Chemistry Commons^™

The Development Of Screening Platforms To Identify Novel Anti-Infectives That Inhibit Protein Synthesis In Pseudomonas Aeruginosa, Casey Anne Hughes

Theses and Dissertations

Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen, is a leading cause of nosocomial infections and is becoming increasingly antibiotic resistant. Aminoacyl-tRNA synthetases (aaRSs) catalyze the covalent attachment of amino acids to their cognate tRNAs and serve as validated targets for the development of new anti-infectives. In P. aeruginosa, the genome contains two genes (tyrS and tyrZ) which encode two distinct TyrRS enzymes. The genes encoding both P. aeruginosa TyrRS-Z and TyrRS-S were cloned, overexpressed in E. coli cells, and purified to homogeneity. Both forms of TyrRS were active in aminoacylation and were developed into screening platforms using scintillation proximity …

Molten-Salt Synthesized Pyrochlore Nanoparticles For Multifunctional Applications, Jose P. Zuniga

Theses and Dissertations

There is a need in the scientific world to design and develop high quality nanomaterials with multifunctional applications. In this work, we explore the molten-salt method (MSS) as a new green method for the synthesis of complex metal oxides. We adjusted all synthesis parameters such as time, temperature and pH to generate an optimum La2Hf2O7 nanoparticle with a well define shape and surface. Activator ions such as Eu3+, Tb3+, Dy3+, Bi3+ and uranium ion (U4+, U6+) were used to monitor its structural and optical behavior effect when doped.

Our results showed effective quantum yield, thermal, pressure stability, near to white …

Design And Synthesis Of 5-Oxo-Ete Receptor Antagonists; And Synthesis Of Neuroprostanes As A Biomarker For The Diagnosis Of Alzheimer’S Disease, Rui Wang

Theses and Dissertations

1) 5-Oxo-ETE (7, Scheme 1) is the most potent eosinophil chemoattractant among all lipid mediators and it can also stimulate a late-phase asthma attack. It is formed by the biotransformation of arachidonic acid (AA, 1, Figure 1). 5-Oxo-ETE (7) elicits eosinophil migration both in vitro and in vivo when injected intradermally in humans, acting via the highly selective OXE receptor (OXE-R). Our group postulated that a selective OXE-R antagonist might be a useful therapeutic agent in late phase asthma. As a result, the first and only series of OXE receptor antagonists which are structural mimics of 5-oxo-ETE (7) have been …

Synthesis Of Photoactive Molecules And Silicon Containing Compounds, Mozhgan Navidi

Theses and Dissertations

Retinoids are a class of synthetic and natural molecules that are functionally and structurally related to Vitamin A. They have various biological roles and potential therapeutic values. Providing treatment for eye diseases requires more detailed understanding of the visual process. However, investigating every aspect of the visual phenomenon is constrained by the difficulties involved in the synthesis of pure retinoids with the desired stereochemistry. Therefore, developing a suitable and valuable synthetic route for 11-cis-retinal and its analogues is highly desirable. The first chapter of this dissertation explains new synthetic pathways for 11-cisretinal. In addition, the total synthesis of stereoselectively deuterium-labeled …

Photocleavable Endogenous And Exogenous Molecules, Charitha Madhusanka Guruge

Theses and Dissertations

The spatiotemporal regulation of biomolecules in their physiological environment is an essential aspect of biological research. In neuroscience, the activity of neurotransmitters can be regulated by protecting the molecules with photoresponsive protecting groups (PPGs), also known as cages. Diverse set of PPGs have been developed for caging of biomolecules. PPGs can be categorized based on their absorbing wavelengths (ranging from UV to near-IR) and photochemical properties (quantum yield, photo-cross section, solubility). PPGs absorb light and undergo intramolecular electron transitions and bond rearrangements that result in the release of the caged substrates. Hence, the caging of a specific substrate is unique …

Effects Of Electrical Stimulation On Glioma Cells In Vitro With Implications For Treating Chronic Pain: Development Of A Model System, David C. Platt

Theses and Dissertations

Glial cells comprise over 70% of the central nervous system cells and exhibit diverse functions including regulation of synaptic transmission, neuron protection/repair, maintenance of neuronal metabolism, and are implicated in the development of persistent neuropathic pain. In addition, a perturbation in the concentration of intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS) has likewise been associated with the development of a chronic pain state. This perturbation in ROS/RNS creates an environment of oxidative stress. However, the mechanism by which the pain signal transmission is modulated, and the roles ROS play in the perpetuation of the pain state are …

Development Of Acceptor-Integrated Crystalline Organic Materials, Brandon Yarbrough

Theses and Dissertations

We report the first example of fullerene-containing porous covalent-organic scaffold, which combines not only crystallinity and porosity, but also integrates the intrinsic properties of a redox-active buckyball, along with the ability to tune electronic properties. Thus, the presented studies not only demonstrate the possibility of merging the strong electron accepting properties of fullerene-based derivatives with the versatility of covalent-organic frameworks (COFs), but also begin the class of crystalline, entirely organic, donor-acceptor fullerene COFs through covalently modifying the channel walls. These studies could foreshadow new avenues for buckyball utilization for applications ranging from organic photovoltaics to molecular electronics.

Nanoscale Control Of Metal Oxideand Carbonaceous Functional Materials, Benjamin W. Lamm

Theses and Dissertations

The controlled fabrication of nanometer scale devices is of fundamental concern for numerous technologies, from separations to electronics and catalysis. The complexity of device architectures calls for the development of synthetic methods that independently control each feature: pore dimensions, wall thickness, and any subsequent functional nanomaterial layers (e.g. photoactive electrocatalysts). Precision control over these orthogonal methods can be used to integrate 3D and 1D nanostructures.

This dissertation presents the development of techniques useful in fabricating highly controlled nanoscale devices. The growth of single-phase bismuth vanadate (BiVO4) by atomic layer deposition (ALD) is demonstrated for the first time, allowing for the …

Catalytic Upgrading Of Aromatic Oxygenates Related To Lignin, Nicholas A. Delucia

Theses and Dissertations

Lignin is one component of lignocellulosic biomass and is the only renewable, naturally-occurring source of aromatics in the world. However, lignin also provides a highly-oxygenated, complex, heterogeneous structure making the procurement of isolated aromatic molecules quite difficult. There has been extensive research in recent years to develop approaches to catalytically breakdown the lignin polymer into monomeric units. This works aims to develop a number of catalytic techniques for the upgrading of these monomeric units of lignin to produce means for producing chemical building blocks as well as suitable fuels from biomass sources.

A method for the silanolysis of alcohols has …

Kinetically Controlled Block Polymer Micelles: Cavitation Induced Exchange And Templates For Nanomaterials, Kayla Alice Lantz

Theses and Dissertations

Kinetically trapped micelles are emerging as a novel platform for a wide range of applications including drug delivery, nanoreactors, and templates for porous nanomaterials. Kinetic control affords decoupling of micelle size from subsequent applications. However, micelle homogenization and size tuning are inherently difficult due to the high barrier toward micelle chain exchange processes. These challenges can be resolved with the use of sonication, which enables switchable exchange where cavitation leads to chain exchange and cessation returns micelles to kinetic entrapment. Small-angle neutron scattering (SANS) measurements were used to quantify exchange during cavitation induced exchange (CIE). The extent of exchange was …

Structural And Functional Studies On 4-Hydroxy- Tetrahydrodipicolinate Reductase: Potential Drug Target In Bacteria, Swanandi Pote

Theses and Dissertations

Antimicrobial resistance has become an alarming public health concern since early 2000’s. Infections caused by multidrug resistant bacteria not only increase the mortality rate but also increase the economic burden globally. One approach to alleviate this issue is to find novel drug targets. In this regard, the bacterial lysine biosynthesis pathway provides several targets that may be used for design of antimicrobial compounds. Bacteria use lysine or meso-diaminopimelate to crosslink the peptidoglycan monomers in the bacterial cell wall. As such, we hypothesize that blocking this pathway will induce defects in the bacterial cell wall that are similar to those …

Emergent Properties And Applications Of Self- Assembled Benzophenone-Containing Materials, Baillie A. Dehaven

Theses and Dissertations

Supramolecular assembly of benzophenone through urea hydrogen bonding interactions facilitates the formation of remarkably persistent triplet radical pairs upon UV-irradiation at room temperature, whereas no radicals are observed in solution. The generation of organic radicals is correlated to the microenvironment around the benzophenone carbonyl, the types of proximal hydrogens, and the rigid supramolecular network. High-Field EPR and variable temperature X-band EPR accompanied by simulations suggest a resonance stabilized radical pair through hydrogen abstraction. Previous work has shown that UV-irradiation of self-assembled benzophenone bis-urea host results in low quantities of radical pairs that can be used to enhance NMR signals …

Impact Of Glutathione Transporters On Subcellular Glutathione Pools And Cell Survival In Saccharomyces Cerevisiae, Crystal Conaway Mcgee

Theses and Dissertations

Thiol-disulfide redox homeostasis is integral for maintaining the redox status of proteins and other thiol-containing molecules within cells. Mitochondria are particularly vulnerable to disruptions in redox balance, due to production of reactive oxygen species (ROS) during oxidative metabolism. Among the many antioxidants and detoxifying enzymes existing in mitochondria, glutathione (GSH) has proven to be critical for the preservation of function and structural integrity of the organelle. Therefore, our studies are aimed at elucidating the factors that control mitochondrial GSH metabolism in the model eukaryote Saccharomyces cerevisiae (baker’s yeast). A critical component of understanding subcellular GSH homeostasis is identifying routes of …

Sustainable Polymers And Antimicrobial Biomaterials From Multicyclic Natural Products, Md Anisur Rahman

Theses and Dissertations

In this dissertation, the development of sustainable polymers and antimicrobial biomaterials from multicyclic natural products is illustrated. In Chapter 1, an overall background and recent development of sustainable polymers from natural product-based renewable biomass, antimicrobial biomaterials, and polymerization methods are introduced. Afterward, the primary research objectives of my doctoral research work are illustrated.

In chapter 2, designing block copolymer architectures toward tough bioplastics from renewable natural rosin was described. One of the most abundant natural biomasses is resin acids, however, most of the polymers derived from resin acids are brittle because of their bulky hydrophenanthrene pendant group. To overcome the …

Anion Pool Directed Electroorganic Synthesis, D.M.M. Madushanka Mevan Dissanayake

Theses and Dissertations

The “Anion pool” approach introduces a greener approach for derivatization of pharmaceutically important molecules by amalgamating both electrochemistry and organic synthesis. This is a base and metal free procedure carried out in organic solvents recommended for pharmaceutical preparations. The anion pool procedure generates reactive nitrogen nucleophiles in situ via electrochemical reduction of heteroaromatic substrates. The adoption of such a methodology prevents generation of waste from bases used for deprotonation. Hydrogen is the main by-product of generation of anion pool, which, if produced at a large enough scale could be used as a renewable fuel. These attributes comply with the principles …

Development Of Nickel Catalyzed Cross-Coupling Methodologies, Ryan J. Key

Theses and Dissertations

In this work, we have addressed some of the issues surrounding catalytic crosscoupling reactions by using a nickel terpyridine catalyst, [Ni(tpy)(py)(CH3CN)2](PF6)2 in the Buchwald-Hartwig amination reaction and a functionalized variant, [(2,2':6',2''- terpyridine-4'-benzoic acid)Ni(II)]Cl2 on SiO2, in Suzuki coupling. These processes are unique in the approaches taken to achieve reactivity. In the Buchwald-Hartwig amination reaction, we used photoredox dual catalytic methods to achieve a sustainable approach to generate secondary and tertiary amines. This report is unique in many ways; most importantly, this method uses N-centered radicals to generate new C-N bonds. This report is also the first report to show generation …

Cooperative Lewis Pairs Based On High-Valent Early Transition Metal Halides And Synthesis Of Their Nitride Complexes, Md. Mamdudur Rahman

Theses and Dissertations

Herein, we report the activation of relatively strong C–H and C–O bonds under mild conditions by a cooperative interaction of TaCl5 and PPh3. An unprecedented activation of nitrile adducts of high-valent transition metals with the formation of novel zwitterionic imido complexes was observed. The scope of the reaction includes a range of substituted unactivated nitriles including the C–H bond activation of both aliphatic and aromatic nitriles.

The cooperative action of a Lewis acidic high-valent transition metal halide (TaCl5 or NbCl5) and a weakly nucleophilic base (NEt3 or PPh3) leads to the deprotonation of a coordinated nitrile and subsequent rearrangement to …

Metal-Organic Frameworks: Photophysics, Energy Transfer, And Electronic Structure, Ekaterina A. Dolgopolova

Theses and Dissertations

The current landscape of technological and industrial related fields is looking for novel materials with enhanced performances, which will not only improve various fields in science, but also can ensure increased environmental safety. Recently, metal-organic frameworks (MOFs) have been shown as a promising type of material for a wide range of applications including gas storage and separation, sensing, and heterogeneous catalysis. The main advantages of MOFs rely on their modular structures as well as their porosity. For instance, the modular nature of MOFs provides a control over chromophore arrangement, systematic tuning of ligand design and synthetic conditions allowing one to …

Nanoparticles With Tunable Fluorophobic Effect Towards Multimodal Coassembly With Block Copolymers, Zachary Michael Marsh

Theses and Dissertations

Nanomaterials are often fabricated using block polymers to direct the placement of nanoparticles via selective intermolecular interactions such as hydrogen bonding. Fluorophobic interactions have emerged as a promising handle to control nanoparticle placement independently from typical hydrophilic approaches. A series of nanoparticles with tunable fluorophobicity were prepared to elucidate the key parameters for harnessing fluorophobic interactions in this context. Mixed ligand fluorinated nanoparticles (ML-FNPs) where prepared to examine the competing roles of each ligand towards fluorophobicity and solubility. The ML-FNP intermolecular interactions were first studied using a custom-made Quartz Crystalline Microbalance (QCM) based technique. The ML-FNPs were then examined for …

Interfacial Ligand Dynamics And Chemistry On Highly Curved Nanoparticle Surfaces: A Plasmon-Enhanced Spectroscopic Study, Esteban Villarreal

Theses and Dissertations

The dynamic interactions between capping ligands and nanoparticle surfaces play a critical role in guiding shape-controlled nanocrystalline growth, imparting unique physical and chemical properties to the nanoparticles. It has been well established that nanoparticles within the size regime of sub 5 nm possess unique heterogeneous catalytic properties, while sub wavelength metallic nanoparticles exhibit tunable plasmonic activity, when these properties are integrated into a single nanoparticle, it presents a significant opportunity to monitor, in real time, the molecular transformations associated with interfacial interactions at the nanoparticle surface. Using plasmon-enhanced Raman scattering as an ultrasensitive spectroscopic tool combining molecular fingerprinting with time …

The Investigation Of Nickel-Based Catalysts For The Oxidative Dehydrogenation Of Ethane, Justin Lane Park

Theses and Dissertations

The Investigation of Nickel-Based Catalysts for the Oxidative Dehydrogenation of Ethane Justin Lane ParkDepartment of Chemistry & Biochemistry, BYU Doctor of Philosophy Chemistry The advancement of creating ethylene from ethane via oxidative dehydrogenation (ODH) rather than the traditional direct dehydrogenation is right on the cusp of commercialization. The oxidative pathway provides a novel route that reduces the operating temperature of this reaction by 400-500°C. A variety of metals including Mo, V, and Ni that have redox properties suitable for the partial oxidation of small chain alkanes have been investigated. Currently, a MoVNbTe oxide is the most promising catalyst but it …

Multi-Instrument Surface Characterization Of Display Glass, Cody Vic Cushman

Theses and Dissertations

Flat panel displays (FPDs) are microfabricated devices that are often fabricated on specialized glass substrates known as display glass. The surface chemistry of the outer few nanometers of display glass can have an important influence on FPD performance and yield. Dsiplay glass surface characterization is difficult because (i) display glass surface composition varies significantly from its bulk composition; (ii) high-surface area forms of glass, such as fibers and powders, may not have the same surface composition as melt-formed planar surfaces, and (iii) the surface composition of display glass may be altered through exposure to chemical treatments commonly used during flat …

Synthesis And Metalation Of Internally Alkylated Porphyrinoids, Alissa Nicole Latham

Theses and Dissertations

The mechanism behind alkyl migration in palladium(II) benzocarbaporphyrins was investigated through the synthesis of a 23-methylcarbaporphyrin. It was found that palladium insertion led to methyl group migration to C21 and it is proposed that this occurs through an oxidative addition onto the palladium metal center, followed by a reductive elimination to transfer the methyl to the internal carbon. A similar rearrangement was observed when 23-methylcarbaporphyrin was reacted with [Rh(CO)2Cl]2 and resulted in the formation of a rhodium(III) complex containing a three-membered rhodacycle. The syntheses of rhodium(I) and rhodium(III) derivatives of other carbaporphyrins, including 21- and 22-methylbenzo-carbaporphyrins, were probed and four …

Fracture Toughness And Fatigue Crack Growth Rate Characterization Of Inconel 718 Formed By Laser Powder Bed Fusion, Charles C. Hohnbaum

Theses and Dissertations

Continuing improvement in the field of AM of metals provides the opportunity for direct fabrication of aerospace parts. AM was once used in large part for rapid prototyping but improvements in technology and increases in the knowledge base of AM materials has provided the opportunity for manufacture of AM parts for operational use. The ability to create low numbers of unique parts without having to invest in expensive tooling provides great economic incentive to utilize this technique. IN718 is the most common high temperature alloy used in the aerospace industry and lends itself readily to formation by LPBF. The superior …

Control Strategies For Multi-Evaporator Vapor Compression Cycles, Sunderlin D. Jackson

Theses and Dissertations

Next-generation military aircraft must be able to handle highly transient thermal loads that exceed the ability of current aircraft thermal subsystems. Vapor compression cycle systems are a particular refrigeration technology that is an attractive solution for dealing with this challenge, due primarily to their high efficiency. However, there are several barriers to realizing the benefits of vapor cycles systems for controlling thermal loads in military aircraft. This thesis focuses on addressing the challenge of controlling vapor cycles in the presence of highly transient evaporator heat loads. Specifically, a linear quadratic regulator (LQR) is designed for a simple vapor cycle system, …

Creep Of Nextel 720/Alumina Ceramic Matrix Composite With Diamond-Drilled Effusion Holes At 1200°C In Air And In Steam, Megan L. Harkins

Theses and Dissertations

A recent study evaluated tensile stress-strain and tensile creep behavior of an oxide-oxide composite (Nextel™720/alumina) with laser-drilled effusion holes at 1200°C. It was determined that the presence of laser-drilled holes degraded the mechanical properties and performance of the CMC as a result of damage caused to the composite microstructure by the laser drilling process. Based on these results, the present effort sought to assess the effects of diamond-drilled holes on the mechanical behavior of this CMC. Tensile properties of the N720/A composite at 1200°C in laboratory air were unaffected by the presence of an array of 17 diamond-drilled effusion holes. …

Process Parameter Development Of Additively Manufactured Af9628 Weapons Steel, Erin M. Hager

Theses and Dissertations

The manufacture of components in Additive Manufacturing processes is limited by the range of materials available. Qualification of materials for Additive Manufacturing is time intensive, and is often specific to a single type of machine. In this study, an approach to selecting power, speed, and hatch spacing values for a newly powderized material, AF9628 weapons steel, is described that results in highly dense (>99.9%) parts on an MLab 200R Cusing. Initial power and speed values used in a weld track study were selected based on a survey of parameters used on similar materials, with a focus on the energy …

Selective Catalysis By Polymer-Supported Ruthenium Nanoparticlesand New Ligand Design For Cooperative And Bimetallic Catalysis, Seyed Hadi Nazari

Theses and Dissertations

The abstract is the summary of three different projects all centered around the generalidea of catalysis which is the general theme of research in the Michaelis laboratory. The firstproject focuses on development of a new heterogeneous catalyst for selective catalysis. In theMichaelis lab, we were interested in the potential of nanoparticle catalysts for regioselectivetransformations. We showed that polymer supported ruthenium nanoparticles performed as areliable catalyst for regioselective reduction of azide to amine. In our study of regioselectivereduction of multiple azide containing substrates, we observed that in presence of ourruthenium nanoparticle catalysts, the least sterically hindered azide group reduced to aminefunctional …

Applications Of Pattern Recognition Entropy (Pre) And Informatics To Data Analysis, Shiladitya Chatterjee

Theses and Dissertations

The primary focus of my work is the application of informatics methods to the fields of materials science and analytical chemistry. The statistical analysis of data has become increasingly important in understanding the properties of materials and analytes. Statistical methods like principal component analysis (PCA) and multivariate curve resolution (MCR) are widely used for analysis in chemistry and other fields given their ability to categorize spectra in an unsupervised way. PCA is relatively easy to apply and has appealing mathematical properties. However, the results can be challenging to interpret, even for experienced users. In contrast, MCR results can be more …

Applications Of Chemically Modified Nitrogen Doped Carbon, Zirconium Phosphate, Metal Organic Frameworks, And Functionalized Graphene Oxide Nanostructured Adsorbents In Water Treatment, Ayyob Mohammed A Bakry

Theses and Dissertations

Water contaminations by many pollutants, especially heavy metals such as Pb(II), Hg(II), Cu(II), Cd(II), and Cr(VI) pose many public health and environmental concerns as reported in the list of hazardous substances compiled by the US Environmental Protection Agency due to their high toxicity, refractory degradation, and ease of entering food chain. Adsorption by chelating resins is proven to be the most effective method for the extraction of metal ions from polluted and wastewater. However, traditional absorbents such as activated carbon, activated alumina, clay, zeolite, etc., show limited adsorption abilities for these heavy metal ions. The major goal of this thesis …