Chemistry Commons^™

Electrochemical Studies Involving Co2 Reduction With Rhenium-Based Catalysts And For Guanosine Monophosphate Oxidation, Kayla A. Milano

Electronic Theses and Dissertations

The following chapter of this thesis will cover the oxidation of guanine monophosphate (GMP). GMP has been linked to numerous conditions when it is oxidized or damaged. There have been two oxidation pathways suggested in association to the oxidation of GMP: EPT and MS-EPT. The ideal conditions for GMP’s oxidation is still be studied and collected. The study focuses on the acetate versus phosphate buffer, varying base concentration in phosphate buffer, and the varying concentration of ruthenium complex, a redox mediator.

The Synthesis Of New Donor-Sigma-Acceptor Compounds As Potential Current Rectifiers, Trey Gautier Vaughan

Electronic Theses and Dissertations

The zwitterionic D-σ-A’s are characterized by having an anionic donor, a cationic acceptor, an intervening sigma-bond bridge, and an aliphatic tail. The aliphatic tail is of such length as to impart greater solubility in organic solvents since the formal charges on the donor and acceptor lead to poor solubility. Additionally, the aliphatic tail is required for Pockels-Langmuir deposition to facilitate the favorable van der Waal’s packing when combined to form dense monolayer registries. These monolayers may then be suitable for measuring the bulk electrical properties.

A Study To Regioselectively Access Fluorinated Triazoles And Isoxazoles, Sweta Adhikari

Electronic Theses and Dissertations

The objective of the thesis is to develop regioselective methods for mono-fluorination of disubstituted triazoles, both 1,4- and 1,5-regioisomer, and isoxazoles. These strategies focus on one-pot direct access to final mono-fluorinated triazoles and isoxazoles. Eventually, these fluorinated substrates will be screened against various biological targets. Similarly, the optimization study of a regioselective method to generate 5-fluoro-1,4-disubstituted triazole was conducted. This reaction also utilized 1,3-dipolar cycloaddition to synthesize fluorinated triazole. However, difluoroalkene was used as a synthetic equivalent of fluoroalkyne for this method. This resulted into the inversion of polarity affording a different regioisomer. Here, fluoronitroalkene was identified as a synthetic …

High Voltage Dye-Sensitized Solar Cells And Molecular Photocatalysis For Co2 Reduction, Roberta Ramalho Rodrigues

Electronic Theses and Dissertations

The development of high voltage solar cells is an attractive way to use sunlight to power electrocatalysts for water oxidation, electrocatalysts for CO2 reduction, and consumer electronics. Through careful molecular dye engineering and redox shuttle pairing, our group has reported a single-junction dye-sensitized solar cell (DSC) employing, for the first time, an iron redox mediator (Fe(bpy)33+/2+) in conjunction with a novel wide band gap dye (RR9). This system generates a high photovoltage of 1.42 V. To the best of our knowledge, this system is the highest photovoltage achieved by a single-junction DSC device without metal oxide doping. The RR9/Fe(bpy)33+/2+ redox …

Intramoleculer Hydrogen Bonding In Epoxide, Thiirane, Aziridine And Phosphirane Containing Cyclopentanols, Ben Edward Smith

Electronic Theses and Dissertations

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 intramolecular interactions …

Bulky Thiolated Gold Nanomolecules: Synthesis, Characterization, Optical Properties, And Atomic Structure, Tanya Clorise Jones

Electronic Theses and Dissertations

Gold nanomolecules (NMs) have a distinct number of gold atoms and thiolate ligands, Aux(SR)y, with unique spectroscopic, electrochemical, and chiral properties which are dependent on “x” and “y”. The properties of NMs are dictated by the type of capping ligand. The overall structure, size, surface percentage of ligands, and structure of an entire gold NM is changed based on the type of ligand used to synthesize it. Ligand type, such as aliphatic, aromatic or bulky play a crucial role in determining the size and composition of such NMs. A NM’s composition and properties vary widely depending on the type of …

The Schrödinger Equation With Coulomb Potential Admits No Exact Solutions, Ilia Toli

Electronic Theses and Dissertations

We prove that the Schrödinger equation with the electrostatic potential energy expressed by the Coulomb potential does not admit exact solutions for three or more bodies. It follows that the exact solutions proposed by Fock [1–3] are flawed. The Coulomb potential is the problem. Based on the classical (non-quantum) principle of superposition, the Coulomb potential of a system of many particles is assumed to be the sum of all the pairwise Coulomb potentials. We prove that this is not accurate. The Coulomb potential being a hyperbolic (not linear) function, the superposition principle does not apply. The Schrödinger equation as studied …

Remediation Of Chlorinated Alkanes By Zero Valent Iron With Vitamin B12 And Utilization Of A Modified Gradual Release Of Responsibility Model In A Large Enrollment Chemistry Course, Nicole Lapeyrouse

Electronic Theses and Dissertations

The following dissertation looks at addressing environmental contaminants in the environment and the integration of an active learning style in an introductory chemistry course. It begins with addressing the concern for chlorinated propanes and ethane in the environment and the importance of looking into environmental remediation applications. This research looks at incorporating vitamin B12 as an environmentally friendly catalyst in the presence of zero valent iron for the reduction of chlorinated propanes and ethane. Chapter 2 presents the analytical methods and conditions in which samples were run. The results from these experiments are discussed in length in Chapter 3. Our …

A Complete Approach To Predict Biodistribution Of Nanomaterials Within Animal Species From In-Vitro Data, Edward Price

Electronic Theses and Dissertations

Smart drug-design for antibody and nanomaterial-based therapies allows for optimization of drug efficacy and more efficient early-stage pre-clinical trials. The ideal drug must display maximum efficacy at target tissue sites, but to track and predict distribution to these sites, one must have a mechanistic understanding of the kinetics involved with the individual cells of the tissue itself. This process can be tracked through biological simulations coupled with in-vitro approaches, which result in a rapid and efficient in-depth understanding of drug transport within tissue vasculature and cellular environment. As a result, it becomes possible to predict drug biodistribution within live animal …

The Evaluation Of Classifier Performance On The Forensic Analysis Of Fire Debris And The Expansion Of The Substrate Database, Alyssa Allen

Electronic Theses and Dissertations

The current protocols in fire debris analysis rely on ignitable liquid pattern recognition and the identification of target compounds. These practices allow fire debris analysts to determine whether a sample contains or is absent of ignitable liquid residue and to classify that type of ignitable liquid based upon subjective thresholds. A statistical approach using computationally mixed datasets was devised in this research to generate an objective approach to the classification of fire debris samples and to determine error rates. Quadratic, linear, and partial least squares linear discriminant analysis (QDA, LDA, and PLS-DA) models were developed and evaluated to determine the …

X-Ray Crystal Structure Of Au36(Sph-Pch3)24 Nanomolecules, Vigneshraja Ganeshraj

Electronic Theses and Dissertations

Au36(SR)24 is one of the most comNanomolecules (NM) in gold NM field and crystal structures of Au36(SR)24 with different thiolate protecting ligand such as tert-butylbenzene thiol, thiophenol and cyclopentane thiol have been reported. It has been predicted that aromatic thiol protected Au36(SR)24 NM have same core structures like the other reported Au36(SR)24 NMs. Due to the steric and electronic conjugation effects the staples on the gold core exhibit minor changes in the bond length without affecting the gold core. By varying the Gold:Thiol ratio the NM size can be controlled. Herein, we report the synthesis, isolation and characterization of two …

Development Of Cobalt And Iron Catalysts Bearing Rigid Polydentate Ligands For Proton Reduction And C-H Bond Oxidation, Lizhu Chen

Electronic Theses and Dissertations

The demand for energy consumption has increased exponentially since the Industrial Revolution. The major source of this energy has been and continues to be fossil fuels. The depletion of fossil fuels and environmental concerns associated with their combustion has motivated us to develop a renewable energy alternative to meet future energy demands. Hydrogen is a clean energy alternative to fossil fuels, which can be generated from solar-driven water splitting. However, more efficient and inexpensive catalysts for the hydrogen evolution reaction (HER) are needed. In this context, hydrogen production has been investigated with a stable and highly reactive cobalt-based catalyst. While …

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 …

Effects Of Halogen Bonding And Nir Tuning Of Dyes For Dye-Sensitized Solar Cells, Alexandra Baumann

Electronic Theses and Dissertations

With current energy demands being met through the utilization of energy sources such as petroleum, natural gas, and coal, the non-renewable nature of these sources will eventually approach depletion as world wide energy consumption increases yearly. As a result the need for a renewable energy alternative has become imminent. One appealing alternative that has gained considerable attention since its development due to a low cost and a high solar to electric conversion efficiency are dye-sensitized solar cells (DSCs). This dissertation describes efforts to design and synthesize improved organic dyes utilizing three analogous methods: first, through decreasing non-productive pathways such as …

Metastable-State Photoacids: Synthesis, Properties, And Applications, Parth Patel

Electronic Theses and Dissertations

Reversible photochromic compounds have the ability to reversibly change its color when it absorbs photons of a particular wavelength. This process of color change is a consequence of structural changes within the compound, such as cis-trans photo-isomerization. Some examples of photochromic compounds are spiropyrans, spirooxazines, diarylethenes and azobenzenes. These compounds have been extensively studied for decades, and are used in various applications such as biomedicine, chemical sensors and harvesting solar energy. However, majority of photochromic compounds are initially activated by ultraviolet (UV) light. The use of UV light is harmful for biological applications and photo-degrade the compound over repeated use. …

The Characterization Of Condom Lubricants And Personal Hygiene Products Using Dart-Tofms And Gc- Ms And The Investigation Of Gold Nanoparticle Behavior In Water And The Interaction With Blood Serum Proteins, Yasmine Moustafa

Electronic Theses and Dissertations

This dissertation is divided into two independent research projects. First, condom lubricants, sexual lubricants, and personal hygiene products (PHPs) were studied using direct analysis in real time-time-of-flight-mass spectrometry (DART-TOFMS) and gas chromatography-mass spectrometry (GC-MS). The purpose addressed the concern of perpetrators resorting to new tactics, i.e. using condoms to remove seminal fluid that could provide a DNA link to a suspect, leading to the need of the consideration of condom lubricants as pieces of sexual assault evidence. Due to condom lubricants having a chemical composition resembling PHPs, the investigation of both sample groups was analyzed to prevent false positives. Although …

Tumor-Targeted Conjugated Polymer Nanoparticles With Encapsulated Iron And Its Biomedical Application For In Vitro Killing Of Melanoma Cell Lines Through Ferroptosis Assisted Chemodynamic Therapy (Cdt), Khalaf Jasim

Electronic Theses and Dissertations

Melanoma represents one of the most aggressive and lethal forms of skin cancer, with annually rising incidences throughout the world. Although chemotherapy modalities remain the mainstay of treatment, the therapeutic potential of chemotherapy typically is hampered by multidrug resistance (MDR) and nonspecific drug distribution that causes side-effects. To surmount such limitations, novel nanoformulations of low band-gap poly ({4,8-bis [(2-ethylhexyl) oxy] benzo [1,2-b:4,5-b?] dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b] thiophenediyl}) (PTB7) and poly [2,1,3-benzothiadiazole- 4,7- diyl [4,4-bis (2-ethylhexyl)- 4H-cyclopenta [2,1-b:3,4-b'] dithiophene-2,6-diyl]] (PCPDTBT) were fabricated by a reprecipitation method. These conjugated polymer nanoparticles were functionalized with the polypeptide endothelin-3 (EDN3-CPNPs) to target melanoma. The …

Magnesium-Based Treatment For The Degradation Of Octachlorodibenzofuran And Trinitrotoluene, Amal Mogharbel

Electronic Theses and Dissertations

The aim of the present research is to investigate the efficacy of using ball-milled zero-valent magnesium (ZVMg) with and without activated carbon (AC) for the dechlorination of polychlorinated dibenzofurans. Three different solvent systems are presented here which are ethanol, ethanol/ethyl lactate (90:10), and 2-butoxyethanol. These solvents in combination with ZVMg with and without activated carbon were tested towards the degradation of octachlorodibenzofuran (OCDF, the most highly chlorinated PCDF congener). All the tested systems were very powerful and reductively dechlorinated OCDF to less chlorinated congeners. However, the system of ball-milled ZVMg and ethanol was the only system which converted OCDF and …

Thermo- And Zero-Valent Iron-Activated Persulfate Oxidation Of 3,5,6-Trichloro-2-Pyridinol In An Aquatic System, Roaa Mogharbel

Electronic Theses and Dissertations

The compound 3,5,6-trichloro-2-pyridinol (TCPy), a metabolite of the broad-spectrum organophosphorous insecticide chlorpyrifos, is both more persistent and more water soluble than its parent compound. This difference, which allows TCPy to more readily leach into surface water and groundwater, has led to widespread contamination of TCPy in soils and aquatic environments. In this study, the degradation of TCPy by sulfate radicals was evaluated using zero valent ironactivated persulfate systems and heat activated persulfate system in aqueous media. Response surface methodology coupled with Box-Behnken design was applied in these studies to evaluate the effects of the independent variables on the mineralization of …

Improved System For Fabrication And Characterization Of Nanophotonic Devices By Multi-Photon Lithography, Rashi Sharma

Electronic Theses and Dissertations

A new system for multi-photon lithography (MPL) was developed and used to fabricate three-dimensional (3D) structures with higher aspect ratio, better resolution, improved fidelity, and reduced structural distortion relative to a conventional implementation of MPL. A set of curved waveguides (Rbend = 19 μm, and 38 μm) and straight waveguides (length = 50 μm, Rbend = ∞) were fabricated in an epoxide photopolymer and optically characterized using light having a wavelength in vacuum of λ0 = 2.94 μm. The optical performance of the waveguides was compared to novel spatially-variant photonic crystals (SVPCs) previously studied in the group. The waveguides were …

Lewis Base Promoted Annulations Of Allenoates With 1,4-Naphthoquinones, Nicole Marie Shoup

Electronic Theses and Dissertations

Lewis base promoted cyclization of allenoates with electron deficient olefins open up the possibility to generate more complex organic structures. By generating more complex molecules, we are able to produce new compounds for biomedical and material applications. Both phosphine and amine Lewis bases offer interesting annulations with allenoates resulting in Lu or Morita–Baylis–Hillman type reactions. Once the Lewis base engages with the allenoate there can be several modes of nucleophilic reactivity that allows for the allenic ester to act as a two or three carbon synthon. The allenoate can then react with varying electron deficient olefins generating more complex molecules …

Chemometric Applications In Fire Debris Analysis: Likelihood Ratios From Naive Bayes And Frequency Of Component And Pyrolysis Product Occurrence, Anuradha Akmeemana

Electronic Theses and Dissertations

One of the major challenges in fire investigation is the determination of the cause of fire. The fire can be accidental or intentional. The determination of ignitable liquid residue (ILR) from fire debris helps the process and this process is called fire debris analysis in forensic science. This is one of the most complex areas in the field of forensics because of the evaporation of the ILR from the debris and the interference of the substrate matrix with the ILR if present. In the present, the final decisions in fire debris analysis are based on categorical statements and it only …

Syntheses Of A Tin (Iv) Meso-Tetra(4-Pyridyl) Porphyrin Dichloride-Tetrachlorobis (Bipy)2 Ruthenium (Ii) Complex And Studies Of Photophysical Properties Of 1-Nitropyrene, Phillip Sharp

Electronic Theses and Dissertations

Development of a photosensitizer that can work in both aerobic and anaerobic environments would increase the robustness of the cancer treatment known as photodynamic therapy. The development of a photosensitizer was first attempted by synthesizing a tin (IV) meso-tetra (4-pyridyl) porphyrin dichloride-tetrachlorobis (Bipy)₂ ruthenium (II) complex. The synthesize of the tin porphyrin was done by a method from literature and had a percent error of 31.58 and 37.31 when comparing the theoretical percentages of carbon (55.39) and nitrogen (12.92) meaning that photosensitizer was not synthesized.

The second type of chromophore that was studied was 1-nitropyrene do determine if it …

Extraction And Purification Of Biologically Active Metabolites From Rhodococcus Sp. Mtm3w5.2, Mohrah Alenazi

Electronic Theses and Dissertations

Rhodococcushas been recognized as a potential antibiotic producer. Recently, a strain of Rhodococcussp. MTM3W5.2 was isolated from a soil sample collected in Morristown, Tennessee and was found to produce an inhibitory compound which is active against other related species. The purpose of this research is to extract, purify and analyze the active metabolite. The compound was extracted from RM broth cultures and purified by preliminary fractionation of crude extract through a Sephadex LH-20 column. Further purification was completed using semi-preparative reversed phase column chromatography. Final purification was obtained using multiple rounds of an analytical C18 HPLC column. Based …

Relative Permittivity As A Function Of Co-Solvent And Impedance Spectroscopy For Quantifying Anions In Solution, Yahya Sami Alseiha

Electronic Theses and Dissertations

This work measured relative permittivity from 15.0 to 55.0 °C of aqueous solutions containing acetone or tetrahydrofuran using a BI 870 dielectric meter. A cubic polynomial fit resulted in coefficients for calculating permittivity as a function of temperature and mole fraction. Literature values for other co-solvent system resulted in similar polynomial coefficients. Using BI 870, permittivity measurements of ionic solutions were not possible because of high conductivity. A simple method using impedance spectroscopy measured these solutions. Impedance decreases with increasing temperature and decreases with increasing ionic strength. Due to the temperature dependence of impedance, all measurements were at 25.0 °C. …

Computational Quantum Chemistry Studies Of The Interactions Of Amino Acids Side Chains With The Guanine Radical Cation., Edward Acheampong

Electronic Theses and Dissertations

Guanine is generally accepted as the most easily oxidized DNA base when cells are subjected to ionizing radiation, photoionization or photosensitization. At pH 7, the midpoint reduction potential is on the order of 0.2 – 0.3 V higher than those of the radicals of e.g. tyrosine, tryptophan cysteine and histidine, so that the radical “repair” (or at least, a thermodynamically favorable reaction) involving these amino acids is feasible. Computational quantum studies have been done on tyrosine, tryptophan, cysteine and histidine side chains as they appear in histones. Density functional theory was employed using B3LYP/6-31G+ (d, p) basis set to study …

Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles

Electronic Theses and Dissertations

The eastern peninsula of Fort Hood Military Installation is underlain by a complex karst spring network. These springs are a primary water source in a protected habitat for endangered songbirds, which has only recently begun to be fully investigated. These Fredericksburg Group springs express both epigenetic and hypogenetic karst signatures. The study area is part of a paleo reef trend, a hydraulically disconnected segment of the northern section of the Edwards Aquifer. This study utilized standard ion index values, repeated measures, and principal component analyses on the chemical profiles of six perennial springs to classify spring water sources and their …

The Regional Distribution And Molecular Interactions Of Phospholipids And Glucose In Mammalian Vitreous Humors., Abigail Nicole Schnepf

Electronic Theses and Dissertations

The vitreous humor (VH) is located in between the lens and the retina. It is composed of 98% water, hyaluronan (HA), collagen, proteins, phospholipids (PLs), and other metabolites. With aging, the VH undergoes liquefaction, a process that causes the gel-like structure of the VH to turn into a liquid and can lead to serious ocular diseases, including retinal detachment, vitreal detachment, and macular hole formation. The liquefaction process is expedited in diabetic VHs. This project focuses on understanding the molecular changes that lead to liquefaction and the reasons for which this process is accelerated with diabetes. Matrix-assisted laser desorption ionization/mass …

Electrochemical And Morphological Properties Of Chloride-Doped Lithium Argyrodite Solid Electrolytes., William Richard Arnold

Electronic Theses and Dissertations

Recently, much attention has been devoted to the development of solid electrolytes to be used in all-solid-state-batteries. One group of promising solid electrolyte (SE) materials are lithium argyrodites, a class of superconductors which are noted for their high ionic conductivities. In particular, halogen doping has been shown to increase both conductivity and stability. The majority of research has focused on material synthesis through solid state reactions, but a novel liquid synthesis method for the preparation of Cl-doped Li7PS6 solid electrolyte provides the advantages of a homogenous product and a rapid, economic synthesis. Here this thesis focuses on the liquid synthesis …

Structure And Thermodynamics Of Polyglutamine Peptides And Amyloid Fibrils Via Metadynamics And Molecular Dynamics Simulations, Riley Workman

Electronic Theses and Dissertations

Aggregation of polyglutamine (polyQ)-rich polypeptides in neurons is a marker for nine neurodegenerative diseases. The molecular process responsible for the formation of polyQ fibrils is not well understood and represents a growing area of study. To enable development of treatments that could interfere with aggregation of polyQ peptides, it is crucial to understand the molecular mechanisms by which polyQ peptides aggregate into fibrils. Many experimental techniques have been employed to probe polyQ aggregation, however, observations from these studies have not lead to a unified understanding of the properties of these systems, instead yielding competing, fragmented theories of polyQ aggregation. This …