Digital Commons Network^™

Towards Carbon Dioxide Reduction: Synthesis And Characterization Of Ccc-Nhc Pincer Iron Complexes., Joshua Mensah

Theses and Dissertations

The industrial revolution came with its downside of emission of greenhouse gases into the atmosphere. The NOAA reported in 2019 that, of the greenhouse gases emitted into the atmosphere, CO2 contributed to about 80% of the increased greenhouse gases hence the need for CO2 Sequestering and Storage (CSS) and ultimately leading to Carbon Capture and Recycling (CCR) as a viable option to convert CO2 into useful forms. The race to find the best catalyst for CCR has led to the synthesis of many organometallic compounds. Pincer complexes catalyzed CO2 reduction has gained notoriety recently because of the tunability and robustness …

Synthesis And Characterization Of Silver(I) And Manganese(Ii) Complexes With Thione Imidazoles, Shannon Keyser, Audrey Lawrence, Jaime M. Murphy Ph.D.

Honors Theses

Coordination polymers are chemical complexes with versatile applications such as catalysts, electrical conduc-tors, non-linear optics, magnetics, chemical sensing, and molecular storage. The polymers are comprised of a repeating series of metal-ligand complexes, which form various structures in varying ratios depending on the metal and ligand used. Certain metal-ligand combinations have shown particular promise as potentially being polymers or, if not polymers, possessing other useful features such as electromagnetic conductivity. Complexes were synthesized using silver(I) and manganese(II) with the ligands methimazole, 2-mercaptoimidazole, and thiocarbanilide with counterions of either chloride or nitrate. These com-plexes were characterized using elemental analysis, infrared spectroscopy, and …

Synthesis, Molecular Characteristics, And Antibacterial Assessment Of Marine Hydroid Aqueous Extract-Based Silver Bio-Nanoparticles, Fredryk Mandey, Aulia Rhamdani Arfan, Rugaiyah Andi Arfah

Makara Journal of Science

This investigation aims to synthesize, analyze the molecularity, and test the ability of bacterial inhibition capability of silver nanoparticles that have been synthesized by simply mixing silver nitrate and aqueous extracts of marine natural products with and without the addition of amylum as a stabilizing agent. This research, with and without the addition of amylum as a stabilizing agent, obtained 39.0 and 55.2 mg of solids of round-shaped morphology silver nanoparticles with diameters of 87.9 and 103.0 nm., respectively. In addition, the antibacterial testing assay against Staphylococcus aureus and Escherichia coli showed some considerably good results. S. aureus with the …

Study Of Solvent-Free, Microwave-Assisted Ring-Opening Reactions Of Phenyl Glycidyl Ether With Azoles, Marygrace Mcafee, Joshua Pack, Brian Walker

Arkansas Women in STEM Conference

Literature precedent supports that microwave-assisted organic synthesis can afford fast, high-yield, and efficient synthetic pathways, often comparable to or better than traditional heating methods. Building on this, our work utilizes microwave-assisted synthesis for the epoxide ring opening of phenyl glycidyl ether through nucleophilic addition, aiming to create both pyrazole and imidazole derivatives. These heterocyclic azole compounds have been shown to be important due to their presence in many natural products, as well as their anti-fungal and other pharmacological activities. We are exploring the use of microwave irradiation under neat (solvent-free) conditions, focused on a streamlined approach to minimize time, energy …

Exploration Of Novel 6,8,9-Trisubstituted Purine Analogues: Synthesis, In Vitro Biological Evaluation, And Their Effect On Human Cancer Cells, Muhammed Fatih Polat, İrem Durmaz Şahi̇n, Rengül Atalay, Meral Tunçbi̇lek

Turkish Journal of Chemistry

Cancer, a leading global cause of mortality, demands continuous advancements in therapeutic strategies. This study focuses on the design and synthesis of a novel series of purine derivatives, specifically 6-(substituted phenyl piperazine)-8-(4-phenoxyphenyl)-9-cyclopentyl purine derivatives (5–11). The motivation behind this endeavor lies in addressing acquired resistance mechanisms in cancer cells, a significant hurdle in current treatment modalities. The synthesis, starting from 4,6-dichloro-5-nitropyrimidine, involves a multi-step process, resulting in seven new purine derivatives. Biological evaluation against human liver, colon, and breast cancer cells (Huh7, HCT116, and MCF7, respectively) was performed using the SRB assay. Among the synthesized analogs, compounds 5 and 6, …

The Effect Of Variation Of N-Substituents On Oxidopyridinium Ions In (4+3) Cycloadditions, Zahria Patrick, Madison Clark

Undergraduate Research Symposium

The aim of this research project is to expand the scope of 4 + 3 cycloadduct chemistry by varying functional groups attached to the prerequisite oxidopyridinium ion for each respective cycloadduct product. While N-substitution of the pyridinium precursor is known to proceed smoothly if alkylated by a lone methyl group, we evaluated the effect a larger alkyl group would have on the overall yield of the 4 + 3 cycloadduct product.

Isobutyl triflate, generated from the known reaction between isobutyl alcohol and triflic anhydride, was reacted with ethyl 5-hydroxy-nicotinate to generate the respective N-isobutyl oxidopyridinium ion in quantitative …

Variables Affecting The Extraction Of Antioxidants In Cold And Hot Brew Coffee: A Review, Brian Yust, Frank Wilkinson, Niny Rao

College of Life Sciences Faculty Papers

Coffee beans are a readily available, abundant source of antioxidants used worldwide. With the increasing interest in and consumption of coffee beverages globally, research into the production, preparation, and chemical profile of coffee has also increased in recent years. A wide range of variables such as roasting temperature, coffee grind size, brewing temperature, and brewing duration can have a significant impact on the extractable antioxidant content of coffee products. While there is no single standard method for measuring all of the antioxidants found in coffee, multiple methods which introduce the coffee product to a target molecule or reagent can be …

Using Quantitative And Kinetic Proteomics To Explore Proteostasis, Nathan Raul Zuniga Pina

Theses and Dissertations

Every cell consists of carefully orchestrated biomolecules such as lipids, carbohydrates, and proteins. To maintain internal stability (homeostasis), cells maintain the right amount of these molecules at the right time and at the right place. This process is especially true for proteins since they are the foundation functional units within the cell. Proteins form structures and perform chemistry that bestows cells overarching functional roles. Cells maintain protein homeostasis (proteostasis) by modulating synthesis, folding, and degradation processes (turnover) to maintain the abundance levels for all proteins. This is the foundational kinetic model of proteostasis that is covered in this work, and …

An Efficient And Chemoselective Method To Generate Arynes, Bryan Metze, Riley A. Roberts, Aleksandra Nilova, David R. Stuart

Chemistry Faculty Publications and Presentations

Arynes hold immense potential as reactive intermediates in organic synthesis as they engage in a diverse range of mechanistically distinct chemical reactions. However, the poor functional group compatibility of generating arynes or their precursors has stymied their widespread use. Here, we show that generating arynes by deprotonation of an arene and elimination of an “onium” leaving group is mild, efficient and broad in scope. This is achieved by using aryl(TMP)iodonium salts (TMP = 2,4,6-trimethoxyphenyl) as the aryne precursor and potassium phosphate as the base, and a range of arynophiles are compatible. Additionally, we have performed the first quantitative analysis of …

Heterocyclic Molecules With Esipt Emission: Synthetic Approaches, Molecular Diversities, And Application Strategies, Nuretti̇n Mengeş

Turkish Journal of Chemistry

Excited-state intramolecular proton transfer (ESIPT) is one of the most essential emission processes in most circumstances because of its dual emission band in most cases and its high Stokes shifts. These distinguishing properties make ESIPT-based probes more suitable for a variety of applications, including analyte sensors, solid-state sensing mechanisms, optical technologies, and biomarkers for endogenous or exogenous compounds in various settings. As a result, researchers around the world are working on ESIPT emissions and developing different scaffolds for various applications or industry demands. This field of study is rapidly expanding and there is a need for an up-to-date review of …

Scandium Triflate-Catalyzed Aromatic Aldehydic C-H Activation, Nicholas Griffin

Honors Projects

Herein described is a scandium triflate-catalyzed C-H activation of commercially available aromatic aldehydes achieved in low yields. The reaction occured in a one-pot synthesis over a two-hour duration and required minimal purification. Inclusion of a fluorine-tagged phenol allowed for reaction monitoring via ¹⁹FNMR.

The Synthesis And Optimization Of Sulfide And Halide Solid Electrolytes For All Solid-State Batteries, Teerth Brahmbhatt

Doctoral Dissertations

Countries and organizations around the world have established ambitious targets to transition away from fossil fuel-based energy sources and devices. The transition is focused on cleaning up power generation by converting coal, natural gas, and oil-based power generation to renewables and nuclear energy. Decarbonizing other sectors of energy use, transportation for example, will require broader electrification. To drive this move away from fossil fuel powered transportation will require portable energy storage devices. Conventional lithium-ion batteries are a popular candidate to lead this shift. However, these batteries often rely on flammable liquid electrolytes and carbon anodes that suffer from low energy …

Design, Synthesis And Immunological Testing Of Minimal Oligosaccharide Epitopes For Glycoconjugate Vaccines Targeting Capsular Polysaccharides Of Serotypes 3, 4, 7f And 9v Of Streptococcus Pneumoniae, Seth A. Taylor

Theses and Dissertations

The rise in antibiotic resistant strains of bacteria has led to the need for new methods of combatting bacterial infection. Since the surfaces of bacteria are covered in uniquely patterned capsular polysaccharides, vaccines targeting these polysaccharides have become a popular field of research for protection against pathogenic bacteria. Though licensed polysaccharide vaccines are commercially available, they lack the efficiency to protect patients that are immunocompromised or at high risk because they elicit T cell independent immune responses, resulting in low-affinity antibodies. To elicit a T cell dependent response and thereby recruit B cells that produce high-affinity antibodies, a vaccine was …

Design, Synthesis, And Kinetic Study Of The First Generation Phenyloxadiazole Compounds And The Second Generation Phenyloxadiazole Compounds And Highly Selective Hydroboration Of Alkenes, Ketones And Aldehydes Catalyzed By A Well-Defined Manganese Complex, Haisu Zeng

Dissertations, Theses, and Capstone Projects

This thesis focuses on two projects. In the first project, my goal was to discover a new variant of phenyloxadiazole compounds that could exhibit increased thiol-reactivity during bioconjugation processes. To achieve this, I synthesized several phenyloxadiazole derivatives and subjected them to NMR kinetic studies to assess their reactivity with a model thiol. Based on the results, I was able to identify a phenyloxadiazole analog that demonstrated enhanced reactivity, which included a chlorine atom located in the meta-position of the phenyl ring.

I provided a detailed description of the synthesis and characterization of the newly discovered phenyloxadiazole analog and demonstrate its …

Synthesizing, Purifying, And Characterizing Molten Chloride Salts, Phillip W. Halstenberg

Doctoral Dissertations

Molten chloride salts have vast potential as heat transfer fluids with both nuclear and concentrated solar power applications. For application in energy systems, the characteristics that govern these systems must be well understood. This work focuses on inorganic molten chloride salts with a special emphasis on the experimental aspect of chemical research. Chapter 2 covers the synthetic approaches for the formation of molten chloride mixtures. Many salts can be purchased from industrial suppliers, but most must be purified therefore, Chapter 3 evaluates various methodology developed for removal of impurities in salt mixtures. Once the salt of proper content and purity …

Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li

McKelvey School of Engineering Theses & Dissertations

Neutrophil extracellular traps involve the rapid translocation of DNA to the outside of the cell under certain stimuli. This structure forms a fibrous network that is able to limit the spread of pathogens and to kill microorganisms. It has also been shown to be present in various pathological processes such as inflammation, autoimmune diseases, and cancer metastasis. Currently, the formation process of NETs in vivo is being extensively studied. However noninvasive detection and quantitation has yet to be achieved. A class of PET tracers are described here that consists of a DNA dye as the backbone that is labeled with …

Synthesis And Characterization Of Rhenium 2,2′-Pyridylnaphthyridine Metal Complexes, Benjamin F. Solomon

Honors Theses

Rhenium (Re) is a group 7 heavy 5d transition metal in the same family as manganese (Mn) and technetium (Tc). Re-carbonyl complexes are known to be catalysts for many different kinds of reactions from C-C bond formation to reduction reactions like CO₂ reduction (CO₂RR)^1,2. With this in mind, we have prepared a set of six Re-carbonyl complexes of 2,2′-pyridyl-1,6-naphthyridine (1,6- pynap) and 2,2′-pyridyl-1,8-naphthyridine (1,8-pynap), a redox non-innocent ligand containing a bpy moiety as well as an additional aryl nitrogen binding location at which another metal-ligand bond could form. We have synthesized these complexes as precursors …

Shared Subnet Synthesis And Application Of Object-Oriented Pres Net, Chuanliang Xia, Maibo Guo, Zhuangzhuang Wang, Yan Sun

Journal of System Simulation

Abstract: Focus on embedded system modeling, a solution to obtain a synthesized net via the shared subnet of an extended Petri net is proposed. Object-oriented technology and Petri net-based representation for embedded system (PRES net) are merged to obtain an object-oriented PRES net (OOPRES net). A method of synthesized operation of the shared subnet of OOPRES net is proposed, and the preservation of the liveness and boundedness of synthesized net system is studied. Taking the modeling analysis of intelligent transportation system as an example, the effectiveness of the synthesized method is verified. The method can provide an effective way for …

Utilizing Deep Learning Methods In The Identification And Synthesis Of Gene Regulations, Jiandong Wang

Theses and Dissertations

Gene expression is the fundamental differentiation and development process of life. Although all cells in an organism have essentially the same DNA, cell types and activities vary due to changes in gene expression. Gene expression can be influenced by many gene regulations. RNA editing contributes to the variety of RNA and proteins by allowing single nucleotide substitution. Reverse transcription can alter the expression status of genes by inducing genetic diversity and polymorphism via novel insertions, deletions, and recombination events. Gene regulation is critical to normal development because it enables cells to respond rapidly to environmental changes. However, identifying gene regulations …

Towards Machine Learning-Based Fpga Backend Flow: Challenges And Opportunities, Imran Taj, Umer Farooq

All Works

Field-Programmable Gate Array (FPGA) is at the core of System on Chip (SoC) design across various Industry 5.0 digital systems—healthcare devices, farming equipment, autonomous vehicles and aerospace gear to name a few. Given that pre-silicon verification using Computer Aided Design (CAD) accounts for about 70% of the time and money spent on the design of modern digital systems, this paper summarizes the machine learning (ML)-oriented efforts in different FPGA CAD design steps. With the recent breakthrough of machine learning, FPGA CAD tasks—high-level synthesis (HLS), logic synthesis, placement and routing—are seeing a renewed interest in their respective decision-making steps. We focus …

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 …

Synthetic Methodologies Using Nucleophile-Electrophile Chemistry, Jacob C. Hood

Graduate Research Theses & Dissertations

Synthetic organic chemistry is a vital part of the modern world – making up 15-20% of the U.S. economy. New synthetic reactions can lower manufacturing costs and create more environmentally friendly processes. Substitution, addition, and superelectrophilic chemistry are potent tools to afford potentially essential compounds. The work outlined in this dissertation recounts the expansion of synthetic methodologies employing substrates with a wide range of electrophilicities toward synthesizing heterocyclic molecules. These concepts are summarized in chapter 1. Chapter 2: N-Heterocyclic alcohols are excellent substrates for superacid-promoted Friedel-Crafts reactions. The N-heterocyclic alcohol ionizes to produce reactive, dicationic intermediates, providing good to excellent …

Para-Methoxybenzylidene Acetal-Protected D-Glucosamine Derivatives As Ph-Responsive Gelators And Their Applications For Drug Delivery, Jonathan Bietsch, Logan Baker, Anna Duffney, Alice Mao, Mary Foutz, Cheandri Ackermann, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Carbohydrate-based low molecular weight gelators (LMWGs) are compounds with the capability to self-assemble into complex molecular networks within a solvent, leading to solvent immobilization. This process of gel formation depends on noncovalent interactions, including Van der Waals, hydrogen bonding, and π–π stacking. Due to their potential applications in environmental remediation, drug delivery, and tissue engineering, these molecules have emerged as an important area of research. In particular, various 4,6-O-benzylidene acetal-protected D-glucosamine derivatives have shown promising gelation abilities. In this study, a series of C-2-carbamate derivatives containing a para-methoxy benzylidene acetal functional group were synthesized and characterized. These compounds exhibited good …

Exploration Of Digital Synthesis, Angelo Indre

Williams Honors College, Honors Research Projects

“An Exploration of Digital Synthesis” is a comprehensive investigation into the world of digital audio and music production. The paper explores the fundamental concepts of sound synthesis, including MIDI, virtual instruments (VSTs), and the JUCE framework. The central focus of the paper is the implementation of a custom synthesizer, which serves as a case study for the practical application of digital synthesis. The paper addresses the key question of how to create a functioning synthesizer from scratch, providing detailed insights into the programming and design process. Overall, the paper represents a significant contribution to the fields of digital audio and …

Synthesis, Densification, And Cation Inversion In High Entropy (Co,Cu,Mg,Ni,Zn)Al2o4 Spinel, Cole A. Corlett, Nina Obradovic, Jeremy Lee Watts, Eric W. Bohannan, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The synthesis, densification behavior, and crystallographic site occupancy were investigated for four different spinel-based ceramics, including a high-entropy spinel (Co_0.2Cu_0.2Mg_0.2Ni_0.2 Zn_0.2)Al₂O₄. Each composition was reacted to form a single phase, but analysis of X-ray diffraction patterns revealed differences in cation site occupancy with the high-entropy spinel being nearly fully normal. Densification behavior was investigated and showed that fully dense ceramics could be produced by hot pressing at temperatures as low as 1375°C for all compositions. Vickers' hardness values were at least 10 GPa for all compositions. The …

Exploring The Role Of Ring Annulation In Polycyclic Aromatic Hydrocarbons For Organic Electronic Applications, Tanner Smith

Theses and Dissertations--Chemistry

Organic materials offer promising potential for the next generation of electronic devices, as their tunability, processability, and low-temperature manufacturing make them a cheap and versatile alternative to traditional silicon-based electronics. The ability to systematically alter the electronic properties of organic materials is vital for their incorporation into device applications. Polycyclic aromatic hydrocarbons (PAHs) are of significant interest for organic electronic applications, as relevant properties are highly dependent on their size, structure, and functionalities, and thus can be tuned to fit a wide variety of applications. Due to the enormous number of structural isomers available in larger PAHs, the development of …

Efforts Towards The Asymmetric De Novo Synthesis Of Lanostanes And Euphanes, Htoo Tint Wai

Dartmouth College Ph.D Dissertations

Tetracyclic triterpenoids are ubiquitous in nature and biology, with members displaying a wide range of medically relevant properties and occupying rather distinct regions of chemical space. Members of this large class include well-known steroid hormones and sterols as well as structurally interesting subclasses such as lanostanes and euphanes, among others. Comprised of the tetracyclic skeleton with three stereodefined quaternary centers at ring-junction positions, lanostanes and euphanes present synthetic challenges that are different from those encountered in efforts targeting the structurally less complex steroid hormones. Lanostanes, in particular, stand as a historically important class of compounds as significant attention has been …

Nano-Engineered Soft Magnets: Potential Application In Water Treatment, Hyperthermia And Molecular (Organic) Magnets, Yohannes Weldemariam Getahun

Open Access Theses & Dissertations

Scrutinizing the remarkable and tunable properties of magnetic materials at a nanoscale size "There's Plenty of Room at the Bottom..." Richard Feynman, this study attempts to find sustainable solutions to some of the deteriorating environmental, health, and energy problems the world is encountering. Due to their simple preparation, surface adaptability, and tunable magnetic and optical properties, magnetic nanoparticles have been extensively investigated in water treatment, cancer therapy, data storage, and more. However, relying on non-reusable and chemical-based treatment agents in water, complex and costly cancer treatment procedures and molecular magnets that operate far below room temperature limited those attempts from …

Synthesis Of Novel Dna-Binding Polyamides To Prevent Cancer-Related Gene Overexpression, Huy Q. Nguyen

Dissertations

Pyrrole-imidazole polyamides (PIPs) are nanomolecular compounds designed to fit in the tight space of DNA minor grooves. As analogs of Netropsin and Distamycin A, PIPs are specifically designed to recognize the base pairs of DNA sequences. PIPs have many biological applications, such as regulating gene expression, biochemistry pathway regulations, and suppressing the development of cancer cells. SETMAR gene is the chimeric fusion of the SET domain with the mariner transposase. Its protein (Metnase) has functions involving DNA repairs in the NHEJ pathway, regulating gene expression, DNA decatenation, etc. Despite not having an active transposable element, SETMAR still has an unknown …

Contra-Thermodynamic Halolactonization Of Lactam-Tethered 5-Aryl-4(E)-Pentenoic Acids For The Flexible And Stereocontrolled Synthesis Of Fused Lactam-Halolactones, Timothy K. Beng, Claire Borg, Morgan J. Rodriguez

All Faculty Scholarship for the College of the Sciences

Halolactonization of alkenoic acids enables the construction of oxygen-heterocycles via intramolecular halonium-induced nucleophilic addition. Although the literature is currently inundated with halolactonizations of 5-aryl-4(E)-pentenoic acids that predictably afford the 6-endo cyclization adducts, methods that reliably alter the innate regioselectivity bias to instead deliver the thermodynamically less favored 5-exo cyclization products are relatively rare. Here, we attempt to bridge this gap and have found mild conditions for contra-thermodynamic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids that lead to the formation of trans-fused lactam-γ-lactones. The natural proclivity for these 5-aryl-4(E)-pentenoic acids to undergo 6-endo cyclization is overridden and 5-exo-trig cyclization predominates. The success of …