Chemistry Commons^™

13c Nmr Substituent Effects On Para-Substituted Tolans: Using Deuteration To Assign 13c Signals In Methyltolan, Reece Crumpler

Honors Theses

Substituents are capable of affecting their molecules via induction, resonance, and field effects. Using the Hammett equation, the effect a range of substituents has on different properties of a molecule can be quantified.¹ Hammett’s parameters have been correlated with the substituent effects on ¹H NMR chemical shifts in different molecules, including experiments on substituted chalcones (1,3-diarylpropenones).² The effect a substituent has on a molecule can also be observed using ¹³C NMR. The chemical shifts of carbons throughout the molecule may be affected by the substituent. This was shown to be true by Wilson and Zehr in …

Synthesis Of Polyethylene Glycol - Trifluoromethyl Sulfonamide And Analysis Of Its Ion-Transport Properties, Andrew Groneck

Honors Theses

This project investigates the synthetic pathway to develop a polyethylene glycol – trifluoromethyl sulfonamide compound to be used as an electrolyte in a proton exchange membrane fuel cell. The inspiration to develop a trifluoromethyl sulfonamide compound tethered to a polyethylene glycol polymer was inspired by the work of David P. Siska and D. F. Shriver in their studies of polysiloxane – trifluoromethyl sulfonamide electrolytes.

In this thesis, I have developed the synthesis of MePEG7-Trifluoromethyl sulfonamide (MePEG7-NHSO2CF3) from monomethylpolyethylene glycol (MePEG7OH). Unfortunately, due to the COVID-19 pandemic, I was unable to complete the depronation and ion-exchange to the Li+ and H+ …

The Synthesis Of A Mepeg-Based Hydroxide Conducting Electrolyte And The Optimization Of The Mepeg-Tosylation Reaction, Andrew Ladner

Honors Theses

As society is becoming increasingly aware of the effects of climate change and the ever-looming threat of a fuel shortage, exploring green and renewable alternative energy production, such as fuel cells, is paramount. This project investigates the synthesis of a polyethylene glycol monomethyl ether (MePEG_n) based polymer as well as the optimization of the MePEG Tosylation reaction. The MePEG explored contains seven polymerized ethoxy groups (MePEG₇). The MePEG₇ polymer was modified by substituting a positively-charged trimethylamine group in the place of the alcohol functional group at the end of the PEG chain. The reason for …

The Histone Deacetylase Inhibitor Largazole: A Potential Chemotherapeutic Agent, Hannah Lynn Carson

Honors Theses

Histone deacetylase enzymes are known for their inherent activity as epigenetic modifiers. Although, they have become recognized for their role in cancer progression and other diseases. But also, histone deacetylases have other non-histone targets, for example, microtubules, which play important roles in cancer metastasis, apoptosis, and replication. With histone deacetylase inhibitors (HDACi), our research explored HDACi effects on breast cancer cell lines. The overall goal was to understand the potential of largazole, a class one histone deacetylase inhibitor on breast cancer cell lines. The research consisted of two parts: sulforhodamine B (SRB) viability assays under hypoxic and normoxic conditions. The …

Detection And Characterization Of Delta-9-Tetrahydrocannabinol And Novel Synthetic Cannabinoid Metabolites Using Human Liver Microsomes, Seema Murugan

Honors Theses

Marijuana and synthetic cannabinoids are the most commonly used and trafficked illicit drug. ∆⁹-tetrahydrocannabinol (THC) is the primary active compound in marijuana. Synthetic cannabinoids were created as a method to study the effects of cannabinoids on the endocannabinoid system, which consists of endogenous cannabinoids, cannabinoid receptors, and the synthetic and degrading enzymes responsible for the synthesis and degradation of endocannabinoids. Cannabinoids activate the same receptors as endocannabinoids. Synthetic cannabinoids gained popularity as recreational drugs due to their ability to avoid detection. Synthetic cannabinoids have been found to have a greater binding affinity to the cannabinoid CB₁ receptor …

Investigation Of The History Of Fingerprinting, Advancements In The Field, And Development Of Potential Methods That Could Improve The Detection Of Endogenous And Exogenous Drugs In Latent Prints, Kristen Malloy

Honors Theses

When someone thinks of fingerprinting, they are most likely going to picture how a latent print is matched to the fingerprint of a suspect based on ridge pattern analysis. However, there is much more information that can be obtained from a latent print. The work performed in this thesis focuses the detection of exogenous and endogenous drugs in latent prints. The experiments performed analyzed fingerprints from volunteers that were contaminated with one of three common painkillers: acetaminophen, acetylsalicylic acid (ASA), and ibuprofen. Three different instruments were tested for this purpose: MALDI-MS, ATR-FTIR, and LC-MS. Based on the results gathered, it …

Synthesis And Characterization Of Transition Metal Scorpionate Complexes For Redox Shuttle Applications In Dye-Sensitized Solar Cells, Chase Lance

Honors Theses

Given the rising global energy demands, alternative renewable energy sources are currently being investigated. The most appealing renewable energy source is solar energy, and dye-sensitized solar cells (DSSCs) in particular are an attractive technology. DSSCs have traditionally utilized iodide/triiodide as the redox mediator couple, which exhibits high efficiencies and fast regeneration of the oxidized dye with little recombination. Recently, the use of alternative redox couples based on transition metal complexes has been studied as a promising substitute due to the tunable design of these complexes. In this study, tridentate tris(pyrazolyl)borate and tris(pyrazolyl)methane ligands with first-row transition metals were designed and …

Intrinsic Buffer Hydroxyl Radical Dosimetry For Hydroxyl Radical Protein Footprinting, Addison Roush

Honors Theses

Hydroxyl radical protein footprinting (HRPF) coupled to mass spectrometry is a powerful technique for the analysis of protein topography as it generates covalent mass labels that can survive downstream sample handling, and it is sensitive to the solvent accessibility of amino acid sidechains. Of the multiple platforms for HRPF, fast photochemical oxidation of proteins (FPOP) utilizes a pulsed 248 nm KrF excimer laser to label proteins by photolyzing hydrogen peroxide. FPOP is the most widely used HRPF platform because it labels proteins faster than unfolding can occur. Variations in FPOP sample conditions make it difficult to compare results between experiments …

Silver-Catalyzed Synthesis Of Disubstituted Fluorinated Isoxazoles, Micah Stewart

Honors Theses

The presence of fluorine can provide organic compounds with useful biological properties, such as increased metabolic stability and drug uptake. Because of these advantages, fluorinated compounds make up about 30% of the drug industry. However, fluorination of complex molecules is difficult due to fluorine’s high electronegativity.

Fluorinated isoxazoles are of particular interest in the pharmaceutical industry. Isoxazoles are five-membered heterocycles with oxygen and nitrogen in the 1, 2 positions that are able to engage in interactions unavailable to other ring structures, conferring advantageous biological properties upon compounds containing them. However, there are limited synthetic routes for fluorinated isoxazoles, and those …

Raman Spectroscopy Study Of Delta-9-Tetrahydrocannabinol And Cannabidiol And Their Hydrogen-Bonding Activities, Kalee Sigworth

Honors Theses

Cannabis and products containing its cannabinoids have grown rapidly in acceptance and use in recent years with legalization of cannabis in many countries and US states. Cannabidiol and Delta-9-Tetrahydrocannabinol are two primary cannabinoids in Cannabis that have been shown to produce analgesic effects along with many other positive side effects for the user. These two cannabinoids interact with receptors in the Central and Peripheral Nervous Systems. No spectroscopic study to our knowledge has been performed to analyze the hydrogen bonding effects of interactions between these two cannabinoids and solvents. Here, we employ theoretical Raman spectra through computational methods to study …

Gold Nanoparticles: Core Conversion Of Au144(Sch2ch2ph)60 To Au99(Sph-Ch3)42 Using Aromatic Thiolate Ligands And Crystallization Of Au99(Sph-Ch3)42, Elizabeth Turnage

Honors Theses

The purpose of this thesis is to synthesize Au₁₄₄(SCH₂CH₂Ph)₆₀ using a two-step synthesis reaction, and then using this product to conduct a core conversion from Au₁₄₄(SCH₂CH₂Ph)₆₀ to Au₉₉(SPh-CH₃)₄₂. The Au₉₉(SPh-CH₃)₄₂ product will then be used to attempt to form crystals using five different crystal set-up methods. Au₁₄₄(SCH₂CH₂Ph)₆₀ is made with aliphatic thiolate ligands, and when it is placed in a mixture containing excess para-methyl benzenethiol, it undergoes a …

Raman Spectroscopic And Quantum Chemical Investigation Of The Effects Of Tri-Methylamine N-Oxide (Tmao) On Hydrated Urea, Hydrated Guanidinium, And Hydrogen Bonded Networks, Genevieve Verville

Honors Theses

Trimethylamine N-Oxide (TMAO), guanidinium, and urea are three important

osmolytes with their main significance to the biophysical field being in how they

uniquely interact with proteins. TMAO is known to stabilize and counteract the

destabilizing effects of both urea and guanidinium. The exact mechanisms by which

TMAO stabilizes and both guanidinium and urea destabilize folded proteins continue

to be debated in the literature. Some studies suggest that solvent interactions do not

play a large role in TMAO’s stabilizing effects and therefore advocate direct

stabilization, whereas others suggest that TMAO counteracts denaturation primarily

through an indirect effect of strong solvent interactions. …

Spectroscopic And Computational Studies Of The Agricultural Active Ingredient Dicamba, James Johnson

Honors Theses

3,6-dichloro-2-methoxy benzoic acid, more commonly known as Dicamba, is the active ingredient in an array of pesticides used on farmlands across the globe. Dicamba’s mode of action works by mimicking the plant hormone auxin, which is synonymous to growth hormones in mammals. The mimicking of auxin results in excessive elongation and growing, which is eventually fatal for plants when the rate of growth can no longer be sustained. Dicamba has risen in prominence in recent years due to drift damage as a result of Dicamba’s high volatility. Having the ability to identify Dicamba is crucial for the agricultural industry. The …

A Diverse View Of Science To Catalyse Change: Valuing Diversity Leads To Scientific Excellence, The Progress Of Science And, Most Importantly, It Is Simply The Right Thing To Do. We Must Value Diversity Not Only In Words, But Also In Actions, César A. Urbina-Blanco, Safia Z. Jilani, Isaiah R. Speight, Michael J. Bojdys, Tomislav Friščić, J. Fraser Stoddart, Toby L. Nelson, James Mack, Renã A. S. Robinson, Emanuel A. Waddell, Jodie L. Lutkenhaus, Murrell Godfrey, Martine I. Abboud, Stephen O. Aderinto, Damilola Aderohunmu, Lučka Bibič, João Borges, Vy M. Dong, Lori Ferrins

Faculty and Student Publications

No abstract provided.

A Synthesis And Analysis Of Anhydrous Hydroxide Ion Conducting Polymer Electrolytes, Stanton Heydinger

Honors Theses

This project investigates the synthesis and physical properties of polyethylene glycol monomethyl ether (MePEGn where n=3 or 7) based polymer electrolytes. The two polymer electrolytes explored in the experiments were designed from two different MePEG chains that varied in their overall length and degree of polymerization. The first MePEG backbone contained three polymerized ethoxy groups and the second contained seven. Both MePEGn polymers were modified by substituting an imidazolium group in place of the alcohol functional group at the end of the PEG chain. This modification was made to create a polymer electrolyte with an attached positive charge that could …

Co-Localization Of Dna I-Motif-Forming Sequences And 5-Hydroxymethyl-Cytosines In Human Embryonic Stem Cells, Yogini P. Bhavsar-Jog, Eric Van Dornshuld, Tracy A. Brooks, Gregory S. Tschumper, Randy M. Wadkins

Faculty and Student Publications

G-quadruplexes (G4s) and i-motifs (iMs) are tetraplex DNA structures. Sequences capable of forming G4/iMs are abundant near the transcription start sites (TSS) of several genes. G4/iMs affect gene expression in vitro. Depending on the gene, the presence of G4/iMs can enhance or suppress expression, making it challenging to discern the underlying mechanism by which they operate. Factors affecting G4/iM structures can provide additional insight into their mechanism of regulation. One such factor is epigenetic modification. The 5-hydroxymethylated cytosines (5hmCs) are epigenetic modifications that occur abundantly in human embryonic stem cells (hESC). The 5hmCs, like G4/iMs, are known to participate in …

Can The Merpas Passive Air Sampler Discriminate Landscape, Seasonal, And Elevation Effects On Atmospheric Mercury? A Feasibility Study In Mississippi, Usa, Byunggwon Jeon, James V. Cizdziel

Faculty and Student Publications

© 2019 by the authors. Accurately measuring gaseous elemental mercury (GEM) concentrations in the atmosphere is important to understand its sources, cycling, distribution, and temporal trends. The MerPAS passive air sampler from Tekran Inc. (Toronto, ON, Canada) captures GEM on sulfur-impregnated activated carbon after it passes through a Radeillo diffusive barrier. Because they are small, relatively low in cost, and require no power, they can be deployed at multiple locations, yielding a much greater spatial resolution, albeit at coarser temporal resolution, compared to active sampling. In this study, we used the MerPAS to measure GEM concentration gradients at a mixed …

Air/Surface Exchange Of Gaseous Elemental Mercury At Different Landscapes In Mississippi, Usa, James V. Cizdziel, Yi Zhang, Divya Nallamothu, J. Stephen Brewer, Zhiqiang Gao

Faculty and Student Publications

© 2019 by the authors. Mercury (Hg) is a global pollutant with human health and ecological impacts. Gas exchange between terrestrial surfaces and the atmosphere is an important route for Hg to enter and exit ecosystems. Here, we used a dynamic flux chamber to measure gaseous elemental Hg (GEM) exchange over different landscapes in Mississippi, including in situ measurements for a wetland (soil and water), forest floor, pond, mowed field and grass-covered lawn, as well as mesocosm experiments for three different agricultural soils. Fluxes were measured during both the summer and winter. Mean ambient levels of GEM ranged between 0.93-1.57 …

Untangling The Formation Of Methoxymethanol (Ch3Och2Oh) And Dimethyl Peroxide (Ch3Ooch3) In Star-Forming Regions, Cheng Zhu, Robert Frigge, Alexandre Bergantini, Ryan C. Fortenberry, Ralf I. Kaiser

Faculty and Student Publications

© 2019. The American Astronomical Society. All rights reserved.. Methoxymethanol (CH3OCH2OH) was recently detected toward the MM1 core in the high-mass star-forming region NGC 6334I. However, the underlying formation mechanisms of this complex organic molecule (COM) as well as its structural isomers ethylene glycol (HOCH2CH2OH) and the hitherto unobserved dimethyl peroxide (CH3OOCH3) are still elusive. Here, we report the very first confirmed synthesis of dimethyl peroxide - at various deuteration levels within interstellar analogous ices of D3-methanol (CD3OH) exposed to ionizing radiation at ultralow temperatures of 5 K. The discrimination of specific isomers is achieved by exploiting reflectron time-of-flight mass …

Descent In Symmetry During Solid State Transitions And Other Anomalies In Mixed Valence Compounds Axmxⅱm1-Xⅲf3 (A = K, Rb, Cs; M = V, Cr; X = 0.0 - 1.0), William O. J. Boo, Daniel L. Mattern, Robert M. Metzger

Faculty and Student Publications

The scope of solid-state transitions, from melting temperatures down to 4.2 K, is described for six systems: K_xVF₃, Rb_xVF₃, Cs_xVF₃, K_xCrF₃, Rb_xCrF₃, and Cs_xCrF₃ (for x = 0.0 to 1.0). Connections are drawn between the compounds’ compositions and structures with the various transitions and ordering events. Upon solidification from the melt and gradual cooling to room temperature, a sequential descent of symmetry appears to occur, from high-symmetry perovskite phases, through possible reconstructive transitions, to phases designated α …

Molecular Oxygen Generation From The Reaction Of Water Cations With Oxygen Atoms, Ryan C. Fortenberry, Tarek Trabelsi, Brent R. Westbrook, Weston A. Del Rio, Joseph S. Francisco

Faculty and Student Publications

© 2019 Author(s). The oxywater cation (H2OO+), previously shown to form barrierlessly in the gas phase from water cations and atomic oxygen, is proposed here potentially to possess a 2A″ ← 4A″ excitation leading to the H2⋯O2+ complex. This complex could then easily decompose into molecular hydrogen and the molecular oxygen cation. The present quantum chemical study shows that the necessary electronic transition takes place in the range of 1.92 eV (645 nm), in the orange-red range of the visible and solar spectrum, and dissociation of the complex only requires 5.8 kcal/mol (0.25 eV). Such a process for the abiotic, …

Effects Of Polyamine Binding On The Stability Of Dna I-Motif Structures, Michael M. Molnar, Shelby C. Liddell, Randy M. Wadkins

Faculty and Student Publications

B-form DNA can adopt alternative structures under conditions such as superhelical duress. Alternative DNA structures are favored when there is asymmetric distribution of guanosine and cytosine on complimentary DNA strands. A guanosine-rich strand can form a four-stranded structure known as a quadruplex (G4). The complimentary cytosine-rich strand can utilize intercalating cytosine−cytosine base pairing to form a four-stranded structure known as the i-motif (iM). Both secondary structures are energetically uphill from double-strand DNA (dsDNA), meaning that additional factors are needed for their formation. Most iMs require slightly acidic conditions for structure stabilization. However, crowding agents such as polyethylene glycols and dextrans …

Blocking Recombinations In Dscs Through Mgo And Pfts Surface Treatments, Kayla Foell

Honors Theses

High voltage dye-sensitized solar cells (DSCs) are becoming novel sources in the production of various fuel precursors, such as carbon monoxide and hydrogen, by powering carbon dioxide reduction, water oxidation, and proton reduction catalysts via sunlight. An important task in order to increase overall efficiency of DSC devices is to minimize recombination (electron flow in an undesirable direction) while increasing photovoltage. Surface treatment modifications can be applied to the TiO2 electrodes within DSC devices in an effort to block recombination without negatively effecting the other device performance metrics: fill factor (FF), short-circuit current density (Jsc), and open-circuit photovoltage (Voc). In …

Theoretical And Experimental Vibrational Modes Of The Borane Pyridine Complex, Benjamin Stratton

Honors Theses

Benjamin Wade Stratton: Theoretical and Experimental Vibrational Modes of the Borane Pyridine Complex (Under the direction of Dr. Nathan Hammer) The Borane Pyridine complex is a molecule that contains a dative bond between the boron and nitrogen atoms. A dative bond is a type of covalent bonding that occurs when both electrons come from the same atom. The B-N bond has been studied in several other molecules such as ammonia borane and determining the frequency at which this bond vibrates has been a topic of interest studied in these molecules as well as several others. This complex has another factor …

Structures, Energetics, And Vibrational Frequencies Of Microhydrated Hexafluorophosphate, Pf6−(H2o)N=1,2 From Dft And Ab Initio Computations, Yasmeen Abdo

Honors Theses

This study systematically examines an anion commonly used in room temperature ionic liquids, hexafluorophosphate PF6−, and its non-covalent interactions with up to two explicit water molecules (PF6 − (H2 O)n where n = 1, 2). Initial low-energy configurations are identified via a set of relaxed angular scans across the edges and faces of the PF6− octahedron using the global hybrid M06-2X density functional with a triple-ζ correlation consistent basis set augmented with diffuse functions on all non- hydrogen atoms (cc-pVTZ for H and aug-cc-pVTZ for P, O, F; denoted haTZ). Full geometry optimizations are performed on these initial structures using …

Elemental Analysis Of Edible Clay From The Copperbelt Province Of Zambia, Amelia M. Craze, Mina L. Brandon

Venture: The University of Mississippi Undergraduate Research Journal

Trace elements in three edible clay samples from an open-air market in Kitwe, Zambia were analyzed for heavy metals using a scanning electron microscope coupled with an energy-dispersive spectrometer. The ingestion of clays has been observed throughout history but persists in many rural countries that lack sufficient access to proper medical care. In many African countries, women have been observed eating clay during pregnancy to reduce nausea or meet their recommended intake of iron. Similar studies identified harmful heavy metals in the makeup of the edible clays, however, the results of this analysis elemental analysis coupled with the SEM for …

Cis/Trans Energetics In Epoxide, Thiirane, Aziridine And Phosphirane Containing Cyclopentanols: Effects Of Intramolecular Oh···O,S,N And P Contacts, Ben E. Smith, Jeremy M. Carr, Gregory S. Tschumper

Faculty and Student Publications

c 2019 by the authors A recent computational analysis of the stabilizing intramolecular OH···O contact in 1,2-dialkyl-2,3-epoxycyclopentanol diastereomers has been extended to thiiriane, aziridine and phosphirane analogues. Density functional theory (DFT), second-order Møller-Plesset perturbation theory (MP2) and CCSD(T) coupled-cluster computations with simple methyl and ethyl substituents indicate that electronic energies of the cis isomers are lowered by roughly 3 to 4 kcal mol−1 when the OH group of these cyclopentanol systems forms an intramolecular contact with the O, S, N or P atom on the adjacent carbon. The results also suggest that S and P can participate in these stabilizing …

Electro- And Photocatalytic Carbon Dioxide Reduction And Thermal Isomerization Of Highly Strained Tricyclocompounds, Weiwei Yang

Electronic Theses and Dissertations

Anthracene-bridged dinuclear rhenium complexes are reported for electrocatalytic and photocatalytic carbon dioxide (CO2) reduction to carbon monoxide (CO). Related by hindered rotation of each rhenium active site to either side of the anthracene bridge cis and trans conformers have been isolated and characterized. Electrochemical studies reveal distinct mechanisms whereby the cis conformer operates via cooperative bimetallic CO2 activation and conversion and the trans conformer reduces CO2 through well-established single-site and bimolecular pathways analogous to Re(bpy)(CO)3Cl. Higher turnover frequencies are observed for the cis conformer (35.3 s−1) relative to the trans conformer (22.9 s−1) with both outperforming Re(bpy)(CO)3Cl (11.1 s−1). Photocatalytic …

Ni And Au Transition Metal Complexes In The Photocatalytic Co2 Reduction Reaction, Shakeyia Davis

Electronic Theses and Dissertations

The production of renewable fuels by the conversion of solar energy into chemical energy is a challenge. Photocatalytic and electrocatalytic conversion of CO2 to usable fuel precursors are approaches to overcoming this challenge. The two-electron reduction of carbon dioxide to carbon monoxide is an appealing process because CO can be used as a commodity chemical in industrial processes. Many molecular CO2 reduction catalysts have been reported and commonly use expensive late transition metals. These systems are inspired by natural photosynthesis and generally combine a photosensitizer, a catalyst, and a sacrificial electron donor. This work focuses nickel and gold complexes as …

The Development Of Novel Rhenium- And Copper-Based Molecular Catalysts For Applications In Energy Conversion Chemistry, Joseph Michael Lee

Electronic Theses and Dissertations

Since the Industrial Revolution, the consumption of fossil fuels has increased dramatically worldwide. The combustion of fossil fuels leads to the generation of carbon dioxide (CO2) emissions. CO2 is a greenhouse gas, but also a C1 feedstock that could be utilized for the generation of renewable fuels and commodity chemicals. However, CO2 is chemically inert and typically demands strong chemical reductants or very negative potentials before it undergoes conversion into reduced carbon products. The desire to carry out CO2 conversion in the presence of water presents a significant challenge, as protons may be reduced to hydrogen gas rather than facilitating …