Metal organic frameworks (MOFs) are nanoporous materials composed of inorganic and organic structural building units (SBUs). Over the last several decades, interest in MOFs has grown considerably partially due to their promising capabilities for carbon capture and storage (CCS) technologies. This is mostly due to their tunable pore chemistry, high internal surface area and unique structural diversity. This thesis focuses on computational methods that were used to analyze and organize a database of hypothetical structures to facilitate MOF discovery. The work done is detailed in two main parts. In the first part of the thesis, a topologically diverse hypothetical MOF database, containing over 300,000 structures, is screened using simplified molecular-input line-entry system (SMILES) strings to identify SBUs in each structure. The structures in the database are then renamed according to the SBUs identified by the SMILES strings algorithm. The renaming of the structures allows users to have a good idea of the geometrical and topological distribution of the database. Furthermore, a quick and reliable test is developed to identify structures with incorrect bonding patterns/missing hydrogen. In the second part of the thesis, density functional theory (DFT) - derived charges are generated for each structure in the hypothetical MOF database. Using these charges, the CO₂/N₂ selectivity is calculated and compared with the selectivity values obtained from another charge generating method, split-charge equilibration (SQE), and it is determined that there is good agreement, r = 0.96, between the two methods. A machine learning model is then developed to identify relationships between geometrical features and CO₂/N₂ selectivity.

Metal-organic frameworks (MOFs) are crystalline materials composed of metal clusters and organic ligands. MOFs that exhibit photoluminescence are promising materials for a broad range of applications. Due to their structural tunability and crystalline nature, luminescent MOFs also provide an excellent platform for studying structure–property relationships of materials. The photophysical properties of three anthracene-dicarboxylic acids – 1,4-anthracene dicarboxylic acid (1,4-ADCA), 2,6-anthracene dicarboxylic acid (2,6-ADCA) and 9,10-anthracene dicarboxylic acid (9,10-ADCA) – were studied in a series of polar aprotic solvents using steady-state absorption, steady-state emission spectroscopy and time-correlated single photon counting (TCSPC) emission lifetime spectroscopy. The addition of carboxylic acid functional groups on the anthracene ring alters photophysical properties to varying degrees depending on the location and protonation state. Density functional theory (DFT) calculations reveal that the lowest-energy ground-state structures of both 2,6-ADCA and 1,4-ADCA have dihedral angles between the carboxylic acids and aromatic planes of θ = 0°, while the same dihedral angle increases to θ = 56.6° for 9,10-ADCA. Time-dependent DFT calculations suggest that the carboxyl groups of 1,4-ADCA and 2,6-ADCA remain coplanar with the anthracene ring system in the excited state. In contrast, the calculations reveal significant changes between the ground and excited geometries for 9,10-ADCA and puckering of the anthracene moiety of is observed. The three anthracene dicarboxylic acids were then incorporated into zirconium-based MOFs. The MOF structures were characterized using powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The steady-state absorption and emission spectra as well as the fluorescence lifetimes of the MOFs were compared to that of the corresponding ligand in solution. The MOFs comprising 9,10-ADCA and 2,6-ADCA formed highly crystalline octahedral shaped crystals and were found to be isostructural with the well-known UiO-66 and UiO-67 frameworks. However, incorporation of the 1,4-ADCA ligand resulted in large rod-shaped crystals. The absorption spectra of the MOFs are broadened and redshifted compared with that of the corresponding free ligands. The emission spectra of the MOFs constructed from 9,10-ADCA and 1,4-ADCA display emission bands that resemble that of the free ligand in acidic solutions, but are slightly broadened and redshifted in the MOF. Little difference is observed between that of 2,6-ADCA within the MOF and in acidic solution. The broadening and redshift observed in the absorption and emission is indicative of intermolecular interactions between anthracene units and/or with the Zr4+ clusters. The fluorescence lifetimes measured for the anthracene-based MOFs show a long component, comparable to the lifetime of the free ligand, along with shorter component. This may also suggest intermolecular interactions between chromophores in the MOFs. Altogether, derivatization of anthracene was shown to have specific effects on the photophysical properties of the parent anthracene molecule. These properties are further altered when the ligand is incorporated into a metal organic framework. Such systematic studies can provide a guide in designing luminescent MOFs with the excited-state properties desired for a given application. / Master of Science

En los últimos años, los esfuerzos para desarrollar una fuente de energía limpia y econó³micamente viable se han incrementado. Estos esfuerzos surgen como respuesta al creciente consumo de combustibles y al alto impacto ambiental y socio-político de la exploración y el uso de hidrocarburos o energía nuclear. Una de las alternativas más prometedoras exploradas hoy en díaa es el uso de H2 como vector energético. Sin embargo, existen algunas limitaciones relacionadas con la producciónn y almacenamiento que deben ser superadas. Centrados en el problema del almacenamiento de H2 , en esta investigación se ha estudiado, empleando técnicas químico-computacionales, las propiedades físico-quí�micas que promueven la adsorción de hidrógeno en sólidos cristalinos microporosos metal-orgánicos (MOFs). A partir del análisis de los resultados, se han identificado algunos parámetros que pueden ser utilizados como referencia para orientar el diseño y la síntesis de nuevos MOFs con mejores propiedades para la adsorción de H2 . A lo largo del estudio, los siguientes aspectos han sido evaluadas en detalle: I. la naturaleza de las interacciones moleculares entre el adsorbato y los diferentes componentes del material y II. las características estructurales que promueven o limitar la adsorción. Estos aspectos fueron estudiados con técnicas de químico-computacionales, tales como cálculos de química cuántica (con métodos los semi-empíricos PM6, HF y MP2) y simulaciones de dinámica molecular y Monte Carlo. Los resultados se analizaron en una función de las propiedades fÃ�sicas de los ma- teriales seleccionados para el estudio. En una primera fase, la interacción de las moléculas de H2 con el MOF-5 se evaluaron a través de cálculos de química cuántica. En vista de que los sitios de adsorciónn más fuertes fueron localizados en posiciones cercanas a los Átomos del metal (Zn (II)), se realiza un estudio adicional con cuatro tipos de centros metálicos...... / Gómez Hernández, DA. (2012). Caracterización de la Adsorción de Hidrógeno en MOFs por Métodos Químico-Computacionales [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17462

This dissertation addresses the following issues. Firstly, to reduce the efficiency roll-off at high current densities or brightness, of green, fluorescent organic light-emitting (OLEDs), we introduced a double-doped structure into the emissive layer. It includes two thin buffer layers and a broad emissive region stacked with two doped layers. This modification better controls charge injection/transport and recombination, boosting EL and PL efficiency. Secondly, aiming for highly efficient phosphorescent OLEDs surpassing the theoretical EQE limit of ~20%, a new class of platinum(II)-based phosphorescent complexes have been designed and synthesized serving as both emitters and electron transporters in straightforward undoped bi-/tri-layered devices. Achieving this without costly doping techniques, these OLEDs boast a relatively low turn-on voltage, extremely high power efficiency, and stable emission color dependent on applied voltages. This design anticipates reduced or no efficiency roll-off even at brightness levels exceeding 20,000 cd/m2, far surpassing DOE technology requirements (only 500-1500 cd/m2). This work sheds light on the influence of molecular design on crystalline packing and optoelectronic device performance and accelerates the development of efficient and stable Pt-based emitters.

Over the past few decades, vast majority of industrial and academic research throughout the world has witnessed the emergence of materials that can serve as ideal candidates for potential utility in desired applications, and these materials are known as Metal Organic Framework (MOFs). This exceptional new family of porous materials is fabricated by linkage of metal ions or clusters and organic linkers via strong bonds. MOFs have been awarded with remarkable interest and widely studied due to their inherent structural methodology (e.g. use of various metals, expanded library of organic building blocks with different geometry and functionality particularly frameworks designed from carboxylate organic linkers) and unquestionably unique structural and chemical features for many practical applications. (i.e. gas storage/separation, catalysis, drug delivery etc). Simply, metal organic frameworks epitomize the beauty of porous chemical structures. From a design perspective, the introduction of the Molecular Building Block (MBB) approach is actively being pursued pathway by researchers toward the construction of MOFs by employing inorganic building blocks and organic linkers and taking advantage of not only their multiple coordination modes and geometries but also the way in which they are reticulated to generate final framework. In this thesis, research studies will be directed toward (i) the investigation of the relationship between experimental parameters and synthesis of well-known fcu –MOF, (ii) rational design and synthesis of new rare earth (RE) based MOFs, (ii) isoreticular materials based on particular MBB ([M3O(RCO2)6]), M= p-and d-block metals, and (iv) zeolite- like metal organic framework assembled from single-metal ion based MBB ([MN2(CO2)4]) via 2-, 3-,and 4-connected organic linkers. Consequently, the porosity, chemical and thermal stability, and gas sorption properties will be evaluated and detailed.

Les polymères de coordination (PC) présentent un intérêt tant fondamental qu'appliqué de par leur structure et composition modulables ouvrant de nouvelles perspectives au niveau des propriétés chimiques (catalyse, conversion matériaux mous-durs…) et physiques (magnétisme, optique…). L'objectif principal de ces études consiste à vérifier le transfert de la structure, méso-structure et composition du PC vers la céramique obtenue par traitement thermique. Dans ce contexte, ce manuscrit décrit des études sur la conversion de polymères de coordination obtenus à partir d'un auto-assemblage entre des métaux 4f, 5f et de la 2,5-dihydroxy-1,4-benzoquinone (DHBQ). Dans un premier temps, des méthodes de synthèses, aqueuse et anhydre en atmosphère contrôlée, ont été mises au point. Ainsi, plusieurs types de PC ont été obtenus (4f, 4f-4f, 4f-5f), les composés mixtes formant des solutions solides. Après caractérisation de ces composés, leur comportement sous traitement thermique a été étudié. Les principaux résultats montrent que les précurseurs à base de DHBQ obtenus par voie aqueuse possèdent une méso-structure micrométrique, formée par l'assemblage de sous-unités monocristallines possédant la même structure cristallographique quelle que soit la morphologie observée. L'étude de l'assemblage de cette méso-structure a permis de contrôler la morphologie du grain élémentaire (cylindre, cube, disque…) avec une très bonne distribution en taille. La mise en œuvre de systèmes anhydres en atmosphère contrôlée a permis d'accéder à une plus large gamme de paramètres micro-structuraux (surface spécifique, porosité…). Pour l'ensemble des composés de type PC, la conversion thermique en céramique n'a pratiquement pas altéré la morphologie des matériaux. Les aspects microstructuraux ont pu être contrôlés via la méthode de synthèse. / Coordination polymers (CP) are of great academic and industrial interest due to flexible structure and composition and offer prospects for original chemical (catalysis, soft-hard materials conversion…) and physical properties (magnetism, optics…). The major interest of these studies is to check the transfer of the structure, meso-structure and composition from the CP to the ceramic via a thermal treatment. In this context, this thesis describes studies on conversion of coordination polymers obtained by self-assembly of 4f and 5f metal ions with 2,5-dihydroxy-1,4-benzoquinone (DHBQ). Aqueous and anhydrous synthetic ways were developed, which yielded different kinds of CPs (4f, 4f-4f, 4f-5f) ; solid solutions were obtained with the mixed compounds. The products were characterized and their behaviour under thermal treatment was studied. The main results show that the DHBQ-based precursors obtained by aqueous way have a micrometric meso-structure, formed by the assembly of micro-crystalline subunits which all posses the same crystallographic structure. The study of the assembly of the meso-structure allowed controlling the morphology of the elementary grain (cylinder, cube, disk ...) with very good size distribution. The implementation of anhydrous systems in a controlled atmosphere allowed yielded a wider range of micro-structural parameters (surface area, porosity ...). For all CP-type compounds, the thermal conversion to ceramic has barely altered the morphology of the materials. The microstructural aspects could be controlled via the method of synthesis.

Les Metal-Organic Framework (MOF) sont des adsorbants très prometteurs pour la séparation des gaz. Formés de centres métalliques reliés par des ligands organiques, ces matériaux présentent une structure organisée avec des pores de taille contrôlée ainsi que des surfaces et des volumes poreux très élevées. La possibilité de faire varier à la fois le centre métallique et le ligand organique donne aux MOFs une très grande diversité qu'on ne retrouve pas chez les zéolithes et les charbons actifs.L'objectif de cette étude a été d'évaluer le potentiel des MOFs en tant qu'adsorbants pour quatre procédés de séparation de gaz. En raison du grand nombre de MOFs disponibles, il a été nécessaire d'élaborer une stratégie pour identifier les matériaux les plus prometteurs dans chaque cas. Cette méthodologie comprend quatre étapes : une étape de criblage, une étape expérimentale, une étape de calcul et une étape d'évaluation.Pour l'étape de criblage, un nouvel appareil dit « à haut débit » a été développé pour mesurer des isothermes approximatives. Ensuite, un certain nombre de matériaux ont été retenus pour faire une étude plus approfondie de leurs propriétés d'adsorption. Des isothermes très précises ont été mesurées par gravimétrie tandis que les enthalpies d'adsorption ont été obtenues par microcalorimétrie. Dans l'étape de calcul, le modèle IAST a été utilisée pour prédire les sélectivités à partir des données en gaz pur. Enfin, les adsorbants ont été classés à l'aide d'un nouveau paramètre de sélection qui regroupe la sélectivité, la capacité efficace et l'enthalpie d'adsorption, où l'importance de chacun des paramètres peut être ajustée en fonction des besoins du procédé. / Metal-Organic Frameworks (MOFs) are seen to be one of the most promising classes of adsorbents for gas separations. Consisting of metal clusters connected by organic linkers to form a fully crystalline network, these materials have record breaking surface areas and pore volumes as well as a wide variety of pore structures and sizes. This, coupled with the possibility to use virtually any transition metal as well as functionalized linkers, gives MOFs the chemical and physical versatility often lacking in traditional adsorbents such as zeolites and activated carbons.The purpose of this study was to evaluate the potential of MOFs as adsorbents for four gas separations of interest to the petrochemical industry. Because of the diversity and number of MOFs available, a methodology was needed to help identify the most promising materials in each case. The proposed methodology comprises four stages: a screening step, an experimental step, a computational step and finally an evaluation step. For the first stage, a high-throughput setup was developed to measure rough adsorption isotherms. A number of materials were then selected for a more thorough investigation of their adsorption properties. Highly accurate isotherms were measured gravimetrically while precise adsorption enthalpies were obtained by microcalorimetry. Step three involved predicting the co-adsorption behaviour from the pure gas isotherms using the Ideal Adsorbed Solution Theory. Finally, the adsorbents were ranked based on a new selection parameter regrouping selectivity, working capacity and adsorption enthalpy where the importance of each term can be adjusted depending on the requirements of the process.

Metal-Organic Materials (MOMs) are an emerging class of crystalline solids that offer the potential for utilitarian design, as one of the greatest scientific challenges is to design functional materials with foreordained properties and eventually synthesize custom designed compounds for projected applications. Polytopic organic ligands with accessible heteroatom donor groups coordinate to single-metal ions and/or metal clusters to generate networks of various dimensionality. Advancements in synthesis of solid-state materials have greatly impacted many areas of research, including, but not limited to, communication, computing, chemical manufacturing, and transportation. Design approaches based on building blocks provide a means to conquer the challenge of constructing premeditated solid-state materials. Single-metal ion-based molecular building blocks, MNx(CO2)y+x, constructed from heterochelating ligands offer a new route to rigid and predictable MOMs. Specific metal bonds are considered responsible for directing the geometry or topology of metal-organic assemblies; these bond geometries constitute the building units, MNxOy. When these building units are connected through appropriate angles, nets or polyhedra can be targeted and synthesized, such as metal-organic cubes and Kagomé lattices. MNx(CO2)y+x MBBs can result in MN2O2 building units with square planar or see-saw geometries, depending on the mode of chelation. Using a 6-coordinate metal and a heterochelating ligand with bridging functionality, TBUs can be targeted for the synthesis of valuable networks, such as Zeolite-like Metal-Organic Frameworks (ZMOFs). Zeolitic nets, constructed from tetrahedral nodes connected through ~145° angles, are valuable targets in MOMs, as they inherently contain cavities and/or channel systems and lack interpenetration. Other design approaches have been explored for the design of ZMOFs from TBUs, such as the use of hexamethylenetetramine (HMTA) as an organic TBU. When this TBU coordinates to a 2-connected metal with appropriate angles, zeolite-like nets rare to metal-organic crystal chemistry can be accessed. Additionally, MNx(CO2)y MBBs have been used to construct metal-organic polyhedra (MOPs), used as supermolecular building blocks (SBBs), that can be peripherally functionalized and ultimately extended into threedimensional ZMOFs. Rational synthesis, mainly based on building block approaches, advances bridging the gap between design and construction of solid-state materials. However, some challenges still arise for the establishment of reaction conditions for the formation of intended MBBs and thus targeted frameworks.

Developing the synthetic control required for the intentional 3-D arrangement of atoms remains a holy grail in crystal engineering and materials chemistry. The explosive development of metal-organic materials in recent decades has shed light on the above problem. Their properties can be tuned by varying the organic and/or inorganic building units. In addition, their crystallinity makes it possible to determine their structures via the X-ray diffraction method. This dissertation will focus on the chemistry and applications of two kinds of metal-organic materials, namely, metal-organic frameworks (MOFs) and metal-organic polyhedra (MOP). MOFs are coordination polymers. Their permanent porosity makes them a good “gas sponge”. In the first section, an isoreticular series of MOFs with dendritic hexacarboxylate ligands has been synthesized and characterized structurally. One of the MOFs in this series, PCN-68, has a Langmuir surface area as high as 6033 m2 g-1. The MOFs also possess excellent gas (H2, CH4, and CO2) adsorption capacity. In the second section, a NbO-type MOF, PCN-46, was constructed based on a polyyne-coupled di-isophthalate linker formed in situ. Its lasting porosity was confirmed by N2 adsorption isotherm, and its H2, CH4 and CO2 adsorption capacity was examined at 77 K and 298 K over a wide pressure range (0-110 bar). Unlike MOFs, MOP are discrete porous coordination nanocages. In the third section, a MOP covered with bulky triisopropylsilyl group was synthesized, which exhibits a thermosensitive gate opening property. This material demonstrates a molecular sieving effect at a certain temperature range, which could be used for gas separation purpose. In the last section, a MOP covered with alkyne group was synthesized through kinetic control. The postsynthetic modification via click reaction with azide-terminated polyethylene glycol turned them into metallomicelles, which showed controlled release of an anticancer drug 5-fluorouracil. In summary, two kinds of metal-organic materials have been discussed in this dissertation, with the applications in gas storage, gas separation, and drug delivery. These findings greatly enrich the chemistry and applications of metal-organic materials.

La détection de faibles quantités de petites molécules volatiles, qu’elles soient polluantes, utilisées comme armes chimiques ou encore explosives présente un intérêt sociétal certain. Les polymères de coordination poreux (PCPs) ou ’Metal-Organic Frameworks‘ (MOFs) sont des solides poreux qui peuvent être décrits par l’association de ligands organiques et de briques inorganiques interagissant par liaisons fortes et définissant une structure cristalline avec des pores de différentes tailles et formes. La large gamme d'application de ces solides (séparation, stockage, biomédecine...) repose sur leurs diversités chimique et structurale. Par exemple, il est possible de synthétiser des MOFs luminescents en utilisant un ligand organique lui-même luminescent. Le coeur tétrazine et ses dérivés sont des bons candidats pour cet objectif, puisqu'ils présentent des propriétés de fluorescence remarquables : émission dans le visible (λem~560 nm), bon rendement quantique. De plus, cette fluorescence peut être modifiée par la présence de molécules riches en électrons, ce qui laisse envisager son utilisation comme capteur moléculaire. Nos travaux se sont de plus focalisés sur des métaux à haut degré d'oxydation (Al(III), Zr(IV)) susceptibles de conférer aux solides une stabilité en milieu aqueux adéquate pour les applications envisagées. Deux acides carboxyliques à base de tétrazine, adaptés à la préparation de MOFs, ont tout d'abord été synthétisés. Le premier a été utilisé pour préparer un MOF à base de zirconium.La structure du solide, et entre autres son caractère flexible, ainsi que ses propriétés optiques ont été étudiées. Particulièrement, ses performances en tant que capteur d'amines aromatiques et de phénol ont été évaluées. La réactivité du second ligand avec les ions lanthanides a aussi été explorée et plusieurs solides ont été isolés, leur structure, caractérisée. Leurs propriétés optiques ont été évaluées, afin d'établir des relations entre la structure du MOF et la fluorescence de la tétrazine. Ensuite, avec ce même ligand, une stratégie de synthèse à ligand mixte a été adoptée pour incorporer la tétrazine dans des MOFs. Il s'agit de partir d'une structure aux propriétés avantageuses (stabilité, porosité) et de substituer une partie de ses ligands organiques ‘inactifs’ par des tétrazines. Ceci peut s'effectuer pendant la synthèse ou via un traitement post-synthétique. Les propriétés optiques des solides obtenus ont été enfin étudiées et leur efficacité en tant que capteur évaluées. / Detection of low concentrations of small organic molecules, which can be hazardous, polluting or used as chemical weapons, represents a societal problem worth addressing. Metal-Organic Frameworks (MOFs) are a class of porous crystalline materials that can be described as an association of inorganic subunits and organic ligands defining an ordered structure with accessible cavities of various size and shape. The wide range of potential applications for these materials (biomedicine, gas separation, catalysis...) relies on their chemical and structural diversity, which allows combining porosity with additional properties. For example, it is possible to synthesize luminescent MOFs through the use of a luminescent organic ligand. The tetrazine core and its derivatives appear as good candidates for such a purpose, as they have a fluorescent emission in the visible spectrum (λem~560 nm) with a good quantum yield. In addition, this fluorescence can be affected by the presence of electron rich molecules, making their use possible as sensors for ions or organic molecules. Our work focused mainly on the design of MOFs based on tetrazine and cations of high charge density (Al(III), Zr(IV)) in order to ensure their stability in water, which is desirable in this field.Two different tetrazine dicarboxylic acids suitable for the preparation of MOFs were first synthesized. The first one was used to prepare a new MOF based on zirconium. The structure of this solid, together with its flexible character and its optical properties were investigated. Especially, its use for the sensing of aromatic amines and phenol was evaluated. The reactivity of the second ligand with lanthanide ions was then investigated and few solids were isolated and structurally characterized. Their optical properties have been studied, in order to establish some relationship between their structure and their fluorescence. Then, with the same ligand, a mixed-ligand strategy has been developed in order to incorporate the tetrazine into MOFs. This involves starting from a non-fluorescent MOF with interesting properties (stability, porosity) and substituting some of the 'inactive' ligands with these tetrazines. This was performed either during the synthesis or as a post-synthetic treatment. The spectroscopic properties of these solids were finally investigated and their efficiencies as sensors evaluated.