Chemistry Commons^™

Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr.

Honors Theses

In this project, the vibrational characteristics/vibrational modes are explored via Raman Spectroscopy for thiolated-gold nanoparticles. This class of compounds is also known as gold nanoparticles (AuNPs). They remain of great interest in research areas such as catalysis, gold dependent nanoelectronics, drug delivery, and sensing, due to their unique size-dependent optical, chiroptical, and electronic properties. Vibrational spectroscopy of thiolated gold nanoparticles are oftentimes considered nontrivial as the compounds strongly absorb light in the visible region of the electromagnetic spectrum, are generally considered weak scatterers, and give off large amounts of fluorescence. This combined with their black appearance, susceptibility to localized heating, …

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 …

Glucose Oxidase And Prussian Blue Nanoparticles Encapsulated Within A Xerogel For Electrochemical Detection Of Glucose, Daniel Baker

Honors Theses

Recent literature reports examples of electrochemical biosensor systems based on the encapsulation of enzymes and metal nanoparticles into a xerogel for the detection of biologically important compounds, such as glucose. While these systems are very successful with acceptable detection limits and linear ranges. However, Prussian Blue modified electrodes have been shown to be better than metal electrodes for the detection of hydrogen peroxide. Here, a biosensor system where a xerogel in formed with both glucose oxidase and Prussian Blue nanoparticles.

Using Tandem Mass Spectrometry And Irmpd Spectroscopy To Determine The Intrinsic Reactions Of Uranyl-Containing Ions, Irena Tatosian

Electronic Theses and Dissertations

Developing a comprehensive understanding of the intrinsic reactivity of uranium-containing species remains an important goal, as it may influence future developments in areas ranging from new approaches to nuclear fuel processing to studies of the migration and fate of the element in the environment. At a more fundamental level, such studies contribute to the understanding of the role that 5-f electrons may play in chemical bonding, the so called “f-electron challenge”. Electrospray ionization (ESI) is an effective way to generate gas-phase complexes containing uranium and uranyl ions for subsequent studies of intrinsic structure and reactivity. Studies in the gas-phase are …

N-Terminal Imine Derivatization For Enhanced De Novo Peptide Sequencing: A Study Of The Fragmentation Pattern Generated From Cid Of Peptide-Imines, Khiry L. Patterson

Electronic Theses and Dissertations

In this work, the fragmentation pattern derived from model peptides derivatized to create N-terminal imines (Schiff bases) were evaluated. Collision-induced dissociation of the protonated peptide-imines ([M+H]⁺) generally produced complete series of the sequence informative a_n and b_n ions, now undoubtedly characteristic of the peptide ion species. A novel product ion was also observed, denoted the y^ǂ ion, determined by IRMPD spectroscopy and density functional theory to be generated from the elimination of the N-terminal amino acid residue despite the N-terminal modification. It was concluded the pathway involved a nucleophilic attack by an amide nitrogen and …

New Synthetic Transformations Utilizing Silyloxyallyl Cations And Epoxonium Ions As Reactive Intermediates, Alexander Houston Cleveland

LSU Doctoral Dissertations

The development of new chemical transformations is of paramount importance in organic chemistry. In fact the study and creation of new reactions often uncovers new chemical reactivities and creates a new area of chemistry. The purpose of this dissertation is to present the development of new synthetic reactions that were uncovered through previous discoveries. Additionally the underlying theme of this work relies on the intermediacy of cationic reactive intermediates such as silyloxyallyl cations and epoxonium ions. Chapters 1 and 2 present the reactivity of novel silyloxyallyl cations. These cationic species are generated via the mild ionization of a-hydroxy silylenol ethers …

Role Of Structural Dynamics In Selectivity And Mechanism Of Non-Heme Fe(Ii) And 2-Oxoglutarate-Dependent Oxygenases Involved In Dna Repair, Sodiq Waheed, Rajeev Ramanan, Shobhit Chaturvedi, Nicolai Lehnert, Christopher J. Schofield, Christo Z. Christov, Tatyana Karabencheva-Christova

Michigan Tech Publications, Part 1

AlkB and its human homologue AlkBH2 are Fe(II)- and 2-oxoglutarate (2OG)-dependent oxygenases that repair alkylated DNA bases occurring as a consequence of reactions with mutagenic agents. We used molecular dynamics (MD) and combined quantum mechanics/molecular mechanics (QM/MM) methods to investigate how structural dynamics influences the selectivity and mechanisms of the AlkB- and AlkBH2-catalyzed demethylation of 3-methylcytosine (m₃C) in single (ssDNA) and double (dsDNA) stranded DNA. Dynamics studies reveal the importance of the flexibility in both the protein and DNA components in determining the preferences of AlkB for ssDNA and of AlkBH2 for dsDNA. Correlated motions, including of a …

Gas Phase Protein Folding Triggered By Proton Stripping Generates Inside-Out Structures: A Molecular Dynamics Simulation Study., Alexander I M Sever, Lars Konermann

Chemistry Publications

The properties of electrosprayed protein ions continue to be enigmatic, owing to the absence of high-resolution structure determination methods in the gas phase. There is considerable evidence that under properly optimized conditions these ions preserve solution-like conformations and interactions. However, it is unlikely that these solution-like conformers represent the "intrinsic" structural preferences of gaseous proteins. In an effort to uncover what such intrinsically preferred conformers might look like, we performed molecular dynamics (MD) simulations of gaseous ubiquitin. Our work was inspired by recent gas phase experiments, where highly extended 13+ ubiquitin ions were transformed to compact 3+ species by proton …

Discovery Of A Dna-Binding Consensus And Potential Genomic Regulatory Binding Sites For The Thermus Thermophilus Hb8 Transcriptional Regulator Ttha1359, Josiah Teague

Master of Science in Chemical Sciences Theses

Transcription factor (TF) proteins act as molecular mechanisms that modulate the initiation of the first step in the expression of genes, gene transcription. Currently, knowledge of the DNA-binding specificities and genes regulated by many TFs, including those of well-studied model organisms such as Escherichia coli and Thermus thermophilus, remains incomplete or lacking which renders gaps in the understanding of the regulatory networks and systems biology of many organisms. Cyclic-AMP receptor protein (CRP) regulators and fumarate and nitrate reduction regulator (FNR) proteins compose the CRP/FNR superfamily of TFs, a diverse subgroup of TFs in bacteria which regulate various gene expression programs. …

Antibacterial Properties Of Novel Amphiphiles, Ariana Simeone

Masters Theses, 2020-current

Hospital acquired infections, particularly antibiotic resistant infections, are a growing concern due to their infection and mortality rate, as well as their growing economic burden, and it has been estimated that by the year 2050 the associated mortality rate will be around 10 million deaths per year. A solution to this is better means of prevention, and amphiphiles, compounds with at least one hydrophilic head group and at least one hydrophobic tail, are promising candidates for stopping the spread of infectious bacteria. Novel amphiphiles with two bipyridinium head groups, separated by a hydrophobic carbon spacer of varying lengths, and each …

Behavior Of Iron Species And Free Radicals In Ambient Pm2.5 And Pm Surrogates, Cholena Russo Ren

LSU Doctoral Dissertations

Air pollution, consisting of ambient particulate matter (PM), has been a rising health concern to the public. PM contains free radicals and have been known to damage human cells; however, their free radical chemistry is not well understood. This study utilized various vacuum and/or heat treatments to study free radical behavior in PM_2.5 (particulate matter with an aerodynamic diameter of 2.5 mm or less) and PM surrogates and simulated sunlight effects on PM_2.5. To mimic PM, iron-silica catalysts (i.e. PM surrogates) were synthesized and real-world ambient PM_2.5 was selected. The free radicals in PM_{2.5 …}

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 …

Small Island Taphonomy In Western Australia, Courtney J. Newberry

Honors Theses

Forensic death investigations rely on postmortem interval estimations to establish a timeline surrounding a decedent’s death. Several methods are used, often together, to make such estimations. One of the main methods is the evaluation of the stage of decomposition; although decomposition follows the same general steps, the length of the process can vary by location and environmental factors. Animal scavenging can also impact decomposition by consuming flesh and impacting insect activity on the remains.

This study investigates the scavenging guilds and rate of decomposition of pig (Sus scrofa) legs on Rottnest Island, Australia. Three sites with unique environments were selected …

Mineral-Surface Chemistry Of Hydroxyapatite And Urea-Rich Solutions, Estefania Garcia

Master of Science in Chemical Sciences Theses

On this planet the development of life requires six essential elements: C, H, O, N, P, and S. These elements are present in gaseous form, with the exception of phosphorus, which is primarily found in solid mineral sources. Phosphorus in biological systems is significant through its involvement in metabolic functions (e.g., Coenzyme A), cell structure (i.e., phospholipid membranes), and genetic storage/transfer (i.e., phosphodiester bonds in DNA and RNA). However, an ambiguity remains with the assimilation of phosphorus in biological systems, caused by its habitual presence in insoluble phosphate mineral sources. Recent research has found that insoluble phosphate …

Using A Novel Cell- Penetrating Peptide Technology To Induce Pluripotency, Laura-Maria Oja

Master of Science in Chemical Sciences Theses

Somatic stem cells have been used as a regenerative medicine tool to treat diseases like leukemia for decades, but they are limited in their ability to self-renew and differentiate. A better alternative, induced pluripotent stem cells (iPSCs), has the ability to generate cells from all three germ layers and avoid tissue rejection as well as bypass the ethical concerns related to embryonic stem cells. In 2006, Takahashi and Yamanaka discovered that only four genes were required to induce pluripotency: Oct4, Sox2, Klf4, and c-Myc (OSKM). Since then, pluripotency has been induced with OSKM most effectively by transfection or transduction. However, …

An Atomistic Study Of The Effects On Mechanical Properties And Bonding Interactions Of Carbon Nanofillers In Nylon 6 Nanocomposites, Michael Roth

Dissertations

Polymers have potential for a wide range of applications. The effectiveness of polymers can be further enhanced through the addition of nanofillers that improve thermal, mechanical, and electrical properties of the polymer. Carbon based nanofillers such as carbon nanotube (CNT), graphene, and carbon nanofibre (CNF) are of particular interest due to their high properties and high aspect ratios. However, limited understanding of the governing interactions of these nanofillers with polymers limits the effectiveness of the final nanocomposite.

The first facet of this dissertation focuses on determining the dominating interactions between pristine CNT and graphene with nylon 6 monomer and the …

Effect Of Selfsame Microparticles On Epoxide Amine Network Formation And Matrix Mechanics, Travis Palmer

Dissertations

Epoxide amine matrices are widely utilized in aerospace carbon fiber reinforced polymer (CFRP) composites having engendered significant reductions in weight and fuel consumption. This dissertation focuses on the effect of constrained space during network formation on the matrix mechanics of these highly complex composite systems. Precipitation polymerization conditions are developed to prepare epoxide amine microparticles (EMs) based on tetraglycidyl-4,4’-methylenedianiline (TGDDM) and isophorone diamine (IPDA). Surface functionality of EMs is tuned via control of epoxide to reactive amine hydrogen ratio, where unreactive, amine- and epoxide-functional EMs are prepared. We demonstrate that EMs are polydisperse, but can be filtered, yielding low dispersity …

Huisgen 1,3-Dipolar Azide-Alkyne Cycloaddition “Click” Reaction In Polymer Synthesis And Curing, Jie Wu

Dissertations

This dissertation’s key focus is on utilizing Huisgen 1,3-dipolar azide-alkyne cycloaddition (AAC) reaction in copolymer synthesis and modification, including thermoplastic block copolymer and commercially available two-component polyurethane system. It can be divided into two major projects, introduced as follows.

The first project involves the development of a modular synthetic approach toward polyisobutylene (PIB)-based triphasic pentablock thermoplastic elastomer with enhanced moisture permeability. This terpolymer consists of a poly(styrene-b-isobutylene-b-styrene) (SIBS) core and appended hydrophilic polymer blocks (HBs). The SIBS core was synthesized via living cationic polymerization (LCP) of isobutylene followed by sequential addition of styrene. AAC was utilized …

Temperature Dependence On Enzymatic Activity Of A82f F87a Mutant And Wild-Type Cytochrome P450 Bm-3, Sally Seder

Undergraduate Theses

Cytochrome P450 is an enzyme mainly found in liver cells. It plays a key role in the breakdown of drugs and toxins by hydroxylating substrates making the substrates more water soluble. P450s are also involved in cholesterol and hormone synthesis. The third P450 from bacterium Bacillus Megaterium (BM3) is used as a model P450 enzyme due to its structural similarity to human P450s and due to its efficiency in the hydroxylation of fatty acids. Within the enzyme’s active site, substrates can occupy a distal or proximal conformation monitored by UV-vis spectroscopy. The proximal conformation is more effective when it comes …

Extraction Of Thyme Leaves And Analysis Of Antibacterial Properties: An Adaptation For Usf Analytical Chemistry Lab Course, Kevin Do, Matthew Barnett

Creative Activity and Research Day - CARD

We streamlined and adapted the thyme leaf extraction and analysis experiment developed by Purcell et al. at the University of California, Berkeley for the analytical chemistry lab course at the University of San Francisco. This experiment used the extraction and analysis of thyme leaves to familiarize students with an integrated laboratory approach, which is becoming increasingly popular in undergraduate chemistry education. The first goal of our research was to adapt the parameters of the experiment to the science writing heuristic (SWH), which moves away from verification-based activities and towards problem-based learning. A lab manual formatted for the SWH gives students …

Effect Of Quinoline Amide Substituents On The Luminescence And Magnetic Resonance Imaging (Mri) Properties Of Bimodal Europium (Iii) Complexes, Brooke Aloe, Marisa Poveda

Creative Activity and Research Day - CARD

Surgical intervention is often necessary in the management of cancer; however, sufficient tumor resection is reliant on adequate discrimination between malignant and healthy tissues. A dual-modality imaging agent with Magnetic Resonance Imaging (MRI) and Optical Imaging capabilities has the potential to improve tumor visualization before and during surgery. Administration of the agent would provide preoperative MR images that localize the bulk of the tumor and intraoperative fluorescence imaging would elucidate tumor margins. Macrocyclic lanthanide complexes possess long-lived luminescent lifetimes, making them ideal candidates for this class of imaging probe; however, the use of high energy lasers to directly excite these …

Oxidation Of Alpha-Pinene Initiated By O(3p) And Analyze Via Synchrotron Radiation, Ryan Rodriguez

Creative Activity and Research Day - CARD

Alpha-pinene oxidation is initiated via photolytically generated atomic oxygen O(3P). Reactions were analyzed at 550 K under 4 torr and 750 K at 5 torr. Reaction products are analyzed using multiplexed photoionization mass spectrometry. Vacuum ultraviolet synchrotron radiation is generated at the Advanced Light Source at the Lawrence Berkeley National Laboratory. Kinetic time traces are used to identify primary products, which are then characterized by comparing the experimental photoionization spectra to literature and/or simulated spectra. Calculations using the CBS-QB3 composite method suggest oxygen addition is the favorable pathway vs hydrogen abstraction, agreeing with experimental data. Branching fractions have determined for …

A Ficellomycin Inspired Platform: Modulating Cytotoxicity By Tuning The Instability Of Substituted Azabicyclo[3.1.0]Hexanes, Nathaniel Garrison

Creative Activity and Research Day - CARD

DNA-damaging natural products, despite their promising activity, are often too toxic for clinical use as anti-cancer chemotherapies. Novel strategies to effectively modulate their cytotoxicity could expand the arsenal of usable drugs. Ficellomycin, a cytotoxic, DNA-alkylating antibiotic with a rare and unstable azabicyclo[3.1.0]hexane core, undergoes an intramolecular cyclization to render itself inert outside of a narrow pH range. Exploration of ficellomycin’s natural capacity for self-regulation may present a novel strategy for modulation of cytotoxicity more generally. Toward this end, we have synthesized a protected ficellomycin precursor in four steps and 6% overall yield. Key steps in the sequence include Sharpless asymmetric …

Diammonium Potassium Citrate, (Nh4)2kc6h5o7, Nilan V. Patel, Joseph T. Golab, James A. Kaduk

Student Publications & Research

No abstract provided.

Functional Nanomaterials By Combining Aminooxy Chemistry And Iodine Activation At Momolayer Protected Clusters., Tirtha Raj Sibakoti

Electronic Theses and Dissertations

Aminooxy (-ONH₂) groups are most commonly known for their chemoselective reaction with carbonyl compounds (aldehydes/ketones) under mild reaction conditions. Aminooxy-based click chemistry is a versatile means of ligation as evidenced by broad application in material science, biology, biochemistry, analytical chemistry, and nanoscience. Our work exploits the facile reaction of aminooxy groups presented on the surface of gold (Au) or palladium (Pd) monolayer protected clusters (MPCs) with various aldehydes via oximation reactions, which form the robust oxime ether adducts. The functionalization of hexanethiolate-stabilized Au MPCs with a newly developed trifunctional amine-containing aminooxy alkanethiol ligand by thiol place-exchange affords aminooxylated …

Determining Particle Size Of Polymeric Micelles In Thermothickening Aqueous Solutions, Jessica Diane Bruer

Graduate Theses/Dissertations

Many active pharmaceutical ingredients (APIs) are poorly soluble and cause inadequate drug absorption. Soluplus^®, a polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, is a commercial excipient (BASF Corp) that enhances the solubility and bioavailability of many APIs. The mechanism of enhancement is related to the ability to form polymeric micelles in solution. These micelles store insoluble APIs in their hydrophobic interior and transport them to targeted sites in the body. An important characteristic of solubility enhancers is the particle size exhibited in solution before and after loading with APIs. This is most commonly determined by dynamic light scattering (DLS) …

Synchrotron Photoionization Study Of The O(3p) + Alpha-Angelica Lactone (Aal) At 550 And 700k, Golbon Rezaei

Creative Activity and Research Day - CARD

The purpose of this research is to study the oxidation of alpha-angelica lactone (AAL) initiated by O(3P) using the synchrotron radiation from the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory. The reaction species are investigated by multiplexed photoionization mass spectrometry. Mass-to-charge ratios, time traces, and photoionization spectra are collected for each primary product to help in their identification. Their adiabatic ionization energies are also obtained. The observed primary products at 550 K are ketene (m/z 42), acetaldehyde (m/z 44), methyl ketene (m/z 56), methyl vinyl ketone (m/z 70), methylglyoxal (m/z 72), dimethyl glyoxal (m/z 86), and 5-methyl-2,4 …

Side-Chain Effects On The Mri And Optical Properties Of Bimodal Imaging Agents, Marisa Poveda

Creative Activity and Research Day - CARD

In the management of cancer distinguishing tumor margins is an ongoing issue that can lead to insufficient removal of cancerous cells or excision of healthy tissue. To overcome this, bimodal imaging agents can be used for preoperative MR imaging to localize the bulk of a tumor, while intraoperative fluorescence imaging illuminates tumor margins for more accurate removal of diseased tissue. Lanthanide ions such as Tb(III) and Eu(III) display luminescent capabilities with long-lived luminescence lifetimes, and when chelated with a chromophore containing ligand, these compounds have the potential to act as both MR and optical imaging probes. The goal of this …

Nano-Scintillators As Next Generation Tools For Optogenetics, Ashley Dickey

All Dissertations

Optogenetics is a technique that is used to study neural pathways and has the ability to activate or silence synaptic behavior using visible light. Currently, the visible light sources used for optogenetics are surgically implanted into the brain tissue, but this harmful and invasive technique may be avoided if suitable scintillating nanoparticles can be inserted via injection. The proposed nano-scintillator particles must adhere to rigorous parameters including being under 100 nm, uniform, nontoxic, and dispersible to be successful in this biological system. The phase, crystallinity, and dopant concentration must be optimized to absorb X-ray radiation and emit photons of the …

Synthesis And Characterization Of Carbon Monoxide Producers Bipyridine Flavonolate Palladium(Ii) And Platinum(Ii) Complexes: Potential Anti-Cancer Agents, Sarah Whitfield

Electronic Theses and Dissertations

Novel designed metal ligand complexes as prodrugs are useful in the effort to find more effective and selective anti-cancer treatments. Carbon monoxide, CO, is known to induce mitochondrial collapse in cancer cells. Herein is described the synthesis of seven novel bipyridine flavonolate palladium(II) and platinum(II) complexes with the property of releasing carbon monoxide, and their characterization with FTIR, UV-Vis, fluorescence, NMR, and ESI mass spectra. Their ability to release carbon monoxide was investigated through oxygenation reaction under various conditions of temperature and light irradiation. The nitroxygenation reaction of the palladium complexes was also studied with nitrosyl hydride, HNO, generated in …