Made available in DSpace on 2016-12-23T14:41:51Z (GMT). No. of bitstreams: 1 Clebson de Jesus Macrino.pdf: 1804272 bytes, checksum: 09ea2017b28151fdc939bc46161d7011 (MD5) Previous issue date: 2013-03-11 / Neste trabalho é descrito a síntese e caracterização dos compostos de picratos de lantanídeos (III), [Ln(pic)3], pic = C6H2N3O7 e (Ln = Eu e Gd)com a 2-aza-ciclooctanona, C7H13NO, (OEN), e N-metil-2-aza-cicloheptanona, C6H10NO(CH3),(NMK). Os compostos de estequiometria [Eu(pic)3.(H2O)11], [Eu(pic)3.(OEN)3], [Eu(pic)3.(NMK)3], [Gd(pic)3.(H2O)11], [Gd(pic)3.(OEN)3] e [Gd(pic)3.(NMK)3] foram sintetizados e caracterizados por procedimentos microanalíticos, infravermelho e medidas de luminescência. A presença das bandas assNO2 e sNO2 devida aos íons picratos e o deslocamento da frequência de estiramento CO das lactamas apresentadas no espectro vibracional dos compostos para regiões de menores energia indicam a coordenação dos ligantes ao centro metálico lantanídico. O efeito da substituição dos respectivos ligantes 2-aza-ciclooctanona e N-metil-2-aza-cicloheptanona no composto picrato de európio (III) hidratado, foi investigado a fim de verificar a influência destes ligantes nas propriedades luminescentes dos respectivos complexos. Foram observadas nos respectivos espectros de emissão as transições características do íon Eu3+. Os estados tripletos dos ligantes foram obtidos por meio dos espectros de emissão dos compostos de gadolínio, permitindo dessa forma correlacioná-los com o nível emissor 5D0 do íon Eu3+. Os parâmetros de intensidades experimentais de Judd-Ofelt (Ω2 e Ω4) e o R02 foram determinados a fim de se avaliar o grau de covalência dos compostos e o efeito da força do campo ligante sobre o íon Eu3+. A taxa de decaimento espontâneo radiativo (Arad), não radiativo (Anrad), tempo de vida (τ) e a eficiência quântica (η) foram calculados e correlacionados entre os compostos preparados com o objetivo de se avaliar a eficiência de emissão de cada composto. O diagrama de cromaticidade foi usado para avaliar o grau de pureza da emissão de cada composto. A estrutura do composto [Eu(pic)3.(OEN)3] foi determinada através da técnica de difração de raios-X pelo método do monocristal, a qual permitiu fazer uma correlação da estrutura com o respectivo espectro de emissão do composto / This paper describes the synthesis and characterization of compounds of lanthanide (III) picrates, Ln(pic)3], pic = C6H2N3O7 e (Ln = Eu e Gd) with 2-aza-cyclooctanone, C7H13NO, (OEN), e N-methyl-2-aza-cycloheptanone, C6H10NO(CH3),(NMK).The compounds of stoichiometry [Eu(pic)3.(H2O)11], [Eu(pic)3.(OEN)3], [Eu(pic)3.(NMK)3], [Gd(pic)3.(H2O)11], [Gd(pic)3.(OEN)3] and [Gd(pic)3.(NMK)3] have been synthesized and characterized by microanalytical procedures, infrared and measures luminescence. The presence of bands assNO2 and SNO2 due to picrates ions and the frequency shift of CO stretching lactams presented in the vibrational spectrum of compounds to lower energy regions indicate the coordination of the ligands to the metal center lanthanide. The effect of replacing binders respective 2-aza-cyclooctanone and N-methyl-2-aza-cycloheptanone the compound of europium (III) picrate hydrate was investigated to verify the influence luminescent properties of these ligands on their respective complexes. Were observed in their emission spectra transitions characteristic of Eu3+ ion. The triplet states of the ligands were obtained through the emission spectra of gadolinium compounds, thus allowing to correlate them with the emitter 5D0 level of Eu3+ ion. The experimental intensities parameters of the Judd-Ofelt (Ω2 and Ω4) and R02 were determined in order to evaluate the degree of covalency of the compounds and the effect of field strength on the binder Eu3+ ion. The spontaneous radiative decay rate (Arad), non radiative (Anrad), lifetime (τ) and quantum efficiency (η) were calculated and correlated with the compounds prepared in order to evaluate the efficiency of emission of each compound. The chromaticity diagram was used to assess the purity of the emission of each compound. The structure of the compound [Eu(pic)3.(OEN)3] was determined using the technique of X-ray diffraction by the method of monocrystal which allowed the structure to make a correlation with the respective emission spectrum of the compound

Orientador: Ítalo Odone Mazali / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T20:07:38Z (GMT). No. of bitstreams: 1 Oliveira_CristineSantosde_M.pdf: 3527061 bytes, checksum: 7dfe90cc79337811bc7955e8a1531586 (MD5) Previous issue date: 2013 / Resumo: O trabalho consistiu na síntese de sistemas nanoestruturados de ZnO contendo Eu em sílica mesoporosa, o vidro poroso Vycor (PVG), utilizando o método de ciclos de impregnação-decomposição (CIDs). Sistemas de nanopartículas puras de ZnO, na forma PVG/10ZnO mostraram que o ZnO apresentou-se predominantemente na forma de sítios de ZnO monodispersos com absorção em 245-250 nm e na forma de nanopartículas, com tamanho médio em torno de 4,5 nm, para as quais inicialmente não se observou uma absorção característica. Através de espectroscopia de luminescência observou-se transferência de energia do ZnO monodisperso para a matriz, porém nenhuma emissão no visível característica de defeitos. Para o sistema PVG/10Eu observou-se transições f-f características nos espectros de emissão e excitação, e a transferência de carga O¿¿Eu. Os sistemas seguintes sintetizados na forma PVG/ZnO@ZnO/M@ZnO, com M = Eu, Al, Sr, Pr e Yb visaram o estudo do sistema principal PVG/ZnO@ZnO/Eu@ZnO, o qual apresentou emissões do Eu relativamente mais intensas do que no sistema PVG/10Eu além de apresentar o favorecimento do crescimento do ZnO sob a forma de nanopartículas, crescendo sobre os aglomerados de dopante. Nessas condições, surge a banda proibida do ZnO em torno de 360 nm, cuja borda é deslocada para menores energias com o número de CIDs, em acordo com uma equação da literatura, indicando um regime de confinamento quântico. Esta banda é observada na luminescência e também transfere energia para a matriz, ainda não sendo observadas emissões de defeitos do ZnO. Estudos com Sr e Al não confirmaram a formação de defeito do tipo Zni decorrente da inserção do íon Eu na rede do óxido. Os espectros de excitação para os sistemas de ZnO contendo Eu não foram conclusivos quanto à transferência de energia devido à presença de bandas do Eu, e num sistema similar substituindo-se por Yb não foi observada esta transferência. Medidas de tempo de vida mostraram um aumento da estabilidade do Eu no sistema com a presença prévia do ZnO, e também sob seu recobrimento. Através das emissões excitônicas do ZnO observou-se o efeito de confinamento quântico também na luminescência, o qual se deu de forma similar ao observado para a análise por absorção no UV-Vis / Abstract: The work consisted in the synthesis of nanostructured systems of ZnO containing Eu loaded in a mesoporous silica, the porous Vycor glass (PVG), using the impregnation-decomposition cycles method (IDCs). Pure ZnO nanoparticles systems synthesized in the form PVG/10ZnO have shown that ZnO presents itself predominantly as monodisperse ZnO sites with absorption at 245-250 nm, and nanoparticles, with mean size around 4,5 nm, for which initially no characteristic absorption had been observed. Through luminescence spectroscopy an energy transfer from monodisperse ZnO to the matrix was observed, but no defect-related emissions. For the PVG/10Eu system Eu characteristic f-f transitions were observed in both emission and excitation spectra, as well as the O¿¿Eu charge transfer. The following systems synthesized in a PVG/ZnO@ZnO/M@ZnO pattern, with M = Eu, Al, Sr, Pr e Yb sought the study of the main system PVG/ZnO@ZnO/Eu@ZnO, which presented Eu emissions relatively more intense than the PVG/10Eu system, also showing favoring growth of ZnO under the form of nanoparticles, which now grow over dopant clusters. Under such condition the ZnO band gap is now observed in UV-Vis absorption analysis, with peaks around 360 nm, whose edge is displaced towards lower energies with increasing number of IDCs, also in agreement with a theoretical equation from the literature, pointing to a condition of quantum confinement. This band is observed in luminescence, and also transfers energy to the matrix, and yet no defect-related emissions are observed for ZnO. Studies with Sr and Al did not confirm the formation of a Zni defect due to the insertion of Eu ions into the oxidefs structure. Excitation spectra for Eu-containing ZnO systems were not conclusive as to the existence of an energy transfer due to the presence of Eu bands in the same range, and in the similar system exchanging Eu3+ for Yb3+ such transfer was not observed. Lifetime measurements have shown an increase in Eu stability within the system with ZnO presence previous to its insertion, or after its coating layer(s). Quantum confinement effect was also observed for the ZnO excitonic emissions in luminescence, showing a similar behavior to that obtained thru UV-Vis absorption analysis / Mestrado / Quimica Inorganica / Mestre em Química

Die sichere Entsorgung hochradioaktiver Abfälle stellt eine wichtige wissenschaftli-che und gesellschaftliche Herausforderung dar. Tongesteine sind potentielle Wirts-gesteine für die Endlagerung dieser Abfälle in einem geologischen Tiefenlager. Ben-tonite sollen dabei als Verfüllmaterial nicht nur für ein Endlager in Tonformationen, sondern auch in kristallinem Gestein dienen. Für eine langfristige Sicherheitsbewer-tung müssen verschiedene Aspekte berücksichtigt werden. Neben geologischen, ge-ochemischen und geophysikalischen Gesichtspunkten spielen auch natürlich vor-kommende Mikroorganismen eine entscheidende Rolle in der Umgebung eines sol-chen Endlagers. Gelangt in einem Worst-Case-Szenario Wasser in das Endlager, können diese mit den freigesetzten Radionukliden wechselwirken und beispielswei-se die chemische Speziation oder den Oxidationszustand verändern. In dieser Arbeit wurden die Wechselwirkungen des anaeroben, sulfatreduzierenden Bakteriums Desulfosporosinus hippei DSM 8344T, einem Vertreter der Gattung Desul-fosporosinus, die in Tongestein und Bentonit vorkommt, mit Uran(VI) und Europi-um(III) mit Hilfe verschiedener mikroskopischer, spektroskopischer und molekular-biologischer Methoden untersucht. Die Ergebnisse lieferten einen umfassenden Einblick in die ablaufenden Wechselwirkungsprozesse und zeigten deutliche Unter-schiede zwischen den untersuchten Elementen auf. Im Zuge dessen wurde ein be-sonderes Augenmerk auf die Untersuchung der Reduktion von Uran(VI) durch D. hippei DSM 8344T gelegt. Für dieses Element konnte eine Immobilisierung in einem gekoppelten Assoziations-Reduktionsmechanismus nachgewiesen werden. Im Ge-gensatz dazu wechselwirkte nur ein geringer Anteil des gelösten Europium(III) mit den Zellen des anaeroben Mikroorganismus, wobei eine teilweise Biopräzipitation von Europiumphosphat beobachtet werden konnte. Die Wechselwirkung des Mikroorganismus mit Uran(VI) wurde zunächst in einem Bikarbonat-gepufferten System untersucht, wobei keine Abnahme der Urankon-zentrationen nachgewiesen werden konnte und damit wahrscheinlich auch keine Reduktion von Uran(VI) in den Überständen erfolgte. Zusätzlich wurden die Expe-rimente in synthetischer Opalinustonporenlösung durchgeführt. Die Untersuchun-gen mit zwei verschiedenen Uran(VI)-Ausgangskonzentrationen (100 µM und 500 µM) zeigten dabei in beiden Fällen eine fast vollständige Entfernung des Urans aus den Überständen. Um genauere Informationen über die Uran(VI)-Speziation in den Überständen zu erhalten, wurden thermodynamische Berechnungen der auftretenden Komplexe sowohl in Bikarbonat-Puffer, als auch in synthetischer Opalinustonporenlösung durchgeführt. Ergänzend dazu wurden die Überstände der Versuche in der Poren-lösung lumineszenzspektroskopisch untersucht. Die thermodynamische Modellie-rung zeigte bei dem pH-Wert des Bikarbonat-Puffersystems (pH 6,8) die Dominanz des 1:3-Uranyl(VI)-Carbonat-Komplexes, wohingegen im Porenwasser (pH 5,5) ein Uranyl(VI)-Laktat-Komplex die vorrangige Spezies darstellte. Die Anwesenheit eines zusätzlichen Carbonat-Komplexes spielte in diesem Fall nur eine untergeordnete Rolle. Die Berechnungen konnten mit Hilfe der Lumineszenzspektroskopie bestätigt werden. Sowohl der dominante Laktat-Komplex, als auch ein geringer Anteil eines Uranyl(VI)-Carbonat-Komplexes konnten im Opalinustonporenwasser verifiziert werden. Die Speziesverteilung zeigte, dass nur der Anteil des Laktat-Komplexes mit steigenden Inkubationszeiten abnahm, wohingegen der Anteil des Carbonat-Komplexes konstant blieb. Dies bestätigte die Ergebnisse der Experimente in Bikar-bonat-Puffer und ließ Schlussfolgerungen dahingehend zu, dass der Carbonat-Komplex von den Zellen offenbar nicht reduziert werden konnte und dadurch die Bioreduktion von der Ausgangsspeziation des Uran(VI) abhängig ist. Fluoreszenzmikroskopische Aufnahmen wiesen einen Einfluss des Urans auf die Zellvitalität und die Biofilmbildung nach. Mit Hilfe der Transmissionselektronenmik-roskopie konnte die Assoziation von Uran vorrangig auf der Zelloberfläche gezeigt werden. Zudem bildeten die Zellen Membranvesikel als mögliche Abwehrreaktion aus, um eine Verkrustung der Zellen zu verhindern. Diese Beobachtungen deuten auf eine Immobilisierung des Urans durch Wechselwirkung mit den Zellen hin. Die Reduktion des Uran(VI) wurde mit Hilfe verschiedener spektroskopischer Me-thoden bestätigt. Dabei zeigten UV/Vis-Untersuchungen der aufgelösten Zellpellets zunächst einen steigenden Anteil an Uran(IV) mit fortschreitender Inkubationszeit. Eine vollständige Reduktion des Urans konnte hingegen nicht nachgewiesen wer-den. HERFD-XANES-Messungen bestätigten die Reduktion des Uran(VI) in den Zell-pellets. Darüber hinaus konnte die Anwesenheit von Uran(V) während des Redukti-onsprozesses beobachtet werden, wodurch ein Ein-Elektronen-Prozess als Redukti-onsmechanismus für diesen Mikroorganismus verifiziert werden konnte. Des Weite-ren handelte es sich dabei um den erstmaligen Nachweis von Uran(V) während der Bioreduktion von Uran(VI) durch sulfatreduzierende Mikroorganismen im Allge-meinen. Ergänzende EXAFS-Untersuchungen konnten die Struktur der Uran(IV)-Verbindung hingegen nicht abschließend aufklären. Mittels Proteomikuntersuchungen als systembiologische Methode konnten Hinweise auf verschiedene während der Uraninkubation stattfindender Prozesse, wie bspw. die Biofilmbildung, den Zellwandumbau und eine Hochregulierung verschiedener Proteine, die in anderen Mikroorganismen für die Reduktion von Uran und anderen Metallen verantwortlich sind, gefunden werden. Des Weiteren konnten auch ver-schiedene Enzyme die an einer Stressreaktion der Zellen beteiligt sind nachgewiesen werden. In den Experimenten mit Europium(III), welches häufig als nicht radioaktives Ana-logon für die dreiwertigen Actinide zum Einsatz kommt, zeigten die Zellen nur eine geringe Wechselwirkung mit dem Lanthanid. Der toxische Einfluss des Schwerme-talls war geringer als in den Untersuchungen mit Uran(VI). Transmissionselektro-nenmikroskopische Aufnahmen zeigten eine Biopräzipitation von Europium(III) mit Phosphaten auf der Zelloberfläche und dadurch eine teilweise Immobilisierung des Metalls. Die aquatische Speziation des Europium(III) zeigte eine vollständige Komplexierung mit Laktat in den Überständen. Dies könnte eine mögliche Erklärung der geringen Wechselwirkung mit den Zellen liefern aufgrund einer Abschirmung des Lanthanids gegenüber zellulären Liganden. In den Zellspektren, ließen sich drei unterschiedli-che Spezies voneinander unterscheiden, eine lose mit den Zellen assoziierte Spezies und zwei zellulär gebundene Komplexe wahrscheinlich mit Carboxyl- oder Phos-phatgruppen. Eine ortsaufgelöste Speziation war mit Hilfe einer Kopplung von kon-fokaler Mikroskopie und Laserspektroskopie möglich. Zusammenfassend liefert diese Arbeit neue Erkenntnisse über die Wechselwirkung sulfatreduzierender Mikroorganismen mit Uran(VI) und Europium(III) und trägt zu einem besseren Verständnis mikrobieller Reduktionsprozesse in der Umwelt bei. Die Immobilisierung von Uran durch eine teilweise Reduktion zu weniger löslichen Uran(IV)-Verbindungen, sowie eine verstärkte Biofilmbildung wirken sich positiv auf die Sicherheit eines Endlagers für hochradioaktive Abfälle in Tongestein aus. Es konnte allerdings auch gezeigt werden, dass stattfindende Wechselwirkungsprozes-se von der Ausgangsspeziation des Metalls abhängen, wodurch die Retention der Radionuklide möglicherweise eingeschränkt wird. Dadurch spielen die erhaltenen Ergebnisse nicht nur eine wichtige Rolle für ein umfassendes Sicherheitskonzept eines nuklearen Endlagers in Tongestein, sondern liefern auch neue Impulse für verschiedene Bioremediationsstrategien radioaktiv kontaminierter Umgebungen. / The safe disposal of high-level radioactive waste is a major scientific and societal challenge. Clay rocks are potential host rocks for the final disposal of the nuclear waste in a deep geological repository. Bentonites should serve as backfill material for a repository not only in clay formations, but also in crystalline rocks. Various aspects have to be considered for a long-term safety assessment. In addition to geological, geochemical and geophysical aspects, naturally occurring microorganisms in the en-vironment of such a repository play a decisive role. In the event of a worst-case sce-nario, if water enters the repository, these microorganisms can interact with the re-leased radionuclides and, for example, change the chemical speciation or oxidation state. In this work, the interactions of the anaerobic sulfate-reducing bacterium Desul-fosporosinus hippei DSM 8344T, a member of the genus Desulfosporosinus, which can be found in clay rock and bentonite, with uranium(VI) and europium(III) were in-vestigated using various microscopic, spectroscopic and molecular biological meth-ods. The results provided a comprehensive insight into the interaction processes and revealed significant differences between the investigated elements. Special attention was paid to the reduction of uranium(VI) by D. hippei DSM 8344T. For this element, an immobilization in a coupled association-reduction mechanism was demonstrated. In contrast, only a small fraction of the dissolved europium(III) interacted with the cells of the anaerobic microorganism, and a partial bioprecipitation of europium phosphate was observed. The interaction of the microorganism with uranium(VI) was first investigated in a bicarbonate-buffered system, where no decrease in uranium concentrations was observed, and thus probably no reduction of uranium(VI) occurs. In addition, ex-periments in synthetic Opalinus Clay pore solution were carried out. The investiga-tions with two different initial uranium(VI) concentrations (100 µM and 500 µM) showed an almost complete removal of uranium from the supernatants in both cas-es. Thermodynamic calculations of the complexes formed were performed in both, bi-carbonate buffer and synthetic Opalinus Clay pore water solution, to obtain more detailed information on uranium(VI) speciation in the supernatants. In addition, the supernatants of the pore water solution were analyzed by luminescence spectrosco-py. Thermodynamic modeling showed the dominance of the 1:3 uranyl(VI)-carbonate complex at the pH of the bicarbonate buffered system (pH 6.8), whereas in the pore water (pH 5.5) a uranyl(VI) lactate complex was the predominant spe-cies. The presence of an additional carbonate complex plays only a minor role in this case. The calculations were confirmed by luminescence spectroscopy. Both the dom-inant lactate complex and a small fraction of a uranyl(VI) carbonate complex could be detected in the Opalinus Clay pore water. The species distribution showed that only the proportion of the lactate complex decreased with increasing incubation times, while the proportion of the carbonate complex remained constant. This con-firmed the results of the experiments in bicarbonate buffer and led to the conclu-sion that the carbonate complex could not be reduced by the cells and therefore the bioreduction was dependent on the initial speciation of uranium(VI). Fluorescence microscopic images showed an influence of uranium on cell viability and biofilm formation. Transmission electron microscopy showed the association of uranium primarily on the cell surface. In addition, the cells formed membrane vesi-cles as a possible defense mechanism to prevent cell incrustation. These observa-tions indicated an immobilization of uranium by its interaction with the cells. The reduction of uranium(VI) was confirmed by various spectroscopic methods. UV/Vis studies of the dissolved cell pellets showed an increasing amount of urani-um(IV) with increasing incubation time. However, a complete reduction of uranium could not be detected. HERFD-XANES measurements verified the reduction of ura-nium(VI) in the cell pellets. In addition, the presence of uranium(V) was observed during the reduction process, confirming a one-electron process as the reduction mechanism for this microorganism. Furthermore, this was the first detection of ura-nium(V) during a bioreduction experiment of uranium(VI) by a sulfate-reducing microorganism in general. However, additional EXAFS studies could not conclusively elucidate the structure of the formed uranium(IV) compound. Using proteomics as a system biology method, evidence was found for various pro-cesses occurring during uranium incubation, such as biofilm formation, cell wall re-modeling, and up-regulation of various proteins responsible for the reduction of uranium and other metals in other microorganisms. In addition, several enzymes involved in a stress response of the cells were detected. In experiments with europium(III), which is often used as a non-radioactive analog of the trivalent actinides, the cells showed little interaction with the lanthanide. Compared to the studies with uranium(VI), the toxic influence of the heavy metal was less pronounced. Transmission electron microscopic images showed a bioprecip-itation of europium(III) with phosphates on the cell surface, resulting in partial im-mobilization of the metal. The aqueous speciation of europium(III) showed a complete complexation with lac-tate in the supernatants. This could be a possible explanation for the low interaction with the cells due to a shielding of the lanthanide from cellular ligands. In the cell spectra, three different species could be distinguished, one loosely associated with the cells and two cellularly bound complexes, probably with carboxyl or phosphate groups. A spatially resolved speciation could be detected by coupling confocal mi-croscopy and laser spectroscopy. To summarize, this work provides new insights into the interaction of sulfate-reducing microorganisms with uranium(VI) and europium(III) and contributes to a better understanding of microbial reduction processes in the environment. The im-mobilization of uranium by a partial reduction to less soluble uranium(IV) com-pounds, as well as the enhanced biofilm formation, have a positive effect on the safety of a repository for highly radioactive waste in clay rock. However, it has also been shown that the interaction processes that take place depend on the initial spe-ciation of the metal, which may limit the retention of radionuclides. Thus, the ob-tained results not only play an important role for a comprehensive safety concept of a repository for nuclear waste in clay rock, but also provide new impulses for differ-ent bioremediation strategies of radioactively contaminated environments.

Die Verfügbarkeit von Metallen in der Geo- und Biosphäre wird durch deren chemische Form, die Speziation, bestimmt. Zur Analyse der Speziation gibt es eine Vielzahl von Techniken. Für spektroskopische Methoden sind untersuchbare Konzentrationsbereiche unter anderem durch entsprechende Detektionsgrenzen eingeschränkt. Vor allem für niedrige Konzentrationen (< 10 µM), wie sie für viele natürliche Systeme von Bedeutung sind, ist die Lumineszenzspektroskopie ein geeignetes Werkzeug. Die Zerlegung spektroskopischer Daten von komplexen Systemen stellt eine zusätzliche Herausforderung dar. Zur Extraktion spektraler Informationen individueller chemischer Spezies werden moderne mathematische Verfahren verwendet. Die so erhaltene spektroskopische Charakterisierung kann zur strukturellen und thermodynamischen Interpretation genutzt werden. In dieser Arbeit wurde die parallele Faktoranalyse (PARAFAC) zur Auswertung spektroskopischer Datensätze genutzt. Diese Technik wurde hier erstmals auf Uranyl(VI)-Systeme angewendet, wodurch eine umfassende lumineszenzspektroskopische Charakterisierung der Uranyl(VI)-Hydrolyse generiert wurde. Zusätzlich wurde der bestehende PARAFAC-Algorithmus (N-way Toolbox) erweitert. Damit wird die Zerlegung auf chemisch interpretierbare Ergebnisse beschränkt und eine direkte Extraktion thermodynamischer Daten ermöglicht. Für die mononuklearen Hydrolysespezies konnten korrigierte Komplexstabilitätskonstanten vorgeschlagen werden, wodurch entsprechende Speziationsrechnungen belastbarer werden. Die extrahierten spektralen Eigenschaften einzelner Spezies wurden anschließend sorgfältig analysiert. Dazu wurden quantenmechanische sowie semiempirische Ansätze genutzt. Neben einerValidierung der angenommenen Speziesbezeichnung wurde dadurch erstmals eine fundierte lumineszenzspektroskopische Signal-Struktur-Beziehung für die Uranyl(VI)-Hydrolyse generiert. Die entwickelten Algorithmen wurden im Rahmen der Arbeit auf komplexere Systeme des Uranyl(VI) und Europium(III) übertragen und deren Gültigkeit nachgewiesen. So konnten neue Erkenntnisse zur Lumineszenzlöschung des Uranyl(VI)-Ions und der Europium(III)-Hydrolyse gewonnen werden. Zudem wurde eine Strategie zur einfachen und akkuraten Bestimmung der Anzahl von Bindungsstellen am Beispiel des Proteins Calmodulin vorgestellt. Der aufgezeigte breite Anwendungsbereich wird zusätzlich durch die erfolgreiche Übertragung der SpecConst-Erweiterung auf andere spektroskopische Techniken (am Beispiel der UV-vis Spektroskopie) erweitert. Die vorgestellten Werkzeuge verbessern die Auswertung spektroskopischer Daten und erweitern das damit verbundene Verständnis komplexer umweltrelevanter Systeme.

The main purpose of the present study were to produce and characterize calcium phosphates, specially hydroxyapatite (Ca10(PO4)6(OH)2) and B-tricalcium phosphate (Ca3(PO4)2), with hierarchical pore arrangement obtained through a new synthesis process using just biocompatible precursors. IUPAC- International Union of Pure and Applied Chemistry classifies the pores in terms of the cavities diameters in mesopores (2 nm <o <50 nm) and macropores (o> 50 nm). The main objectives were twofold. The first was the template development using a surfactant, cetyltrimethyl ammonium bromide (C16TAB), and gelatinized corn starch to obtain a hierarchical arrangement of pores form meso to macropores. The second aspect was the production of hydroxyapatite doped with Eu3+ for drug delivery systems equipped with luminescent probes. For this purpose, pure samples and calcium phosphatedoped samples with 6 mol% of Eu3+ were produced with C16TAB and / or corn starch. The following experimental characterization techniques were employed: X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), scanning electron microscopy (SEM), Small angle Xray scattering (SAXS) and the Ultralow angles X-ray scattering (USAXS), photoluminescence and cytotoxicity test. XRD revealed that the solutions drip order and the type of organic template promotes variations in the crystallites dimensions and induces the appearance of B- Ca2(P2O7), a-Ca2(P2O7) and carbonated calcium phosphate phases with of the main B-TCP phase. XAFS technique showed that the Eu3+ incorporation occurred preferentially in the Ca(1) sites of HAP. The luminescence results also revealed that the symmetry of the Eu3+ ion is affected by solutions drip order and the presence of C16TAB solution in the reactive medium. The hierarchical arrangement of pores was evaluated by SAXS / USAXS and SEM analysis. The results indicated that only C16TAB was not able to induce proses, whereas the samples produced with combination of corn starch and C16TAB presented meso and macropores structures. In vitro cytotoxicity tests revealed excellent biocompatibility of our calcium phosphate porous systems. / O presente estudo tem como foco a caracterização dos fosfatos de cálcio, em especial a hidroxiapatita (Ca10(PO4)6(OH)2) e B-tricálcio fosfato (Ca3(PO4)2), com hierarquia de poros obtidos através de um novo processo de síntese usando precursores biocompatíveis. Em estruturas inorgânicas, a IUPAC- International Union of Pure and Applied Chemistry classifica os poros em termos dos diâmetros em mesoporos (2 nm < o < 50 nm) e macroporos (o >50 nm). Os objetivos propostos na tese envolvem dois aspectos, o primeiro relacionado com o desenvolvimento de um molde orgânico constituído por dois compostos: surfactante Brometo de Cetiltrimetilamônio (C16TAB) e amido de milho gelatinizado para formação de estruturas com hierarquia de porosidade de meso e macroporos. O segundo aspecto é em relação a produção de hidroxiapatita dopada com Eu3+ para uso em sistemas porosos de liberação de fármacos dotados de sonda luminescente. Para tanto, foram preparadas amostras de hidroxiapatitas e B-tricálcio fosfato dopadas com 6 mol% de Eu3+ sintetizadas na presença do C16TAB e/ou amido de milho. Foram empregadas as seguintes técnicas de caracterização: a difração de raios X (XRD), estrutura fina de absorção de raios X (XAFS), microscopia eletrônica de varredura (SEM), espalhamento de raios X a baixos ângulos (SAXS) e a ultra baixos ângulos (USAXS), espectroscopia de fotoluminescência e testes de citotoxicidade. Dos resultados de XRD foi constatado que a ordem de gotejamento das soluções de partida e o tipo de molde orgânico empregado promove variações nas dimensões dos cristalitos dos fosfatos de cálcio e surgimento de fases B-Ca2(P2O7), a-Ca2(P2O7) e fosfatos de cálcio carbonatados junto com a fase cristalina do B-TCP. Na investigação por XAFS foi avaliado a simetria local de incorporação do Eu3+ na estrutura da hidroxiapatita. Os resultados revelam que a incorporação de Eu3+ se dá em maior escala em sítios de Ca(1) do que no de Ca(2). Os resultados de fotoluminescência também revelaram que a simetria do íon Eu3+ é afetada pela ordem de gotejamento das soluções de partida e pela presença do C16TAB no meio reativo. Em relação a formação de arranjos com hierarquia de porosidade os resultados de SAXS/USAXS e SEM indicaram que o molde constituído por C16TAB não formaram poros, enquanto que as amostras com molde da combinação entre amido de milho e C16TAB apresentaram estruturas de meso e macroporos. Testes de citotoxicidade in vitro revelaram que os sistemas de fosfatos de cálcio porosos desenvolvidos não são tóxicos.

Die Verfügbarkeit von Metallen in der Geo- und Biosphäre wird durch deren chemische Form, die Speziation, bestimmt. Zur Analyse der Speziation gibt es eine Vielzahl von Techniken. Für spektroskopische Methoden sind untersuchbare Konzentrationsbereiche unter anderem durch entsprechende Detektionsgrenzen eingeschränkt. Vor allem für niedrige Konzentrationen (< 10 µM), wie sie für viele natürliche Systeme von Bedeutung sind, ist die Lumineszenzspektroskopie ein geeignetes Werkzeug. Die Zerlegung spektroskopischer Daten von komplexen Systemen stellt eine zusätzliche Herausforderung dar. Zur Extraktion spektraler Informationen individueller chemischer Spezies werden moderne mathematische Verfahren verwendet. Die so erhaltene spektroskopische Charakterisierung kann zur strukturellen und thermodynamischen Interpretation genutzt werden. In dieser Arbeit wurde die parallele Faktoranalyse (PARAFAC) zur Auswertung spektroskopischer Datensätze genutzt. Diese Technik wurde hier erstmals auf Uranyl(VI)-Systeme angewendet, wodurch eine umfassende lumineszenzspektroskopische Charakterisierung der Uranyl(VI)-Hydrolyse generiert wurde. Zusätzlich wurde der bestehende PARAFAC-Algorithmus (N-way Toolbox) erweitert. Damit wird die Zerlegung auf chemisch interpretierbare Ergebnisse beschränkt und eine direkte Extraktion thermodynamischer Daten ermöglicht. Für die mononuklearen Hydrolysespezies konnten korrigierte Komplexstabilitätskonstanten vorgeschlagen werden, wodurch entsprechende Speziationsrechnungen belastbarer werden. Die extrahierten spektralen Eigenschaften einzelner Spezies wurden anschließend sorgfältig analysiert. Dazu wurden quantenmechanische sowie semiempirische Ansätze genutzt. Neben einerValidierung der angenommenen Speziesbezeichnung wurde dadurch erstmals eine fundierte lumineszenzspektroskopische Signal-Struktur-Beziehung für die Uranyl(VI)-Hydrolyse generiert. Die entwickelten Algorithmen wurden im Rahmen der Arbeit auf komplexere Systeme des Uranyl(VI) und Europium(III) übertragen und deren Gültigkeit nachgewiesen. So konnten neue Erkenntnisse zur Lumineszenzlöschung des Uranyl(VI)-Ions und der Europium(III)-Hydrolyse gewonnen werden. Zudem wurde eine Strategie zur einfachen und akkuraten Bestimmung der Anzahl von Bindungsstellen am Beispiel des Proteins Calmodulin vorgestellt. Der aufgezeigte breite Anwendungsbereich wird zusätzlich durch die erfolgreiche Übertragung der SpecConst-Erweiterung auf andere spektroskopische Techniken (am Beispiel der UV-vis Spektroskopie) erweitert. Die vorgestellten Werkzeuge verbessern die Auswertung spektroskopischer Daten und erweitern das damit verbundene Verständnis komplexer umweltrelevanter Systeme.:Danksagung I Abkürzungen IV 1 Motivation 1 2 Einleitung und Hintergrund 4 2.1 Speziation 4 2.1.1 Hydrolyse 6 2.2 Uran 7 2.2.1 Uranyl(VI) 13 2.3 Optische Spektroskopie 14 2.3.1 Absorptionsspektroskopie 15 2.3.2 Lumineszenz 16 2.3.3 Uranyl(VI)-Lumineszenz 18 3 Material und Methoden 24 3.1 Chemikalien 24 3.2 Komplexbezeichnung 25 3.3 Probenvorbereitung 26 3.4 Absorptionsspektroskopie 27 3.5 Lumineszenzspektroskopie 27 3.5.1 Continuous Wave Spektroskopie 27 3.5.2 Zeitaufgelöste laserinduzierte Fluoreszenzspektroskopie 30 3.6 Datenauswertung - PARAFAC 34 3.7 Extrapolation auf Standardbedingungen 38 4 Ergebnisse und Diskussion 40 4.1 Methodenentwicklung 40 4.1.1 Exponentielle Einschränkung für PARAFAC - ’ExpConst’ 40 4.1.2 Speziationseinschränkung für PARAFAC - ’SpecConst’ 42 4.1.3 Spektrenzerlegung 45 4.2 Validierung der Methoden am Beispiel der Uranyl(VI)-Hydrolyse 51 4.2.1 Hydrolyse von 10−5 M Uranyl(VI) 51 4.2.2 Hydrolyse von 10−8 M Uranyl(VI) 62 4.2.3 Absorptionsspektroskopie der Uranyl(VI)-Hydrolyse 72 4.3 Übertragung der Methoden auf komplexere Uranyl(VI)-Systeme 75 4.3.1 Das Uranyl(VI)-Carbonat-System 75 4.3.2 Das Uranyl(VI)-Halogenid-System 79 4.4 Übertragung der Methoden auf Europium(III)-Systeme 86 4.4.1 Die Europium(III)-Hydrolyse 86 4.4.2 Interaktion von Europium(III) mit Calmodulin 94 5 Zusammenfassung 103 Literaturverzeichnis 106 Abbildungsverzeichnis 131 Tabellenverzeichnis 134 Publikationen im Rahmen dieser Arbeit i Konferenzbeiträge iii Eidesstattliche Erklärung iv Versicherung v

Submitted by HIGOR HENRIQUE DE SOUZA OLIVEIRA null (higor6@itelefonica.com.br) on 2016-03-14T01:11:55Z No. of bitstreams: 1 Tese de Doutorado.pdf: 10715169 bytes, checksum: 67bc136f2489ae6944e6a9db6998967a (MD5) / Approved for entry into archive by Sandra Manzano de Almeida (smanzano@marilia.unesp.br) on 2016-03-15T17:52:52Z (GMT) No. of bitstreams: 1 oliveira_hhs_dr_araiq_par.pdf: 1487328 bytes, checksum: dc6bd8f68483e98dd23a89fc9938b22d (MD5) / Made available in DSpace on 2016-03-15T17:52:52Z (GMT). No. of bitstreams: 1 oliveira_hhs_dr_araiq_par.pdf: 1487328 bytes, checksum: dc6bd8f68483e98dd23a89fc9938b22d (MD5) Previous issue date: 2016-02-24 / Luminescência é a emissão de luz decorrente da excitação de átomos, íons, moléculas ou materiais. Quando a excitação é realizada por radiações ionizantes, o material luminescente é denominado cintilador e possui aplicações tecnológicas relacionadas à detecção dessas radiações de alta energia. A conformação desses materiais tem impacto direto em seu custo e aplicabilidade e atualmente, há uma busca por novas conformações de materiais luminescentes para aplicação em diversos dispositivos. Sistemas bidimensionais, como filmes finos nanoestruturados, possuem potencial aplicação em nanotecnologia e os processos de auto-organização desses sistemas têm sido crescentemente estudados e empregados. Neste trabalho, as propriedades luminescentes do polioxometalato [Eu(W5O18)2]9- foram estudadas em função de sua conformação em sólido estendido, filmes de Langmuir e de Langmuir-Blodgett, com ênfase em medidas de luminescência com excitação por radiação ultravioleta ou raios X. O sólido Na9[Eu(W5O18)2].14H2O foi preparado pela mistura de soluções de tungstato de sódio e nitrato de európio em pH e temperatura adequados. Medidas de espectroscopia de fotoluminescência do sólido evidenciam a presença de íons Eu3+ ao menos em dois sítios não-centrossimétricos, sendo um deles de menor simetria com relação ao outro. Com o aumento da temperatura, as distorções provocadas pelas vibrações térmicas e pela saída das moléculas de água de hidratação diminuem a simetria local ao redor dos íons Eu3+ em ambos os sítios. As mudanças nas propriedades luminescentes decorrentes do aumento da temperatura são irreversíveis a partir de 100oC, temperatura na qual inicia-se a desidratação do sólido. A excitação via transferência de carga dos ligantes para os metais favorece a emissão proveniente dos íons Eu3+ nos sítios menos distorcidos enquanto a excitação direta nos níveis intraconfiguracionais dos íons Eu3+ favorece a emissão proveniente dos íons Eu3+ nos sítios mais distorcidos. O mecanismo de cintilação nesse sólido tem contribuição significativa do processo de transferência de energia de estados relacionados à transferência de carga para os níveis excitados dos íons Eu3+ e a eficiência desse processo diminui com a incidência de raios X, provavelmente devido à criação de defeitos eletrônicos nos grupos (W5O18)6-, levando à diminuição da eficiência do processo de absorção e transferência de energia para os íons Eu3+ e consequentemente, à diminuição da intensidade de emissão em função do tempo de exposição à radiação X. Os filmes de Langmuir do sistema misto surfactante/polioxometalato assumem empacotamento compacto, estável e parcialmente reversível na interface subfase-ar. O sistema projetado e montado pelo grupo de pesquisa do Laboratório de Materiais Luminescentes para a realização de medidas de espectroscopia de fotoluminescência com excitação ultravioleta in situ na cuba de Langmuir-Blodgett permite correlacionar as propriedades luminescentes de filmes de Langmuir com os diferentes níveis de organização da monocamada, sendo uma poderosa ferramenta na caracterização desses filmes. Os filmes de Langmuir-Blodgett do sistema misto surfactante/polioxometalato foram preparados com elevada taxa de transferência e apresentam intensidade de emissão linearmente dependente do número de camadas depositadas. Nestes filmes, os íons Eu3+ ocupam ao menos dois sítios não-centrossimétricos com tempos de vida distintos e a variação da temperatura provoca alterações quase completamente reversíveis em suas propriedades luminescentes. / Luminescence is the emission of light resulting from the excitation of atoms, ions, molecules or materials. When ionizing radiation is used in the excitation, the luminescent material is called scintillator and has technological applications related to the detection of these high energy radiations. The conformation of these materials has direct impact on theirs cost and applicability and currently, there is a search for new conformations of luminescent materials for application in several devices. Two-dimensional systems, as nanostructured thin films, have potential applications in nanotechnology and the self-assembly processes of these systems have been increasingly studied and employed. In this work, the luminescent properties of the polyoxometalate [Eu(W5O18)2]9- were studied as a function of its conformation in solid bulk, Langmuir and Langmuir-Blodgett films, with emphasis on X-ray- and UV-excited luminescence measurements. Solid Na9[Eu(W5O18)2].14H2O was prepared by mixing sodium tungstate and europium nitrate solutions in suitable temperature and pH. Photoluminescence measurements of the solid sample evidence the presence of Eu3+ ions at least two non-centrosymmetric sites. With increasing temperature, the distortions caused by thermal vibration and dehydration process decrease the local symmetry around the Eu3+ at both sites. Changes in the luminescent properties are irreversible after temperatures above 100°C, temperature at which it begins the solid dehydration. Ligand to metal charge transfer excitation promotes the emission from the Eu3+ ions at less distorted site while the direct excitation in intraconfigurational levels of Eu3+ ions promote the emission from the Eu3+ ions at more distorted site. The scintillation mechanism of this solid has significant contribution of the energy transfer process from charge transfer states to the excited levels of Eu3+ ions and the efficiency of this process decreases by the incidence of X-rays, probably due to the creation of electronic defects at groups (W5O18)6-, decreasing the efficiency of the absorption and energy transfer processes and consequently, decreasing the emission intensity with the exposure to X-rays. Langmuir films of the surfactant/polyoxometalate system assume compact, stable and partially reversible packaging at the subphase-air interface. The system to performing in situ photoluminescence spectroscopy at Langmuir-Blodgett trough, designed by research group of the Luminescent Materials Laboratory, allows the correlation between the luminescent properties of Langmuir films and the monolayer organization level, being a powerful tool in the characterization of these films. Langmuir-Blodgett films of the surfactant/polyoxometalate system were prepared with high transfer rate and the films present emission intensity linearly dependent on the number of deposited layers. In these films, Eu3+ ions occupy at least two non-centrosymmetric sites with different lifetimes and the temperature variation causes almost completely reversible changes in their luminescent properties.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Hybrid coordination networks such as metal-organic networks, also known as MOF (Metal Organic Framework), have attracted great attention from the scientific community due to their wide diversity and wide range of applications, however, the investigation of applications of these structures still forms a large area of research, with great exploration potential, either through experimental or theoretical chemistry. The present work aims at the use of computational chemistry methods with focus on semiempirical methods for the study of MOFs, so we will initially address results regarding the evaluation of the prediction capacity of solid phase structures of MOFs containing lanthanide as a metallic center. Performed using the semi-empirical methods Sparkle/AM1, Sparkle/PM3, Sparkle/PM6, Sparkle/PM7, Sparkle/RM1 and RM1. The results obtained from the calculation of optimization of the structures suggest that the Sparkle/PM3 and Sparkle/RM1 methods provide more accurate results, with less variability and great agreement with the experimental data, both structural and luminescent. The health application study initially evaluated the structure of the drug doxorubicin and MOF ZnDBC ([Zn(BDC)(H2O)2]n), and then evaluated the drug’s anchoring potential, in order to obtain results that justify the MOF to be chosen as a candidate for application as a drug carrier. This analysis resulted in obtaining a viable anchorage between the MOF lamellae. A simulation of the effects of temperature variation on the structure of the MOF EuBTC ([Eu2(MELL)(H2O)6]) and its effect on the luminescent properties was performed to obtain data that could validate your application with gunshot residues marker, aiming at its use in public safety. This analysis explored the potential of structural description of Sparkle/PM3 as well as the obtaining of luminescent properties, which led to the conclusion that the increase in temperature resulted in an increase in the emission quantum yield caused by the loss of water molecules contained in the first sphere of the coordinating polyhedron. For the application of MOFs in energy, an investigation was carried out regarding the degree of adsorption of the hydrogen gas and methane in the IRMOF-8 and in this one after the doping of its aromatic rings with aluminum atoms, in order to elucidate the effect that the realization of this Doping brings the storage capacity of these gases, for use in gas storage cylinders used in motor vehicles. And it was verified a slight reduction in the storage capacity of the methane gas, since for the hydrogen gas no significant changes were verified. Finally, a study was carried out to evaluate the capture capacity of carbon dioxide and hydrogen sulfide gases in IRMOF-8 and in this doped with aluminum, so the same structure of the previous study was used. It was found that doping gave a considerable increase in the degree of adsorption, being more effective for the carbon dioxide, whose interactions had energy of magnitude of a chemical adsorption. / As redes metalorgânicas também conhecidas como MOF (do inglês Metal Organic Framework) têm atraído grande atenção da comunidade científica devido a sua ampla diversidade e vasta gama de aplicações. Entretanto, a investigação de aplicações destas estruturas ainda configura uma grande área de pesquisa, com potencial de exploração, seja por meio de um viés experimental ou teórico. O presente trabalho tem como objetivo o uso de métodos de química computacional com foco em métodos semiempíricos para o estudo das MOFs. Assim, inicialmente abordaremos resultados referentes à avaliação da capacidade de predição das estruturas em fase sólida de MOFs contendo íons lantanídeos como centro metálico. Este estudo foi realizado através do uso dos métodos semiempíricos Sparkle/AM1, Sparkle/PM3, Sparkle/PM6, Sparkle/PM7, Sparkle/RM1 e o RM1. Os resultados obtidos a partir do cálculo de otimização das estruturas sugerem que o método Sparkle/PM3 e o Sparkle/RM1 proporcionam resultados mais exatos, com menor variabilidade e grande concordância com os dados experimentais, tanto estruturais como luminescentes. Foi avaliado o potencial de ancoragem da doxorrubicina na MOF ZnDBC ([Zn(BDC)(H2O)2]n). Esta análise mostrou viabilidade de ancoragem entre as lamelas da MOF. Além disso, foi realizada uma simulação dos efeitos da variação da temperatura sobre as propriedades luminescentes da MOF EuBTC ([Eu2(MELL)(H2O)6). Com isso, buscou-se validar a aplicação desta MOF como marcador de resíduos de disparo de arma de fogo. Esta análise explorou o potencial de descrição estrutural do Sparkle/PM3, bem como obtenção de propriedades luminescentes. A elevação da temperatura resultou no aumento do rendimento quântico de emissão, causado pela perda de moléculas de água contidas na primeira esfera do poliedro de coordenação. Para aplicação de MOFs na área de energia, foi realizada uma investigação referente ao grau de adsorção de gás hidrogênio e metano na IRMOF-8. Foi realizada a inclusão de átomos de alumínio nos anéis aromáticos, visando elucidar qual o efeito provocado sobre a capacidade de armazenamento desses gases. A dopagem levou a uma leve redução na capacidade de armazenamento do gás metano. Já para o gás hidrogênio não foram verificadas alterações significativas. Por fim, foi feito um estudo de avaliação da capacidade de captura dos gases dióxido de carbono e sulfeto de hidrogênio na IRMOF-8, tanto pura quanto dopada com alumínio. Notou-se que a dopagem proporcionou um considerável aumento no grau de adsorção, sendo mais efetivo para o dióxido de carbono, cujas interações tiveram energia de magnitude de uma adsorção química. / São Cristóvão, SE