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Metal organic frameworks based microcantilever gas sensors for detection of volatile organic compoundsEllern, Ilya 20 September 2013 (has links)
Metal Organic Frameworks (MOFs) are a new class of nanoporous materials with
high surface area, thermal/chemical stability and a taylorable pore size. These properties
make MOFs ideal for storage and gas separation applications. Piezoresistive
microcantilever sensors are microfabricated devices that are highly sensitive to surface
strain due to doped single crystal silicon regions. Changes in resistance generated by
surface strain can be measured with a high degree of accuracy using a Wheatstone bridge
and basic instrumentation. This thesis will discuss the use of piezoresistive
microcantilever sensors as a transduction mechanism for detection of volatile organic
compounds (VOC's) using MOF coatings. It will be shown that by coating a
microcantilever with MOFs it is possible to detect low levels of different VOC's
(hundreds of parts per million). Excellent sensitivity and a simple transduction
mechanism make these devices low power and highly compact. Such devices would be
capable of detecting a plethora of different analytes at low concentrations. Devices were
engineered for maximum response and microfabricated in the cleanroom with high yield.
A custom setup for testing the devices was designed and machined. A number of MOFs
were selected and tested, their response was recorded and analyzed. Twelve different
analytes including eleven VOC's and water were used to characterize the MOFs.
Microcantilever sensors were shown to be durable, reliable and stable in long term testing
despite being subjected to many different analytes. MOF coatings proved flexible,
durable, stable and reversible. This work will show a promising new technology for a
next generation gas sensor.
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Development of Metal–Organic Frameworks for Catalysis : Designing Functional and Porous CrystalsCarson, Fabian January 2015 (has links)
Metal–organic frameworks, or MOFs, have emerged as a new class of porous materials made by linking metal and organic units. The easy preparation, structural and functional tunability, ultrahigh porosity, and enormous surface areas of MOFs have led to them becoming one of the fastest growing fields in chemistry. MOFs have potential applications in numerous areas such as clean energy, adsorption and separation processes, biomedicine, and sensing. One of the most promising areas of research with MOFs is heterogeneous catalysis. This thesis describes the design and synthesis of new, carboxylate-based MOFs for use as catalysts. These materials have been characterized using diffraction, spectroscopy, adsorption, and imaging techniques. The thesis has focused on preparing highly-stable MOFs for catalysis, using post-synthetic methods to modify the properties of these crystals, and applying a combination of characterization techniques to probe these complex materials. In the first part of this thesis, several new vanadium MOFs have been presented. The synthesis of MIL-88B(V), MIL-101(V), and MIL-47 were studied using ex situ techniques to gain insight into the synthesis–structure relationships. The properties of these materials have also been studied. In the second part, the use of MOFs as supports for metallic nanoparticles has been investigated. These materials, Pd@MIL-101–NH2(Cr) and Pd@MIL-88B–NH2(Cr), were used as catalysts for Suzuki–Miyaura and oxidation reactions, respectively. The effect of the base on the catalytic activity, crystallinity, porosity, and palladium distribution of Pd@MIL-101–NH2(Cr) was studied. In the final part, the introduction of transition-metal complexes into MOFs through different synthesis routes has been described. A ruthenium complex was grafted onto an aluminium MOF, MOF-253, and an iridium metallolinker was introduced into a zirconium MOF, UiO-68–2CH3. These materials were used as catalysts for alcohol oxidation and allylic alcohol isomerization, respectively. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 5: Manuscript.</p>
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Structure-property relationships in framework materials : anomalous mechanics by designCollings, Ines Emily January 2014 (has links)
Framework materials that contain molecular bridging ligands between metal nodes—as seen in coordination polymers—not only give rise to enhanced structural diversity, but also to a range of useful and unusual mechanical properties. This thesis demonstrates the general structure–property relationships that are developed for coordination polymers in order to enable prediction and design of their mechanical properties, and hence structural flexibility. Variable-temperature and -pressure diffraction experiments are employed for the determination of their mechanical properties, namely by calculating thermal expansion and compressibility coefficients. The anomalous and varied mechanical responses observed are rationalised by the important structural features, or the so-called mechanical building units (XBUs), of the coordination polymers. The XBUs are considered within the setting of framework topology, geometry, and composition in order to establish general design principles for targeting different degrees of flexibility within coordination polymers. The XBUs are identified first in silver(I) 2-methylimidazolate, Ag(mim), a framework which is comprised of structural motifs of varying strength, namely argentophilic interactions, hinge points and metal–ligand bonding. The anomalous mechanical responses in Ag(mim) are shown to be rationalised entirely by the XBUs present in the structure. The XBU abstraction is then applied to a range of other coordination polymers and shown to correspond directly with the anomalous responses known in these materials. The metal–ligand–metal linker XBU is investigated further in both cadmium imidazolate, Cd(im)<sub>2</sub>, and zinc cyanide, Zn(CN)<sub>2</sub>. Here, the linker chemistries are completely different between the two frameworks, but the diamondoid arrangement of the linkers, and thus the topology, is the same. The structural responses of the two frameworks are examined to unravel the extent of topology- and chemistry-driven mechanics. It is found that the topology dominates the atomic displacements of both frameworks, indicating the existence of common soft-mode dynamics which are likely to extend to other coordination polymers with the same topology. The three-dimensional framework-hinging XBUs in zinc isonicotinate, Zn(ISN)<sub>2</sub>, and indium deuterium terephthalate, InD(BDC)<sub>2</sub>, are considered next. These frameworks have the same topology but contrasting framework geometries, evident from the differing c/a-lattice parameter ratios. In this case, a geometric formalism is derived which can predict the direction of framework mechanical anisotropy in Zn(ISN)<sub>2</sub> and InD(BDC)<sub>2</sub> and other uniaxial coordination polymers. Finally, a family of ABX<sub>3</sub>-type transition metal(II) formates are investigated, where both the B-site and A-site cations are varied. The chemical modifications give rise to variations in B- or A-site cation sizes, which are found to correlate with the magnitude of mechanical responses. These structure–mechanical property relationships—based upon framework topology, geometry and composition—are presented in separate chapters, and in each case generalised so that they can be applied to a range of coordination polymers. Hence the design principles determined here can provide the materials science community with an intuition on the type and magnitude of responses possible in these materials under different external stimuli.
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Synthesis and characterization of crystalline microporous materials : investigation of new synthetic routesTian, Yuyang January 2014 (has links)
Conventionally, crystalline microporous materials such as zeolites and metal-organic frameworks (MOFs) are synthesized through the hydrothermal route or the trial-and-error approach. Other synthetic strategies may lead to the synthesis of microporous materials with new architectures or interesting properties. The general aim of this thesis is to investigate some new synthetic routes towards crystalline microporous materials. A top-down and post-synthesis method is reported in Chapter 4. Some zeolites are built up by layers and double-4-ring pillars. Germanium is preferentially located in the double-4-ring sites of a zeolite framework and is hydrolytically unstable. The idea of the top-down method is to disassemble these zeolites to the layer structures by dissolving the Ge-containing pillars and reassemble them to a new framework. This method is applied to the germanosilicate IWW and ITH zeolites for the first time. The effects of framework chemical compositions, Ge distributions and disassembling conditions on the top-down treatment process are investigated. The products obtained from the top-down treatment are characterised. An ionic liquid assisted strategy for the synthesis of zeolites is described in Chapter 5. The ionic liquid assisted strategy is a solvent free reaction. The raw materials are transformed to zeolites through a solid state reaction. The ionic liquids are first used as structure-directing agents (SDAs) in this solvent free reaction to replace the expensive quaternary ammonium hydroxide. A TON zeolite is synthesized using 1-ethyl-3-methylimidazolium bromide as the SDA. Moreover, the ionic liquid assisted strategy is considered as a “green chemistry” synthetic route due to the high yield of the zeolites and the minor production of waste water. Many aluminophosphates have been successfully synthesized through ionothermal routes. Most of them are synthesized using 1-alkyl-3-methylimidazolium based ionic liquids. A new ionic liquid, 1-(2-hydroxyl-ethyl)-3-methylimidazolium chloride ([HOEmim]Cl), is prepared and used for the ionothermal synthesis of aluminophosphate materials. A zeolite analogue with the CHA framework has been synthesized. At high synthetic temperatures, the products are large single crystals. The structures of the framework and the SDA are investigated by single crystal diffraction and other characterisation methods. Flexible MOF materials are usually synthesized by a trial-and-error approach. Recently a flexible MOF compound was synthesized using 5-sulfoisophthalic acid (SIP) as the ligand. It was proposed the sulfonate is weakly coordinated to the metal, which brings flexibility to the compound, and the carboxylate groups keep the framework intact. 2-sulfoterephthalic acid (STP) which also contains one sulfonate group and two carboxylate groups is believed to be an alternative ligand for the targeted synthesis of flexible MOFs. In Chapter 7, a MOF compound is synthesized using STP and 4, 4'-bipyridine (Bpy) as ligands to validate the proposed strategy can be generalized. Variable temperature single crystal diffraction analysis solves the structure and reveals a reversible structure transformation upon dehydration and rehydration.
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Effect of guest uptake and high pressure on Zn- and Zr- metal-organic frameworksHobday, Claire Louise January 2017 (has links)
Porous materials are essential to our everyday lives, for example as an effective catalyst in the cracking of crude oil, or as water softeners in washing powder. When developing novel functional porous materials, it is necessary to fully understand their structure-property relationships to maximise their ability to be used in industrially relevant settings. This thesis aims to understand the mechanical and adsorption properties of a class of porous solids metal-organic frameworks (or MOFs), which have many potential applications owing to their tuneable structures. Due to the inherent 3-D crystalline structure of MOFs, a wide range crystallographic techniques were used to determine structure-property relationships. To achieve maximum in-depth structural knowledge, both classical and quantum theoretical approaches were also applied to complement the understanding of both the energetics and structural details. Chapters One and Two begin with an overview of the state of the art studies carried out on MOFs, focusing on the use of high-pressure crystallography to understand their properties. In addition, there is emphasise on the importance of complementary computational methods that are used in the characterisation of MOFs. In Chapter Three, an isostructural series of MOFs (zeolitic imidazolate frameworks, or ZIFs) were studied for methanol adsorption by employing both experimental and molecular simulation techniques. These frameworks are gating materials, where the imidazole linker rotates upon adsorption of guest, and it was found that through ligand substitution the gate opening angle and onset pressure to gating could be tuned. By using high-pressure Xray crystallography the structure of the ZIFs were studied upon the uptake of guest and the degree of ring rotation quantified. In combination with periodic DFT and grand canonical Monte Carlo simulations the energy barrier to rotation and energies of adsorption could be calculated, respectively. Chapter Four focuses on one ZIF in particular, ZIF-8 ((Zn6(MeIm)12, MeIm = 2- methylimidazole) and details the adsorption of a selection of gases into the pores. The experimental method of cryogenic gas loading into a diamond anvil cell in this chapter is novel to MOFs. This method, in combination with molecular crystallography, is used to determine the structural response of the framework to guest-uptake as well as the crystallographic positions of the adsorption sites. In combination with in silico methods, the adsorption energies of guest-sites could be calculated, detailing which interactions drive the gating behaviour. The method of cryogenic loading highlighted how extreme conditions can be used to extract useful information about structural behaviour of MOFs on uptake of gas molecules into the pores, and when used in combination with computational methods, we have a powerful tool to analyse both positions and energies of adsorption sites. With this information, progress can be made in developing MOFs to maximize favourable interactions and lead to the development of MOFs with better selective gas storage properties. Chapter Five focuses on the synthesis and characterisation of the physical properties of a series of Zr-containing MOFs, called UiO-MOFs. The high valency of Zr(IV) and 12-fold coordination of the metal cluster in these materials, are associated with high shear and bulk moduli, which surpass those of other MOFs. A combination of single-crystal nano-indentation, high-pressure X-ray diffraction studies, density functional theory (DFT) calculations, and first-principles molecular dynamics (MD) simulations were used to determine the compressibility, elasticity and hardness of these materials, whose mechanical robustness was correlated to their different structural features, in-particular, how using non-linear linkers between the metal clusters stabilises the framework to compression. Chapter Six expands upon the series of Zr-MOFs in Chapter Five, and looks at how the mechanical properties of these MOFs are affected upon increasing the linker length. The experimentally determined elastics modulus of one of the frameworks, UiO-sdc (Zr6O4(OH)4(sdc)6 where sdc =4,4’-stillbene dicarboxylate), was found to lie above those of other highly porous MOFs. In addition, the elastic modulus was found to decrease linearly as a function of increasing the linker length, extending the structure-property relationships determined in Chapter Five.
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Luminescent lanthanide metal-organic frameworks and dendrimer complexes for optical biological imaging / Réseaux metallo-organiques et complexes de dendrimères luminescents à base de lanthanides pour imagerie optiqueFoucault-Collet, Alexandra 23 September 2013 (has links)
Les composés à base de lanthanides luminescents possèdent des propriétés uniques offrant de nombreux avantages pour l’étude de problèmes biologiques et pour le diagnostic. Ils résistent notamment à la photodécomposition, possèdent des temps de vie de luminescence longs ainsi que des bandes d’émissions étroites qui ne se recouvrent pas. De plus, certains lanthanides émettent dans le proche infrarouge, ce qui les rend particulièrement intéressants pour des applications d'’imagerie in vivo. De part l’interdiction des transitions f → f, les cations lanthanides ont des coefficients d’extinction très faibles. C’est la raison pour laquelle, il est nécessaire d’utiliser un ou plusieurs sensibilisateur(s) (comme un chromophore organique) pour exciter le lanthanide par « effet antenne ». Nous proposons ici de nouveaux composés émettant dans le proche infrarouge dont la structure permet d’incorporer une densité importante de lanthanides et de sensibilisateurs par unite de volume : i) les nano-MOF Yb-PVDC-3 constitués de chromophores dérivés de dicarboxylates de phenylènevinylène qui sensibilisent les cations Yb3+ du réseau. ii) les complexes formés avec des ligands dendrimères dérivés de polyamidoamine de génération 3 capables de sensibiliser 8 lanthanides (Eu3+, Yb3+, Nd3+) par le biais de 32 antennes dérivées du groupe 1,8-naphthalimide. La caractérisation physique, photophysique et la biocompatibilité de ces composés ont été réalisées. Ils ont montré une bonne stabilité dans différents environnements. Leur faible cytotoxicité a permis d’obtenir des images de microscopie proche infrarouge sur cellules vivantes. La preuve de principe que les nano-MOFs et les dendrimères complexant des lanthanides peuvent être utilisés comme rapporteurs luminescents in cellulo et in vivo a été ici établie. Les résultats obtenus valident la stratégie d’utiliser ce type de matériel pour augmenter le nombre de photons émis par unité de volume afin d’obtenir une meilleure sensibilité de détection. / Unique properties of luminescent lanthanides reporters explain their emergence for bioanalytical and optical imaging applications. Lanthanide ions possess long emission lifetimes, a good resistance to photodecomposition and sharp emission bands that do not overlap. In addition, several lanthanides emit in the near infrared (NIR) region of the electromagnetic spectrum making them very interesting for in vivo imaging. Free lanthanide cations have low extinction coefficients due to the forbidden nature of the f → f transition. Therefore, lanthanides must be sensitized using a photonic converter such as an organic chromophore through the “antenna effect". We report here new near-infrared emitting compounds whose structure allows to incorporate a high density of lanthanide cations and sensitizers per unit volume: i) nano-MOF Yb-PVDC-3 based on Yb3+ sensitized by phenylenevinylene dicarboxylates. ii) polymetallic dendrimer complexes formed with derivatives of new generation-3 polyamidoamine dendrimers. In these complexes, 8 lanthanide ions (Eu3+, Yb3+, Nd3+) can be sensitized by the 32 antenna derived from 1,8-naphthalimide. These two families of compounds were fully characterised for their physical, photophysical properties as well as for their biological respective compatibilities. They are stable in various media and their low cytotoxicity and emission of a sufficient number of photons are suitable for near-infrared live cell imaging. One of the main goal outcomes of this work is the establishment of the proof of principle that nano- MOFs and lanthanide derived dendrimers can be used for the sensitization of NIR emitting lanthanides to create a new generation of NIR optical imaging agents suitable for both in cellulo and in vivoapplications.The present work also validates the efficiency of the strategy to use both types of nanoscale systems described here to increase the number of emitted photons per unit volume for an improved detection sensitivity and to compensate for low quantum yields.
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Synthesis and Characterization of 2D and 3D Metal Organic FrameworksJanuary 2019 (has links)
abstract: Among the alternative processes for the traditional distillation, adsorption and membrane separations are the two most promising candidates and metal-organic frameworks (MOFs) are the new material candidate as adsorbent or membrane due to their high surface area, various pore sizes, and highly tunable framework functionality. This dissertation presents an investigation of the formation process of MOF membrane, framework defects, and two-dimensional (2D) MOFs, aiming to explore the answers for three critical questions: (1) how to obtain a continuous MOF membrane, (2) how defects form in MOF framework, and (3) how to obtain isolated 2D MOFs. To solve the first problem, the accumulated protons in the MOF synthesis solution is proposed to be the key factor preventing the continuous growth among Universitetet I Oslo-(UiO)-66 crystals. The hypothesis is verified by the growth reactivation under the addition of deprotonating agent. As long as the protons were sufficiently coordinated by the deprotonating agent, the continuous growth of UiO-66 is guaranteed. Moreover, the modulation effect can impact the coordination equilibrium so that an oriented growth of UiO-66 film was achieved in membrane structures. To find the answer for the second problem, the defect formation mechanism in UiO-66 was investigated and the formation of missing-cluster (MC) defects is attributed to the partially-deprotonated ligands. Experimental results show the number of MC defects is sensitive to the addition of deprotonating agent, synthesis temperature, and reactant concentration. Pore size distribution allows an accurate and convenient characterization of the defects. Results show that these defects can cause significant deviations of its pore size distribution from the perfect crystal. The study of the third questions is based on the established bi-phase synthesis method, a facile synthesis method is adopted for the production of high quality 2D MOFs in large scale. Here, pyridine is used as capping reagent to prevent the interplanar hydrogen bond formation. Meanwhile, formic acid and triethylamine as modulator and deprotonating agent to balance the anisotropic growth, crystallinity, and yield in the 2D MOF synthesis. As a result, high quality 2D zinc-terephthalic acid (ZnBDC) and copper-terephthalic acid (CuBDC) with extraordinary aspect ratio samples were successfully synthesized. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2019
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Design of Metal-Organic Frameworks for Carbon Capture Applications: Approaches for Adsorptive Separation of CO2/N2 and O2/N2 MixturesJanuary 2019 (has links)
abstract: The large-scale anthropogenic emission of carbon dioxide into the atmosphere leads to many unintended consequences, from rising sea levels to ocean acidification. While a clean energy infrastructure is growing, mid-term strategies that are compatible with the current infrastructure should be developed. Carbon capture and storage in fossil-fuel power plants is one way to avoid our current gigaton-scale emission of carbon dioxide into the atmosphere. However, for this to be possible, separation techniques are necessary to remove the nitrogen from air before combustion or from the flue gas after combustion. Metal-organic frameworks (MOFs) are a relatively new class of porous material that show great promise for adsorptive separation processes. Here, potential mechanisms of O2/N2 separation and CO2/N2 separation are explored.
First, a logical categorization of potential adsorptive separation mechanisms in MOFs is outlined by comparing existing data with previously studied materials. Size-selective adsorptive separation is investigated for both gas systems using molecular simulations. A correlation between size-selective equilibrium adsorptive separation capabilities and pore diameter is established in materials with complex pore distributions. A method of generating mobile extra-framework cations which drastically increase adsorptive selectivity toward nitrogen over oxygen via electrostatic interactions is explored through experiments and simulations. Finally, deposition of redox-active ferrocene molecules into systematically generated defects is shown to be an effective method of increasing selectivity towards oxygen. / Dissertation/Thesis / Masters Thesis Chemical Engineering 2019
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Crystal Engineering of Functional Metal-Organic Material Platforms for Gas Storage and Separation ApplicationsElsaidi, Sameh Khamis 17 September 2014 (has links)
Metal-organic materials (MOMs) represent a unique class of porous materials that captured a great scientific interest in various fields such as chemical engineering, physics and materials science. They are typically assembled from metal ions or metal clusters connected by multifunctional organic ligands. They represent a wide range of families of materials that varied from 0D to 3D networks: the discrete (0D) structures exemplified by metal-organic polyhedra (MOPs), cubes and nanoballs while the polymeric 1D, 2D and 3D structures exemplified by coordination polymers (CPs). Indeed, the porous 3D structures include metal-organic frameworks (MOFs), porous coordination polymers (PCPs) and porous coordination networks (PCNs). Nevertheless, MOMs are long and well-known from more than 50 years ago as exemplified by CPs that were firstly introduced in early 1960s and reviewed in 1964. However, the scientific interest toward MOMs has been enormously grown only since late 1990s, with the discovery of MOMs with novel properties, especially the high permanent porosity as exemplified by MOF-5 and HKUST-1. The inherent tunability of MOMs from the de novo design to the post-synthetic modification along with their robustness, afford numerous important families of nets "platforms" such as pcu, dia, tbo, mtn and rht topology networks.
There are more than 20,000 crystal structures of MOMs in the Cambridge Structure Database (CSD). However, only a few of the networks can be regarded as families or platforms where the structure is robust, fine-tunable and inherently modular. Such robustness and inherent modularity of the platforms allow the bottom-up control over the structure "form comes before function" which subsequently facilitates the systematic study of structure/function in hitherto unprecedented way compared with the traditional screening approaches that are commonly used in materials science. In this context, we present the crystal engineering of two MOM platforms; dia and novel fsc platforms as well we introduce the novel two-step synthetic approach using trigonal prismatic clusters to build multinodal 2D and 3D MOM platforms.
For the dia platform, we introduce a novel strategy to control over the level of the interpenetration of dia topology nets via solvent-template control and study the impact of the resulting different pore sizes on the squeezing of CH4, CO2 and H2 gases. New benchmark material for methane isosteric heat of adsorption was produced from this novel work.
Indeed we introduce the crystal engineering of a novel versatile 4,6-c fsc platform that is formed from linking two of the longest known and most widely studied MBBs: the square planar MBB [Cu(AN)4]2+( AN = aromatic nitrogen donor) and square paddlewheel MBB [Cu2(CO2R)4] that are connected by five different linkers with different length, L1-L5. The resulting square grid nets formed from alternating [Cu(AN)4]2+ and [Cu2(CO2R)4] moieties are pillared at the axial sites of the [Cu(AN)4]2+ MBBs with dianionic pillars to form neutral 3D 4,6-connected fsc (four, six type c) nets. Pore size control in this family of fsc nets was exerted by varying the length of the linker ligand whereas pore chemistry was implemented by unsaturated metal centers (UMCs) and the use of either inorganic or organic pillars. 1,5-naphthalenedisulfonate (NDS) anions pillar in an angular fashion to afford fsc-1-NDS, fsc-2-NDS, fsc-3-NDS, fsc-4-NDS and fsc-5-NDS from L1-L5, respectively. Experimental CO2 sorption studies revealed higher isosteric heat of adsorption (Qst) for the compound with the smaller pore size (fsc-1-NDS). Computational studies revealed that there is higher CO2 occupancy about the UMCs in fsc-1-NDS compared to other extended variants that were synthesized with NDS. SiF62- (SIFSIX) anions in fsc-2-SIFSIX form linear pillars that result in eclipse [Cu2(CO2R)4] moieties at a distance of just 5.86 Å. The space between the [Cu2(CO2R)4] moieties is a strong CO2 binding site that can be regarded as being an example of a single-molecule trap; this finding has been supported by modeling studies.
Furthermore, we present herein the implementation of the two-step synthetic approach for the construction of novel multinodal MOM platforms, using the trigonal prism cluster [M3(µ3-O)(RCO2)6] as a precursor to build novel stable multinodal 2D and 3D frameworks. In the first step, the bifunctional carboxylate ligands are reacted with Fe+3 or Cr+3 salts to isolate highly symmetrical decorated trigonal prismatic clusters with diverse decoration such as pyridine, amine and cyano coordinating functional groups using pyridine carboxylate, amino carboxylate, cyano carboxylate type ligands, respectively. Afterward, the isolated highly soluble trigonal prismatic salts were reacted in the second step with another metal that can act as node or linker to connect the discrete trigonal prismatic clusters to build 2D or 3D networks. Indeed, we were able to develop another novel high-symmetry Cu cluster [Cu3(µ3-Cl)(RNH2)6Cl6] by utilizing CuCl2 salt and amine decorated trigonal prismatic cluster. Two novel 3D water stable frameworks with acs and stp topologies have been afforded.
Our work on the crystal engineering design and synthesis of new MOM platforms offer an exceptional level of control over the resulting structure including; the resulting topology, pore size, pore chemistry and thereby enable the control over the resulting physicochemical properties in a manner that facilitates the achieving of the desired properties.
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Synthesis, Characterization and Mechanistic Studies of Biomolecules@mesoMOFsChen, Yao 24 June 2014 (has links)
Encapsulation of biomolecules is of great interest to research advances related to biology, physiology, immunology, and biochemistry, as well as industrial and biomedical applications such as drug delivery, biocatalysis, biofuel, food and cosmetics. Encapsulation provides functional characteristics that are not fulfilled by free biomolecules and stabilizes the fragile biomolecules. In terms of biocatalysis, solid support can often enhance the stability of enzymes, as well as facilitate separation and recovery for reuse while maintaining activity and selectivity. Various kinds of materials have been used for encapsulation of biomolecules, among which, porous materials are an important group. Metal-organic frameworks (MOFs) have attracted much attention and emerged as a new generation of highly porous functional materials with potential in a variety of fields such as gas separation and storage, catalysis, sensors and biomedical applications. Their structural versatility and amenability to be designed with specific functionality, together with their extra-large surface areas confer them a special place amongst traditional porous materials. In particular, because ligands can be designed with particular organic functional groups for specific interactions with biomolecules, they are attractive in the stabilization and retention of enzyme/proteins for biomedical or biocatalysis applications. With enlarged pore sizes, mesoporous (pore sizes in the range of 2 to 50 nm) MOFs are of great interest in the encapsulation of proteins. In this dissertation, I am focusing on the encapsulation of biomolecules into mesoporous MOFs (mesoMOFs) to estabilish the biomolecules@mesoMOF platform, including synthesis, characterization and mechanistic studies of a series of novel biomolecules@mesoMOF materials, and to develop the biomolecule@mesoMOFs platform for various applications.
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