abstract: We report the synthesis of novel boronic acid-containing metal-organic frameworks (MOFs), which was synthesized via solvothermal synthesis of cobalt nitride with 3,5-Dicarboxyphenylboronic acid (3,5-DCPBC). Powder X-ray diffraction and BET surface area analysis have been used to verify the successful synthesis of this microporous material. We have also made the attempts of using zinc nitride and copper nitride as metal sources to synthesize the boronic acid-containing MOFs. However, the attempts were not successful. The possible reason is the existence of copper and zinc ions catalyzed the decomposition of 3,5-Dicarboxyphenylboronic acid, forming isophthalic acid. The ended product has been proved to be isophthalic acid crystals by the single crystal X-ray diffraction. The effects of solvents, reaction temperature, and added bases were investigated. The addition of triethylamine has been shown to tremendously improve the sample crystallinity by facilitating ligand deprotonation / Dissertation/Thesis / Masters Thesis Chemical Engineering 2014

abstract: An urgent need for developing new chemical separations that address the capture of dilute impurities from fluid streams are needed. These separations include the capture of carbon dioxide from the atmosphere, impurities from drinking water, and toxins from blood streams. A challenge is presented when capturing these impurities because the energy cost for processing the bulk fluid stream to capture trace contaminants is too great using traditional thermal separations. The development of sorbents that may capture these contaminants passively has been emphasized in academic research for some time, producing many designer materials including metal-organic frameworks (MOFs) and polymeric resins. Scaffolds must be developed to effectively anchor these materials in a passing fluid stream. In this work, two design techniques are presented for anchoring these sorbents in electrospun fiber scaffolds. The first technique involves imbedding sorbent particles inside the fibers: forming particle-embedded fibers. It is demonstrated that particles will spontaneously coat themselves in the fibers at dilute loadings, but at higher loadings some get trapped on the fiber surface. A mathematical model is used to show that when these particles are embedded, the polymeric coating provided by the fibers may be designed to increase the kinetic selectivity and/or stability of the embedded sorbents. Two proof-of-concept studies are performed to validate this model including the increased selectivity of carbon dioxide over nitrogen when the MOF ZIF-8 is embedded in a poly(ethylene oxide) and Matrimid polymer blend; and that increased hydrothermal stability is realized when the water-sensitive MOF HKUST-1 is embedded in polystyrene fibers relative to pure HKUST-1 powder. The second technique involves the creation of a pore network throughout the fiber to increase accessibility of embedded sorbent particles. It is demonstrated that the removal of a blended highly soluble polymer additive from the spun particle-containing fibers leaves a pore network behind without removing the embedded sorbent. The increased accessibility of embedded sorbents is validated by embedding a known direct air capture sorbent in porous electrospun fibers, and demonstrating that they have the fastest kinetic uptake of any direct air capture sorbent reported in literature to date, along with over 90% sorbent accessibility. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2018

Thesis advisor: Jeffery A. Byers / Thesis advisor: Chia-Kuang Tsung / Homogeneous catalysts are advantageous in selective catalysis due to the well-defined active site at the molecular level. The poor recyclability, bimolecular aggregation, and undesired poison resistance of homogeneous catalysts hinder further industrial application despite the controlled reaction pathway due to the homogeneous environment. On the other hand, heterogeneous catalysts are preferred in industry due to their high recyclability and high activity. Yet, poor selectivity due to undefined active sites is a drawback. The construction of a host-guest system where a molecular level catalyst is incorporated into the Metal-Organic Framework (MOF) provides a promising solution to bridge those two fields. This composite maintains the advantages of homogeneous and heterogeneous catalysts and overcomes the disadvantages. However, finding an incorporation method that is versatile with minimum synthetic modification of the host and guest remains one of the challenges. In the first part of this dissertation, a new concept called “aperture-opening encapsulation’’ is introduced for incorporating large and diverse guest molecules into MOFs without changing the identity of either the guest or MOF. The approach capitalizes on the existence of linker exchange reactions, which, as our kinetic studies show, proceed via competition between associative and dissociative exchange mechanisms. The second part describes how this method is applied to incorporate a molecular catalyst into the cavity of UiO-66 for the hydrogenation of carbon dioxide to formate, which is a useful application for energy related industry. The developed hybrid composite showed the ability to be recycled, showed no evidence of bimolecular catalyst decomposition, and was less prone to catalyst poisoning. These results demonstrate for the first time how the aperture-opening process resulting from linker dissociation in MOFs can be utilized as a strategy to synthesize host-guest materials useful for chemical catalysis. After the establishment of the hybrid catalyst, the last part of the dissertation describes our efforts into the investigation of mass transport in catalysis. The understanding of the interaction between the host-guest is beneficial for the development of biological analogs in the future. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

The present thesis mainly proposes to explore the potential of aza-macrocycles in metal-organic frameworks (MOFs) for applications related to unprecedented open macrocycle cavities. Strategies such as direct arylation of secondary amines as well as multidentate coordination were applied to constrain the intramolecular flexibility of as-obtained macrocyclic compounds. Several desired materials, i.e. MMCF-4, MMCF-5/MMCF-5t/MMCF-5t-aa, MMCF-5, HMMCF-1, were obtained. They are proved superior to traditional materials in the field of "turn-on" lanthanide luminescence, deep desulfurization of flue gas, recovery of Platinum-group metals, etc. Powder/single-crystal X-ray diffraction (PXRD/SCXRD), synchrotron-based X-ray and extended X-ray absorption fine structure (EXAFS), density functional theory (DFT) theoretical calculations, etc., were employed for deep-understanding the mechanisms. These studies shed light on the construction of hierarchically porous materials with two levels of porosity, i.e., one from the frameworks and the other one from the aza-macrocycles. Incorporation of aza-macrocycles into the MOF architectures not only leads to fundamental significance in bridging the chemistry of MOFs with supramolecular chemistry but also elicits unique properties from the hybrid materials obtained. As a paradigm for constructing frameworks with accessible macrocyclic cavities based on "constrained" aza-macrocycle ligands, this thesis paves the way for the further development of this framework family in the future.

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Over the last 20 years, there has occurred an increase in the number, scope, and impact of nanomaterials projects. By leveraging the Surface Plasmon Resonance of metallic nanoparticles for labelling, sensing, and treatment, researchers have demonstrated the versatile utility of these nanomaterials in medicine. The literature provides evidence of use of simple, well-known chemistry for nanomaterials synthesis when the focus is new applications of nanomaterials. A case in point, is the synthesis of metallic nanoparticles, whereby HAuCl4, CuCl2, Cu(acac)2, and AgNO3 are typically employed as nanoparticle precursors. Unfortunately, the use of these precursors limits the number of applications available to these materials - particularly for AuNPs in medicine, where the byproducts of nanoparticle synthesis (most often surface-adsorbed reductants, toxic stabilizers, and growth directors) cause nanoparticles to fail clinical trials. Despite the several thousand publications detailing the advancements in nanoparticle therapeutics, as of 2017, there were only 50 FDA-approved nanoparticle formulations. Less than 10 were based on metallic nanoparticles. This is a problem because many of these nanoparticle therapeutics demonstrate potent cell killing ability and labeling of cells. A solution to this problem may be the use of weakly coordinated, monovalent metal complexes, which require only one electron to reduce them to their metallic state. Further, by designing nanoparticle syntheses around these monovalent complexes, we can employ weaker, environmentally friendly stabilizers. This strategy also forgoes the use of exogenous reducing agents, because the monovalent complexes can be reduced and stabilized by one reagent. Herein we investigate the use of Au(Me2S)Cl, [Cu(MeCN)4]BF4, and AgBF4 with green stabilizers to synthesize a variety of nanomaterials. We find that a range of sizes of spherical particles, as well as a range of sizes of gold triangular prisms can be synthesized by using techniques that follow this strategy.

Industrial productions need the separation processes, but they are quite energyintensive, which occupy about half of the total energy consumption. Membranetechnology based on a non-thermal route is expected to reduce the associated energy duties by ~90%, but effective membrane materials capable of precisely isolating targeted species from complex mixtures are highly needed. Metal-organic frameworks (MOFs), possessing the tuneable pore size and geometry, are regarded as the promising platform for molecular separations and membrane design. This dissertation illustrates the rational design and the guided fabrication for various MOF membranes. Respectively, different gas separation applications were addressed by using these membranes, such as light hydrocarbon separations, carbon dioxide (CO2) captures and natural gas purifications. A versatile strategy for membrane fabrication is developed based on the electrochemical method. Following this, a family of face-centered cubic (fcu) MOF membranes were obtained, which possess different ligands and different clusters, namely rare-earth hexanuclear or zirconium hexanuclear clusters. Two MOF membranes based on fumarate (fum) linker, Zr-fum-fcu-MOF and Y-fum-fcu-MOF, showed efficient separation for the propylene/propane binary mixture, as well as the butane/isobutane equimolar mixtures, respectively. Further aperture editing applied to Zr-fum-fcu-MOF via mixed-linker approach permits the introduction of shape irregularity to the parent trefoil-shaped apertures, inducing an ideal shape-mismatch with tetrahedral CH4 molecules and blocking their transportation while affecting linear molecules slightly such as nitrogen (N2) and CO2. The resultant Zr-fum67-mesaconate (mes)33-MOF membranes exhibit great promise for natural gas purification, including efficient nitrogen rejection and simultaneous removal of CO2 and N2 from natural gas. In addition, a unique CO2-recognition membrane based on a fluorinated MOF (KAUST-7) is constructed for multipurpose CO2 capture, including CO2/H2, CO2/N2 and CO2/CH4 separation. The specific affinity to CO2 coupling with the molecular sieving capability of KAUST-7 enables the membrane to be nearly only permeable to CO2, excluding both smaller H2 molecule and larger N2 or CH4 molecules. Moreover, in order to be closer to the real applications, the defective Zr-fum-fcu- MOF nanoparticles based mixed-matrix membranes are constructed for natural gas purification under practical conditions

Biologics such as DNA and protein have immense biomedical applications, especially in diagnosis and therapy. However, many barriers hinder these applications, including biologics transport and liability in biological systems. Therefore, biocompatible and stable nanocarriers with high Biologics loading efficiency can provide a platform for advances in biologics applications. Metal-organic frameworks (MOFs) have gained significant interest within the biomedical field, mainly because of their building block versatility, porosity, stability, and chemical and biological functionality. Currently, increasing research is dedicated to improving MOFs biocompatibility, stability, and functionality for drug delivery. Using biomolecules as organic linkers could improve biocompatibility, physiological condition stability, and biological functionality. The main goal of this dissertation is to investigate the applicability of biomolecule-based Metal-organic frameworks (BioMOFs) as nanocarriers to achieve cellular delivery of active biologics. Herein, we analyzed adenine and saccharate metal−organic frameworks (BioMOF) in terms of biocompatibility, loading capability, protection, and cellular delivery of biologics. Our findings suggest that the usage of biomolecules as an organic linker generates BioMOFs with reduced cytotoxicity compared with the widely used MOFs such as Zinc Imidazole framework-8 (ZIF-8). In addition, the base-pairing functionality of coordinated adenine of KAUST-BioMOFs (KBMs) is preserved and can be used to load ssDNA. Both KAUST-BioMOFs (KBMs) and Zinc adenineated framework (ZAF) load, protect, and deliver functional ssDNA to cells. In addition, we showed the possibility of in situ encapsulation of active lysozyme in zinc saccharate (Zn-Sac) with modified synthesis procedures.

With the increasing demand for energy consumption and the limitations of traditional carbon-based energy sources, the importance of renewable energy generation is undeniable. Among the various methods for generating and storing energy, green hydrogen production through photocatalytic water splitting has gained significant interest. However, despite numerous studies dedicated to finding the perfect material, achieving large-scale industrial applications is still a distant goal. Metal-Organic Frameworks (MOFs) have emerged as a particularly intriguing option due to their exceptional tunability and versatility. Nevertheless, there remains a substantial gap in our understanding of their performance and fundamental aspects. In this study, we focus on Ti-based MOFs, which have shown great promise owing to the redox properties of titanium. We introduce a novel Ti-oxo chain pyrene MOF called ACM- 1, which exhibits remarkable activity in both the hydrogen evolution reaction (HER) and organic transformations. This outstanding performance can be attributed to the high mobility of photogenerated electrons and the strong localization of holes within the material. To further enhance the photocatalytic activity of ACM-1, we employ defect engineering techniques, specifically fluorination of the metal-oxo units. The introduction of fluorine effectively reduces the band gap of the material, leading to improved light absorption capabilities and a significant boost in photocatalytic performance. Additionally, we synthesize a new MOF named ICGM-1, which shares isochemical characteristics with the well-studied MIL-125-NH2. Despite the identical NH2-bdc linker, ICGM-1 differs in terms of its Ti-sbu composition, providing a unique opportunity to investigate the influence of node geometry on photocatalytic activity. Our study reveals that the rod-type geometry is unfavorable due to lower electron charge mobility, highlighting the importance of node architecture in designing efficient photocatalysts. Finally, we report the synthesis of two new Zr-based MOFs, ACM-10 and ACM-11, based on the redox-active TTFT linker. Through Ti grafting, we demonstrate the potential of ACM-10 for HER, further expanding the range of viable MOF photocatalysts.

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