Physical Sciences and Mathematics Commons^™

Recent Studies On The Synthesis Of Medicinal Molecules., Paige Monsen

Electronic Theses and Dissertations

Medicinal chemistry interfaces synthetic organic chemistry, natural product chemistry and chemical biology, with a goal of yielding therapeutic agents. Natural products or compounds derived from natural sources such as plants, animals, and microorganisms, are often biologically active and render that compound a likely drug lead. For thousands of years humankind has utilized natural products for medicinal purposes and consequently scientists take advantage of both these compounds’ core structural characteristics and their modes of actions on selected targets as inspiration to develop therapeutics. Because the total synthesis of such complex molecules can be cumbersome and expensive, semi-synthetic methods on isolated natural …

Synthesis And Characterization Of Novel Organic Ligands With Their Complexes Of Platinum, Copper And Uranium, Mustafa Adnan Yasin Aldulaimi

Dissertations

Transition metal complexes of symmetrical and asymmetrical Schiff bases have played a significant role in the field of coordination, inorganic, and bioinorganic chemistry as models for biological, analytical, industrial, and pharmaceutical applications. Over recent years a great deal of interest has developed in new transition metal complexes of Schiff base ligand. The preparation of novel organic ligands is the most important step in the development of metal complexes that exhibit unique properties and novel reactivity. To highlight the presentation of this dissertation and to provide more detailed investigations, the dissertation was separated into six chapters according to the sequence of …

Synthesis, Self-Assembly, And Material Applications Of Unimolecular Polyviologens, Abigail Delawder

Arts & Sciences Electronic Theses and Dissertations

Intellectual Gaps: Synthesis of high molecular weight, unimolecular, and sequence-defined polyviologens; spatiotemporal control over mechanical properties of materials using visible and near-IR light; on-demand, post hoc manipulation of materials

Intellectual Merit: Robust method for synthesizing higher-order polyviologens of distinct molecular weight; control the change in the mechanical properties of polymer-based, crosslinked materials using a wide range of wavelengths of light; degradation of viologen-crosslinked hydrogels

To understand fundamentally how viologens behave within a polymer chain, we needed a better and more efficient way of synthesizing these long chains of polyviologens. As simple as this process looks on paper, the synthesis is …

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. …

Exploration Of Fluorinated Α,Β-Dehydroamino Acids And Their Structure, Austin Lesueur

Undergraduate Honors Theses

This thesis explores the synthesis of fluorinated α,β-dehydroamino acids, specifically a fluorinated dehydrovaline derivative. Previous work has been done on the equivalent dehydrovaline derivative without fluorine present and this work builds toward the fluorinated version with the goal of comparing the two structurally. The synthesis presented here pulls from previous synthetic strategies employed for dehydrovaline while also exploring the synthetic impact of the electronegative fluorine atoms.

Facile Synthesis Of Metal Oxides, Sulphides, And Phosphides For Enhanced Energy Applications, Alfred Nkhama

Electronic Theses & Dissertations

An access to reliable, sustainable, eco-friendly and cost-effective energy supply is being challenged by the global increase in population and the rapid technological advancement. Sophisticated systems, machinery and various devices being innovated, require the steady energy supply for their operations and applicability. To have reliable energy, numerous researches are being conducted through various approaches across the world. In this research work, the facile approach in investigating and tuning the materials properties was employed to improve energy properties of metal oxides. Nanostructured NiFe-oxide and CoFe-oxide were synthesized using a facile coprecipitation method. It was revealed that; nanostructured materials have favorable structures …

Applications Of Sodium Azide In The Synthesis Of Tetrazines And Hydrolysis Reactions, My Le

Honors Theses

The inverse electron demand Diels−Alder cycloadditions of heterocyclic azadienes have provided a robust methodology for synthesizing highly substituted and functionalized heterocycles. It is widely used in organic synthesis and the pharmaceutical industry in the divergent construction of screening libraries and bioorthogonal conjugation. Each heterocyclic azadiene was found to possess a unique reactivity toward different classes of dienophiles, display predictable modes of cycloaddition, and exhibit substantial substituent electronic effects impacting their intrinsic reactivity and cycloaddition regioselectivity. Synthesis of 1,2,4,5-tetrazine has been reported in the literature since the late 19th century, showing scientists' tremendous interest in its application.

Herein we attempt to …

Synthesis Of A Dd-Π-Aa Organic Dye For Dye-Sensitized Solar Cells, Hope Lovell

Honors Theses

This project investigates the synthesis of a DD-π-AA (dual donor/dual acceptor) organic dye as a potential sensitizer for dye-sensitized solar cells (DSCs). The design of this dye was based off previous research that found dual donor/dual acceptor dyes exhibited promising results when used in a DSC. The donor groups, acceptor groups, and π-bridge were chosen for their stability, ability to absorb in the near-infrared (NIR) region, and intramolecular charge transfer (ICT) abilities.

While many components of the dye were synthesized, the final stages of the synthetic scheme were not completed due to the loss of time from COVID-19. Had the …

Synthesis Of Bulky And Polar Galactonoamidines For The Inhibition Of The Human Α-Galactosidase, Ifedi Orizu

Graduate Theses and Dissertations

Glycosidases are amongst the most abundant enzymes in nature. This is due to their role in the degradation of carbohydrates which are the major source of carbon or earth. The absence or malfunction of glycosidases is implicated in numerous diseases such as cancers, diabetes, and lysosomal storage disorders, which make them important drug targets for study in medicinal chemistry. The seminal work by Pauling and Wolfenden showed that enzymes bind to their substrate at the transition state with very strong affinity. Wolfenden estimated the dissociation constant to be around 10-22M. This encouraged the design of glycosidase inhibitors which mimicked one …

Nitro Group Reduction For Use In Organic, Cathodic Materials, Brock G. Goeden

Honors Thesis

The industrial demand for higher capacity, light-weight battery materials has skyrocketed in recent years due to heavy investments in portable electronics, electronic vehicles, and renewable energy sources. However, rechargeable battery technology has seen little improvement since the invention of the Lithium-Ion battery in the 1980s. The low energy density of the traditionally utilized LiCoO2 cathodic material (specific capacity: 272 mAh g-1), has limited its potential to meet these increasing demands. To solve this problem, our research group is investigating new types of lightweight, organic, polymeric materials with conductive backbones as a possible replacement for the cathodic materials in Lithium-Ion batteries. …

Electrospinning Fibers Via Complex Coacervation, Xiangxi Meng

Doctoral Dissertations

Electrospun fibers are high-surface-area materials widely used in applications ranging from batteries to wound dressings. Typically, an electrospinning precursor solution is prepared by dissolving a high-molecular-weight polymer in an organic solvent to form a sufficiently entangled solution. Our approach bypasses the requirement for entanglements and completely avoids toxic chemicals by focusing on using an aqueous complex coacervates solution. Coacervates are a dense, polymer-rich liquid phase resulting from the associative electrostatic complexation of oppositely charged macroions. We were the first to demonstrate that liquid complex coacervates could be successfully electrospun into polyelectrolyte complex (PEC) fibers. A canonical coacervate system was formed …

Comparisons Of Silver Nanoparticle Synthesis Methods By Microwave And Non-Microwave Using Hydrogen Gas As A Reducing Agent, Sofia Erech Hanapin

Honors Theses

Synthesis and characterization of silver nanoparticles are of current interest. This research project describes a simple and rapid synthesis of silver nanoparticles upon reduction of Silver (I) oxide (Ag2O) by molecular hydrogen (H2) at elevated temperature (70 – 100 °C) and a pressure of > 1 atmosphere by heating the aqueous mixture using a common kitchen microwave. This reaction generates naked silver colloids that contain no foreign stabilizers other than metal particles in aqueous media. Its application of an antibacterial effect was monitored by using biological cultures using the Kirby-Bauer Test.

An Investigation Of Cross-Links On Crystallization And Degradation In A Novel, Photocross-Linkable Poly (Lactic Acid) System, Nicholas Baksh

USF Tampa Graduate Theses and Dissertations

Polymeric molecular structure consists of repeating units bonded together. Mechanicalproperties can be altered without affecting chemical makeup by altering the number of these units. Small molecules can be introduced and/or polymers can be modified to form bonds between molecular chains. Cross-linking, as this is called, also introduces mechanical variation with minimal effects on chemical composition. Lastly, polymer chains reorient themselves in response to intermolecular forces. This temperature dependent response is known as crystallization. Although chemistry is unaltered, mechanical properties can depend highly on the percent of the sample that is crystallized.

Cross-linking is known to enhance the mechanical properties of …

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 …

Synthesis Of A Series Of Ag(I)-Nhc Complexes For Future Antibacterial Studies, Alyssa Malto

Honors Program Theses

For thousands of years, silver (Ag) has been widely used for medicinal purposes due to its broad-spectrum antimicrobial properties. While medicinal silver usage declined with the advent of antibiotics, there has been a renewed interest in therapeutic silver coordination compounds to combat the spread of antibiotic resistance. N-heterocyclic carbenes (NHCs) are promising ligands for silver metallodrugs due to their wide structural variety that allows for tunability of the complex’s overall steric and electronic properties and previously established bioactivity against various pathogens and cancer cell lines. There is potential for efficacy against biofilms, a type of microbial growth pattern that is …

The Chemistry Of Superelectrophilic Phosphonium Ions, Nathan David Scanlon

Graduate Research Theses & Dissertations

A series of aryl-substituted phosphines have been prepared using superelectrophilic aromatic substitution chemistry. This chemistry involves reactive phosphonium-carbenium dications and related species. In addition to low molecular weight aryl-substituted phosphines, we also are able to prepare functionalized polystyrene products.

Relating Detonation Parameters To The Detonation Synthesis Of Nanomaterials, Martin Langenderfer

Doctoral Dissertations

“This research investigates the physical and chemical processes that contribute to the detonation synthesis of silicon carbide nanoparticles. Bulk production of SiC nanoparticles through detonation is possible due to pressures achieved over 20 GPa and temperatures over 2000 K as well as quenching rates in excess of 13 billion K/second. These conditions catalyze reaction and bottom-up molecular growth while retaining particles < 100 nm in diameter. In this work, detonation synthesis of SiC was demonstrated by incorporation of polycarbosilane, an SiC precursor material, into an RDX/TNT explosive matrix prior to detonation. Detonation Synthesis of SiC was also accomplished by reacting elemental silicon with carbon liberated by the detonation of negatively oxygen balanced TNT. Hydrodynamic simulation of a 60:40 mass ratio RDX/TNT detonation created conditions thermodynamically suitable to produce cubic silicon carbide within the first 500 nanoseconds after the passage of the detonation wave while carbon remains chemically reactive for molecular formation. Simulations and experimental tests indicated that loading configuration and impedance mismatch of the precursor additives used in detonation synthesis results in conditions in the additives that exceed the accepted detonation pressure of the explosive by greater than three times. Finally, a full factorial experimental design showed increasing silicon concentration, reducing silicon size, and reducing oxygen balance by adjusting the ratio of RDX to TNT decreased the explosives detonation pressure by 20% and increased the soot yield and concentration of SiC observed in the detonation products by 82% and 442% respectively”--Abstract, page iv.

Novel Acetylcholine Chloride Based Water Immiscible Deep Eutectic Solvent: Formulation, Characterization And Application In Drug Solubilization, Shiksha Subedi

Electronic Theses and Dissertations

Deep eutectic solvents (DESs) are the emerging class of new and inexpensive solvents composed of two or three safe components capable of self-association through hydrogen bond interaction. The depression in the melting point characterizes DESs compared to those of the individual components. These solvents have properties like the traditionally used ionic liquids (ILs), but they can offset the significant drawbacks of ILs, such as biodegradability, toxicity, and complex synthesis. Due to these remarkable advantages, the research in DESs is increasing exponentially. However, current deep eutectic solvents still have limitations to apply to the real chemical industries due to hydrophilicity and …

Synthesis, Crystal Engineering, And Material Properties Of Small-Molecule Organic Semiconductors, Emma Holland

Theses and Dissertations--Chemistry

Small-molecule organic materials are of increasing interest for electronic and photonic devices due to their solution processability and tunability, allowing devices to be fabricated at low temperature on flexible substrates and offering utility in specialized applications. This tunability is the result of functionalization through careful synthetic strategy to influence both material properties and solid-state arrangement, both crucial variables in device applications. Functionalization of a core molecule with various substituents allows the fine-tuning of optical and electronic properties, and functionalization with solubilizing groups allows some degree of control over the solid- state order, or crystal packing. These combinations of core chromophores …

Synthesis Of Guaipyridine Alkaloids Rupestines C, D And K With Studies Toward The Synthesis Of Rupestines B, J, L And M, Briana J. Mulligan

WWU Graduate School Collection

Hepatocellular carcinoma (HCC) is a type of primary liver cancer that is responsible for roughly 700,000 deaths around the world each year. While invasive treatment methods for HCC have proven to be limited, there are drug treatments available that show promising features. The structural elements of these drugs have given rise to an interest in guaipyridine alkaloids, specifically a family of naturally occurring guaipyridine alkaloids known as the rupestines. The rupestines have previously been isolated from the flowers of the plant Artemisia rupestris. This plant has been known for its reported antitumor, antiviral and antibacterial properties when used in traditional …