Chemistry Commons^™

In Situ Nmr Parameter Monitoring Systems And Methods For Measuring Ph And Temperature, Ming Huang, Lingyu Chi, Rex E. Gerald Ii, Jie Huang, Annalise R. Pfaff, Klaus Woelk

Electrical and Computer Engineering Faculty Research & Creative Works

Devices and methods are provided for measuring temperatures and pHs of a sample in situ using NMR spectroscopy, and for sealing one or more ends of a capillary tube after a reference material has been added to the capillary tube, which is used in an in situ NMR temperature measurement device. A method for measuring a pH of a sample in situ using NMR spectroscopy includes providing an in situ NMR pH measurement device. This device includes a sample housing member configured to house a target sample, at least one pH sensor configured to exhibit an NMR spectral change due …

A Closer Look At The Synthesis And Characterization Of Alkaline Earth Metal Tetraarylborates And Heteroleptic Tetraarylborate Pyrazolates, Ashley Clements

Renée Crown University Honors Thesis Projects - All

Compounds containing s-block metals are highly sought after as precursor materials for the Metal Organic Chemical Vapor Deposition (MOCVD) process with applications for novel and improved electronic materials. Previous work in the Ruhlandt Group has been focused on the synthesis and characterization of novel homoleptic alkaline earth (Ae) metal pyrazolate and tetraarylborate complexes, while understanding the importance of secondary interactions such as M- in the isolation of these compounds. More recently, it was further proposed that the pyrazolate and tetraarylborate ligand systems combined with an Ae silyl amide via transamination may very well result in an improved heteroleptic MOCVD potential …

Design Of Cotton Fabric-Based Binary And Ternary Composite Materials Containing Nanostructured Zno, Tio2, And Plasmonic Nanoparticles: Photocatalytic Applications, Latanya Downer

Master of Science in Chemical Sciences Theses

Nanostructure metals and metal oxides can be used for surface functionalization and combined with different materials to increase functionality. Recently, surface functionality has been of interest due to its multi-component and its ability to generate new material properties. One of its main application is the creation of nanomaterials because of its novel physical properties which contribute towards stabilization, strength, and catalytic properties. Nanomaterials makes it possible to fabricate objects in the nanoscale size range which offers beneficial physical properties. The nanomaterial distinctiveness allows for the creation of materials with unique characteristics for different applications such as photocatalytic coatings. Semiconductor and …

Preparation Of Organometallic Cobalt(Iii) Complexes Containing Bidentate Chiral Amine Ligands As Potential Transfer Hydrogenation Catalysts, Luccas C. Do Carmo

Honors Theses

Mixed coordination sphere cobalt(III) complexes containing a chiral bidentate amine ligand and an organic carbocyclic ligand have been prepared and characterized. The integration of this mixed ligand environment involving an organometallic and Werner-type ligand along with the earth abundant metal in a high oxidation state has the potential for interesting reactivity. Complexes of the type [Co(CpR)(X-DPEN)(I)](I), where CpR = cyclopentadienyl (Cp, R = H) or pentamethylcyclopentadienyl (Cp*, R = Me) and X = meso-1,2-, 1R,2R-, and 1S,2S-, have been prepared by ligand substitution from [Co(CpR)(I)2(CO)] with 1,2-diphenyletheylenediamine (DPEN). The outer sphere iodide is readily exchangeable with sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaBArF) or …

Theoretical Studies Of Naphthoquinone Reactivity Toward Amines, Kevin Lee

Honors Theses

Quinones are a class of organic compounds containing a six-membered unsaturated cyclic ring with two carbonyl groups and are biologically relevant due to their ability to participate in redox reactions. Experiments have showed that quinones can induce protein modifications including oligomerization and polymerization by binding to proteins. To complement these experimental studies, theoretical studies of naphthoquinone reactivity toward an amino group were conducted. The reactions between three naphthoquinones, 1,2-naphthoquinone (ONQ), 1,4-naphthoquinone (PNQ), and 2-hydroxy-1,4-naphthoquinone (HNQ), and methylamine, a N-containing nucleophile, were investigated. For each naphthoquinone, the first step of both 1,2- and 1,4-additions at all possible C=O positions were examined. …

Active Colloid Behavior Exhibiting Soft-Sphere Characteristics For Non-Newtonian Solvent, Courtney Baier

Honors Theses

The purpose of analyzing soft-sphere Brownian particles with varying velocities and densities is to be able to predict their interaction behavior once a force has been applied. The particles portray different behaviors depending on if the particles are passive or active Brownian particles. The data studied was collected from simulations, and there are no attractive forces involved in the particles’ interactions. Mean square displacement graphs, radial distribution graphs, structure factor graphs, and viscosity as a function of density and velocity were used to examine and compare the data generated. Experimental data was analyzed by a program to be interpreted into …

Crystal Structures Of Dotma Chelates From Ce³+ To Yb³+ : Evidence For A Continuum Of Metal Ion Hydration States, Mark Woods, Katherine M. Payne, Edward J. Valente, Benjamin E. Kucera, Victor G. Young

Chemistry Faculty Publications and Presentations

The crystal structures of chelates formed between each stable paramagnetic lanthanide ion and DOTMA are described. A total of 23 individual chelates structures were obtained, in each chelate the coordination geometry around the metal ion is best described as a twisted square antiprism (torsion angle -25.0° – - 31.4°). Despite the uniformity of the general coordination geometry provided by the DOTMA ligand, there is a considerable variation in the hydration state of each chelate. The early Ln3⁺ chelates are associated with a single inner sphere water molecule, the Ln-OH₂ interaction is remarkable for being very long. After a …

Synthesis And Evaluation Of 1,2,4-Oxadiazolidinones: The Search For A Potential Non-Β-Lactam Β-Lactamase Inhibitors., Chimdi Eke Kalu

Electronic Theses and Dissertations

β-lactam antibiotics have been the most widely used drug of choice to combat infectious disease caused by bacteria. Unfortunately, their effectiveness is drastically threatened by bacterial β-lactamases. β-lactamases is responsible for the resistance to most antibiotic drugs. For decades, β-lactam β-lactamases inhibitors have been used to reduce bacterial resistance; however, in this study 1,2,4-oxadiazolidinone derivatives as a non-β-lactam β-lactamases inhibitor against TEM-1 and P99 β-lactamases. The significance of oxadiazolidinone is the prominent five-membered ring scaffold in its structure, which is configurationally stable and present in other biologically active compounds such as linezolid and avibactam. Oxadiazolidinones were synthesized by treating nitrones …

The Protective Effect Of N-Acetylcysteine Amide Against Paraquat-Induced Neurotoxicity, Burhan Ates, Nigar Vardi, Hakan Parlakpinar, Merve Goksin Karaaslan, Ismet Yilmaz, Nuran Ercal

Chemistry Faculty Research & Creative Works

N-acetylcysteine amide (NACA) is a new antioxidant molecule with powerful radical scavenging properties. The aim of this study was to investigate neuroprotective effects of NACA against paraquat (PQ) toxicity in the midbrains of rats by using motor coordination tests and biochemical and histological analysis. Thirty adult Wistar albino rats were divided into three groups: Group 1: control (n = 10), Group 2: PQ (10 mg/kg) (n = 10), and Group 3: PQ (10 mg/kg) + NACA (100 mg/kg) (n = 10). NACA was administrated intraperitoneally 30 min before PQ injection. Performance was measured for a period of 28 days. The …

The Forensic Analysis Of Skin-Safe Stamp Pad Inks, Swetha Rajagopal

Student Theses

Skin-safe stamp pad inks are currently being used at locations such as clubs, zoos and other events with the purpose of stamping individuals that visit the location. This is done in an attempt to monitor the number and activity of visitors. Ink manufacturing companies generally tend to experiment with a number of different combinations of the different components of ink, in order to obtain desirable properties. The combinations are usually proprietary and that very nature of the inks ends up making them, possibly unique and individual. The analysis, identification and possible individualization of the chemical composition of these inks could …

Studies On Regulation Of Dihydrotestosterone Binding To And Releasing From The Androgen Receptor, Tahyra M. Resto Santos

Theses and Dissertations

The androgen receptor (AR) is a nuclear receptor that responds to testosterone and 5α-dihydrotestosterone (DHT) by modulating gene expression in a variety of cells, including prostate and muscle tissues. Studies of small molecule interaction with AR have shown diphenyl compounds inhibiting through a binding site labeled Binding Function 3 (BF3). The goal of this research is to analyze the interaction of the BF3 site with DDT and related compounds. Amino acids that are exposed on the surface of the BF3 that might interact with different compounds were mutated. Mutant proteins were tested experimentally for their impact on the inhibition the …

The Development Of Screening Platforms To Identify Novel Anti-Infectives That Inhibit Protein Synthesis In Pseudomonas Aeruginosa, Casey Anne Hughes

Theses and Dissertations

Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen, is a leading cause of nosocomial infections and is becoming increasingly antibiotic resistant. Aminoacyl-tRNA synthetases (aaRSs) catalyze the covalent attachment of amino acids to their cognate tRNAs and serve as validated targets for the development of new anti-infectives. In P. aeruginosa, the genome contains two genes (tyrS and tyrZ) which encode two distinct TyrRS enzymes. The genes encoding both P. aeruginosa TyrRS-Z and TyrRS-S were cloned, overexpressed in E. coli cells, and purified to homogeneity. Both forms of TyrRS were active in aminoacylation and were developed into screening platforms using scintillation proximity …

Molten-Salt Synthesized Pyrochlore Nanoparticles For Multifunctional Applications, Jose P. Zuniga

Theses and Dissertations

There is a need in the scientific world to design and develop high quality nanomaterials with multifunctional applications. In this work, we explore the molten-salt method (MSS) as a new green method for the synthesis of complex metal oxides. We adjusted all synthesis parameters such as time, temperature and pH to generate an optimum La2Hf2O7 nanoparticle with a well define shape and surface. Activator ions such as Eu3+, Tb3+, Dy3+, Bi3+ and uranium ion (U4+, U6+) were used to monitor its structural and optical behavior effect when doped.

Our results showed effective quantum yield, thermal, pressure stability, near to white …

Development Of Highly Efficient Catalyst And Reactions For Organic Synthesis: Monophosphine-Coordinated Palladacycle Complexes For Cross-Coupling Reactions/Polymerizations, Jie Dong

Dissertations, Theses, and Capstone Projects

Transition metal-catalyzed cross-coupling reactions such as Suzuki-Miyaura cross-couplings, are among the most powerful transformations in organic synthesis. They have been extensively used for the synthesis of a wide variety of organic compounds. Recently the Suzuki cross-coupling reaction has been extended to conjugated polymer synthesis, especially the controlled Suzuki cross-coupling polymerization for polymers with the desired length. My research is on developing highly efficient monophosphine-coordinated palladacycle complexes for cross-coupling reactions/polymerizations.

Based on the understanding of transition metal-catalyzed Suzuki cross-coupling reactions including polymerization, my dissertation started with Pd(0)- and Ni(0)-catalyzed borylation reactions of aryl halides and tosylates with bis(pinacolato)diboron to access arylboronates …

Novel Heterocyclic Methodology For The Construction Of Natural Products, Robert C. Lapo

Dissertations, Theses, and Capstone Projects

The synthesis of heterocyclic compounds and their incorporation into total synthesis strategies are described. Three synthetic methodologies toward substituted indoles, isochromans, and fused multi-ring oxazolidinones have been examined. With the progress that has been made, further investigations will hopefully carry the concept to completion.

Chapter I is an introductory examination of the varied types and systematic nomenclature of heterocyclic structures, including common names. This continues on to their commercial and industrial usage, and their great importance in biological systems and natural product chemistry. Finally, examples of heterocycles in fused-ring natural products and examples of historical and/or commercial value are examined …

Preparation Of Enantioenriched Alkyltin Species And Their Application In Stereospecific Transformations, Glenn O. Ralph

Dissertations, Theses, and Capstone Projects

Organometallic reagents containing the tin-carbon bond are used extensively in modern synthetic chemistry for the formation of new bonds to carbon. Over recent decades, transition metal catalyzed cross coupling reactions between two C(sp²) centers have been widely developed. However, the introduction of a C(sp³) center complicates the catalytic cycle, and opens unproductive chemical pathways which lead to isomerization, elimination, and racemization. Our lab has developed a modified-Stille reaction to combat the deleterious effects of β-hydride elimination. Our protocol enables unactivated 2° alkyl organotin nucleophiles to undergo efficient cross coupling reactions with C(sp²) electrophiles, avoiding …

A Pretargeted Spect Imaging Strategy Employing Technetium-99m Based On Bioorthogonal Diels-Alder Click Chemistry, Justin H. Walsh

Dissertations, Theses, and Capstone Projects

A series of related N₃S ^99mTc-peptide complexes were synthesized and tested for use in pretargeting SPECT imaging that utilizes the bioorthogonal Diels-Alder click reaction between tetrazine (Tz) and transcyclooctene (TCO). The objective was to optimize the excretory pathways of the ^99mTc-peptide complexes for maximum tumor targeting with the in vivo “click” and minimum non-target uptake. The ^99mTc–tetrazine constructs were prepared by reaction of ^99mTc-peptide complexes (^99mTc-FKC, ^99mTc-FKCR, ^99mTc-DKC, and ^99mTc-SKC) with Tz-NHS or Tz-PEG₅-NHS to form ^99mTc FK(Tz)C, ^99mTc-FK(PEG₅-Tz)CR, ^99mTc-DK(PEG₅-Tz)C, …

Synthesis And Characterization Of Dielectric And Multiferroic Nanocrystalline Transition Metal Oxide Materials And Nanocomposites, Frederick A. Pearsall

Dissertations, Theses, and Capstone Projects

Nanocrystalline transition metal oxides with unique chemical, physical, magnetic and dielectric properties have very broad applications, ranging from photocatalysis, capacitor energy storage and 4-state memory. Frequency stable, high permittivity nanocomposite capacitors produced under mild processing conditions offer an attractive replacement to MLCCs derived from conventional ceramic firing. In one project reported herein, 0-3 nanocomposites were prepared using BaTiO₃ (barium titanate, BTO) nanocrystals, suspended in a poly(furfuryl alcohol) matrix, resulting in a stable, high effective permittivity, low and stable loss dielectric. Effective medium approximations were used to compare this with similar nanocomposite systems. The use of synthesized BTO nanocrystal photocatalysts …

Mild Synthesis Of Perylene Tetracarboxylic Monoanhydrides With Potential Applications In Organic Optoelectronics, Xizhe Zhao

Dissertations, Theses, and Capstone Projects

Perylene tetracarboxylic derivatives are considered good n-type semi-conductors. In past decades, there has been extensive study on their synthesis and electronic properties. Because of the high electron affinity, the ability to form π-π stacks, they have been widely utilized in organic photovoltaic solar cells, field-effect transistors and light-emitting diodes. Many of those applications prefer unsymmetrically substituted perylene tetracarboxylic derivatives. Perylene monoanhydrides are the most versatile intermediates for the preparation of unsymmetrically substituted perylene tetracarboxylic derivatives. In this thesis, I focused on introducing new synthesis methods for perylene monoanhydrides with labile functional group and their potential applications in organic optoelectronics.

In …

Peptide Mediated Co-Assembly Of Porphyrin: Towards Sustainable Biomaterials For Light Harvesting And Catalysis, Wsm Nadeesha K. Wijerathne

Dissertations, Theses, and Capstone Projects

The diverse molecular functions of naturally occurring biomaterials designed from proteins are fundamentally based on a set of conserved building blocks, namely the 20 gene coded amino acids. The supramolecular structures and functions of proteins dictates by the self-assembly, where the complexity of proteins arise from a large number of amino acids. Generation of biomimetic systems that resemble the structures and functions of proteins is of great interest yet challenging due to the tremendous complexity of the natural systems. It is important to investigate alternative strategies to design much simpler systems that exhibit the same or similar function as proteins. …

Raman And Surface Enhanced Raman Spectroscopy For Forensic Analysis: Case Studies On The Identification Of Illicit Substances And Artist Pigments, Abed Haddad

Dissertations, Theses, and Capstone Projects

Raman spectroscopy is an effective tool for detecting trace amounts of material by fingerprint-like vibrational spectra. At times, the weak intensity of Raman scattering can make it difficult to distinguish trace materials. This shortcoming is addressed by surface‐enhanced Raman spectroscopy (SERS), which produces strong signal enhancements when target compounds are near metal nanoparticles. For the first part of this thesis, the identification of fentanyl and carfentanil, main culprits in the opioid epidemic, was done using normal Raman and the SERS spectroscopy. As an aid in the assignment of the spectral lines, a computational model was built using Density Functional Theory …

Development Of Granulated Adsorbent For Clean-Up Of Water Contaminated By Cesium, Esther Alorkpa

Electronic Theses and Dissertations

A study was conducted on sol-gel synthesis of an adsorbent (phosphotungstic acid embedded in silica gel, H-PTA/SiO­₂) of radioactive cesium. A novelty of this work is covalent bonding of PTA to the surface of solid support that prevents leaching from the surface of the material. The sample was granulated with a binder, aluminium oxide (γ-Al₂O₃). Solid-state NMR and FT-IR spectroscopy were used to confirm the presence of Keggin units of PTA in the bound materials. Thermal analysis of H-PTA/SiO­₂ - γ-Al₂O₃ (50 %) showed that the water content in the …

Preparation And Evaluation Of Uranium Alloys Based On Burnup, Andrew Jonathan Swift

UNLV Theses, Dissertations, Professional Papers, and Capstones

Next generation fast reactor designs utilizing metallic fuel are being developed as an alternative fuel cycle option in an effort to reduce carbon emissions. Historically, oxide fuels have been the industry standard, but interest in metallic fuel systems has grown considerably due to their thermal conductivity, fissile atom density, inherent safety, and ability to reach progressively higher burnups. Chemical complexity of metallic fuel systems increase as a function of burnup from fission product ingrowth and associated fuel cladding chemical interactions (FCCI) brought on by elemental redistribution and phase formation. To date, the most extensive operational study for metallic fuel was …

Use Of Anodic Stripping Voltammetry To Study The Size-Selective Electrophoretic Deposition And Aggregation-Dependent Oxidation Of Metal Nanoparticles., Stacy L. Allen

Electronic Theses and Dissertations

This dissertation describes how anodic stripping voltammetry (ASV) was used to study size-controlled electrophoretic deposition (EPD) and the aggregation-dependent oxidation properties of citrate-stabilized Au nanoparticles (NPs). EPD of citrate-coated Au NPs occurs in the presence of hydroquinone (HQ) onto indium-tin-oxide-coated glass electrodes (glass/ITO) at potentials positive of the HQ oxidation potential. HQ oxidation produces protons at the electrode surface, which serve to neutralize the citrate molecules that electrostatically stabilize the Au NPs. Neutralization leads to the loss of stabilization and deposition onto the electrode. EPD in the presence of ferrocyanide, a non-proton-producing molecule, at oxidation potentials resulted in no deposition …

Synthetic Methods And Biological Applications Of Nitrogen Heterocycles To Compounds Of Biological Interest., Jarrid Ronnebaum

Electronic Theses and Dissertations

Thalidomide analogues were synthesized utilizing optimized click conditions from 3-azidoglutarimide and an array of arylacetylenes or N-ethynyl/N-propargyl phthalimide derivatives. The intermediate, 3-azidoglutarimde, was pivotal and yielded a new and scalable synthesis. The reaction conditions utilized a copper sulfate/sodium ascorbate system in aqueous tetrahydrofuran to propagate the dipolar cycloaddition reactions between the azidoglutarimide and the alkynyl coupling partners. The first explored substrates were substituted arylalkynes to optimize the click reaction. Arylalkynes selected were to exhibit similar electron deficient rings to mimic phthalimide. Along with the synthesis of click thalidomide analogues, click analogue of the antiangiogenic and more potent …

Preparation And Characterization Of Ruthenium-Gold Raman-Active Catalytic Surfaces, Thang Nguyen

Student Scholar Symposium Abstracts and Posters

Heterogeneous reactions at the gas-solid interface play a major role in many important industrial and environmental processes. These reactions typically rely on metal surfaces, to act as a catalyst between gas phase reactants and products. The catalysts lower the transition state barrier in the formation of the products. The mechanisms of reactions on catalysts is often not fully known due to the difficulty of observing the bond breakage and formation between gaseous molecules at the interface. One method in which the catalytic mechanism can be studied is by using Raman Spectroscopy. However, one drawback of this method is the fact …

Design And Synthesis Of 5-Oxo-Ete Receptor Antagonists; And Synthesis Of Neuroprostanes As A Biomarker For The Diagnosis Of Alzheimer’S Disease, Rui Wang

Theses and Dissertations

1) 5-Oxo-ETE (7, Scheme 1) is the most potent eosinophil chemoattractant among all lipid mediators and it can also stimulate a late-phase asthma attack. It is formed by the biotransformation of arachidonic acid (AA, 1, Figure 1). 5-Oxo-ETE (7) elicits eosinophil migration both in vitro and in vivo when injected intradermally in humans, acting via the highly selective OXE receptor (OXE-R). Our group postulated that a selective OXE-R antagonist might be a useful therapeutic agent in late phase asthma. As a result, the first and only series of OXE receptor antagonists which are structural mimics of 5-oxo-ETE (7) have been …

Plant-Based Crosslinked Polymers, Jackie Davies

Honors Capstones

No abstract provided.

Chemistry And Structure Of Ru/Sio2 And Ru/Al2o3 Interfaces, Sameer Ezzat

Electronic Theses and Dissertations

The resistivity size effect in nanoscale metals is of both scientific and technological interest, the latter due to its importance to interconnects between transistors in integrated circuits. In this work we report the variation of resistivity associated with surface scattering of ex-situ annealed single crystal Ru thin films grown on sapphire substrates by sputter deposition. A set of samples were overcoated with dielectric and subjected to a variety of reducing and oxidizing anneals. The changes in the chemistry and structure of the dielectric interface induced by the anneals, as determined by x-ray reflectivity and x-ray photoelectron spectroscopy measurements, are related …

Detection Of Mercury Through Surface Plasmon Resonance Of Immobilized Gold Nanorods, Khang Trieu

Electronic Theses and Dissertations

Mercury is a known environmental pollutant that can damage the brain, heart, kidney and lungs upon exposure. Emissions from fossil fuel plants can release mercury into the air, where it can settle into the water supply and be exposed to human and aquatic life. The use of gold nanorods functionalized on solid substrates as a mercury sensor in tap water samples is investigated herein. The functionalization of the substrates involves the physical immobilization of the nanorods onto the solid surface through the use of (3-mercaptopropyl)trimethoxysilane (MPTMS). The immobilization of the nanorods drastically increases their stability, allowing for use in complicated …