Physical Sciences and Mathematics Commons^™

Hypervalent Iodine Compounds With Carboxylate And Tetrazolate Ligands, Avichal Vaish

Chemistry Theses and Dissertations

In modern organic chemistry, hypervalent (HV) iodine(III) compounds are frequently used as oxidizing agents but application of λ³-iodanes in polymer and material chemistry is still underexplored. This dissertation describes the preparation of dynamic and self-healing materials by employing ligand exchange reactions involving HV iodine(III) compounds of the type ArIL₂ (Ar = Aryl, L = ligand, e.g., carboxylate or (pseudo)halide). These compounds can undergo ligand exchange reactions in presence of nucleophiles (Nu^-) to form ArINu₂. Diacetoxyiodo benzene was successfully employed as a crosslinker to prepare dynamic and self-healing gels derived from carboxylate-containing polymers. Furthermore, …

Cell-Trappable Chemiluminescent Probes For Monitoring Hydrogen Sulfide In Living Cells, Briley Bezner

Chemistry Theses and Dissertations

Hydrogen sulfide (H2S) is an important biological signaling molecule that has been recognized alongside nitric oxide and carbon monoxide as being a small gasotransmitter that is enzymatically produced and impacts multiple physiological functions. To detect hydrogen sulfide, there has been a focus on developing fluorescent probes to target particular analytes; however, fluorescent probes lack sensitivity and depth penetration due to background autofluorescence and light scattering. Chemiluminescence does not require light excitation, which greatly reduces the amount of autofluorescence and photoactivation.

In order to detect hydrogen sulfide in living systems with high sensitivity, a series of sterically stabilized 1,2-dioxetane chemiluminescent reduction-reaction …

Evaluation Of The Mechanisms And Effectiveness Of Nano-Hydroxides, Wood And Dairy Manure-Derived Biochars To Remove Fluoride And Heavy Metals From Water, Anna Rose Wallace, Wenjie Sun Dr, Chunming Su Dr

Civil and Environmental Engineering Theses and Dissertations

The development of effective treatment processes for the removal contaminants, such as fluoride and heavy metals, from polluted water have been urgently needed due to serious environmental health and safety concerns. In this dissertation, a variety of materials including various (hydro)oxide nanomaterials, biochars and surface modified biochar were studied to evaluate their effectiveness and mechanism on removing fluoride or mixed heavy metals from water.

In the Chapter 2, this study investigated the adsorptive removal of fluoride from water using various (hydro)oxide nanomaterials, focusing on ferrihydrite, hydroxyapatite (HAP) and brucite, which have the potential to be used as sorbents for surface …

Polyarylenes: Synthesis And Characterization Towards Advanced Applications, Stephen Budy

Chemistry Theses and Dissertations

A series of semi-fluorinated and non-fluorinated Diels−Alder step-growth polyarylene polymers and co-polymers were synthesized via typical oil bath heating (days/weeks) and more rapid microwave-assisted polymerization (hours). The polymers were characterized by multi-nuclear (¹H, ¹³C, and ¹⁹F) NMR and ATR−FTIR spectroscopy, thermal analysis (TGA, DSC, and DMA), GPC, XRD, water contact analysis (WCA), and refractive index (RI) measurements. The NMR spectra indicated a mixture of para and meta conformations through the polymer backbone increasing to more para with greater fluorine content. Thermal gravimetric analysis revealed the fluorine-containing polyarylenes possessed the highest char yields at almost 80% at …

The Process Of Establishing Theoretically Grounded Measures Of Science And Chemistry Identity For Use In Undergraduate Chemistry Courses, Kathryn Nicole Hosbein

Dissertations and Theses

Identity has been theorized to aid in student persistence toward science, engineering, technology, and math (STEM) degrees. However, before we can explore the impacts of learning environments on identity, and subsequently persistence, robust measures that can aid in understanding how identity is fostered need to be available. This research study aims to create measures of identity by expanding an existing physics identity framework and contextualizing it to science and chemistry identities. Development of the measures was carried out through two distinct phases that provided evidence for reliability and multiple aspects of validity.

The first phase of the study used qualitative …

Hierarchical Conjugated Polymer Systems Prepared By Controlled Chain-Growth Polymerization, Chunwa Peter Kei

LSU Doctoral Dissertations

π-Conjugated polymer materials may have a significant economic impact on society by providing means for designing affordable, flexible, and portable organic electronic devices. Their successful commercialization will depend on major scientific advancements, which will challenge human society to seek out ever more detailed and fundamental processes to command. Controlled polymerization affords such a power; allowing for the design of meticulous and precisely defined systems granting detailed insight into structure-property relationships in the polymer materials and bettering understanding of novel physical phenomena.

This dissertation primarily focuses on development and preparation of well-defined hierarchically organized macromolecular systems. The novel chain-growth polymerization methodologies …

The Roundtable Of Scientific Communication: From Classroom To Course Creation, Back To Classroom And Beyond, Sean P. Hickey

University of New Orleans Theses and Dissertations

This research encompasses many aspects of chemical education research including curriculum and pedagogical changes to the freshman and sophomore courses. Curriculum changes included the addition of recitations to the general chemistry and organic chemistry lectures and the creation of four new classes, CHEM 1001, 1002, 3091, and 3092. The addition of recitations was not limited to but was focused on improving DFW rates for these courses.

CHEM 3091 and 3092 are chemistry internship and undergraduate teaching assistant classes. These courses were necessary to offer outside internship opportunities and training for undergraduate teaching assistants, respectively. CHEM 1001 and 1002 are chemistry …

Design And Synthesis Of Tlr2 And Tlr6 Heterodimer Ligands, A Triply Functionalized Α-Galcer Derivative For Identifying Proteins Involved In Glycolipid Trafficking, And The Disaccharide Of Staphylococcus Aureus Cp8 Towards A Self-Adjuvanting Vaccine, Sara Mayeth Mata

Theses and Dissertations

Toll like receptors (TLRs) are found on B cells, macrophages, monocytes, and dendritic cells, and these cells belong to the innate immune system that recognizes antigens and induces multiple cell responses through the release of cytokines. TLR1, TLR2 and TLR6 function as heterodimers, either as TLR1/TLR2 or TLR2/TLR6 to recognize lipopeptides. TLR1/2 dimer activation releases inflammatory cytokines, while TLR2/TLR6 dimer activation releases immunomodulatory cytokines. Based on the size of the binding pocket between TLR2 and TLR6, it was hypothesized that lipopeptides, such as FSL1, could be simplified while keeping overall activity. FSL1 is a lipopeptide first isolated from Mycoplasma salivarum …

Hypervalent Iodine(Iii) Compounds With (Pseudo)Halide And Tetrazole Ligands In The Synthesis Of Functional Polymers, Rajesh Kumar

Chemistry Theses and Dissertations

The organic compounds of iodine(III) with the general formula ArIL₂ (Ar = aryl, L = (pseudo) halides) degrade homolytically upon irradiation or heating to the corresponding monovalent iodine compound (ArI) and the radicals L^• . If the latter contains a functional group, they can be used to initiate the polymerization of vinyl monomers to afford chain end-functionalized linear polymers. When "conventional" monovinyl monomers are copolymerized with di- or multivinyl monomers (crosslinkers) in the presence of relatively high concentrations of rapidly decomposing ArIL₂ compounds, highly branched polymers are formed that contain multiple chain-end functionalities derived from the radicals …

Oxidative C–C And C–Heteroatom Reactivity Of High-Valent Nickel Complexes, Sofia Marie Smith

Arts & Sciences Electronic Theses and Dissertations

ABSTRACT OF THE DISSERTATION

Oxidative C–C and C–Heteroatom Reactivity of High-Valent Nickel Complexes

by

Sofia M. Smith

Doctor of Philosophy in Chemistry

Washington University in St. Louis, 2019

Professor Liviu M. Mirica, Chair

Professor Kevin D. Moeller, Co-Chair

Nickel catalysts are commonly used for cross-coupling reactions such as Negishi, Kumada and Suzuki couplings. While Ni(0), Ni(I), and Ni(II) intermediates are most relevant in these transformations, Ni(III) and Ni(IV) species have also been recently proposed to play a role in catalysis. The formation of C–C and C–heteroatom bonds plays a fundamental role in organic transformations, and today cross-coupling reactions are one …

Unravel Allostery Mechanism Through Molecular Dynamic Simulations With Machine Learning Approaches, Hongyu Zhou

Chemistry Theses and Dissertations

Allostery is referred to as protein function changes due to external perturbations, and ubiquitous in the living cells. Investigation of the allosteric mechanism is essential for developing drugs or assisting protein engineering. Recently, the population shift model has been proposed to explain the allosteric mechanism. This model emphasizes the importance of conformational distribution in the allostery. In the past several years, I have been continuously working on developing computational methods to explore and quantify protein allostery mechanism. By fully utilizing protein simulation results, several machine learning related methods have been applied to protein systems to investigate the underlying conformational changes …

From General Chemistry To Anatomy And Physiology: Revalidating And Adapting Assessments And Models, Victoria Fisher

Theses and Dissertations

The 1980s saw an increasing demand for education standards that would create a scientifically literate society. In response, the American Association for the Advancement of Science (AAAS) published a report that outlined four themes that are characteristic of a scientifically literate individual: systems, models, constancy and change, and scale (1). In 1993, the AAAS published the Benchmarks for Science Literacy which outlined common scientific skills that a student should be able to demonstrate by grades 2, 5, 8, and 12 (2). Beyond the AAAS scale was not included in national science educational standards until 2012 when the National Research Council …

Synthesis And Analysis Of 6-Acetyl-1,2,3,4-Tetrahydropyridine, A Major Contributor To ‘Mousy’ Off-Flavor In Sour And Wild Beers, Liesel Krout

Thinking Matters Symposium Archive

Unexpected tastes can negatively impact consumer experience in the beer industry. One such taste, a ‘mousy’ off-flavor, is diminishing the quality of sour and wild beers throughout the brewing community. The unpleasant flavor is a result of the combined presence of three organic compounds: 6-acetyl-1,2,3,4-tetrahydropyridine (ATHP), 2-acetyl-1-pyrroline, and 2-ethyl-3,4,5,6-tetrahydropyridine. Because of its unpredictable nature, brewers must wait for the compound to disappear before distribution, costing them valuable time and revenue. The factors responsible for formation, reasons for persistence, and degradation timelines of the compounds were unknown. A method for quantification was therefore necessary to determine those characteristics, and such quantification …

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 …

Reactivity Of Molybdenum And Tungsten Sulfido Complexes With First-Series Transition Metals, Khalil Mudarmah

ETD Archive

Ammonium tetrathiomolybdate (ATTM) is an important compound in bioinorganic chemistry, with medicinal applications. Metal complexes of sulfur-containing ligands have been widely used as building block in biology and inorganic chemistry. This project aims to increase the number of Mo-S and W-S complexes that may contribute to fields such as bioinorganic and medicinal chemistry, by the preparation of heterometallic complexes containing both Mo or S and a metal of the first transition series. The homobimetallic complex anion salts (Et4N)2[Mo2(S)2(μ-S)2(edt)2] (1) and (Et4N)2[W2(S)2(μ-S)2(edt)2] (2) have been prepared from ATTM and ammonium tetrathiotungstate (ATTW) in order to start our work. The overnight treatment …

A Computational Approach To Predicting And Understanding New Psychoactive Substances (Nps) For Developing A Database For State And Federal Crime Laboratories, Caroline Amelia Spencer

Electronic Theses and Dissertations

The object of this dissertation was to use a computational approach to predict and understand new psychoactive substances (NPS) to develop a database for state and federal crime. The primary scope of the dissertation was to better understand the interactions that take place between new psychoactive substances and their corresponding receptors. Through analysis of the interactions between the amino acids within the receptors and the NPS an understanding into the pharmacology and toxicology of these drugs can be gained. NPS such as synthetic cannabinoids fentanyl and its analogs and kratom have become more problematic for both state and federal crime …

Mathematical Modeling Of Type 1 Diabetes, Gianna Wu

HMC Senior Theses

Type 1 Diabetes (T1D) is an autoimmune disease where the pancreas produces little to no insulin, which is a hormone that regulates blood glucose levels. This happens because the immune system attacks (and kills) the beta cells of the pancreas, which are responsible for insulin production. Higher levels of glucose in the blood could have very negative, long term effects such as organ damage and blindness.

To date, T1D does not have a defined cause nor cure, and research for this disease is slow and difficult due to the invasive nature of T1D experimentation. Mathematical modeling provides an alternative approach …

Studying Carbon Dioxide Solvent Properties By Microwave Spectroscopic Investigations Of Vinyl Fluoride/Carbon Dioxide Clusters And Developing New Approaches To Decode Rotational Spectra, Prashansa Kannangara

Masters Theses

Supercritical carbon dioxide (sc-C0₂) is an excellent green solvent, but its properties are not thoroughly understood. For example, fluorinated compounds have higher than expected solubility in sc-C0₂. Microwave spectroscopy is one way to learn more about sc-C0₂ because it can be used to determine detailed structures of small clusters of molecules. The purpose of this investigation was to study weak hydrogen bonding interactions in complexes of fluorinated ethylene (solute) with carbon dioxide (C0₂, solvent). Investigations on dimers with one C0₂ molecule and fluorinated ethylene were carried out previously and found two different …

Approaches To The Search Of Platinum Anticancer Agents: Derivatizing Current Drugs And Incorporating Hdac Inhibition, Chao Feng

University of the Pacific Theses and Dissertations

Platinum-based anticancer drugs, such as cisplatin, carboplatin, and oxaliplatin, have been approved for clinical use worldwide for decades. Despite their enormous success, their widespread application is hindered by either cross-resistance or toxic side effects, including nephrotoxicity and neurotoxicity. The need to overcome these drawbacks has stimulated the search for new platinum-based drugs.

This dissertation will start with the accidental discovery of cisplatin, followed by an introduction of other platinum-based anticancer agents, including the action mechanism, general structures, and development history. Picoplatin is a newer generation of platinum-based anticancer agent. The bulky 2-methylpyridine as a non-leaving group on picoplatin could reduce …

Synthesis Of An Archazolid Based Enzyme Inhibitor, Cooper A. Vincent

WWU Graduate School Collection

The archazolids are a family of natural products that display powerful growth inhibitory activity against a number of human cancer cell lines. This activity has been linked to inhibition of the vacuolar-type ATPase (V-ATPase) and more recently cyclooxygenase (COX) enzymes. Using the archazolid structure as a starting point, several simplified analogues have been prepared and assayed for their V-ATPase and COX inhibitory activity. These simplified analogues were prepared using a novel Suzuki coupling with yields over 80%. They were assayed to investigate both their V-ATPase and COX inhibitory activity. In our assays there was no COX inhibition, while there was …

Exploring The Molecular Origin Of Jet Fuel Thermal Oxidative Deposition Through Statistical Analysis Of Mass Spectral Data And Pyrolysis Gas Chromatography/Mass Spectrometry Of Deposits, Krege Matthew Christison

University of the Pacific Theses and Dissertations

ASTM D3241 (Standard Test Method for Thermal Oxidation Stability of Aviation Turbine Fuels) measures the thermal oxidative stability of jet fuels under elevated temperature and pressure conditions. When jet fuels fail ASTM D3241, either at the refinery or in the distribution system, there can be supply disruptions and financial losses. Understanding the causes of poor thermal oxidative stability in jet fuels could help prevent or mitigate issues. In order to develop a deeper understanding of the molecular precursors that lead to ASTM D3241 failures, a number of analytical methodologies and data treatment techniques have been developed, applied, and reported here. …

Computational Modeling As A Tool For Designing Ligands And Receptors, Waqas S. Awan

Legacy Theses & Dissertations (2009 - 2024)

Computational methods can be used for a wide range of applications, especially regarding DNA and RNA. Interactions such as sugar torsions, receptor-ligand interactions, ligand docking/drug docking, receptor modeling, and drug design are excellent candidates for computational analysis and in silico experiments. The use of molecular dynamics software (GROMACS) coupled with molecular design software (MOE) produce insights that may have been otherwise difficult to assess. All these problems are academic in nature but have practical uses outside of academia. Understanding alternate linkages can lead to antibiotic assays to address potential superbug epidemics. Modeling DNA superstructures can provide insight into how large …

Synthesis And Adsorption Experiments With Metal-Organic Frameworks For High School And Undergraduate Laboratory Settings, Kate Holley

Legacy Theses & Dissertations (2009 - 2024)

Seven experiments are described and outlined here that introduce high school and undergraduate students to metal–organic frameworks (MOFs) and their applications. The experiments were designed to be completed with basic laboratory equipment and supplies and without the use of expensive characterization instruments, simulating typical high school chemistry laboratory conditions. Students synthesized two well-known MOFs, HKUST-1 and aluminum fumarate, using simple, safe, and rapid methods (fast enough to be performed within the time constrains of a typical high school class). Students then use their synthesized MOFs to explore their inherent sorption properties. In one set of experiments, the synthesized MOFs are …

Roaming Transition States And Highly Accurate Thermochemistry: A Pepico Study Of Two Small Combustion Systems, Kyle John Covert

University of the Pacific Theses and Dissertations

Two small combustion systems, methyl hydroperoxide (CH₃OOH) and 2-propanol ((CH₃)₂CHOH), were studied using imaging photoelectron photoion coincidence spectroscopy (iPEPICO), which combines photoelectron spectroscopy and photoionization mass spectrometry to detect coincident photoelectron-photoion pairs. In the photon energy range of 11.4–14.0 eV, energy selected CH₃OOH⁺ ions dissociate into CH₂OOH⁺, HCO⁺, CH₃⁺, and H₃O⁺ ions. The lowest-energy dissociation channel is the formation of the cation of the smallest “QOOH” radical, CH₂OOH⁺. A statistical rate model fitted to the …

Implication Of Inorganic Nitrogen And Phosphorous Species As A Cause Of A Harmful Algal Bloom Event In Caesar Creek Lake, Ohio And Its Tributaries, Baxter Jeffrey Foskuhl

Browse all Theses and Dissertations

Agricultural runoff poses a threat to the Wilmington, Ohio municipal water supply and its source waters. A harmful algal bloom (HAB) was documented in June 2019 in Caesar Creek Lake, Waynesville, Ohio. This study seeks to establish baseline nutrient concentrations in Caesar Creek Lake (Warren County, Ohio) and its tributaries, and to identify potential non-point sources of excess nitrogen and phosphorous that contributed to the HAB event. In collaboration with the Wilmington Water Department, dissolved inorganic nitrogen DIN-[N] (sum of NH3-[N], NH4+-[N], NO2--[N], NO3--[N] concentrations), dissolved phosphorous DP-[P], particulate phosphorous PP-[P], total phosphorous TP-[P] (total sum of DP-[P] and PP-[P] …

In Vitro Uptake And Biodistribution Of Silver Nanoparticles In Vero 76 Cells, Miriam A. Crane

Browse all Theses and Dissertations

The number of consumer products containing nanomaterials over the last eight years has increased over two-fold. Silver is one of the most commonly used materials in consumer goods nanoparticle fabrication.1 Thus, the uptake and biodistribution of silver nanoparticles (AgNPs) within mammalian cells can provide insight into their possible toxicological effects. In this study, starch-capped AgNPs of an average diameter of 9 ± 5 nm were synthesized via a bottom-up method, and characterized by Raman spectroscopy, transmission electron microscopy (TEM), inductively couple plasma optical emission spectroscopy (ICP-OES), and absorption spectroscopy. Vero 76 cells were incubated with 0.0, 0.1, 1.0, and 3.0 …

Characterizing Body Fluids With Raman Spectroscopy : Towards Real World Application, Marisia Ann Fikiet

Legacy Theses & Dissertations (2009 - 2024)

This project continues the research on a new method of body fluid identification and furthers its field capabilities. This method of identification uses Raman spectroscopy and advanced chemometrics to distinguish between body fluids. It is an improvement on current methods because it is confirmatory, non-destructive, and has simple sample preparation. The first objective of this research is to create a model for differentiating body fluids for a new desktop instrument. It was determined that due to resolution differences from a research grade instrument, a new model needed to be made for this the desktop instrument. This model will be able …