In dieser Arbeit werden das Potential der mechanochemischen Synthesemethode zur Herstellung von metallorganischen Gerüstverbindungen (MOFs) vorgestellt und mögliche Anwendungsgebiete aufgezeigt. Im Forschungsfokus bezüglich schnellerer und effizienterer Darstellungsmethoden ist die Mechanochemie eine aussichtsreiche Alternative. Die Feststoff-Reaktion ist ohne die Verwendung von Lösungsmitteln durchführbar, zeichnet sich durch verkürzte Reaktionszeiten und quantitativen Eduktumsatz aus und gilt somit als Green Chemistry-Methode, die stetig wachsende Bedeutung erlangt. Die Ergebnisse dieser Arbeit belegen, dass über die mechanochemische Synthese metallorganische Verbindungen in allen Dimensionalitäten herstellbar sind. Die Reaktionsparameter sind auf die Herstellung isostruktureller und strukturanaloger Verbindungen übertragbar. Es wurden Synthesebedingungen identifiziert, die die Produktbildung beeinflussen, so dass ihre Kontrolle zur gezielten Herstellung verschiedener Verbindungen diente. Des Weiteren wurden Reaktionsparameter ermittelt, die einen Einfluss auf die Eigenschaften des Produkts ausüben. Im Hinblick auf eine größtmögliche spezifische Oberfläche wurde die Synthese optimiert und eine postsynthetische Aktivierungsprozedur entwickelt, die gemeinsam in einer verbesserten Gasadsorptionskapazität resultieren und auf andere Verbindungen übertragbar sind. Die Ergebnisse zur Gasspeicherung zeigen ein erstes Anwendungspotential für mechanochemisch synthetisierte MOFs auf, die als feine Pulver mit vergrößerter Oberfläche erhalten werden. Weiterhin wurde die Einlagerung von Solvensmolekülen in die Poren eines MOFs untersucht. Dabei zeigte sich, dass das MOF seine Gitterparameter an die jeweiligen Gastmoleküle anpasst. Das Potential zur Interkalation von Feststoffen wird anhand der Einlagerung pharmazeutischer Wirkstoffmoleküle belegt. Katalytische Untersuchungen zeigen eine gute Aktivität des mechanochemisch synthetisierten Rohprodukts. / In this work the potential of mechanochemical synthesis to produce metal-organic frameworks (MOFs) is presented and possible applications for the materials are shown. In the focus of research regarding faster and more efficient methods of synthesis, mechanochemistry is an promising alternative. This solid-state reaction can be carried out without the use of solvent, exhibits shortened reaction times and a quantitative turnover of reactands. Therefore it is a method of green chemistry, and its importance is constantly increasing. The results show that mechanochemical synthesis is capable of producing metal-organic compounds in all dimensionalities. The reaction conditions can be transferred to synthesize isostructural and structural analogous compounds. Parameters influencing the formation of products were identified, and their control led to a well-aimed design of various compounds. In addition, conditions influencing the properties of the product were determined. In terms of a specific surface area as large as possible, the synthesis was optimized and a postsynthetic activation was developed, together resulting in an improved capacity for gas adsorption and transferrable to other compounds. The results concerning gas storage present one possible application of mechanochemically synthesized MOFs, that are produced as fine powders with enlarged surfaces. Furthermore, intercalation of solvent molecules in the pores of a MOF was investigated. It shows that the MOF adjustes its lattice paramters to the guest molecules. The potential to intercalate solid-state compounds is demonstrated using pharmaceutical drug molecules. Catalytic investigations show a good activity of the mechanochemically synthesized raw product.

Zr and Hf based MOFs with enhanced pore accessibility for large molecules and good hydrothermal stability were obtained using a bent dithienothiophene dicarboxylate and Zr4+ or Hf4+ source. A modulator (benzoic acid) facilitates formation of an eight-connecting cluster leading to a new framework which adopts reo topology. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Die Entwicklung und Synthese im Bereich neuartiger poröser Systeme, im speziellen Metallorganische Gerüstverbindungen (engl.: Metall-organic Frameworks; MOFs), wird weltweit in vielen Forschergruppen intensiv bearbeitet. Aufgrund der Möglichkeit, dass sich die Materialeigenschaften individuell designen lassen und letztendlich spezifische Eigenschaften für eine ausgewählte Anwendung bereitgestellt werden können, stellen MOFs für einen weiten Forscherkreis eine interessante Materialienklasse dar. Im Rahmen dieser Arbeit stand die Synthese von neuartigen MOFs im Vordergrund, welche geeignete Eigenschaften für eine effiziente Speicherung von Gasen im Nieder- als auch im Hochdruckbereich besitzen. Dabei wurde zum einen Augenmerk auf die Synthese mesoporöser MOF-Systeme gelegt. Hier lag die größte Herausforderung darin, die erhaltenen hochporösen Materialien in einer stabilen gastfreien Form zu erhalten. Ein weiterer Schwerpunkt war die Untersuchung von flexiblen MOF-Verbindungen und deren Eigenschaften in Abhängigkeit der Synthesebedingungen und der adsorbierten Spezies. Auf Basis der Copolymerisation verschiedener multifunktioneller Linkermoleküle konnten zwei mesoporöse Verbindungen und dazugehörige Isomorphe synthetisiert werden (DUT-6, DUT-23; DUT = Dresden University of Technology). Mit diesen Verbindungen konnte über die Kombination von unterschiedlich funktionellen Linkermolekülen eine erhöhte Netzwerkstabilität und damit einhergehend erhöhte Porosität erhalten werden. Sämtliche Verbindungen zeigen ausgezeichnetes adsorp-tives Verhalten und können aufgrund ihrer verschiedenen Eigenschaften in Bereichen der Hochdruckadsorption, Katalyse oder enantioselektiven Trennung Einsatz finden. Im zweiten Teil der Arbeit wurde das flexible Verhalten der „pillar-layer“ Verbindungen DUT-8(M) (M = Ni, Co, Zn, Cu) näher untersucht. Diese isomorphe Reihe zeichnet sich durch ihre hohe Netzwerkflexibilität in Abhängigkeit der integrierten Gastmoleküle sowie dem vorliegendem Metall-Dimer aus. DUT-8(M) zeigt unterschiedliche Adsorptionseigenschaften und unterschiedliches Stabilitäts- sowie Flexibilitätsverhalten.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2017-03-24T17:20:10Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese MAML BIBLIOTECA.pdf: 9163873 bytes, checksum: a3dedf9afddd54463bad724f48c71013 (MD5) / Made available in DSpace on 2017-03-24T17:20:10Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese MAML BIBLIOTECA.pdf: 9163873 bytes, checksum: a3dedf9afddd54463bad724f48c71013 (MD5) Previous issue date: 2016-07-26 / CAPES / Resíduos de tiro (GSR) são evidências físicas de grande valor forense em casos envolvendo o uso de armas de fogo. Mas apesar de sua importância, existe uma carência metodológica para a caracterização do GSR proveniente de munição ambiental (NTA). Adicionalmente, o tamanho micrométrico das partículas geradas torna sua detecção em uma cena de crime ou em um suspeito uma tarefa difícil, podendo originar falsos-negativos. Neste sentido, tem sido proposto o uso de materiais luminescentes para a marcação química e óptica de munições. O presente trabalho aborda o desenvolvimento de marcadores luminescentes baseados na rede metal-orgânica (MOF) [Ln(BTC)] (em que BTC = ácido trimésico), desde a sua síntese, aplicação e avaliação da toxicidade, assim como seu uso na codificação de munição e sua caracterização junto aos resíduos orgânicos de disparo (OGSR). Por isto, este trabalho é dividido em cinco capítulos. No primeiro são discutidos aspectos relativos à síntese da MOF [Eu(BTC)] e à sua influência nas propriedades estruturais, térmicas e espectroscópicas dessa rede. Para tal, os métodos de síntese hidrotermal convencional e hidrotermal assistido por micro-ondas (MW), com diferentes tempos de síntese e proporções metal:ligante, são analisados. Com os métodos adotados, a MOF [Eu(BTC)] foi obtida com elevada cristalinidade, estabilidade térmica e luminescência. Adicionalmente, sínteses mais curtas e proporção metal:ligante 1:1 produziram redes com maior pureza de fase. Neste caso, o método assistido por micro-ondas se destacou devido ao rápido tempo de síntese. No segundo capítulo é apresentada a eficiência dessa MOF como marcador luminescente de munições. Com esta rede, além da detecção visual dos resíduos luminescentes (LGSR), técnicas como espectroscopia de emissão e microscopia eletrônica de varredura acoplada a espectroscopia por dispersão de energia (MEV/EDS) foram usadas para caracterizar e confirmar a presença do LGSR nos resíduos coletados, tanto da arma como das mãos do atirador. No terceiro capítulo são apresentados os dados relativos à avaliação da toxicidade oral aguda e subaguda da MOF [Eu(BTC)] em ratos. Para avaliação da toxicidade aguda, o protocolo 423 da OECD (Organisation for Economic Co-operation and Development) foi utilizado. Como resultado, nenhum sinal de toxicidade foi observado até mesmo para a dosagem mais elevada, e a dose letal média (DL50) foi estimada em 5000 mg/kg. Com isto, a MOF [Eu(BTC)] foi classificada na categoria menos tóxica do GHS (Globally Harmonized System). A toxicidade subaguda foi avaliada através da administração por 7 dias consecutivos de 300 mg/kg e, apesar de observados sinais graves de toxicidade, estes foram atribuídos à aspiração do material particulado para o pulmão, e não a toxicidade do marcador. Estes resultados atribuem a MOF [Eu(BTC)] uma elevada margem de segurança para aplicação como marcador de GSR. No quarto capítulo é proposto um método de codificação de munição baseado no uso de marcadores co-dopados [Y1-xLnx(BTC)] com os íons Eu3+, Sm3+, Tb3+ e/ou Yb3+. Após a realização de disparos, o marcador utilizado em cada munição foi identificado por MEV/EDS em função da composição química dos resíduos em 100% dos casos (sem que o analista tivesse conhecimento do marcador presente em cada munição). Além disso, foi possível estabelecer correlações atirador-arma-local do disparo através da composição dos resíduos em 89% dos casos. E no último capítulo é abordada a caracterização simultânea dos resíduos orgânicos e luminescentes por meio da microscopia Raman. Com a metodologia proposta, através de uma única medida foi possível determinar o tipo de marcador e pólvora utilizados, fornecendo um código muito seguro para caracterização e classificação inequívoca dos resíduos como provenientes de disparo de arma de fogo. Além disso, o LGSR atuou como sonda luminescente ajudando a coletar o OGSR em distâncias acima daquelas normalmente abordadas na literatura. / Gunshot residue (GSR) are physical evidences of great forensic value in firearms-related crimes. Despite its importance, there is a methodologic need for the characterization of GSR from non-toxic ammunition (NTA). In addition, the micrometric size of the generated particles makes its detection in a crime scene or on a suspect a hard task, which may produce false-negatives. In this sense, the use of luminescent materials has been proposed for chemical and optical marking of ammunition. This work presents the development of luminescent markers based on the metal-organic framework (MOF) [Ln(BTC)], since its synthesis, application and toxicity evaluation, as well as its ability to encode ammunitions and its simultaneous characterization with the organic gunshot residue (OGSR). Hence, this work is divided in five chapters. In the first chapter, aspects related to the synthesis of the MOF [Eu(BTC)] and its influence on the structural, thermal and spectroscopic properties are discussed. To this end, conventional hydrothermal synthesis and microwave(MW)-assisted hydrothermal synthesis, with different reaction times and metal:ligand proportions are analyzed. With the chosen methods, the MOF [Eu(BTC)] was obtained with high crystallinity, thermal stability and luminescence. However, faster synthesis and 1:1 metal:ligand proportion produced frameworks with higher phase purity. In this case, the MW-assisted method stood out due to the faster reaction time. In the second chapter, the efficiency of the MOF [Eu(BTC)] as a luminescent marker for ammunition is presented. With this framework, besides visual detection of the luminescent residues (LGSR), techniques as emission spectroscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy (MEV/EDS) were used to characterize and confirm the presence of LGSR in the residues collected, both on the gun and in the shooter’s hand. In the third chapter, data related to the evaluation of acute and subacute oral toxicity of the MOF [Eu(BTC)] in rats is presented. For evaluation of acute oral toxicity, the OECD (Organisation for Economic Co-operation and Development) 423 guideline was used. As a result, no signs of toxicity was observed even at the highest dose, and the median lethal dose (LD50) estimated was 5000 mg/Kg. There by, the MOF [Eu(BTC)] was classified in the less toxic category of GHS (Globally Harmonized System). The subacute toxicity was evaluated by consecutive administration of 300 mg/Kg for 7 days and, despite severe toxicity signs were observed, they were attributed to the aspiration of the particulate material into the lungs, but not to the marker’s toxicity. These results give a high safety margin for application of this MOF as a GSR marker. In the fourth chapter an ammunition encoding method is proposed based on the use of the co-doped markers [Y1-xLnx(BTC)] with the ions Eu3+, Sm3+, Tb3+ and/or Yb3+. After shots, the markers used in each ammunition was identified by SEM/EDS due the chemical composition of the residues, in 100% of the cases (without the analyst’s knowledge of which marker was present in each ammunition). Furthermore, shooter-weapon-location correlations was established by the composition of the residues in 89% of the cases. And in the last chapter the simultaneously characterization of the organic and luminescent residues was performed by Raman microscopy. With the proposed methodology, the type of marker and gunpowder used were identified by a single run, providing a security code for its characterization and the unequivocal classification of the residues as coming from firearm discharge. Furthermore, the LGSR acted as a luminescent probe, helping to collect the OGSR further than those reported in the literature.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-09-21T18:06:41Z No. of bitstreams: 1 sergiorodriguestavaresfilho.pdf: 12924949 bytes, checksum: e801383f9a72858db012935c840d4d15 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-09-22T15:21:43Z (GMT) No. of bitstreams: 1 sergiorodriguestavaresfilho.pdf: 12924949 bytes, checksum: e801383f9a72858db012935c840d4d15 (MD5) / Made available in DSpace on 2017-09-22T15:21:43Z (GMT). No. of bitstreams: 1 sergiorodriguestavaresfilho.pdf: 12924949 bytes, checksum: e801383f9a72858db012935c840d4d15 (MD5) Previous issue date: 2017 / O elemento zinco apresenta inúmeras aplicações e vantagens, devido à sua baixa toxicidade e sua biocompatibilidade. Alguns compostos, como os hidroxissais (HSL) e os hidróxidos duplos lamelares (HDL), os carboxilatos lamelares e as MOF, demonstram ser excelentes materiais com diversos potenciais de aplicabilidades. Algumas dessas aplicações são os processos de intercalação, adsorção e catálise. Nesse trabalho, foram investigados os processos de catálise da produção de biodiesel pelo acetato de zinco (um carboxilato lamelar), os processos de intercalação de moléculas tensoativas e das porfirinas aniônicas de ferro(III) pelos hidroxissais e os hidróxidos duplos lamelares, as propriedades adsortivas do ZIF-9 e os processos de esfoliação de uma série de carboxilatos de zinco lamelares e das moléculas tensoativas intercaladas em HDL e HSL. A fim de conduzir todo o estudo e essas investigações, foram feitos cálculos de estrutura eletrônica baseados na Teoria do Funcional da Densidade (DFT) a partir do pacote Quantum Espresso. No caso dos processos de esfoliação dos carboxilatos de zinco e de intercalação/esfoliação das moléculas tensoativas, uma comparação de funcionais de troca e correlação (PBE e vdW-DF) e do método semiempírico DFT-D2 foi feita para a contabilização das forças de van der Waals desses sistemas. Esse mesmo estudo metodológico foi feito para as propriedades do ZIF-9. Para o estudo de intercalação dos porfirinatos de ferro(III), um estudo do efeito de polarização de spin e da correção de Hubbard foi empregado para as propriedades estruturais e eletrônicas. Foi possível prever algumas propriedades de relevância como as energias de esfoliação para a família estudada de carboxilatos de zinco, assim como para os surfactantes intercalados em HDL e em HSL. As energias de adsorção das moléculas envolvidas nas reações de esterificação/transesterificação e a barreira de energia da formação de alcóxido permitiram a compreensão desses processos a nível atomístico. Uma elucidação estrutural foi também alcançada para as intercalações das moléculas tensoativas desidratadas e hidratadas, e dos porfirinatos de ferro(III). As propriedades adsortivas do ZIF-9 também foram estudadas, a fim de predizer a seletividade das moléculas estudadas (CO2, H2S, metanol e etanol). / The zinc element presents various applications and advantages due to its low toxicity and its biocompatibility. Some compounds, such as the hydroxide salts (LSH) and the double hydroxide salts (LDH), the layered carboxylates and the MOFs, are excelent materials with many potentials. Some of these applications are the intercalation processes, adsorption and catalysis. In this work, the catalysis of the biodiesel production with zinc acetate (a layered carboxylate) as the catalyst, the intercalation of surfactants and anionic iron(III) porphyrins in LDH and LHS, the adsorption properties of ZIF-9 and the exfoliation of a series of layered zinc carboxylates and the surfactants intercalated in LDH and LHS were investigated. In order to conduct all this study and these investigations, electronic structure calculations based on DFT by the Quantum Espresso package were performed. In the case of the exfoliation of the zinc carboxylates and the intercalation/exfoliation of the surfactants, a comparison of the exchange-correlation functionals (PBE and vdW-DF) and the semiempiric method DFT-D2 was made to capture the van der Waals forces of these systems. This same methodological study was made for the properties of ZIF-9. For the study of the intercalation of the anionic iron(III) porphyrins, the effect of the spin polarization and the Hubbard correction were investigated for the structural and electronic properties. Certain aspects could be predicted such as the exfoliation energies of the studied family of layered zinc carboxylates and also for the surfactants intercalated in LDH and LHS. The adsorption energies of the molecules involved in the esterification/transesterification reactions and the energy barrier of the alkoxide formation favored the comprehension of these processes at an atomistic scale. A structural elucidation was also achieved for the intercalation of the dehydrated and hydrated surfactants, and the anionic iron(III) porphyrins. The adsorption properties of ZIF-9 were also studied, in order to predict the selectivity of the studied molecules (CO2, H2S, methanol e ethanol).

Les réseaux zéolithiques à base d'imidazolate (e.g. ZIF-8) sont des matériaux membranaires attractifs pour la séparation de gaz, sous réserve de pouvoir disposer de membranes de haute qualité, stables et reproductibles sur des supports industriels. Dans ce travail plusieurs stratégies ont été examinées pour développer des membranes nanocomposites à base de ZIF-8 confiné dans les macropores de supports céramiques tubulaires. Trois approches ont été comparées: i) croissance de germes, ii) croissance in situ et iii) conversion de ZnO. L'influence des paramètres de synthèse (formulation des solutions de précurseurs, température & durée de réaction, type de support & prétraitement…) sur les caractéristiques et performances des membranes a été étudiée. Le protocole optimum retenu repose sur la conversion solvothermale de couches minces de ZnO déposées par ALD sur les grains du support. Les membranes nanocomposites ZIF-8/ZnO/α-Al2O3 sont sélectives pour la séparation de gaz contenant H2. / Zeolitic Imidazolate Frameworks (e.g. ZIF-8) are attractive membrane materials for gas separation, provided that high quality, stable and reproducible membranes can be prepared on industrial supports. In this work several strategies were investigated in order to develop nanocomposite ZIF-8 based membranes confined in the macropores of tubular ceramic supports. Three approaches were compared: i) seeded growth, ii) in situ growth and iii) ZnO conversion. The influence of synthesis parameters (precursor solution formulation, reaction temperature & duration, support type & pre-treatment…) on membrane characteristics and performance were studied. The selected optimum protocol was based on the solvothermal conversion, using a 2-methylimidazole/methanol solution, of a ZnO thin layer uniformly deposited by Atomic Layer Deposition on the grains of a ceramic support. The nanocomposite ZIF-8/ZnO/α-Al2O3 membranes exhibited enhanced selectivities for the separation of H2-containing gas mixtures.

Les réseaux de coordination, ou Metal Organic Frameworks (MOFs), sont des architectures cristallines hybrides organiques-inorganiques qui présentent des propriétés découlant de leurs compostions et de leurs architectures. L'objectif de ce travail fut la synthèse contrôlée de nouveaux réseaux de coordination homo- (MOFs) et hétérométalliques (M'MOFs) à base de ligands dipyrrines (dpms). Dans une première partie, une stratégie de synthèse basée sur l'auto-assemblage a permis l'obtention d'une nouvelle famille de réseaux constituée de MOFs luminescents [CdII(dpm)2] et de MOFs [NiII(dpm)2]. Dans une seconde partie, l'utilisation d'une stratégie séquentielle a permis de préparer des M'MOFs de type grille basés sur différents cations métalliques primaires (CuII, PdII, ZnII) et différents nœuds métalliques secondaires (CdCl2, Cd(NCS)2, Fe(NCS)2). Ces M'MOFs font partie des rares exemples d’architectures modulables conçues par une approche rationnelle et prédictible. De plus, il a été montré que ces composés pouvaient être synthétisés en une seule étape par une méthode avantageuse de synthèse "one pot". Pour finir, une stratégie "zip-Unzip-Rezip" consistant à convertir des MOFs préalablement formés en M'MOFs hétérométalliques par l'emploi de ligands auxiliaires a été mise au point. Cette nouvelle voie permet d'incorporer aisément de la fonctionnalité dans des architectures. / Coordination networks or Metal Organic Frameworks (MOFs) are hybrid organic-Inorganic crystalline architectures displaying properties resulting from their composition and organization. The aim of this work was to synthesize, in a controlled manner, dipyrrin based new homometallic (MOFs) and heterometallic (M'MOF) coordination networks.In the first part, a strategy based on self-Assembly leading to the formation of a new family of luminescent networks [CdII(dpm)2] MOFs and [NiII(dpm)2] MOFs is described.In a second part, generation of grid-Type M'MOFs based on different primary cations (CuII, PdII, ZnII) and secondary metallic nodes (CdCl2, Cd(NCS)2, Fe(NCS)2) by a sequential strategy is presented and discussed. These M'MOFs are among the rare examples of predesigned architectures displaying substantial modularity. Importantly, it has been also demonstrated that these architectures may be efficiently prepared by a "one pot" procedure. Finally, a "zip-Unzip-Rezip" strategy consisting in the conversion of preformed MOFs into M'MOFs using auxillary ligands was developed. This unprecedented approach allows the introduction of functionality within the architectures.

Depuis une quinzaine d’années, les matériaux poreux de type Metal Organic Frameworks (MOFs) offrent de nouvelles perspectives dans le cadre du stockage d’hydrogène par adsorption. Ces matériaux possèdent une structure et un réseau de pores particulièrement bien adaptés à l’adsorption des gaz. Ainsi, le téréphtalate de Chrome (III) (MIL-101(Cr)), composé chimiquement très stable, possède une grande capacité de stockage de l’hydrogène, du dioxyde de carbone et du méthane. Afin de renforcer sa capacité de stockage d’hydrogène, un dopage au charbon actif (AC) du matériau a été envisagé. Les synthèses des matériaux dopés et non-dopés ont été réalisées et, pour cela, différents agents minéralisants (acide fluorhydrique, acide acétique et acétate de sodium) ont été testés. Les matériaux synthétisés furent caractérisés par diffraction des rayons X (DRX), par microscopie électronique à balayage (MEB), par analyses thermogravimétriques (ATG) et par adsorption d’azote à 77K. Les capacités de stockage d’hydrogène de ces matériaux à 77 K et 100 bar ont été évaluées par mesures des isothermes d’adsorption d’hydrogène, réalisées par méthodes volumétrique et gravimétrique. Les résultats obtenus par ces deux méthodes sont en parfait accord et le matériau composite affiche une capacité d’adsorption de 13.5 wt%, qui est supérieure à celle du matériau non dopé (8.2 wt% dans les même conditions expérimentales). Les cinétiques d’adsorption ont été mesurées à 77 K par méthode volumétrique. Les résultats obtenus ont été comparés au modèle de la force motrice linéaire, Linear Driving Force (LDF). Un modèle de diffusion dépendant de la température a été développé afin de tenir compte des variations de températures qui se produisent durant le processus d’adsorption. / Since the last 15 years, the porous solids such as Metal-Organic Frameworks (MOFs) have opened new perspectives for the development of adsorbents for hydrogen storage. The structure and the pore networks of these materials are especially adapted to the adsorption of gases. The chromium (III) terephthalate-based MIL-101(Cr) is a very stable material which exhibits good adsorption uptakes for hydrogen (H2), carbon dioxide (CO2) and methane (CH4).In this study, syntheses were carried out by different ways and several mineralizing agents such as hydrofluoric acid (HF), acetic acid (CH3COOH) and sodium acetate (CH3COONa) have been tested. Moreover, Activated Carbon (AC) has been introduced in the framework to create an AC incorporated composite material with an enhanced specific surface area. Conventional techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and nitrogen (N2) adsorption isotherms at 77 K were used for materials characterizations.In the aim to evaluate hydrogen storage capacities of these materials, hydrogen adsorption isotherms were measured at 77 K via both volumetric and gravimetric methods, and the obtained results are in good agreement. A hydrogen uptake value of 13.5 wt% has been measured at 77 K and 100 bar for the composite material which shows a great improvement of hydrogen capacity compared to the pristine MIL-101(Cr) (8.2 wt%).Finally, hydrogen adsorption kinetics has been measured at 77 K using volumetric method. The obtained results were compared to the Linear Driving Force (LDF) and a temperature dependent diffusion model was also considered to take into account the temperature variations which occur during the adsorption process.

Les polymères de coordination poreux appelés Metal Organic Frameworks (MOF) sont envisagés pour des développements et applications prometteuses dans la catalyse par exemple. La compréhension des mécanismes de synthèse et leurs croissances cristallines restent cependant un défi. Actuellement, seules quelques études in-situ ont été réalisées pour rationnaliser la synthèse des MOFs, comme des suivis par résonance magnétique nucléaire, par spectroscopie de masse ou par diffraction des rayons X en dispersion d'énergie. Nous proposons, l'analyse thermodifférentielle qui est une technique plus aisée à mettre en oeuvre et permet un suivi calorimétrique en continu pour identifier les phénomènes thermiques régissant la synthèse tels que la réaction de formation et la cristallisation. Grâce à ces analyses thermiques, le domaine réactionnel est déterminé et l'importance des différents paramètres influençant la synthèse sont étudiés, comme la température et les vitesses de chauffage et de refroidissement ainsi que la concentration des réactifs. Ce suivi calorimétrique a été appliqué à la synthèse de nouveaux composés de coordination poreux à base d'un dérivé tetra acide carboxylique de la porphyrine pour en comprendre les étapes réactionnelles importantes. La détermination des structures cristallines montre que certains appartiennent à la classe des Porphyrin Paddle-Wheel Frameworks. De nouvelles approches pour la synthèse de MOFs sont également proposées, en utilisant des ligands organiques acides, imines, oximes et bases de Schiff / Porous coordination polymers so called Metal Organic Frameworks (MOFs) are considered for promising development and applications such as in catalyst. However, the understanding of the synthesis mechanisms and crystal growth is a challenge. Currently, only a few in-situ studies have been done to rationalize the synthesis of MOFs, such as monitoring by nuclear magnetic resonance, mass spectroscopy and energy dispersive X-ray diffraction. In this manuscript the differential scanning calorimetry is proposed as an easier technique to implement that allows a continuous calorimeter tracking to identify the phenomena which govern the synthesis such as the formation reaction and crystallization temperatures. With such thermal analyses, the temperature range of the reaction was determined and the importance of various parameters influencing the synthesis was studied, such as heating temperatures and cooling speeds or reactant concentration. This was applied to the synthesis of new porous coordination compounds based on porphyrin acid derivative in order to understand the important reaction steps. Crystal structure determinations show that some are Porphyrin Paddle-Wheel Frameworks. New approaches to the MOFs synthesis are also proposed using organic ligands like acids, imines, oximes and Schiff bases

Flexible metal-organic frameworks (MOFs) are capable of changing their crystal structure as a function of external stimuli such as pressure, temperature, and type of adsorbed guest species. DUT-49 is the first MOF exhibiting structural transitions accompanied by the counterintuitive phenomenon of negative gas adsorption (NGA). Here, we present high pressure in situ ¹²⁹Xe NMR spectroscopic studies of a novel isoreticular MOF family based on DUT-49. These po-rous materials differ only in the length of their organic linkers causing changes in pore size and elasticity. The series encompasses both, purely microporous materials as well as materials with both, micropores and small mesopores. The chemical shift of adsorbed xenon depends on xenon-wall interactions and thus, on the pore size of the material. The xenon adsorption behavior of the different MOFs can be observed over the whole range of relative pressure. Chemical shift adsorption/desorption isotherms closely resembling the conventional, uptake-measurement based isotherms were obtained at 237 K where all materials are rigid. The comparable chemical environment for adsorbed xenon in these isoreticular MOFs allows establishing a correlation between the chemical shift at a relative pressure of p/p₀ = 1.0 and the mean pore diameter. Furthermore, the xenon adsorption behavior of the MOFs is studied also at 200 K. Here, struc-tural flexibility is found for DUT 50, a material with an even longer linker than the previously known DUT-49. Its structural transitions are monitored by ¹²⁹Xe NMR spectroscopy. This compound is the second known MOF showing the phenomenon of negative gas adsorption. Further increase in the linker length results in DUT-151, a material with interpenetrated network topology. In situ ¹²⁹Xe NMR spectroscopy proves that this material exhibits another type of flexibility compared to DUT-49 and DUT-50. Further surprising observations are made for DUT-46. Volumetric xenon adsorption measurements show that this non-flexible microporous material does not exhibit any hysteresis. In contrast, in situ ¹²⁹Xe NMR spectroscopically detected xenon chemical shift isotherms exhibit a hysteresis even after longer equilibration times than in the volumetric experiments. This indicates kinetically hindered re-distribution processes and long-lived metastable states of adsorbed xenon within the MOF persisting at the time scale of hours or longer.