Growing concerns regarding chemical weapons and toxic chemicals require the development and testing of robust materials and methods to capture and destroy these harmful chemicals. This dissertation discusses the fundamental properties (e.g., structure, stability and activity) of metal oxyhydroxide based 3-dimensional porous materials, such as metal organic frameworks (MOFs), and covalent organic frameworks (COFs), and their applications for gas capture and degradation, especially for toxic gases and chemical warfare agent simulants. We report and verify that the active sites in UiO-67 MOFs are the metal nodes (oxyhydroxides) and developed a paradigm which correlates the activities of the MOFs, the metal oxyhydroxides and their precursors. This new understanding can help researchers choose the optimum metal for the intended applications by avoiding the tedious and time-consuming procedures of MOF synthesis and purification. In addition, to characterize and understand the structures of active sites in UiO-67 MOFs, temperature programmed desorption mass spectrometry (TPD-MS) and in situ Fourier-transform infrared (FTIR) spectroscopy were performed under ultra-high vacuum (UHV) and revealed unconventional binding sites and assisted in the successful characterization of missing linker defects. Here, our research helped in identification of a new class of binding sites, via NH-π interactions, in UiO-67 MOFs will assist researchers working in the areas of gas storage/release in developing better materials. This study should facilitate the structural understanding of MOFs, their important attributes such as defects and their chemistry in the presence of toxic gases. After successful identification of active species in MOFs, with the ultimate goal of isolating andii depositing the active sites on porous carbonaceous materials, e.g., COFs, we have engineered a facile technique to synthesize robust nanoparticle-COF and evaluated the reasons for its improved catalytic properties over other materials. The discoveries and their implications discussed in this thesis address fundamental knowledge gaps and should aid the rational design of superior materials for in operando applications. / Chemistry

Advanced supercapacitor electrodes require the development of materials with dense redox sites embedded into conductive and porous skeletons. Two-dimensional (2D) conjugated metal–organic frameworks (c-MOFs) are attractive supercapacitor electrode materials due to their high intrinsic electrical conductivities, large specific surface areas, and quasi-one-dimensional aligned pore arrays. However, the reported 2D c-MOFs still suffer from unsatisfying specific capacitances and narrow potential windows because large and redox-inactive building blocks lead to low redox-site densities of 2D c-MOFs. Herein, we demonstrate the dual-redox-site 2D c-MOFs with copper phthalocyanine building blocks linked by metal-bis(iminobenzosemiquinoid) (M2[CuPc(NH)8], M = Ni or Cu), which depict both large specific capacitances and wide potential windows. Experimental results accompanied by theoretical calculations verify that phthalocyanine monomers and metal-bis(iminobenzosemiquinoid) linkages serve as respective redox sites for pseudocapacitive cation (Na+) and anion (SO42–) storage, enabling the continuous Faradaic reactions of M2[CuPc(NH)8] occurring in a large potential window of −0.8 to 0.8 V vs Ag/AgCl (3 M KCl). The decent conductivity (0.8 S m–1) and high active-site density further endow the Ni2[CuPc(NH)8] with a remarkable specific capacitance (400 F g–1 at 0.5 A g–1) and excellent rate capability (183 F g–1 at 20 A g–1). Quasi-solid-state symmetric supercapacitors are further assembled to demonstrate the practical application of Ni2[CuPc(NH)8] electrode, which deliver a state-of-the-art energy density of 51.6 Wh kg–1 and a peak power density of 32.1 kW kg–1.

Photoschalter sind Moleküle, die eine reversible lichtgesteuerte Umwandlung zwischen zwei Zuständen mit unterschiedlichen Eigenschaften durchlaufen. In den letzten zehn Jahren hat der Einbau dieser photochromen Moleküle in intelligente, auf Stimuli ansprechende Materialien zunehmende Aufmerksamkeit erregt, da sie die einzigartige Fähigkeit bieten, makroskopische Eigenschaften mit einem externen optischen Stimulus reversibel zu verstärken und zu verändern. Die begrenzte Leistung von Photoschaltern in festen Medien bleibt eine Herausforderung. In diesem Zusammenhang werden in dieser Arbeit zwei wichtige Aspekte näher untersucht. Erstens der Prozess der Entwicklung neuer Photoschalter mit maßgeschneiderten Eigenschaften und zweitens die Implementierung von Photoschaltern in feste Materialien und die damit verbundenen Herausforderungen. Im ersten Teil dieser Arbeit wurde Dynamisch-kovalente Chemie (DCC) verwendet, um die Entdeckung und Entwicklung einer neuartigen Klasse von Photoschaltern mit drei Zuständen zu beschleunigen. Die dynamische Natur der zentralen Doppelbindung von α-Cyanodiarylethenen wurde genutzt, um ein thermodynamisches Gleichgewicht mit anderen Arylacetonitrilen herzustellen. Die entwickelte Methode kombiniert eine schnelle Diversifizierung mit einer Rasterung auf spezifische Eigenschaften, die durch einen externen Stimulus aufgedeckt werden, und ermöglicht die effiziente Untersuchung der Beziehung zwischen Struktur und den zugehörigen Eigenschaften. Im zweiten Teil der Arbeit wird die Entwicklung und die Synthese eines Zweikomponenten-Kern-Schale-MOFs mit einem internen nicht-funktionalisierten Kompartiment, das von einer dünnen photoschaltbaren Außenschale bedeckt ist, vorgestellt. Diese Strategie ermöglicht ein effizientes Schalten des Chromophors und die resultierende dünne „intelligente“ Schale fungiert als modulare kinetische Barriere für die molekulare Gastdiffusion in das Material, die durch Licht gesteuert werden kann. / Photoswitches are molecules that undergo a reversible light-triggered conversion between two states with different properties. In the past decade, the incorporation of these photochromic molecules in smart stimuli-responsive materials has gained increased attention as it offers the unique ability to reversibly amplify and change macroscopic properties with an external optical stimulus. The limited performance of photoswitches in solid mediums remains a challenge. In this context two important aspects are studied in more detail in this thesis. First, the process of developing new photoswitches with tailored properties and second, the implementation of photoswitches in solid materials and the challenges associated with it. In the first part of this thesis dynamic covalent chemistry (DCC) was used to accelerate the discovery and development of a novel three-state photoswitch class. The dynamic nature of the central double bond of α-cyanodiarylethenes was exploited to establish a thermodynamic equilibrium with other arylacetonitriles. The developed DCC tool combines fast and efficient diversification with screening for specific photochemical properties revealed by an external stimulus, enabling the rapid study of the relationship between structure and the associated properties. The second part of this thesis summarizes the design and synthesis of a two-component core-shell MOF with an internal non-functionalized compartment covered by a thin photoswitchable outer shell. This strategy allows efficient switching of the chromophore and the resulting thin “smart” shell acts as a modular kinetic barrier for molecular guest diffusion into the material that can be controlled by light.

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Clean air is an indispensable prerequisite for human health. The capture of small toxic molecules requires the development of advanced materials for air filtration. Two-dimensional nanomaterials offer highly accessible surface areas but for real-world applications their assembly into well-defined hierarchical mesostructures is essential. DUT-134(Cu) ([Cu2(dttc)2]n, dttc=dithieno[3,2-b : 2′,3′-d]thiophene-2,6-dicarboxylate]) is a metal–organic framework forming platelet-shaped particles, that can be organized into complex structures, such as millimeter large free-standing layers (carpets) and tubes. The structured material demonstrates enhanced accessibility of open metal sites and significantly enhanced H2S adsorption capacity in gas filtering tests compared with traditional bulk analogues.

We present an autonomous, chemical logic gate based on a switchable metal–organic framework (MOF) composite, containing carbon nanoparticles and a Pt catalyst. The switchable MOF composite performs as AND logic gate. Hydrogen and oxygen gas streams serve as binary inputs. Catalytically formed water induces a structural transition (crystal volume expansion) of the MOF, and as a consequence, a detectable drop in conductance of the composite as a ‘true’ output only if both gases come in contact with the composite.

The synthesis of five homoleptic transition metal complexes of bis-(phenyl)-diisoindol-aza-methene is described together with the optical, electrochemical and thermal properties of these compounds. Additionally, crystal structures for the Co and the Zn complex are reported. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

La conception de nouveaux matériaux fonctionnels a une longue histoire. Durant les deux dernières décennies, le domaine des polymères organiques et inorganiques a attiré l'attention des chercheurs. Plus important encore, les matériaux poreux tels que les Metal Organic Frameworks (MOFs), en anglais, Covalent Organic Frameworks (COFs), en anglais, ainsi que des polymères de coordination poreux sont maintenant étudiés de manière intensive en raison de leurs applications potentielles, comprenant le stockage de gaz, la séparation de gaz, la catalyse et la détection. D'un autre côté, les polymères contenant du Pt ont montré l'application potentielle dans les cellules solaires et les diodes électroluminescentes. Le mémoire est divisé en trois sections principales présentant des résultats nouveaux. Dans la première section, le chapitre 2 traite essentiellement de la formation de polymères de coordination (CP) avec des sels CuX (X = Cl, Br, I) et trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1), soit dans le PrCN ou PhCN. Les polymères résultants sont soit 2D (bidimensionel) ou 1D (unidimensionel). Cependant, en presence de PrCN ou de PhCN, le CP 2D obtenu avec le CuBr n'a pas incorporé de solvant dans ses espaces vides. D'autre part, le CP 2D et le reste des CP 1D obtenus avaient soit des molécules de solvant de cristallisation dans leurs cavités ou coordonnés au cuivre sur la chaîne. Les unités cuivre-halogénures étaient soit des rhomboïdes Cu2X2 ou le cubane Cu4I4. Leurs mesures photophysiques en présence et en l'absence de molécules de solvant de cristallisation ont été effectuées. En outre, la porosité du CP a été évaluée par BET (N2 à 77 K). Le vapochromisme du CP 2D sans solvant et des CP 1D ont été étudiés, ainsi que les mesures de sorption du CO2 ont été effectuées. De plus, nous avons utilisé CuCN et L1 dans MeCN pour former de nouveaux CP’s. Ceci est rapporté dans la deuxième section, le chapitre 3. Le CP obtenu était inattendu : L1 s’est rompu et du cyanure CN‾ s’est coordonné sur le Pt. Ceci a conduit à la formation d’un CP 1D zigzag. Généralement, les CP sont formés avec L1 via des liens Cu-S ou/et Cu([éta]2-C≡C), mais pas dans le cas du CuCN qui lui forme une chaîne 1D (CuCN)n où le L1 rompu se lie avec cette chaîne via un lien Cu-N. Les propriétés photophysiques et de stabilité thermique ont été étudiées. La troisième section (Chapitre 4) traite d'une exploration des CP formés par la reaction des sels CuX (X = Cl, Br, I) et le trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1) ou le trans-[p-MeSC6H4C≡C-Pt(PEt3)2-C≡CC6H4SMe] (L2) dans du MeCN afin de trouver des tendances. L'utilisation de L1 a donné lieu à un CP 2D ou 1D CPs avec le MeCN piégé à l'intérieur des cavités, il y a de l’espace vide. L2 a conduit uniquement à des CP 1D sans molecules de solvant de cristallisation. Des analyses thermogravimétriques, photophysique et des mesures d’adsorption de gaz (uniquement pour ceux avec du solvant) ont été étudiées. / Abstract: The design of new functional materials has a long history. For the past two decades, the field of organic and inorganic polymers has attracted attention of researchers. More importantly, porous materials such as Metal Organic Frameworks (MOFs), Covalent Organic Frameworks (COFs) as well as porous coordination polymers are now being intensively studied due to their potential applications including gas storage, gas separations, catalyst and sensing. On another hand, Pt-containing polymers have shown potential applications in solar cells and light emitting diodes. The masters’ thesis is mainly divided into three main sections presenting new results. In the first section; Chapter 2 mainly discusses the formation of coordination polymers with CuX salts (X= Cl, Br, I) and trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1), in either PrCN or PhCN. The resulting polymers obtained were 2D (bidimensional) CPs or 1D (unidimensional) CPs in all cases. However, 2D CPs obtained when CuBr salt is used by either using PrCN or PhCN did not incorporate the solvents in their cavities. On the other hand, the 2D CP and the rest of 1D CPs obtained had either the crystallization molecules in the cavities or coordinated to the copper cluster. The copper-halide clusters were either the rhomboids Cu2X2 fragments or the step cubane Cu4I4. The photophysical measurements in the presence and absence of solvent crystallization molecules were performed. In addition, the porosity of the CPs was evaluated by adsorption isotherms. The vapochromism of the solvent-free 2D and 1D CPs were investigated as well as CO2 sorption measurements were perfomed. Furthermore, we then attempted to use CuCN and L1 in MeCN which is reported in the second section as Chapter 3. The obtained CP was unexpected as L1 broke and a cyanide (CN‾) ion coordinated to the Pt atom leading to the formation of zigzag 1D CP. The coordination bonds Cu-S or/and Cu([eta]2-C≡C) were generally observed with L1, but not in the CuCN case. Instead a 1D chain of (CuCN)n was made and the broken L1 now binds the chain via a Cu-N bond. The photophysical and thermal stability properties were studied. Lastly, the third section, Chapter 4 deals with a potential predictability of CP formation by using CuX salts (X= Cl, Br, I) and either trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1) or trans-[p-MeSC6H4C≡C-Pt(PEt3)2-C≡CC6H4SMe] (L2) in MeCN as the solvent. The use of L1 resulted in either 2D or 1D CPs with the MeCN trapped inside of the cavities while L2 resulted in 1D CPs without MeCN being present in their cavities. The thermogravimetric, photophysical as well as gas sorption measurements (only for those with crystalisation molecules) were perfomed.

Made available in DSpace on 2014-12-17T15:42:25Z (GMT). No. of bitstreams: 1 VivianeOC_DISSERT.pdf: 3402531 bytes, checksum: e2e7a469bf001a9ef16d573773ea7bda (MD5) Previous issue date: 2014-01-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Metal Organic Frameworks (MOFs) are supramolecular structures consisted of ions or metal clusters coordinated to organic ligands which are repeated in two or three dimensions. These structures have atracted much attention due to their properties such as low density, high specific surface area and large volume of pores. In this work, MOFs consisted of zinc clusters connected by ditopic ligands, terephthalic acid (1,4- H2BDC) or isophthalic acid (1,3-H2BDC) were synthesized. To obtain the proposed materials, different routes and synthetic parameters were tested, such as the molar ratio of the precursors, the addition of template molecules, the type of solvente, the addition of organic base or the type of a counter-ion of Zn salt. It was found that the variation of these parameters led to the formation of different metalorganic structures. The solids obtained were characterized by XRD, SEM and IR. For the samples identified as MOF- 5, it was verified that the structure was composed of both interpenetrated and non interpenetrated structures. These samples showed a low stability, becoming totally transformed into another structure within less than 72 hours. The addition of the nickel and/or cobalt was found to be a promissing method for increasing the stability of MOF- 5, which in this case, still remained unconverted to another structure even after 15 days of exposure to air. The samples prepared from 1,3-H2BDC were probably new, still unknown Metal Organic Frameworks / Redes Metalorg?nicas (MOFs) s?o estruturas supramoleculares constitu?das de ?ons ou clusters met?licos coordenados com ligantes org?nicos que se repetem em duas (2D) ou tr?s (3D) dimens?es. Essas estruturas t?m atra?do muita aten??o devido ?s suas propriedades, como por exemplo, baixa densidade, elevada ?rea superficial espec?fica e elevado volume de poro livre. Neste trabalho foram sintetizadas MOFs formadas por clusters met?licos de zinco conectados por ligantes dit?picos, ?cido tereft?lico (1,4- H2BDC) ou isoft?lico (1,3-H2BDC). Para a obten??o dos materiais propostos foram testadas diferentes rotas e par?metros de s?ntese, tais como, raz?o molar dos precursores, adi??o de mol?culas de molde, tipo de solvente, adi??o de base org?nica ou do contra-?on do sal de Zn. Constatou-se que a varia??o destes par?metros pode conduzir a forma??o de diferentes estruturas metalorg?nicas. Os s?lidos obtidos foram caracterizados por DRX, MEV e IV e TG. Para as amostras onde foi identificada a rede metalorg?nica MOF-5 verificou-se a exist?ncia de por??es de estrutura interpenetrada, assim como de estrutura n?o interpenetrada. Estas amostras apresentaram baixa estabilidade, convertendo-se totalmente em outra estrutura num per?odo de tempo inferior a 72 h. A adi??o de n?quel e/ou cobalto mostrou-se promissora para o aumento de estabilidade da MOF-5, a qual foi identificada mesmo ap?s 15 dias de exposi??o ao ar. Dentre as amostras preparadas com 1,3-H2BDC apenas uma estrutura foi identificada, com base nos bancos de dados de estruturas conhecidas, levando a crer que tr?s redes metalorg?nicas obtidas apresentam estruturas in?ditas