Metal–organic frameworks (MOFs) represent an important platform to immobilize and stabilize electroactive molecular catalysts due to their porosity, high surface area and well characterized three-dimensional structure. Most efforts in this area have been dedicated to the development of photocatalysts and traditional heterogeneous catalysts based on both precious and abundant transition metals. However, little work has been done to design nickel-based MOF electrocatalysts for organic synthesis. In this work we describe the synthesis of three linkers containing a bipyridine moiety, where two of the linkers are dicarboxylate extended linkers and one is a bispyrazole extended linker. The two dicarboxylate linkers are combined with zirconium clusters to build MOFs of the UiO-n family. The bispyrazole linker was used to synthesize copper-based MOFs. The developed MOFs function as support for the immobilization of nickel (II) species in isolated sites within the frameworks. Following this, the redox properties of these MOFs were studied by the means of electrochemistry. The structure of the organic linkers was confirmed by 1H NMR spectroscopy and mass spectrometry, and two of the linkers are new molecules never synthesized before. The synthesized MOFs were characterized by powder X-ray diffraction, where the MOFs of the UiO-n family showed small crystallite sizes. Similarly, the MOFs based on the bispyrazole linker showed low crystallinity. Metalation of the MOFs with a [Ni(phen)3]Cl2 complex was studied using UV-Vis spectroscopy and scanning electron microscopy, both techniques confirmed the immobilization of the nickel catalyst in the UiO-n MOFs. The electrochemical properties of the MOFs were studied using cyclic voltammetry. Both UiO-n MOFs showed a non-reversible event for the reduction of Ni(II) and the MOFs based on the bispyrazole linker showed a quasi-reversible event for the Cu(II)/Cu(I) couple.

Esta tesis doctoral resume nuestros esfuerzos por contribuir al desarrollo de nuevos catalizadores heterogéneos basados en compuestos Metal-Orgánico estructurados (MOFs). Para ello, y con el fin de cubrir un amplio espectro de posibilidades en el diseño de catalizadores basados en MOFs, se han considerado distintos materiales en los que los centros catalíticos se encuentran situados en los nodos metálicos, en los ligandos orgánicos o encapsulados en el interior del sistema poroso del material. En consecuencia, los resultados presentados se organizan en tres bloques, en función de dónde se localizan los centros activos dentro del material. A lo largo de este estudio se ha prestado especial interés en evaluar el verdadero potencial de los MOFs con respecto a otros catalizadores homogéneos y heterogéneos existentes, así como en determinar su estabilidad y reusabilidad, ya que se trata de las dos objeciones más importantes que se plantean al considerar el uso de los MOFs para aplicaciones catalíticas. En el primer bloque de resultados se ha evaluado la actividad catalítica de varios MOF con iones Cu2+ en los nodos metálicos en reacciones que pueden ser catalizadas por otros catalizadores homogéneos y heterogéneos que contienen este mismo tipo de centros. En particular, varios MOFs de cobre han demostrado ser catalizadores heterogéneos activos, selectivos, estables y reusables para la oxidación aeróbica de alquenos activados (Capítulo 1), acoplamiento oxidativo C-O por activación directa de enlaces C-H (Capítulo 2), síntesis regio-selectiva de triazoles por adición “click” de azidas a alquinos (Capítulo 3), así como para la síntesis de propargilaminas y derivados heterocíclicos mediante reacciones de acomplamiento de multicomponentes. (Capítulo 4). Para completar este bloque de resultados, en el capítulo 5 se evalúa el comportamiento de MOFs con oxo-agregados de Zr con propiedades semiconductoras como fotocatalizadores para la generación de H2 por disociación de agua . En el capítulo 6 se describe el desarrollo de un nuevo método de modificación post-síntesis que permite convertir los grupos amino libres en los ligandos de un MOF en especies quelante tipo oxamato, lo que nos permite introducir centros catalíticos metálicos adicionales directamente anclados a las paredes del MOF. El potencial de esta estrategia se demuestra a través de la introducción de iones Cu2+ y el estudio de la actividad catalítica de los materiales resultantes en reacciones típicas catalizadas por los nuevos centros, como las ya descritas en los Capítulos 3 y 4. Como último bloque de esta tesis, en el Capítulo 7 se describe la preparación de nanopartículas de Pd encapsuladas en el interior de MOFs de Zr (UiO-66 y UiO-67) mediante adsorción en fase gas de un precursor de Pd seguida de descomposición/reducción mediante irradiación con luz UV. La localización de las nanopartículas metálicas exclusivamente en el interior de las cavidades estructurales confiere al material propiedades de selectividad de forma, como demostramos para la reducción selectiva de compuestos carbonílicos con diferente impedimento estérico a los correspondientes alcoholes. / Luz Mínguez, I. (2014). Materiales metal orgánicos estructurados como catalizadores heterogéneos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48489

The development of therapeutic drugs or drug systems that enhance a cancer patient's quality of life during treatment is a primary goal for many researchers across a wide range of disciplines. Many investigators turn to nanoparticles (~50-200 nm in size) that tend to accumulate in tumor tissues in order to deliver active drug compounds to specific sites in the body. This targeted delivery approach would reduce the total body effects of current cancer drugs that result in unwanted (sometimes painful and even fatal) side effects. One of the main obstacles however, is ensuring that drugs incorporated into the nanoparticles are anchored such that premature drug release is prohibited. Also, while it is important to ensure strong drug-nanocarrier interactions, the nanocarrier must be able to release the drug when it has reached its biological target. We have developed a nanocarrier that provides a platform for drug systems that could achieve this drug release via the use of a light "trigger". Metal-Organic Frameworks (MOFs) are a relatively new class of often highly porous materials that act as "sponges" for the absorption of various small molecules. MOFs are so named because they consist of metal clusters that are linked by organic compounds to form networked solids that are easily tuned based on the choice of metal and organic "linker". We have developed a MOF nanocarrier incorporating benign zirconium (IV) metal clusters bridged by an organic component that changes shape when illuminated with a light source. The resulting material is therefore not stable upon irradiation due to the organic linker shape change that disturbs the MOF structure and causes it to degrade. When loaded with drugs, this photo-enhanced degradation results in the release of the cargo thereby, providing a handle on controlling drug release with the use of a light trigger. We have demonstrated that in the presence of the MOF nanocarrier incorporating 5-fluorouracil (a clinically available cancer drug), very low toxicity to human breast cancer cells is observed in the dark, however, cell death occurs in the presence of a light source. These reports offer a model MOF nanocarrier system that could be used to incorporate various drugs and therefore tune the system to an individual patient's needs. Furthermore, we also developed a material that is capable of providing magnetic resonance imaging (MRI) contrast by changing the metal to manganese (II). MRI contrast agents are compounds that serve to either darken or brighten an MRI image based on the agent used and therefore they aid in clinical diagnosis by making internal abnormalities easier to spot. Currently gadolinium (III) complexes are the most widely used contrast agents; however, the toxicity of gadolinium (III) has been shown to be responsible for the development of nephrogenic systemic fibrosis in some patients. This manganese material has also shown useful for the attachment of fluorescent dyes that can aid in the benchtop optical diagnosis of biopsies. These reports provide a basis for developing ways to offer controlled drug delivery in cancer patients and to aid in cancer diagnosis using MOF materials, in an effort to reach the goals of comfortable cancer treatment. / Ph. D. / The development of therapeutic drugs or drug systems that enhance a cancer patient’s quality of life during treatment is a primary goal for many researchers across a wide range of disciplines. Many investigators turn to nanoparticles (~50-200 nm in size) that tend to accumulate in tumor tissues in order to deliver active drug compounds to specific sites in the body. This targeted delivery approach would reduce the total body effects of current cancer drugs that result in unwanted (sometimes painful and even fatal) side effects. One of the main obstacles however, is ensuring that drugs incorporated into the nanoparticles are anchored such that premature drug release is prohibited. Also, while it is important to ensure strong drug-nanocarrier interactions, the nanocarrier must be able to release the drug when it has reached its biological target. We have developed a nanocarrier that provides a platform for drug systems that could achieve this drug release via the use of a light “trigger”. Metal-Organic Frameworks (MOFs) are a relatively new class of often highly porous materials that act as “sponges” for the absorption of various small molecules. MOFs are so named because they consist of metal clusters that are linked by organic compounds to form networked solids that are easily tuned based on the choice of metal and organic “linker”. We have developed a MOF nanocarrier incorporating benign zirconium (IV) metal clusters bridged by an organic component that changes shape when illuminated with a light source. The resulting material is therefore not stable upon irradiation due to the organic linker shape change that disturbs the MOF structure and causes it to degrade. When loaded with drugs, this photo-enhanced degradation results in the release of the cargo thereby, providing a handle on controlling drug release with the use of a light trigger. We have demonstrated that in the presence of the MOF nanocarrier incorporating 5-fluorouracil (a clinically available cancer drug), very low toxicity to human breast cancer cells is observed in the dark, however, cell death occurs in the presence of a light source. These reports offer a model MOF nanocarrier system that could be used to incorporate various drugs and therefore tune the system to an individual patient’s needs. Furthermore, we also developed a material that is capable of providing magnetic resonance imaging (MRI) contrast by changing the metal to manganese (II). MRI contrast agents are compounds that serve to either darken or brighten an MRI image based on the agent used and therefore they aid in clinical diagnosis by making internal abnormalities easier to spot. Currently gadolinium (III) complexes are the most widely used contrast agents; however, the toxicity of gadolinium (III) has been shown to be responsible for the development of nephrogenic systemic fibrosis in some patients. This manganese material has also shown useful for the attachment of fluorescent dyes that can aid in the benchtop optical diagnosis of biopsies. These reports provide a basis for developing ways to offer controlled drug delivery in cancer patients and to aid in cancer diagnosis using MOF materials, in an effort to reach the goals of comfortable cancer treatment.

This dissertation explores the development and optimization of Metal-Organic Frameworks (MOFs) and Nanoparticle Organic Hybrid Materials (NOHMs) for efficient CO₂ capture and investigates enhanced sorbent regeneration using a non-thermal transfer. Chapter 2 introduces the versatility and challenges of MOFs, including their structural adaptability and issues with hydrostability, highlighting the need for water-resistant modifications or coatings to maintain functionality in humid conditions. Chapter 3 and 4 focus on advancements in MOF design for CO₂ capture and the synthesis of encapsulated MOFs with enhanced durability against moisture, using HKUST-1 integrated with hydrophobic polymer PTMSP as an example to demonstrate its potential despite challenges in optimizing CO₂ sorption efficiency when exposed to water. Chapter 5 explores NOHMs, particularly ionically tethered polyethylenimine (NIPEI), for creating air-filter-like fiber mat systems with significant CO sorption capabilities, even under low CO₂ concentrations and humid conditions, suggesting further material and design optimization for industrial applications. Chapter 6 presents a modeling study on gas transport behaviors within NOHM-polymer interfaces, utilizing Molecular Dynamics (MD) simulations to enhance our understanding of CO₂ sorption dynamics, pointing towards the importance of ion diffusion rates and the distribution of gas molecules for improved capture efficiency. Chapter 7 delves into CO₂ desorption techniques, comparing microwave radiation to conventional thermal heating, showing the efficiency and energy-saving benefits of microwave regeneration, especially when incorporating Fe₃O₄ magnetite into NOHMs. This chapter also stresses the necessity of innovative reactor designs to ensure uniform heating and address technical challenges like nanoscale temperature measurement and uneven heat distribution. Chapter 8 extends the discussion to future research directions, emphasizing the potential of NOHMs for CO₂ capture and conversion, the exploration of their electrochemical performance, and the need for understanding CO₂ transport mechanisms for enhanced conversion efficiency. It calls for comprehensive evaluations of sorbents in terms of stability, kinetics, capacity, selectivity, and cost-effectiveness, alongside advancements in microwave regeneration technology to overcome current limitations in sorbent heating efficiency. Overall, this dissertation underscores the ongoing need for innovative solutions to improve CO₂ capture technologies, highlighting the promise of MOFs and NOHMs in addressing climate change challenges through scalable carbon capture, utilization, and storage (CCUS) applications.

Yes / Grinding solid reagents under solvent-free or low-solvent conditions (mechanochemistry) is emerging as a general synthetic technique which is an alternative to conventional solvent-intensive methods. However, it is essential to find ways to scale-up this type of synthesis if its promise of cleaner manufacturing is to be realised. Here, we demonstrate the use of twin screw and single screw extruders for the continuous synthesis of various metal complexes, including Ni(salen), Ni(NCS)2(PPh3)2 as well as the commercially important metal organic frameworks (MOFs) Cu3(BTC)2 (HKUST-1), Zn(2-methylimidazolate)2 (ZIF-8, MAF-4) and Al(fumarate)(OH). Notably, Al(fumarate)(OH) has not previously been synthesised mechanochemically. Quantitative conversions occur to give products at kg h−1 rates which, after activation, exhibit surface areas and pore volumes equivalent to those of materials produced by conventional solvent-based methods. Some reactions can be performed either under completely solvent-free conditions whereas others require the addition of small amounts of solvent (typically 3–4 mol equivalents). Continuous neat melt phase synthesis is also successfully demonstrated by both twin screw and single screw extrusion for ZIF-8. The latter technique provided ZIF-8 at 4 kg h−1. The space time yields (STYs) for these methods of up to 144 × 103 kg per m3 per day are orders of magnitude greater than STYs for other methods of making MOFs. Extrusion methods clearly enable scaling of mechanochemical and melt phase synthesis under solvent-free or low-solvent conditions, and may also be applied in synthesis more generally. / EPSRC (EP/L019655/1)

[ES] Se han preparado varios materiales metal orgánicos de circonio MOF-808 para evaluar sus propiedades catalíticas en reacciones tipo Meerwein-Ponndorf-Verley (MPV) para la reducción de compuestos carbonílicos. En particular, se han sintetizado compuestos tipo MOF-808 modificados en los que una pequeña fracción de los ligandos trimesato presentes en el MOF original se ha reemplazado por ligandos dicarboxilato, como una estrategia para inducir la creación controlada de defectos estructurales. Los ligandos utilizados han sido: isoftalato (MOF-808-IPA), 3,5-piridindicarboxilato (MOF-808-Pydc), 5- aminoisoftalato (MOF-808-NH2) y 5-hidroxiisoftalato (MOF-808-OH). Todos los materiales obtenidos presentan una elevada cristalinidad y son isoreticulares respecto al MOF-808 original. Se ha evaluado la actividad catalítica del MOF-808 original y de los materiales modificados en reacciones tipo MPV, utilizando ciclohexanona como compuesto modelo. Todos los materiales presentan una elevada actividad catalítica, superior a la del tereftalato de circonio UiO-66 utilizado como referencia. Esta mayor actividad catalítica se corresponde a un mayor número de iones Zr4+ con insaturación coordinativa presentes en el MOF-808 con respecto al UiO-66. Además, los materiales MOF-808-IPA y MOF-808-Pydc presentan una mayor actividad que el MOF-808 original, lo que se debe a la presencia de centros activos menos congestionados estéricamente debido a la introducción de los ligandos dicarboxilato. Una ventaja adicional de compuestos MOF-808 con respecto al UiO-66 es su sistema de poros más grande, lo que permite la conversión de moléculas de mayor tamaño. Para evaluar esta característica, se ha utilizado un compuesto de gran tamaño, la estrona, capaz de penetrar en los poros del MOF-808 pero no en el UiO-66. En consecuencia, el MOF-808 es capaz de convertir por completo la estrona de forma selectiva a estradiol, mientras que el UiO-66 apenas presenta actividad. Además, cuando se usa el MOF-808 como catalizador, se produce una cantidad considerable del isómero 17alfa-estradiol, difícil de obtener por otros medios, por lo que las propiedades de diastereoselectividad del MOF-808 en reacciones MPV resultan de gran interés preparativo. Con el fin de estudiar en mayor detalle la diastereoselectividad de reacciones MPV catalizadas por MOF-808, se ha estudiado la reducción de ciclohexanonas substituidas: 3-metilciclohexanona (3MeCH), 2-metilciclohexanona (2MeCH) y 2-fenil-ciclohexanona (2PhCH). En función del alcohol utilizado como reductor y de la posición del grupo substituyente en la ciclohexanona, el MOF-808 favorece selectivamente la formación de uno u otro isómero, con una diastereoselectividad variable: 82%, 61% y 94%, respectivamente para 3MeCH, 2MeCH y 2PhCH. Es posible racionalizar estos resultados considerando la formación preferencial de uno u otro estado de transición en el espacio confinado disponible dentro de los poros del MOF. Las características energéticas del proceso se han analizado mediante el uso combinado de estudios cinéticos y cálculos teóricos. Finalmente, en vista las interesantes propiedades del MOF-808 como catalizador para reacciones MPV, se ha extendido con éxito el uso de este material a la preparación de compuestos hidroxiesteroides de difícil obtención y de interés farmacológico mediante la reducción quimio-, regioy diastereoselectiva del correspondiente oxoesteroide. De esta forma, se han conseguido obtener en un solo paso de reacción y con una elevada selectividad los siguientes compuestos: 17alfa-estradiol, 5alfa- androstan-3beta,17alfa-diol y epitestosterona, lo que demuestra el potencial del MOF-808 como catalizador para la síntesis de compuestos de alto valor añadido. / [CA] S'han preparat varis materials metall orgànics de zirconi MOF-808 per avaluar les seves propietats catalítiques en reaccions tipus Meerwein-Ponndorf-Verley (MPV) per a la reducció de composts carbonílics. En particular, s'han sintetitzat composts tipus MOF-808 modificats en els que una petita fracció dels lligands trimesat presents en el MOF original s'han reemplaçat per lligands dicarboxilats, com una estratègia per induir la creació controlada de defectes estructurals. Els lligands utilitzats han sigut: isoftalat (MOF-808-IPA), 3,5-piridindicarboxilat (MOF-808-Pydc), 5-aminoisoftlatat (MOF-808- NH2) i 5-hidroxiisoftalat (MOF-808-OH). Tots els materials preparats presenten una elevada cristal·linitat i són isoreticular respecte al MOF-808 original. S'ha avaluat l'activitat catalític del MOF-808 original i dels materials modificats en reaccions tipus MPV, utilitzant ciclohexanona com a compost model. Tots els materials presenten una elevada activitat catalítica, superior a la del tereftalat de zirconi UiO-66 utilitzat com a referència. Aquesta major activitat catalítica es correspon a un major nombre d'ions Zr4+ amb insaturació coordinativa presents en el MOF-808 respecte a l'UiO-66. A més, els materials MOF-808-IPA i MOF-808-Pydc presenten una major activitat que el MOF-808 original, el que és debut a la presència de centres actius menys congestionats estèricament debut a la introducció dels lligands dicarboxilat. Un avantatge addicional dels MOF-808 respecte a l'UiO-66 és el seu sistema de porus més gran, que permet la conversió de molècules de major tamany. Per avaluar aquesta característica, s'ha utilitzat un compost de gran taman, l'estrona, capaç de penetrar en els porus del MOF-808 però no en els de l'UiO-66. En conseqüència, el MOF-808 és capaç de convertir completament l'estrona de forma sel·lectiva a l'estradiol, mentre que l'UiO-66 gairebé no presenta activitat catalítica. A més, quan s'usa el MOF- 808 com a catalitzador, es produeix una quantitat considerable de l'isòmer 17alfa-estradiol, difícil d'obtenir per altre medis, de manera que les propietats de diastereoselectivitat del MOF-808 en reaccions MPV resulten de gran interès preparatiu. Per tal d'estudiar en major detall la diastereoselectivitat de reaccions MPV catalitzades per MOF-808, s'ha estudiat la reducció de ciclohexanones substituïdes: 3-metilciclohexanona (3MeCH), 2- metilciclohexanona (2MeCH) i 2-fenil-ciclohexanona (2PhCH). En funció de l'alcohol usat com a reductor i de la posició del grup substituent en la ciclohexanona, el MOF-808 afavoreix selectivament la formació d'un o de l'altre isòmer, amb una diastereoselectivitat variable: 82%, 61% y 94%, respectivament per a 3MeCH, 2MeCH y 2PhCH. És possible racionalitzar aquest resultats considerant la formació preferent d'un o l'altre estat de transició en l'espai confinat disponible dins dels porus del MOF. Les característiques energètiques del procés s'han analitzat mitjançant l'ús combinat d'estudis cinètics i càlculs teòrics. Finalment, en vista de les interessants propietats del MOF-808 com a catalitzador per a reaccions MPV, s'ha estès amb èxit l'ús d'aquest material a la preparació de composts hidroxiesteroids de difícil obtenció i d'interès farmacològic mitjançant la reducció quimio-, regio- i diastereoselectiva del corresponent oxoesteroid. D'aquesta manera, s'ha aconseguit obtenir en un únic pas de reacció i amb una elevada selectivitat els següents composts: 17alfa-estradiol, 5alfa-androstan-3beta,17alfa-diol i epitestosterona, el que demostra el potencial del MOF-808 com a catalitzador per a la síntesi de composts d'alt valor afegit. / [EN] Various zirconium-containing MOF-808 compounds have been prepared as potential catalysts for the Meerwein-Ponndorf-Verley (MPV) reduction of carbonyl compounds. Modified MOF-808 have been synthethized in which a small fraction of the trimesate ligands present in pristine MOF-808 has been replaced by dicarboxylate ligands, as a strategy to induce a controlled creation of defects. The linkers used are: isophthalate (MOF-808-IPA), 3,5-pyridinedicarboxylate (MOF-808-Pydc), 5-aminoisophthalate (MOF-808-NH2) and 5-hydroxyisophthalate (MOF-808-OH). All these compounds are highly crystalline and isoreticular with pristine MOF-808. The catalytic activity of pristine and defect engineered MOF-808 has been evaluated for MPV reactions, using cyclohexanone as model substrate. All the materials show a higher catalytic activity than that of zirconium terephthalate UiO-66 used as reference. This higher activity is attributed to the higher amount of coordinatively unsaturated Zr4+ ions in MOF-808 than in UiO-66. Moreover, MOF- 808-IPA and MOF-808-Pydc are more active than pristine MOF-808, which is due to the creation of less sterically crowded sites due to the introduction of defective dicarboyxlate linkers. A further advantage of MOF-808 over UiO-66 is the presence of a wider pore system, which allows converting bulkier substrates. To evaluate this characteristic, a bulky ketone has been used; estrone, which can enter the pores of MOF-808 but not those of UiO-66. Accordingly, MOF-808 can fully convert estrone selectively to estradiol, while UiO-66 shows barely any catalytic activity. Interestingly, when MOF- 808 is used as catalysts, a noticeable amount of the isomer 17alpha-estradiol is produced, which is difficult to obtain by other means. Therefore, the diastereoselective properties of MOF-808 for MPV reactions are interesting from the preparative point of view. In order to investigate in more detail the diastereoselective properties of MOF-808 for MPV reactions, various substituted cyclohexanones have been considered: 3-methylcyclohexanone (3MeCH), 2- methylcyclohexanone (2MeCH) and 2-phenylcyclohexanone (2PhCH). Depending on the alcohol used as reducing agent and the position of the substituent in the cyclohexanone molecule, MOF-808 selectively favors the formation of one isomer or the other with a different diastereoselectivity: 82%, 61% and 94%, respectively for 3MeCH, 2MeCH y 2PhCH. These results can be rationalized by considering the preferential formation of a given transition state in the confined space available inside the MOF pores. The energetic characteristics of the process have been analyzed by a combined use of kinetic studies and theoretical calculations. Finally, in view of the interesting properties of MOF-808 as catalyst for MPV reactions, this material has been successfully applied to the preparation of a number of challenging hydroxysteroid compounds with pharmacologic interest through a chemo-, regio- and diastereoselective reduction of the corresponding oxosteroid. In this way, it has been possible to prepare in one single reaction step the following compounds: 17alpha-estradiol, 5alpha-androstan-3beta,17alpha-diol and epitestosterone. This demonstrates the high potential of MOF-808 as a catalysts for the synthesis of high added value compounds. / I want to thank the European Union’s Horizon 2020 research and innovation program for a contract under the Marie Sklodowska-Curie grant agreement No. 641887 (Project acronym: DEFNET). / Mautschke, H. (2019). Zirconium Metal Organic Frameworks as Heterogeneous Catalysts for Meerwein-Ponndorf-Verley Reactions [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/130203

The past few decades have witnessed an almost exponential increase in interest in the field of metal organic frameworks (MOFs), which can be evidenced from the large number of scientific articles being published routinely in this area. The MOFs are crystalline hybrid materials built via the judicial use of inorganic metal ions and organic linkers, thereby bridging the gap between purely inorganic and organic materials. The structural versatility and the potential tunability of the MOFs imparts unique physicochemical and thermomechanical properties, which have rendered them immensely useful in the branches of chemistry, material science, physics, biology, nanotechnology, medicine as well as environmental engineering. The MOFs have been shown to be promising as materials for gas storage and separation, sensors, ferroelectric and non-linear optical materials, magnetism, catalysis, drug delivery etc and researchers have been devising strategies to utilize the MOFs to tackle a number of global challenges of the twenty-first century. A survey of the literature reveals that the linear organic linkers, 1,4- benzenedicarboxylic acid (BDC) and 4,4’-biphenyldicarboxylic acid (BPDC), have been the organic linkers of choice for the construction of stable, porous and multifunctional MOFs. The aim of this thesis has been to monitor the effect that the presence of a functional group in between the benzene rings of the BPDC would have on the overall structures and the properties of the MOFs. Thus, as part of the investigations, the preparation of the MOF compounds using 4,4’-sulfonyldibenzoic acid (SDBA) and 4,4’- azodibenzoic acid (ABA) have been accomplished. Along with the conventional hydrothermal and solvothermal synthetic techniques, the liquid-liquid biphasic reaction method was also utilized for the synthesis of some of the compounds. The structures of the compounds were ascertained from single crystal X-ray diffraction technique. Proton conductivity studies were performed on Mn based porous MOFs using AC impedance spectroscopy. The ferroelectric behavior in a Co based porous MOF was established using dielectric and polarization vs electric field measurements. The labile nature of the lattice solvent molecules was established utilizing single crystal X-ray diffraction studies and water sorption experiments. In addition, the site selective substitution in a homometallic MOF and the subsequent conversion to a mixed-metal spinel oxide upon thermal decomposition, have also been studied. Chapter 1 of the thesis is a brief overview of the metal organic framework compounds and summarizes the various important structures that have been reported in literature and the interesting properties that they exhibit. In chapter 2, the proton conductivity behavior, solvent mediated single crystal to single crystal (SCSC) and related structural transformations in a family of Mn and Co based porous MOFs with SDBA have been presented. Also presented are the results of the site selective substitution of Mn by Co in a homometallic Mn based MOF and it’s subsequent decomposition to CoMn2O4 spinel oxide nanoparticles. In chapter 3, the syntheses, structures and the magnetic properties of the pentanuclear Mn5 based MOF compounds with SDBA have been presented. The role of the time and the temperature in the formation of the compounds has also been presented. In chapter 4, the dehydration/rehydration mediated switchable room temperature ferroelectric behavior, the single crystal to single crystal solvent exchange studies and selective gas sorption behavior in an anionic Co based MOF with SDBA has been discussed. In chapter 5, the use of the liquid-liquid biphasic synthetic route in the formation of Zn and Cd based MOFs with ABA has been discussed. Structural transformations between the one dimensional Zn based compounds and the heterogeneous catalytic studies using the Cd based compounds have also been presented.

In dieser Arbeit ein neues bioanalytisches Konzept untersucht, das nanoskalige Zeolith-Imidazolat-Frameworks (ZIFs) als Marker für antikörperbasierte Analysemethoden einsetzt, einschließlich Enzyme-Linked-Immunosorbent-Assay (ELISA) und Lateral Flow Immunoassay (LFIA). Der Vorteil von ZIFs als Marker gegenüber etablierten Materialien ist ihre vielseitige, einfache und kostengünstige Synthese. Dazu gehört die Möglichkeit, niedermolekulare Substanzen für zusätzliche Sensorzwecke zu verkapseln und für eine hohe Selektivität stabil an Biomakromoleküle zu konjugieren. Als modellhafter Zielanalyt von Relevanz wurden Phthalat-Acylester (PAEs) ausgewählt. Die Relevanz des Nachweises von PAEs ergibt sich aus ihren Eigenschaften als endokrin wirksame Chemikalien (EDCs) und krebserregend. In Kombination mit der Tatsache, dass PAEs aufgrund ihrer Verwendung als Weichmacher in Kindergeschirr, Spielzeug, Trinkflaschen und anderen Produkten auf Polyvinylchlorid-Basis in der Umwelt reichlich vorhanden sind, zeigt, wie wichtig der routinemäßige Nachweis von PAEs in Trinkwasser oder Lebensmitteln ist. / This work explores a new bioanalytical concept that employs nanosized Zeolite Imidazolate Frameworks (ZIFs) particles as labels for antibody-based analytical methods, including enzyme-linked immunosorbent assay (ELISA) and lateral flow immunoassay (LFIA). The advantage of ZIFs as labels over established materials is their versatile, facile, and cheap synthesis. This includes the ability to encapsulate low molecular weight substances for additional sensing purposes and for stable conjugation to biomacromolecules for high selectivity. As a model target analyte of relevance Phthalate acyl esters (PAEs) have been selected. The relevance of the detection of PAEs is due to their properties as endocrine disrupting chemicals (EDCs) and carcinogenic. Combined with PAEs being abundant on the environment because of their use as plasticizers in plastic-made tableware for children, toys, drinking bottles and other polyvinylchloride-based products, shows the importance or their routine detection of drinking water or foods being so critical.

Biomimetic catalysis is an important research field, as a better understanding of nature´s powerful toolbox for the conversion of molecules can lead to technological progress. [FeFe]-hydrogenases are very efficient catalysts for hydrogen production. These enzymes play a crucial role in the metabolism of green algae and certain cyanobacteria. Their active site consists of a diiron complex that is embedded in an interactive protein matrix. In this thesis, two pathways for mimicking the outer coordination sphere effects resulting from the protein matrix are explored. The first is the construction of model complexes containing phosphine ligands that are coordinated to the iron center as well as covalently linked to the bridging ligand of the complex. The effect of such linkers is an increased energy barrier for the rotation of the Fe(CO2)(PL3)-subunit, which potentially could stabilize a terminal hydride that is an important intermediate in the proton reduction cycle. The second pathway follows the incorporation of [FeFe]-hydrogenase active site model complexes into metal-organic frameworks (MOFs). Resulting MOF-catalysts exhibit increased photocatalytic activity compared to homogenous references due to a stabilizing effect on catalytic intermediates by the surrounding framework. Catalyst accessibility within the MOF and the influence of the framework on chemical reactivity are examined in the work presented. Furthermore, an initial step towards application of MOF-catalysts in a device was made by interfacing them with electrodes. The work of this thesis highlights strategies for the improvement of biomimetic model catalysts and the knowledge gained can be transferred to other systems mimicking the function of enzymes.

This research aimed to develop new composite membranes using a polymer of intrinsic microporosity (PIM-1) and metal organic frameworks (MOFs) for use in gas separations. PIM-1 was successfully synthesised using the high temperature method (40 min, 160 oC) and the resulting polymer was cast into membranes. PIM-1 membranes were chemically modified by reacting hexamethylenediamine (HMDA) with the nitrile group of PIM-1 to form HMDA-modified PIM-1 membranes. Surfaces of PIM-1 membranes were also modified by basic hydrolysis to form amide-modified PIM-1 membranes. These polymer materials were characterized by different techniques (GPC, NMR, ATR-IR, TGA, Elemental analysis and nitrogen sorption analysis). In addition, eight MOF materials [MIL-101(Cr), ED-g-MIL-101(Cr), TEPA-g-MIL-101(Cr), MIL-101(Cr)-NH2, MIL-101(Al)-NH2, UiO-66(Zr), UiO-66-NH2 and UiO-66(COOH)2] were successfully synthesized. They were chosen due to having high surface areas and large porosity. These MOF compounds were characterized using PXRD, SEM, TGA, and low pressure N2.Successful PIM-1/MOF MMMs were fabricated utilising PIM-1 and the MOFs outlined above with various loadings. The highest MOF loading achieved was 28.6 wt. %, apart from MIL-101(Cr)-NH2, for which it was 23.1 wt. %, and MIL-101(Al)-NH2, for which it was 19.8 wt. %. The morphology of MMMs was characterized by scanning electron microscopy (SEM), proving the dispersion of MOF fillers. Novel PIM-1 supported MOF membranes were successfully prepared by depositing ZIF-8 and HKUST-1 layers on the surfaces of unmodified and modified PIM-1 membranes. These materials were characterized using PXRD, SEM, ATR-IR and SEM-EDX. Gas permeation properties of the MOF/PIM-1 MMMs and PIM-1 supported MOF membranes were determined using a time lag method. Most MMMs tested showed an increase in the permeability and stable selectivity as the MOF amount was increased. However, this was not true for MIL-101(Al)-NH2, where the permeability and selectivity decreased. In contrast, PIM-1 supported ZIF-8 and HKUST-1 membranes caused a sharp decrease in the permeability and increase in the selectivity.