxidising hydrochloric leach liquor that does not only additionally contain platinum and rhodium but also a number of base metals. In contrast to many extractants described in the literature these new extractants – unsaturated monomeric dithioethers as well as oligomeric mixtures of ligands with vicinal dithioether units – are highly selective for palladium(II). Due to their geometric and electronic preorganisation they form stable square-planar chelate complexes with palladium(II). For the development of the solvent extractant a series of unsaturated dithioethers, which are based on a rigid 1,2-dithioethene unit that is imbedded in an electron-withdrawing backbone, with polar end-groups has been synthesised. In addition to the determination of the crystal structures of the ligands and their dichloridopalladium complexes, the electro- and photochemical properties, the complex stabilities and the behaviour in solution have been investigated. Solvent extraction experiments showed the superiority of some of our ligands over conventionally used extractants in terms of their very fast reaction rates. Considering criteria that are essential for industrial utilisation like: robustness towards oxidation, achieving of high extraction yields (even at a high hydrochloric acid content of the leach liquor), fast extraction kinetics and a high selectivity for palladium(II), 1,2-bis(2-methoxyethylthio)benzene was selected as the extractant of choice. Building on this a solvent extraction system close to industrial practice was devised. After stepwise adaption of the aqueous phase from a model solution to the oxidising hydrochloric leach liquor, the selection of a diluent suitable for commercial operations (1,2-dichlorobenzene) and of an efficient stripping agent (0.5 M thiourea in 0.1 M HCl) has been accomplished. The high selectivity of that solvent extraction system for palladium(II) could be verified and its reusability and suitability for practical application have been proven. Further it was shown that small amounts of the thioether sulfoxide 1-[(2-methoxyethyl)sulfanyl]-2-[(2-methoxyethyl)sulfinyl]benzene form when the dithioether ligand 1,2-bis(2-methoxyethylthio)benzene gets in contact with oxidising media. Under acidic conditions this thioether sulfoxide gets protonated and accelerates the extraction like a phase transfer catalyst; without decreasing the selectivity for palladium(II). The molecular structure of the corresponding dichloridopalladium complex reveals that the nonprotonated ligand coordinates palladium(II) in a similar manner to the dithioether via the chelating sulfur atoms. Mixtures of oligo(dithioether) ligands and the monomeric 1,2-bis(2-methoxyethylthio)benzene have been adsorbed on silica gel and amberlite® XAD 2. These SIRs (solvent impregnated resins) have been used for solid phase extraction experiments. The oligo(dithioether) ligands are based on 1,2- dithiobenzene or 1,2-dithiomaleonitrile units, which are connected via tris(oxyethylene)ethylene or trimethylene chains. With the help of batch experiments it could be shown how structural differences, like the chelating unit, the kind of linking chain and the type of supporting material, impact the extraction yield, kinetics and loading capacity. The SIRs containing silica gel establish the extraction equilibrium much faster than those containing amberlite® XAD 2. On the other hand, the extractants permanently remain on amberlite® XAD 2, in contrast to silica gel. In a hydrochloric medium 1,2-dithiobenzene derivatives are better extractants than 1,2-dithiomaleonitrile derivatives. In column experiments with the oxidising hydrochloric leach liquor and reusable SIRs based on 1,2-dithiobenzene derivatives impregnated into amberlite® XAD 2, it appeared that for the implementation of high loading capacities very low flow rates are required. The selectivity for palladium(II) of these solid phase extractants could be demonstrated, although the eluates, in contrast to the eluates gained from the solvent extraction experiments, contained not only palladium but also small amounts of platinum, aluminium, iron and lead.
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Density functional theory study on the interstitial chemical shifts of main-group-element centered hexazirconium halide clusters; synthetic control of speciation in [(Zr6ZCl12)] (Z = B, C)-based mixed ligand complexesShen, Jingyi 29 August 2005 (has links)
The correlation between NMR chemical shifts of interstitial atoms and electronic structures of boron- and carbon-centered hexazirconium halide clusters was investigated by density functional theory (DFT) calculation. The influences of bridging halide and terminal ligand variations on electronic structure were examined respectively. Inverse proportionality was found between the chemical shifts and the calculated energy gaps between two Kohn-Sham orbitals of t1u symmetry, which arose from the bonding and antibonding interaction between the zirconium cage bonding orbitals and the interstitial 2p orbitals. Chemical shielding properties of the interstitial atoms were calculated with Gauge Including Atomic Orbital (GIAO) method. Stepwise ligand substitution of terminal chlorides on [(Zr6CCl12)Cl6]4-cluster by tri(n-butyl)-phosphine oxide (Bu3PO) was conducted with the aid of TlPF6. Composition of the reaction mixtures was analyzed by use of both 13C and 31P NMR. A preliminary scheme for synthesis and separation of [(Zr6CCl12)Cl6-x(Bu3PO)x]x-4 (x = 3 ?? 5) mixture based on solubility difference was reevaluated. Three 1,10-phenanthroline based bidentate ligands, namely, 2,9-Bis(diphenyl-phosphinyl)-1,10-phenanthroline, 2,9-Bis(diethoxyphosphoryl)-1,10-phenanthroline, and 2,9-Bis(di-n-butoxyphosphoryl)-1,10-phenantholine, were synthesized for bridge-chelating the hexazirconium clusters. Coordination chemistry of these ligands with the [Zr6BCl12] and [Zr6CCl12] clusters was subject to preliminary investigation.
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Efeito de adjuvantes sobre absorção de zinco e manganês na adubação foliar / Effect of adjuvants on the absorption of zinc and manganese in foliaMARTINS, Rosmany Aires Cunha 23 July 2009 (has links)
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Rosmary Aires Cunha.pdf: 811607 bytes, checksum: 37675c904b954048b34612362bb4c3d2 (MD5)
Previous issue date: 2009-07-23 / The objective of the present work was to evaluate the effect of lecithin,
starch and silicon may have in the efficiency of foliar feeding, that is: Can these products
really contribute to the absorption and translocation of minor nutrients? Can the source of
nutrient, sulfate and chelate, influence the result? The experiment was carried out under
greenhouse condition at Univerdidade Federal de Goiás (Jataí unit)/GO, set in a completely
randomized design, with six replications, four factors in study and two levels each, making a
2x2x2x2 factorial arrangement , totalizing 16 treatments. Moreover, it was added a control
as an additional treatment, totalizing then, 102 experimental units. Each experimental unit
was constituted by a vase of collard green plant. The treatments consisted of 2 minor nutrient
sources (sulfate and chalate) and of absence and presence of three substance added to the
spray solution: lecithin dewaxed (L), a commercial silicon surfactant (S), and stanch (A).
After analyses of the leaves, 30 days after de pulverization, it was clear that the amount of
zinc and manganese was influenced by the adjutants and kind of fertilizer. The use of lecithin
increased the absorption of zinc sulfate whereas the use of silicon increased only the
absorption of zinc chalate. Both chelate and sulfate increased the absorption of manganese.
The starch drove to a reducing absorption of zinc chelate. / O presente trabalho teve por objetivo avaliar os efeitos da lecitina, amido e
silicone sobre a eficiência da adubação foliar, utilizando-se sais e quelatos como fonte de
micronutrientes. Para isso foi realizado um experimento onde se avaliou os efeitos da adição
de diferentes adjuvantes em relação à absorção e translocação de zinco e manganês na
forma de sais e quelatos. O delineamento utilizado foi o inteiramente casualizado, com seis
repetições, com quatro fatores em estudo e dois níveis cada, perfazendo um fatorial 2x2x2x2,
totalizando dezesseis tratamentos. Além dos tratamentos, foi adicionado testemunha como
tratamento adicional, perfazendo, assim, um total de 102 parcelas. Cada parcela foi
constituída por um vaso contendo uma planta de couve manteiga. Os tratamentos constaram
de combinações entre 2 fontes (sulfato e quelato) e de presença ou ausência de três
substâncias na calda de pulverização: lecitina de soja desengordurada (L), um siliconado
comercial (S) e gel de amido de mandioca (A). A determinação dos efeitos constituiu-se na
análise do teor de zinco e manganês nas folhas novas 30 dias após a pulverização. A adição
de lecitina aumentou a absorção do zinco aplicado na forma de sulfato ao passo que o
produto siliconado aumentou a absorção apenas do zinco quelatizado. Tanto a lecitina
quanto o produto siliconado, quando adicionados a calda de pulverização, aumentaram o
teor de manganês. O gel de amido não aumentou a absorção de nenhum micronutriente,
levando até mesmo a uma redução do da absorção do quelato de zinco.
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In-vivo und In-vitro-Stabilität und Metabolismus von Gemischtligandkomplexen des 99m TcGupta, Antje 16 October 2000 (has links)
No description available.
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Synthèse stéréosélective de motifs polypropionates via la chimie des radicaux : application à l'élaboration de l'hémisphère ouest de la narasineBrazeau, Jean-François 08 1900 (has links)
Cet ouvrage traite principalement de la synthèse de motifs polypropionates de type
stéréopentade ainsi qu’une application à la synthèse d’une molécule naturelle possèdant
des propriétés biologiques. La stratégie envisagée pour l’élaboration de ces motifs
récurrents dans plusieurs structures d’origine naturelle fait appel à la chimie des radicaux. Cette thèse se divise en différents chapitres dans lesquels la versatilité de la méthodologie développée sera démontrée.
En premier lieu, il sera question de présenter l’importance de la synthèse de motifs polypropionates. Le domaine couvert par la chimie de ces molécules complexes
hautement fonctionnalisées a contribué énormément à l’avancement de nos
connaissances en synthèse organique, particulièrement dans le contexte des réactions impliquant des molécules acyliques. Une brève description des méthodes connues est
présentée afin de saisir l’étendue des défis restants pour construire efficacement tous les isomères possibles des polypropionates de type stéréopentade.
La stratégie proposée est basée sur une approche contrôlée entièrement par le
substrat. Ce contrôle s’appuie sur le choix judicieux de l’acide de Lewis activant les
deux réactions impliquées, soit la réaction de Mukaiyama et le transfert d’hydrogène.
La seconde section de cette thèse concerne principalement le développement d’une
réaction de Mukaiyama impliquant un éther d’énol silylé portant un lien pouvant être
homolytiquement brisé dans la réaction suivante et un aldéhyde de type propionate. Le contrôle de l’aldolisation provient de la nature de l’acide de Lewis. Une espèce
monodentate (BF3·OEt2) génère une relation 3,4-syn selon le modèle dit Felkin-Anh
tandis que les acides de Lewis bidentates mènent à la relation 3,4-anti via un état de
transition définit comme Cram-chélate. Une optimisation des conditions réactionnelles
en variant l’acidité et la stoechiométrie de l’acide de Lewis de titane a permis de
construire diastéréosélectivement le produit de Mukaiyama ayant une relation 3,4-anti.
En outre, la nature des complexes impliqués dans ces réactions a été élucidée par des
études RMN 13C à basse température.
Une fois les précurseurs radicalaires synthétisés, notre méthodologie de réduction
par transfert d’hydrogène contrôlée également par les acides de Lewis s’avère très efficace. Les acides de Lewis dérivés d’aluminium mènent sélectivement à la relation 2,3-syn selon un contrôle endocyclique tandis que les acides de Lewis de bore permettent la création des relations 2,3-anti en se basant sur une stabilisation par les divers facteurs de contrôle de molécules acycliques. Cette stratégie novatrice nous a ainsi permis de construire efficacement les 16 diastéréoisomères possibles.
Le chapitre suivant concerne l’application de cette méthodologie à la synthèse de
l’hémisphère ouest de la salinomycine et de la narasine. Plusieurs défis synthétiques ont
été relevés à cette occasion par la présence de nombreux centres stéréogènes contigus.
Nous avons réalisé que la relation stéréochimique 2,3-anti de la salinomycine n’est pas accessible sélectivement par la chimie des radicaux via l’effet exocyclique. Des études ont été entreprises afin de comprendre cette perte de sélectivité. Les conclusions suggèrent que les substituants sur le cycle imposent un biais conformationnel conduisant à des faibles sélectivités. Une alternative utilisant un réactif de crotylsilane chiral a été
développée pour arriver à la molécule cible. Cette situation est différente dans le cas de
la narasine où la présence du méthyle sur le carbone en position β du radical bloque
efficacement l’approche d’une des faces d’attaque par l’hydrure. Des sélectivités
impressionnantes nous ont permis de construire le fragment C1-C9 de la narasine de manière expéditive et efficace. Finalement, l’élongation sélective utilisant à nouveau la séquence d’aldolisation de Mukaiyama/réduction radicalaire suivie d’un couplage de type aldol stéréosélectif conduit au fragment C1-C17 de la narasine (hémisphère ouest)en 19 étapes avec un rendement global de l’ordre de 7 %.
En dernier lieu, nous nous sommes penchés sur la réactivité des α-bromo-β-
alkoxycétones lors de transfert d’hydrogène. Nous avons découvert que la chimie de ces
derniers pourrait s’avérer utile dans le contexte de la synthèse de motifs complexes
polypropionates. La présence d’un centre stéréogène de l’autre coté de la cétone semble avoir un impact sur la sélectivité. / This thesis focuses on a new methodology for the synthesis of polypropionate stereopentads with an application to the synthesis of a natural molecule that possess
interesting biological properties. The key steps of our strategy to elaborate those motifs will use radical chemistry previously developped in our group.
First, the importance of synthesizing polypropionate motifs is presented. In recent
years, polypropionate systems have stimulated extensive interest due to their association with a broad spectrum of biologically active targets with proven or potential use in medicine, including those with antibiotic and anticancer properties. Many of the approaches reported used chiral reagents and took advantage of double asymmetric induction. Not surprisingly, mismatched scenarios were at times noticed and yet, no single strategy has been reported leading directly to all 16 stereopentad diastereoisomers. Thus, the rapid and facile assembly of the polypropionate framework would be very beneficial and is still an active area of research.
The second section of this work describes our contribution to this area with the
development of a fully substrate-controlled sequence of Mukaiyama aldol reaction
followed by a hydrogen transfer reaction on aldehydes having the stereotriad array. The
aldol reaction can be performed under Felkin-Anh or Cram-chelate pathway to give
either the 3,4-syn or 3,4-anti relationship, respectively. This reaction was optimized
using different Lewis acids to give excellent yield and diastereoselectivity. We found that an excess of TiCl3(OiPr) in our Mukaiyama reactions increased the chelating ability of the Lewis acid, thus leading to improved diastereoselectivity. Low temperature 13C NMR was performed to obtain more information on the complexes present in solution. Once the radical precursors were obtained, the hydrogen transfer step was
performed. Aluminum-containing Lewis acids led to the exclusive formation of the 2,3-
syn isomer under the endocyclic effect while controlling factors described for acyclic
molecules were sufficient enough to give the 2,3-anti as a sole diastereoisomer, such as
cases in which a boron-containing Lewis acid was added prior to the tin hydride. One
limitation was observed with this scenario and resolved using the exocyclic effect to
access all 16 polypropionate stereopentad motifs.
To further demonstrate the synthethic potential of our methodology, we engaged on
the synthesis of the western hemisphere of both salinomycin and narasin. The synthetic
challenges related with these molecules are numerous due to the large number of
adjacent stereogenic centers. We realized that the 2,3-anti stereochemical relation of
salinomycin was not selectively accessible via radical chemistry under the exocyclic
effect. Different substrates were tested to understand this limitation and we concluded
that the substituents on the ring impose a conformationnal bias unfavorable to good
selectivty. Still, we found an alternative employing a chiral crotylsilane to access this 2,3-anti relationship α to the six-membered ring. This situation is different in the case of narasin where the β-methyl substituent blocks efficiently the hydride attack from the upper face. Impressive selectivities were observed and the synthesis of the C1-C9 fragment of narasin was accomplished in an expeditive manner. Finally, the elongation using a second sequence of stereoselective Mukaiyama aldol reaction/radical reduction followed by an aldol coupling led to the construction of the western hemisphere of narasin in 19 synthethic steps with an overall yield of 7 %.
Finally, we decided to focus our attention to the chemistry of α-bromo-β-
alkoxyketones in hydrogen transfer reactions. We found that their ability to give selective transformations could be beneficial in the context of synthesizing complex polypropionate motifs. The presence of a stereogenic center on the other side of the ketone seemed to have a great impact on the selectivity.
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Synthèse diastéréosélective du fragment C1-C13 de la zincophorine par approche combinée utilisant une séquence d'aldolisation de Mukaiyama suivie d'une réduction radicalaireGodin, François January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
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Preparo e avaliação dos complexos de derivados de tiossemicarbazonas com(67/68 Ga) gálio, [99mTc] tecnécio e (111In)índio, como potenciais agentes para detecção de tumores / Preparation and evaluation of the thiosemicarbazone derivative complexes (67/68Ga)gallium, [99mTc]technetium and (111In)Indium as potential agents for tumor detectionLafratta, Alyne Eloise 06 June 2016 (has links)
Nas últimas décadas a medicina nuclear tornou-se uma grande aliada no auxílio ao diagnóstico de doenças e também para o tratamento do câncer. Parte deste sucesso está relacionada à constante pesquisa e desenvolvimento de novos radiofármacos. Uma classe de molécula que vem se mostrando promissora para o tratamento de tumores, tanto na sua forma orgânica quanto na forma de complexos organo-metálicos, é a tiossemicarbazona e seus derivados, os quais também podem formar complexos com radioisótopos metálicos dando origem a radiofármacos para diagnóstico e terapia. Neste trabalho foram preparados complexos com o ligante benzil-5-hidroxi-3-metil-5-fenil-4,5-diidro-1H-pirazol-1-carboditionato (H2bdtc) com os radioisótopos [99mTc]tecnécio, (67/68Ga)gálio e (111In)índio, e foram avaliados a pureza radioquímica, Log P e a estabilidade na presença de L-cisteína, L-histidina, soro albumina humana (SAH) e plasma de sangue humano; também foram avaliadas a taxa de captação dos radiofármacos in vitro em células de melanoma murino B16F10 e TM1M, além da avaliação da captação ex vivo e in vivo utilizando camundongos C57B/6 inoculados com as duas linhagens tumorais. Com o [99mT]tecnécio foram obtidos dois complexos diferentes, dependendo da concentração do PBS na solução, sendo que em um deles foi possível confirmar sua estrutura como [[99mTc]O(bdtc)(Hbdtc)] a partir do complexo de rênio [ReO(bdtc)(Hbdtc)], o outro complexo de [99mTc]tecnécio, bem como de (67/68Ga)gálio e (111In)índio não tiveram a estrutura caracterizada. A eficiência de marcação dos complexos foi superior a 90 %, com Log P maior que 1 para os complexos [[99mTc]O(bdtc)(Hbdtc)], [[99mTc]-bdtc] e [67/68Ga-bdtc] e 0,9 para [111In-bdtc]. Todos os complexos se mostraram com boa estabilidade na presença de L-cisteína e L-histidina, principalmente na primeira hora de incubação, mas não o foram na presença de SAH e plasma. A captação in vitro dos complexos em células B16F10 e TM1M variou entre 0,6 % e 1,8 %, e nos estudos de biodistribuição ex vivo foi obesrvada intensa e persistente captação hepática e no baço, superando 90 %, e captação no tumor variando de 0,2 % a 3 %, enquanto que nas imagens in vivo não foi possível observar de forma uma adequada captação nos tumores a ponto de permitir o uso como agente de diagnóstico. Os resultados permitem concluir que os complexos de derivados tiossemicarbazonas podem formar complexos com diferentes metais, mas novos derivados devem ser preparados para tentar melhorar o desempenho nos sistemas biológicos. Os experimentos com animais foram aprovados pela Comissão de Ética em Pesquisa da Faculdade de Medicina - USP, processo 372/12 / In recent decades, nuclear medicine has been used as diagnostic agent for disease and for the treatment of cancer. Part of this success is related to the constant research and development of new radiopharmaceuticals. Thiosemicarbazone and their derivatives have proven to be promising agent for the treatment of tumors, both in its organic form or as organo-metallic complexes. Also, they can to form complexes with metal radioisotopes giving radiopharmaceuticals for diagnosis and therapy. In this work we prepared complex of benzyl-5-hydroxy-3-methyl-5-phenyl-4,5-dihydro-1H-pyrazol-1-carboditionato (H2bdtc) with radioisotopes [99mTc]technetium (67/68Ga)gallium and (111In)indium and the radiochemical purity, Log P and stability in the presence of L-cysteine, L-histidine, human serum albumin (HSA) and human blood plasma were assessed; also were assessed the in vitro uptake rate of radiopharmaceuticals in murine melanoma cells B16F10 and TM1M, besides the evaluation of ex vivo uptake and in vivo using C57Bl/6 mice inoculated with both tumor lines. With [99mT] technetium two different complexes were obtained, depending on the concentration of the PBS in the solution, and one of them was had its structure to confirm as [[99mTc]O(bdtc)(Hbdtc)] from the standard rhenium complex [ReO(bdtc)(Hbdtc)], the other [99mTc] echnetium complex as well as (67/68Ga)gallium and (111In)indium not have characterized the structure. The labeling efficiency of compleos was higher than 90%, with log P higher than 1 for the complexes [[99mTc]O(bdtc)(Hbdtc)], [[99mTc]-bdtc] and [(67/68Ga)-bdtc] and 0.9 to [111In-bdtc]. All the complexes showed good stability in the presence of L-cysteine and L-histidine, especially in the first hour of incubation, but not in the presence of HSA and plasma. The uptake in vitro complexes in B16F10 and TM1M cells varied between 0.6% and 1.8%, and in ex vivo biodistribution studies was obesrvada intense and persistent liver uptake and spleen, exceeding 90%, and tumor uptake in changing from 0.2% to 3%, while in vivo imaging was not possible to observe a properly uptake in tumors, not allowing to use these molecules as a diagnostic agent. The results indicate that the thiosemicarbazone derivative complex can give complexes with different metals, but new derivatives should be prepared to try to improve performance in biological systems. The animal experimentation was approved by Comissão de Ética em Pesquisa da Faculdade de Medicina - USP, proccess 372/12
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Ligand Design of Sulfur-Centered Chelates / Ligandendesign Schwefel zentrierter ChelateSchulz, Thomas 15 March 2010 (has links)
No description available.
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Pyrazolbasierte zweikernige Zink(II)-Komplexe als Modellsysteme zum Verständnis der Rolle des Zinks in enzymatischen Reaktionen / Pyrazol based bimetallic zinc(II)-complexes as a model system to understand the role in enzymatic reactionsAlvariño Gil, Miguel 01 November 2006 (has links)
No description available.
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Zweikernige Zinkkomplexe als Modellverbindungen für Hydrolasen / Dinuclear zinc complexes as model compounds for hydrolasesBauer-Siebenlist, Bernhard 27 April 2004 (has links)
No description available.
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