Synthesis, Characterization And Crystal Growth Of I2-Ii-Iv-Vi4 And I4-Ii-Iv2-Vi7 Diamond-Like Semiconductors With Potential In Ir-Nlo Applications,
2019
Duquesne University
Synthesis, Characterization And Crystal Growth Of I2-Ii-Iv-Vi4 And I4-Ii-Iv2-Vi7 Diamond-Like Semiconductors With Potential In Ir-Nlo Applications, Jennifer Glenn
Electronic Theses and Dissertations
In this dissertation, several new and existing diamond-like semiconductors (DLSs) were synthesized and investigated for their potential in infrared nonlinear optical (IR-NLO) applications. In Chapter 2 growth of large single crystals of Li2MnGeS4 was carried out using iodine vapor transport and a newly created graphite-tube containment system. This crystallization method produced sizable single crystals on the scale of 2x1x1 mm3, that were used to determine the material’s magnetic properties. Magnetization data indicate that the compound is antiferromagnetic with a Néel temperature of 10 K and an effective magnetic moment of 5.6 /f.u.. The specific heat …
Lanthanum-Based Perovskites As An Effective Electrocatalyst For Water Splitting And Energy Storage Applications,
2019
Pittsburg State University
Lanthanum-Based Perovskites As An Effective Electrocatalyst For Water Splitting And Energy Storage Applications, Xavier Martinez
Electronic Theses & Dissertations
Recent changes in global weather patterns have accented the need a shift from fossil fuels to a cleaner energy option. As part of an overall plan, hydrogen production for fuel cells offer substantial power without carbon emissions. Overall water splitting, with the aid of a low cost electrocatalyst could prove to be an abundant green fuel source. Utilizing readily available transition metals, three perovskite nanostructures were studied as a multifunctional material for hydrogen production as well as an energy storage material. LaCoO3 (LCO), LaFeO3 (LFO), and LaMnO3 (LMO) were synthesized and characterized by X-ray diffraction (XRD) …
Deposition Of Platinum Particles On Surface-Modified Carbon Ultramicroelectrodes,
2019
East Tennessee State University
Deposition Of Platinum Particles On Surface-Modified Carbon Ultramicroelectrodes, Caitlin Millsaps
Undergraduate Honors Theses
Nanoparticles are used as electrocatalysts due to their large surface area-to-volume ratios. Most studies of nanoparticle electrocatalysis are performed on collections of particles on a support, which represent ensemble average behavior influenced by spatial distribution of the nanoparticles. Therefore, recent emphasis has been placed on analyzing electrocatalytic behavior of single particles. The focus here is to develop carbon ultramicro- and nanoelectrode platforms for studying the electrocatalytic properties of single metal nanoparticles. Ultramicroelectrodes were prepared using chemical vapor deposition of carbon in pulled quartz capillaries. Electrode diameters were determined by cyclic voltammetry. Electrodes were modified using a soft nitriding technique to …
Gas Chromatography Analysis Of Co2 Reduction Photocatalysis With Zinc Dipyrrin Complexes,
2019
East Tennessee State University
Gas Chromatography Analysis Of Co2 Reduction Photocatalysis With Zinc Dipyrrin Complexes, Alex Day
Undergraduate Honors Theses
Bis(1,3,7,9-tetramethyl-5-mesityldipyrrinato)zinc(II) (ZnDPY) was synthesized in the lab by the McCusker group and a procedure was created to analyze its ability as a photosensitizer, a molecule that provides the energy for the reaction to occur by capturing light energy and turning it into a form that can be used by the photocatalyst. While more work is needed, preliminary steps have been made to create a process that can analyze the amount of carbon monoxide produced by a photocatalytic CO2 reduction reaction with ZnDPY as the photosensitizer. Progress has been made via the setup of a reaction apparatus, targeted gas chromatography …
Synthesis And Characterization Of Dielectric And Multiferroic Nanocrystalline Transition Metal Oxide Materials And Nanocomposites,
2019
CUNY Graduate Center
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 …
Surface Immobilization Of Terpyridine Compounds,
2019
University of Arkansas, Fayetteville
Surface Immobilization Of Terpyridine Compounds, Elizabeth Hallett
Chemical Engineering Undergraduate Honors Theses
The deoxydehydration (DODH) of polyols to alkenes is a promising method of producing high-value chemical feedstocks from biomass-derived materials. Current catalytic systems for DODH require the use of costly reducing agents that generate stoichiometric amounts of chemical waste. Immobilizing catalysts on electrode surfaces using chemical linking groups eliminates the need for sacrificial reductants. In this work, glassy carbon electrodes were modified with 4’-(3,4-dihydroxyphenyl)-2,2’:6’,2’’-terpyridine to investigate o-benzoquinone as a potential linking group for DODH, and possibly for other reactions. Previous studies involving electrodes modified with quinone-containing compounds have primarily been focused on catalyzing the oxidation of NADH; the nature or …
Preparation Of Enantioenriched Alkyltin Species And Their Application In Stereospecific Transformations,
2019
CUNY Graduate Center
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,
2019
CUNY Graduate Center
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, …
Development Of Granulated Adsorbent For Clean-Up Of Water Contaminated By Cesium,
2019
East Tennessee State University
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 …
An Investigation Of Alkylboron Transmetallation In Palladium-Catalyzed Suzuki Reactions,
2019
CUNY Graduate Center
An Investigation Of Alkylboron Transmetallation In Palladium-Catalyzed Suzuki Reactions, Benjamin Murray
Dissertations, Theses, and Capstone Projects
Through the past 40 years, carbon-carbon cross-coupling reactions have greatly enhanced the ability of chemists to synthesize C(sp2)-C(sp2) bonds and more recently C(sp2)-C(sp3) bonds. In particular, the Suzuki reaction has proven to be invaluable with its high yields, good functional group tolerance, and low toxicity of reagents. One of the component steps of the catalytic cycle of this reaction is transmetallation, in which the nucleophilic species transfers its organic component to the metal center (generally palladium). The mechanism of transfer from primary alkylboron nucleophiles was studied in the 1990's via use of …
Effect Of A Coordinating Pyridine Moiety On The Sap And Tsap Isomer Populations Of Bimodal Lanthanide (Iii) Complexes,
2019
The University of San Francisco
Effect Of A Coordinating Pyridine Moiety On The Sap And Tsap Isomer Populations Of Bimodal Lanthanide (Iii) Complexes, Marisa Poveda, Osasere M. Evbuomwan
Creative Activity and Research Day - CARD
Paramagnetic Chemical Exchange Saturation Transfer (PARACEST) agents are lanthanide complexes that generate contrast through the slow-to-intermediate exchange of paramagnetically-shifted protons or water molecules. Although PARACEST agents have shown promise as molecular imaging agents, in-vivostudies have been limited due to the masking of the CEST signal by spin-relaxation exchange (T2ex) and Magnetization Transfer (MT) effects. The majority of PARACEST agents studied to date have been Ln(III)DOTA-tetraamides which can either adopt the square antiprismatic (SAP) or twisted square antiprismatic (TSAP) geometries in solution. The more compact nature of the SAP isomer, combined with its slower bound-water exchange kinetics, makes …
The Lowest-Energy Isomer Of C2Si2H4 Is A Bridged Ring: Reinterpretation Of The Spectroscopic Data Based On Dft And Coupled-Cluster Calculations,
2019
ORISE Fellow
The Lowest-Energy Isomer Of C2Si2H4 Is A Bridged Ring: Reinterpretation Of The Spectroscopic Data Based On Dft And Coupled-Cluster Calculations, Jesse J. Lutz, Larry W. Burggraf
Faculty Publications
The lowest-energy isomer of C2Si2H4 is determined by high-accuracy ab initio calculations to be the bridged four-membered ring 1,2-didehydro-1,3-disilabicyclo[1.1.0]butane (1), contrary to prior theoretical and experimental studies favoring the three-member ring silylsilacyclopropenylidene (2). These and eight other low-lying minima on the potential energy surface are characterized and ordered by energy using the CCSD(T) method with complete basis set extrapolation, and the resulting benchmark-quality set of relative isomer energies is used to evaluate the performance of several comparatively inexpensive approaches based on many-body perturbation theory and density functional theory (DFT). Double-hybrid DFT methods are found to …
G-Quadruplex Dynamics Contribute To Regulation Of Mitochondrial Gene Expression,
2019
Swarthmore College
G-Quadruplex Dynamics Contribute To Regulation Of Mitochondrial Gene Expression, M. Falabella, J. E. Kolesar, C. Wallace, D. De Jesus, L. Sun, Y. V. Taguichi, C. Wang, T. Wang, Irene M. Xiang , '18, J. K. Alder, R. Maheshan, W. Horne, Joshua R. Turek-Herman , '16, P. J. Pagano, C. M. St. Croix, N. Sondheimer, Liliya A. Yatsunyk, F. B. Johnson, B. A. Kaufman
Chemistry & Biochemistry Faculty Works
Single-stranded DNA or RNA sequences rich in guanine (G) can adopt non-canonical structures known as G-quadruplexes (G4). Mitochondrial DNA (mtDNA) sequences that are predicted to form G4 are enriched on the heavy-strand and have been associated with formation of deletion breakpoints. Increasing evidence supports the ability of mtDNA to form G4 in cancer cells; however, the functional roles of G4 structures in regulating mitochondrial nucleic acid homeostasis in non-cancerous cells remain unclear. Here, we demonstrate by live cell imaging that the G4-ligand RHPS4 localizes primarily to mitochondria at low doses. We find that low doses of RHPS4 do not induce …
Drug Improvement And Design Involving G-Protein Coupled Receptors,
2019
Taylor University
Drug Improvement And Design Involving G-Protein Coupled Receptors, Gabriel Saliba
Chemistry & Biochemistry Student Projects
No abstract provided.
A Chemical Overview Of Opioid Receptors And Their Agonists,
2019
Taylor University
A Chemical Overview Of Opioid Receptors And Their Agonists, Noah Kuszak
Chemistry & Biochemistry Student Projects
This work is a brief overview of the three main opioid receptors and some current research of the ways we can change the agonists and how they affect the opioid receptor pathway.
Dentin Biomodification Potency Of Proanthocyanidins,
2019
Taylor University
Dentin Biomodification Potency Of Proanthocyanidins, David J. Ryker
Chemistry & Biochemistry Student Projects
No abstract provided.
Cationic Cobalt (Ii) Hydroformylation,
2019
Louisiana State University and Agricultural and Mechanical College
Cationic Cobalt (Ii) Hydroformylation, Drew Michael Hood
LSU Doctoral Dissertations
While investigating a bimetallic cobalt hydroformylation catalyst a new class of monometallic cationic cobalt (II) hydroformylation catalyst were discovered. These newly discovered catalyst proved to be very unique with high hydroformylation activity under mild conditions. The pre-catalyst were characterized using various methods including NMR, EPR, MS, and X-ray crystallography. Similarly the active catalyst was also investigated using NMR, EPR, FTIR, and X-ray crystallography. Various catalyst modifications were investigated for their effects on hydroformylation activity. Likewise various reaction parameters were probed to determine their effect on hydroformylation activity. Finally the best cationic cobalt (II) catalyst were directly compared to industry standards …
Investigating Cationic Metal Centers For Hydroformylation,
2019
Louisiana State University and Agricultural and Mechanical College
Investigating Cationic Metal Centers For Hydroformylation, Ryan Alexander Johnson
LSU Doctoral Dissertations
Bimetallic cooperativity can potentially increase activity of reactions. This concept is another way to increase reactivity besides simply focusing on the steric and electronic effects of a ligand. A binucleating tetrasphosphine ligand has been developed to showcase bimetallic cooperativity between two rhodium metal centers. Hydroformylation is a widely used industrial process to produce aldehydes from alkenes, H2, and CO. The dirhodium catalyst, [Rh2(μ-CO)(CO)3(rac-et,ph-P4-Ph)](BF4)2,is highly active leading to favorable results when using a DMF/water solvent system, 1-hexene, 90 psi 1:1 H2/CO, and 90° C: initial turnover frequency …
Facile And Efficient Synthesis Of Thiosemicarbazone Derivatives With Functionalized Pendant Amines.,
2019
University of Louisville
Facile And Efficient Synthesis Of Thiosemicarbazone Derivatives With Functionalized Pendant Amines., Anna E Davis
College of Arts & Sciences Senior Theses
Bis-thiosemicarbazones are an important class of ligands for the synthesis of transition metal complexes with applications in medicine and electrochemistry.1,2 Among the most studied of these complexation ligands is diacetyl-2,3-bis(N4-methyl-3-thiosemicarbazone) (denoted as ATSM, 1, Figure 1).2,3 Derivatives of 1 with various amines in place of the methylamine of ATSM have previously been reported, including diacetyl (N4-methylthiosemicarbazone-N4′-dimethylthio-semicarbazone) (denoted as ATSM/DM, 2).4 In this work, we pursue the development of a library of ATSM derivatives with a variety of functionalized pendant amines with a range of electronic and steric …
Metal-Assisted Hydrolysis Reactions Involving Lipids: A Review,
2019
University of Richmond
Metal-Assisted Hydrolysis Reactions Involving Lipids: A Review, Dominique E. Williams, Kathryn B. Grant
Chemistry Faculty Publications
This report covers major advances in the use of metal ions and complexes to hydrolyze ester and phosphate ester lipid bonds. These metal-based Lewis acids have been investigated as catalysts to isolate fatty acids from biological sources, as probes to study phospholipid bilayer properties, as tools to examine signal transduction pathways, and as lead compounds toward the discovery of therapeutic agents. Metal ions that accelerate phosphate ester hydrolysis under mild conditions of temperature and pH may have the potential to mimic phospholipase activity in biochemical applications.
