Physical Sciences and Mathematics Commons^™

Synthesis And Characterization Of Mixed Ligand Complexes Of Ruthenium(Ii) Containing 2,2’-Bipyridine And 3,3’-Dimethyl-1,1’- Methylenebisimidazolium Ligands; A New Synthetic Approach, Matthew Schneider

Theses and Dissertations

Research into solar cells has been prioritized given the global demand for better renewable energy technologies. This demand is a result of the long-term use of fossil fuels, which generates significant pollution in highly populated urban areas. One potential solar cell technology is the dye-sensitized solar cell (DSSC). This kind of solar technology utilizes organometallic dyes to expand the types of wavelengths solar cells can use to generate electricity.12 Ruthenium(II) metal complexes of this type have been investigated heavily for this purpose.13,14,36 The main reasoning behind this is the metal-to-ligand charge-transfer (MLCT) phenomenon that such complexes exhibit. MLCT has often …

Pyridyl Bis-Urea Macrocycles As Supramolecular Synthons And The Design And Synthesis Of Small Molecule Pharmaceuticals Targeting Ly6k, Devan D. Buchanan

Theses and Dissertations

Assembled pyridyl bis-urea macrocycles have been utilized as 1D supramolecular synthons to construct hierarchical assemblies. These macrocycles have both urea and pyridyl functional groups and can form non-covalent interactions with hydrogen or halogen bond donors through symmetric, ditopic acceptor motifs. Bis-urea macrocycles offer interesting capabilities as synthons to organize donors into well-defined crystal structures. In part, this is due to the urea motifs’ propensity to assemble through hydrogen bonding. New, asymmetric pyridyl macrocycles were synthesized, crystallized, and experimentally probed to determine how symmetry affects their assembly and utility as supramolecular synthons.

The Uphadhyay group identified small molecules, including NSC11150, …

Applications Of Vanadium Phthalocyanine In Catalytic, Acid-Based Medium To Couple Sugar Molecules, Juan Ricardo Luna

Theses and Dissertations

The vanadium-substituted tetraazatetrabenzoporphyrin, vanadium phthalocyanine, was synthesized via reflux and characterized using FITR and XRD analysis. Subsequent to synthesis, the vanadium phthalocyanine was studied as a catalyst in redox reactions to convert fructose to different molecules, the products were predominately levulinic methyl ester and heptadionic acid. The ability to convert fructose to other compounds, such as alkyl levulinic derivative, is an important process to help eliminate reliance on traditional chemical feed stocks and promote alternative fuels. Levulinic acid has been commonly used as a starting material in the synthesis of biofuels and a precursor for pharmaceuticals, plasticizers, THF derivatives, γ-valerolatone. …

Fabrication Of Metal-Silicon Nanostructures By Reactive Laser Ablation In Liquid, Eric J. Broadhead

Theses and Dissertations

Metal-silicon nanostructures are a growing area of research due to their applications in multiple fields such as biosensing and catalysis. In addition, silicon can provide strong support effects to metal nanoparticles while being more cost effective than traditionally used supports, like titania. Traditional wet-chemical methods are capable of synthesizing metal-silicon nanostructures with a variety of composition and nanoparticle shapes, but they often require high temperatures, toxic solvents, strong reducing agents, or need capping agents added to stabilize the nanoparticles. Laser processing is an emerging technique capable of synthesizing metal-silicon composite surfaces that offers a faster, simpler, and greener synthesis route …

Aqueous Kinetics Of Α-Hydroxyhippuric Acid Derivatives Bearing Electron-Withdrawing Groups As A Function Of Ph And Buffer Catalysts, Mohamad Imad Rafie

Theses and Dissertations

It has been shown that carbinolamides are intermediates in the enzyme-catalyzed synthesis of -amidated peptides. Although carbinolamides are important intermediates in the production of these hormones and have roles in other biological venues, little attention has been given to their mechanisms of reaction in water, and, thus, it is difficult to speculate how their reaction would be enzymatically catalyzed. The purpose of the work presented here was to synthesize structural analogs of the biological intermediates and study their mechanism of breakdown in water. -Hydroxyhippuric acid, a substrate for the enzymatic system, provides an easily modified template for the study of …

A Study In Molecular Recognition: Synthesis Of A Β-Sheet Mimic & Quantitation Of Metal Ions In Aqueous Solutions Through Solid Supported Semi-Selective Chemosensors, Tyler G. Fenske

Theses and Dissertations

From the hydrophobic effect, which is responsible for the organization of amphipathic molecules into cellular membranes, to the highly specific hydrogen binding patterns found in DNA base pairs that keeps our genetic material “zipped up”, non-covalent and reversible interactions are critical to properly functioning biological processes. Molecular recognition is an area of study that seeks to better understand these observed phenomena. In a general sense, association of “Host” and “Guest” molecules are based on ionic forces, hydrophobic interactions, cation-π effects, π-π stacking, conformational restriction, and many others. This dissertation will primarily focus on two projects that have an emphasis on …

Preparation Of Polymeric Materials From Bio-Renewable Sources, Jason Douglas Smith

Theses and Dissertations

The focus of this project was to develop methodologies for the preparation of novel polymeric materials from bio-renewable sources. In order to complete this task we needed (a) unfettered access to bio-based materials and ways to convert them to value needed chemicals, as well as, (b) reaction protocols that would allow greater diversity during the synthesis of polymeric compounds so as to affect the properties of these materials.

Our research group has a background in converting plant-based materials like cellulose into value added chemicals employing catalytic reactions. The polymerization of these monomers was then conducted utilizing the Baylis-Hillman reaction. The …

Synthesis Of Small-Molecule Fluorescent Probe And Polymers For Bioapplication: Bioimaging And Enzyme Stabilization, Yanmei Xu

Theses and Dissertations

In chapter one, we designed, synthesized and characterized two cysteine sensors CCPAP and CCPAN, with improved water solubility, cell penetration ability, and potential targeting selectivity. Two types of positive charged groups, i.e. triphenylphosphonium and pyridinium were introduced respectively to the frame structure CCP by coupling carboxylic acid with amine to improve the cell permeability and cysteine selectivity. ESI-MS, NMR and IR were employed to characterize the molecular structures of the two novel probes. These probes have better water solubility than the parent molecule DCP, and better cell penetration capability than CEP, which could further distinguish the cysteine concentration differences in …

Synthesis And Characterization Of Polydiene-Grafted Nanoparticles, Zaid Mohammed Abbas Alajeeli

Theses and Dissertations

This dissertation presents the design, synthesis, and characterization of polydiene grafted nanoparticles as a way to tailor nanocomposite interfaces and properties via interface design. The polymerization of dienes was done via reversible addition fragmentation chain transfer (RAFT) polymerization. The grafting of polymer chains on the surface of silica nanoparticles can be controlled through the molecular design of the RAFT agents attached to the nanoparticles surface. The properties of the nanocomposites largely depended on the interface between the particles and the polymer matrix. In the first part of this work, the polymerization of diene monomers was done on 15 nm diameter …

Design, Synthesis, Characterization, And Applications Of Matrix Free Polymer Nanocomposites, Yucheng Huang

Theses and Dissertations

This dissertation focuses on the design, synthesis, characterization and application of matrix free polymer nanocomposites. Reversible addition-fragmentation chain transfer (RAFT) polymerization was used to synthesize block copolymers and polymer grafted silica nanoparticles with precise control over architectures.

In the first chapter, thermoplastic elastomer (TPE) grafted nanoparticles were prepared by grafting block copolymer poly(styrene-block-(n-butyl acrylate)) onto silica nanoparticles (NPs) (~15nm) via surface initiated RAFT polymerization. The effects of polymer chain length and graft density on the mechanical properties were investigated using films made solely from the grafted NPs. The ultimate tensile stress and elastic modulus increased with the increase of PS …

Synthesis And Reactivity Of Carborane Backbone Pincer Complexes, Bennett J. Eleazer

Theses and Dissertations

In organometallic chemistry, boron-centered ligand systems represent a powerful synthetic strategy for the promotion of a variety of catalytic transformations. These ligands offer a versatile array of bonding motifs, which can function as borane, boratrane, boryl, borate, or borylenes type ligands, and are likely the strongest σ-donors in the anionic series of ligands based on boron, carbon, nitrogen, and oxygen. Carboranes, which are icosahedral boron clusters of the type C2B10H12, offer unique potential as metal ligands, such as their bonding to exohedral metal centers being dominated by two-center-two-electron σ-bond interactions, their three-dimensional cluster structure providing considerable steric shielding to a …

Substituted Hydroxylamines As Nitrogen Transfer Reagents: Direct Synthetic Pathways To Structurally Rich Heteroatomic Scaffolds, Dylan John Quinn

Theses and Dissertations

Nitrogen is found in virtually all valuable chemical compounds. The abundance of atmospheric nitrogen however, is rendered inaccessible because of the strong N-N triple bond, ultimately preventing its practical utilization in synthetic organic synthesis. The development of powerful nitrogen transfer reagents, such as substituted hydroxylamine derivatives, have played an important role in the introduction of nitrogen into valuable chemical scaffolding.

Herein is reported the methodological development of synthetic nitrogen placement into a range of valuable heteroatomic compounds. This work shows that O-Substituted Hydroxylamine can be used to furnish small heteroatomic compounds, particularly nitriles. Whereas, N-Substituted Hydroxylamine can be employed to …

Synthesis And Characterization Of Metallic Nanoparticles For Catalytic Applications, Sarah Smith

Theses and Dissertations

In recent years, research has focused on reducing the cost of catalysts in a variety of ways including using less expensive materials, improving the synthetic method, and increasing the catalytic activity, recovery, and recyclability. Typically with nanoparticles, the size, shape, composition, and surface coating have an effect on catalytic activity.^1-2 In this work, we focused on reducing the cost of precious metal based catalysts by altering the synthetic methods.

One way to lower the cost of synthesizing precious metal nanoparticles is by debasing the precious metal with a second cheaper more abundant metal. CuPd nanoparticles were synthesized in oleylamine …

Part 1: Design, Synthesis, And Evaluation Of Novel Gram-Positive Antibiotics Part 2: Synthesis Of Dihydrobenzofurans Via A New Transition Metal Catalyzed Reaction Part 3: Design, Synthesis, And Evaluation Of Bz/Gabaa Α6 Positive Allosteric Modulators, Christopher Michael Witzigmann

Theses and Dissertations

Part 1. Lead compound SK-03-92 represents a new scaffold for antibiotic drug discovery. Development of a new process for the synthesis of analogs has led to the development of a number of new ligands with even more potent activity against gram-positive bacteria, including drug-resistant strains of S. aureus. Compounds 36 and 38 represent some of the most potent analogs developed thus far, and preliminary results indicate that they are also not cytotoxic. Research into a Heck-mediated transition metal catalyzed pathway towards electron-rich stilbenoid analogs has greatly expanded the scope of future SAR studies. This development has led to 14 new …

Synthesis Attempts And Plausible Applications Of Dithiolated Ortho –Carboranyl Transition Metal Complexes And Synthesis Of Bulky Terphenyls, Surendra Bahadur Karki

Theses and Dissertations

The reaction of coordination compounds of palladium, rhodium, ruthenium and nickel with thiolated ortho-carborane derivatives- 1,2-dimercapto-o-carborane (1,2-(HS)2-1,2- C2B10H10 ) and 9,12- dimercapto-o-carborane (9,12-(HS)2-1,2- C2B10H10 ) and with carbornanyl dicarboxylate has been studied. To further investigate the chemistry of o-carboranyl dithiolate, both of the reported literature dithiols have been employed to study the reactivity with some of the above mentioned transition metal coordination compounds. The 1,2-dimercapto-o-carborane reacts with bis(triphenylphosphine)palladium(II) chloride [PdCl2(PPh3)2] to form a square planar bis(triphenylphosphine)palladium(II) carboranyl dithiolate (PdC2B10S2(PPh3)2) complex. With the inspiration from the reactivity of the dithiols and versatility of carboranyldithiolate ligand in organometallic chemistry, new avenue of …

Materials Discovery By Crystal Growth: Synthesis, Structure Determination, Magnetic, And Optical Properties Of Complex Lanthanide Containing Oxides, Oxyhydroxides, And Oxyfluorides, Allison Marie Latshaw

Theses and Dissertations

Exploratory crystal growth is a versatile technique and one that can advance materials discovery. Through exploratory crystal growth, it is possible to synthesize many new materials that can have applications in many fields, including solid-state lighting. There exist many adaptations for exploratory crystal growth, including the use of alkali halide flux growth and hydroflux growth, both reported herein. By changing variants in these techniques like reactant ratios, temperature, reaction profile, and, most importantly here, the flux compositions, it is possible to change the products formed or fine tune reactions for product purity.

For solid-state lighting applications, compounds that adopt colorless …

Synthesis And Utility Of Bis-Urea Macrocycles As Nanoreactors And As Ligands For Metal Organic Materials, Sahan R. Salpage

Theses and Dissertations

“Supramolecular chemistry” powered by non-covalent interactive forces forms the crux in the area of host-guest chemistry. Supramolecular assemblies often have different chemical and physical properties than that of its individual molecular entities and are used to develop novel functional materials. Our expertise involves making functional materials from macrocycles, which contain two urea groups and two rigid C shaped spacer groups. These individual macrocyclic components can self-assemble through hydrogen bonding and other non-covalent interactions to form porous supramolecular assemblies that can be used as confined reaction environments and as ligands to synthesize novel metal organic materials.

This dissertation focuses on studying …

Part I. The Development Of Non-Secosteroidal Vitamin D Receptor Modulators Part Ii. The Development Of A Universal Gtp-Ase Assay, Kelly Ann Teske

Theses and Dissertations

The vitamin D receptor is a nuclear hormone receptor that regulates cell proliferation, cell differentiation, calcium homeostasis and immunomodulation. The receptor is activated by the vitamin D metabolite, 1,25-dihydroxyvitamin D3, which induces a cascade of events including the recruitment of coactivators that activate transcription of specific VDR target genes. Thousands of VDR agonists have been synthesized based on the secosteroid scaffold of 1,25-dihydroxyvitamin D3. However, most of these ligands are metabolically unstable, have sub-optimal drug-like properties, and induce hypercalcemia in vivo. The limited numbers of VDR antagonists reported bear the same secosteroid scaffold and thus exhibit similar problems encountered by …

Enantiospecific Stereospecific Strategy For The Total Synthesis Of Sarpagine And Macroline Related Oxindole Alkaloids: First Total Synthesis Of Affinisine Oxindole, Isoalstonisine, Alstofoline, Macrogentine, N(1)-Demethylalstonisine, Alstonoxine A And Second Generation Synthesis Of Alstonisine, German Oscar Fonseca Cabrera

Theses and Dissertations

The (7R)-sarpagine/macroline related oxindole alkaloids (-)-isoalstonisine (27) and (-)-macrogentine (31) together with the (7S)-sarpagine/macroline related oxindole alkaloids (-)-affinisine oxindole (24), (-)-alstonoxine A (19), (+)-alstonisine (8, second generation total synthesis), (+)-Na-demethylalstonisine (17) and (+)-alstofoline (18) were concisely synthesized during these studies.

These oxindole alkaloids were isolated from plants of the genus Alstonia which is characterized by the preponderance of sarpagine/macroline-type indole and oxindole alkaloids. Plants that belong to this genus are mainly distributed over tropical regions of Central America, Africa, and Asia where they are used locally in traditional medicine, for example, in the treatment of malaria and dysentery. The main …

Asymmetric Synthesis Of Tryptophan Driviatives And Its Application To Streamlined Synthesis Of Tryprosatain A And B, Matthew Huisman

Theses and Dissertations

Tryprostatins have been shown to be potential antitumor antimitotic agents. Tryprostatins have been isolated from the fermentation broth of marine fungal strain Aspergillus fumigatus in trace amounts. Our lab has developed a phase-transfer-catalyzed asymmetric alkylation reaction to produce protected tryptophans (Trp) with high enantioselectivity (90-95% ee) as synthetic precursors to Tryprostatins. Studies of Tryprostatins indicate that manipulation of ring-A may cause enhanced activity. We propose a general synthetic route to several new tryprostatins that may be tolerant to ring-A analogues of gramine utilizing achiral reactants. The synthesis of Tryprostatin B has been completed with 20% overall yield in 7 steps. …

Synthesis, Surface Functionalization, And Biological Testing Of Iron Oxide Nanoparticles For Development As A Cancer Therapeutic, Stanley E. Gilliland Iii

Theses and Dissertations

Iron oxide nanoparticles are highly researched for their use in biomedical applications such as drug delivery, diagnosis, and therapy. The inherent biodegradable and biocompatible nanoparticle properties make them highly advantageous in nanomedicine. The magnetic properties of iron oxide nanoparticles make them promising candidates for magnetic fluid hyperthermia applications. Designing an efficient iron oxide nanoparticle for hyperthermia requires synthetic, surface functionalization, stability, and biological investigations. This research focused on the following three areas: optimizing synthesis conditions for maximum radiofrequency induced magnetic hyperthermia, designing a simple and modifiable surface functionalization method for specific or broad biological stability, and in vitro and in …

Design, Synthesis, Characterization, And Evaluation Of Surface Modified Boronate Ester Covalent Organic Frameworks, Matthew W. Di Carmine

Theses and Dissertations

Covalent Organic Frameworks (COFs) were first reported in 2005 and are analogous to Metal Organic Frameworks (MOFs), with proposed applications in separation, storage and sequestration. Since COFs are comprised of lighter elements they are considered more advantageous for weight-sensitive applications. However, COFs are susceptible to degradation by weak nucleophiles such as water (i.e. hydrolysis). The Lavigne group has focused on developing structure-property relationships for COFs. It was previously demonstrated that the porosity of the COFs could be tailored by incorporating small alkyl chains on one monomer. Inclusion of these alkylated monomers into COF materials effectively increased the COF hydrophobicity resulting …

Facile Synthesis And Characterization Of A Thermally Stable Silica-Doped Alumina With Tunable Surface Area, Porosity, And Acidity, Maryam Khosravi Mardkhe

Theses and Dissertations

Mesoporous γ-Al2O3 is one of the most widely used catalyst supports for commercial catalytic applications. The performance of a catalyst strongly depends on the combination of textural, chemical and physical properties of the support. Pore size is essential since each catalytic system requires a unique pore size for optimal catalyst loading, diffusion and selectivity. In addition, high surface area and large pore volume usually result in higher catalyst loading, which increases the number of catalytic reaction sites and decreases reaction time. Therefore, determination of surface area and porosity of porous supports is critical for the successful design and optimization of …

Modified Seed Growth Of Iron Oxide Nanoparticles In Benzyl Alcohol: Magnetic Nanoparticles For Radio Frequency Hyperthermia Treatment Of Cancer, Stanley E. Gilliland Iii

Theses and Dissertations

Iron oxide nanoparticles have received sustained interest for biomedical applications as synthetic approaches are continually developed for precise control of nanoparticle properties. This thesis presents an investigation of parameters in the benzyl alcohol synthesis of iron oxide nanoparticles. A modified seed growth method was designed for obtaining optimal nanoparticle properties for magnetic fluid hyperthermia. With a one or two addition process, iron oxide nanoparticles were produced with crystallite sizes ranging from 5-20 nm using only benzyl alcohol and iron precursor. The effects of reaction environment, temperature, concentration, and modified seed growth parameters were investigated to obtain precise control over properties …

Synthesis, Characterization, And Application Of High Surface Area, Mesoporous, Stabilized Anatase Tio2 Catalyst Supports, Rebecca Elizabeth Olsen

Theses and Dissertations

Nanomaterials have attracted substantial attention in the area of catalysis due to the unique properties they exhibit such as high surface areas, intricate pore networks and unique morphologies. TiO2 has attracted attention as a catalyst since the discovery of its high photocatalytic activity by Fuishima and Honda in 1972. Given its high thermal stability, low cost, low environmental impact, and versatility, TiO2 is a widely used commercial catalyst and catalyst support. TiO2 is used in many applications such as photocatalysis is also an excellent support material for noble metals in a number of oxidative synthesis and pollution-control reactions. Though TiO2 …

Synthesis And Immunological Evaluation Of Type I, Type Ii, And Gamma Delta Nkt Cell Antigens, Brian L. Anderson

Theses and Dissertations

The purpose of the immune system is to protect our bodies from infection. One way it accomplishes this task is through the presentation of foreign pathogens to NKT cells. After an antigen is presented to the T cell receptor, activated NKT cells quickly release soluble chemical signals, termed chemokines and cytokines, that modulate the response of the immune system. Due to the immunological relevance of NKT cell activation, we developed and synthesised non-natural analogs of immunostimulatory type I, II, and gamma delta NKT cell antigens. The immunological evaluations of these analogs resulted in identification of sulfatide as a gamma delta …

Facile Synthesis And Improved Pore Structure Characterization Of Mesoporous Γ-Alumina Catalyst Supports With Tunable Pore Size, Baiyu Huang

Theses and Dissertations

Mesoporous γ-alumina is the most extensively used catalysts support in a wide range of catalytic processes. The usefulness of γ-alumina relies on its favorable combination of physical, textural, thermal, and chemical properties. Pore structure properties are among the most important properties, since high surface area and large pore volume enable higher loading of active catalytic phases, while design of pore size and pore size distribution is critical to optimize pore diffusional transport and product selectivity. In addition, accurate determination of surface area (SA), pore volume (PV) and pore size distribution (PSD) of porous supports, catalysts, and nanomaterials is vital to …

Silylation-Based Kinetic Resolution Of Α-Hydroxy Carbonyl Compounds And Synthesis Of Chiral Isothiourea Catalysts, Yan Zhang

Theses and Dissertations

The thesis describes the silylation-based kinetic resolution for α-hydroxy carbonyl compounds catalyzed by isothiourea catalyst as well as our effort to make novel chiral isothiourea catalyst.

In Chapter 1, general background will be introduced, including chirality, general methods to obtain enantiopure compounds and kinetic resolution. In Chapter 2, the mechanism of the chiral recognition was discussed and a novel isothiourea catalyst was design to investigate the mechanism. The synthesis of the new catalyst was also described in this chapter.

In Chapter 3, the silylation-based kinetic resolution for α-hydroxy carbonyl compounds will be discussed. Since silylation-based kinetic resolution have already been …

The Synthesis And Structural Characterization Of Metal Oxide Nanoparticles Having Catalytic Applications, Stacey Janel Smith

Theses and Dissertations

Nanotechnology is blossoming into one of the premiere technologies of this century, but the key to its progress lies in developing more efficient nanosynthesis methods. Variations in synthetic technique, however, can cause variations in size, structure, and surface characteristics, thereby altering the physical properties and functionality of the particles. Careful structural characterizations are thus essential for understanding the properties and appropriate applications for particles produced by new synthetic techniques.In this work, a new ‘solvent-deficient’ method is presented for the synthesis of an unprecedentedly wide range of metal oxide nanomaterials including at least one metal oxide from each group in Groups …

Design And Synthesis Of Cationic Steroid Antimicrobial Compounds, Synthesis Of Glycolipids Recognized By Natural Killer T Cells And Development Of Tlr-1, Tlr-6 Heterodimer Binders And Studies Of Their Immunology Activities, Yanshu Feng

Theses and Dissertations

Cationic steroid antimicrobial agents (CSAs) are a family of bile acid derivatives. These compounds are amphiphilic and mimic endogenous antimicrobial peptides. The antimicrobial activities of CSA-13 have been investigated and due to portent bactericidal activities and low toxicity, a large amount of CSA-13 is demanded for clinic trails and other antimicrobial applications. During our studies, we optimized the synthetic route of CSA-13, so that it can be prepared at the kilogram, even in tons scale. We investigated three routes and one of them is suitable for industry, because only recrystallization is needed in the synthesis. Natural killer T cells (NKT …