Chemistry Commons^™

Enhancing Upconversion Nanoparticle Performance Of Nayf4: Yb,Tm With Doping Optimization And Shell Addition And Of Nayf4: Yb,Er With Yb,Nd Shell Addition, Ashleigh M. Chov

Honors Thesis

Upconversion (UC), is a phenomenon that occurs when low-energy excitation (usually near-infrared (NIR)) results in higher-energy emission. Upconversion nanoparticles (UCNPs) are particles less than 100 nm in size that are synthesized using rare earth metals such as Yb, Er, Tm, and Y. UCNPs have important applications in a variety of fields, including bio-imaging, security printing, and latent fingerprint development. Traditional methods for latent fingerprint development such as fluorescent powder dusting have several drawbacks including low contrast, high background interference, and autofluorescence. NIR-to-NIR UCNPs are composed of NaYF₄: Yb, Tm and emit 800 nm light under 980 nm excitation …

Optimization Of The Mechanochemical Synthesis Of Several Distinct Compounds., Joseph Ryan Williams

Honors College Theses

Mechanochemical synthesis, as used in this work, is the mechanical milling of reagents to drive reaction. It is often considered a greener alternative to traditional solution-based methods of synthesis. This work will describe the mechanochemical synthesis of furan-2-yl(pyrrolidin-1-yl)methanethione and N-hexadecylfuran-2-carbothioamide, the optimization of the mechanochemical synthesis of 1,3-dibenzylbenzimidazolium bromide as well as the kinetics of this reaction, and finally the ongoing development of the mechanochemical synthesis of N,N′-dioctyl-2,2′-bipyridine-4,4′-dicarboxamide.

This work studied both the traditional method and mechanochemical method for synthesis of furan-2-yl(pyrrolidin-1-yl)methanethione, as well as the mechanochemical method for N-hexadecylfuran-2-carbothioamide. While initial work was promising, it was …

295— Biomimicry: Investigating The Active Site Model Of Lactate Racemase, Stephanie Podguski, Maisy Ross

GREAT Day Posters

Because of humans’ heavy impact on nature with industrialization and resource extraction, biomimetics, also known as biomimicry, is a study that has emerged. Biomimetics utilizes observations from nature to comprehend the principles of underlying mechanisms and apply concepts that may benefit science, medicine, engineering and the like. An area of biochemistry we are applying this to is the lactate racemase enzyme.This metalloenzyme is found in many prokaryotic organisms and catalyzes the interconversion between the two optical isomers of lactic acid. The structure of this enzyme consists of a square-planar nickel (II) ion coordinated by a histidine residue and a pincer …

Inorganic Chemistry Faculty Value Student-Centered Learning, But Time Constraints And Student Evaluations Discourage Change, Jenna Savage, Hope Heideman

19th Annual Celebration of Undergraduate Research and Creative Activity (2020)

Improving student success in chemistry requires faculty change, but change is hard. The Interactive Online Network of Inorganic Chemists (IONiC) is a community of practice (CoP) that offers teaching resources for inorganic chemistry faculty. We are studying the ways in which CoPs can promote faculty change. IONiC is supporting twenty inorganic chemistry faculty in implementing effective teaching methods into their foundation-level inorganic chemistry courses. In order to better understand how faculty make decisions about teaching, these faculty were interviewed about their teaching beliefs, approaches, and dissatisfactions. The interview data were coded via thematic content analysis and have shown that inorganic …

Battery Application Of Silver Molybdate Materials, Brendan Michael Godsel

Undergraduate Honors Papers

As the demand for renewable energy grows, the investigation of potential battery materials continues to progress hastily. Many devices and machines of present day are operated by battery technology, and their energy requirements warrant which kinds of batteries will power them. The battery in a phone requires hundreds, possibly thousands, of uses and needs to be able to recharge quickly. The battery in the implantable cardiac defibrillator (ICD), the battery by which this product was inspired, is only used once, but it must last years before it is replaced. The cathode of the ICD battery is comprised of a silver …

Scanning Electron Microscopy (Sem) Investigation Of Morphology Changes In The Reduction Of Silica Nanoparticles To Elemental Silicon, Allison M. Cairns

University Honors Theses

The application of silicon nanoparticles varies from energy storage materials, to drug-delivery, and molecular recognition. Various chemical and physical properties of the Si nanoparticles arise from their morphology. This paper aims to reveal the morphology of Si nanoparticles following magnesiothermic reduction of silica (SiO₂) nanoparticles. Two sets of SiO₂ nanoparticles were used, commercially available NanoXact nanoparticles and laboratory-synthesized Stöber nanoparticles. A Zeiss Sigma VP FEG SEM was used to examine the morphology. Following the magnesiothermic reduction, the nanoparticles were etched with HF. Ten sets of images were taken of both Stöber and NanoXact nanoparticles: 1,2: the SiO …

Dissipation Of Benzobicyclon And Benzobicyclon Hydrolysate In A Louisiana Rice Field, Xavier Poole

LSU Master's Theses

Pesticide resistance in rice fields is an ongoing issue that has resulted in the development and use of pesticides with new modes of action. Benzobicyclon is the first registered hydroxyphenylpyruvate(HPPD)-inhibiting pesticide in the United States and has gained attention as a resistance management strategy to control weed pests in rice fields. Understanding the environmental fate and dissipation mechanisms of benzobicyclon is important due to the unique rotation of rice and crayfish in Louisiana on the same fields. Benzobicyclon persistence into the crayfish growing seasons may lead to unintended consequences for crayfish growth and production, assuming there is toxicity to crawfish. …

Assessing The Ecological Risk Of Heavy Metal Sediment Contamination From Port Everglades Florida, Dimitri G. Giarikos, Laura White, Amy C. Hirons

SECLER Data

Port sediments are often contaminated with metals and organic compounds from anthropogenic sources. Port dredging can remobilize contaminated sediments, resulting in harmful impacts to the benthic community. Twelve sediment cores were collected from four Port Everglades, Florida sites and a control site; surface sediment was collected at two nearby coral reef sites. Sediment cores, sampled every 5 cm, were quantified for 14 heavy metals using induced coupled plasma mass spectrometry (ICPMS). Geo-accumulation index shows moderate-to-strong contamination of As and Mo in port sediments, and potential ecological risk indicates moderate-to-significantly high overall metal contamination. Arsenic port sediment concentrations exceed threshold effect …

Electrochemical Studies Of Cobalt(Ii) Diphenylazodioxide Complexes, Lakshmi Balarama, Kylin A. Emhoff, Ahmed M.H. Salem, Jovana Hanna, Mohamed N. Alsabony, Mekki Bayachou, Jerry Mundell, W. Christropher Boyd

Chemistry Faculty Publications

The electrochemical behavior of the unusual cobalt(II) diphenylazodioxide complex salts [Co(az)₄](PF₆)₂ 1 and [Co(bpy)(az)₂](PF₆)₂ 2 has been studied by cyclic voltammetry. Each complex displays two quasireversible redox couples, which are proposed to correspond to a reduction of Co(II) to Co(I), followed by a ligand-based reduction. Irreversible reductions of 1 are observed at more negative potentials, and are proposed to arise from deposition of elemental Co and the decomposition of transiently formed Co(-I) species. Spectroelectrochemical experiments on both 1 and 2, involving electrolytic reduction followed by reoxidation, are consistent with …

Geochemical Analysis And Heat-Treatment Of Natural Sapphires From Madagascar And Tanzania In Oxidizing And Reducing Conditions, Lukas Karuza, Dr. Michael B. Wolf, Brian Konecke Phd

Geology: Student Scholarship & Creative Works

Natural or synthetic sapphires can be heat-treated to improve the clarity by removing “silk” (inclusions) and to change color by introducing color-inducing elements (i.e., chromophores) into the lattice structure or changing their valency. Due to these reasons, sapphires can be heat-treated to increase their monetary value. Twenty natural blue (C1), 20 green (C2), and 20 clear (C3) sapphires from Madagascar and Tanzania were heat-treated in a muffle furnace in oxidizing and reducing conditions, from 1200 to 1600℃, for 10-hour soak time. In total, 5 experiments were conducted in which soak time remained constant: experiment 1 was performed at 1200℃, exp. …

Synthesis And Reactivity Of A New Platinum(Ii) Complex, Maria Lew

Scripps Senior Theses

Alkanes are some of the most abundant organic molecules, yet currently there are no efficient ways of directly converting them to more functional molecules. One viable method of direct functionalization is C–H bond activation by transition metal catalysts. The focus of this research has been the synthesis of a new Pt(II) pincer complex to be used in mechanistic investigations of C–H activation, as well as the beginnings of those investigations. The complex [NN^ON]PtMe was successfully synthesized. Reactions with various acids indicated that [NN^ON]PtMe is capable of reductively eliminating methane after addition of two equivalents of acid. …

Biophysical And X-Ray Structural Studies Of The (Gggtt)3ggg G-Quadruplex In Complex With N-Methyl Mesoporphyrin Ix, Linda Yingqi Lin , '20, S. Mccarthy, Barrett M. Powell , '18, Yanti Manurung , '20, Irene M. Xiang , '18, W. L. Dean, B. Chaires, Liliya A. Yatsunyk

Chemistry & Biochemistry Faculty Works

The G-quadruplex (GQ) is a well-studied non-canonical DNA structure formed by G-rich sequences found at telomeres and gene promoters. Biological studies suggest that GQs may play roles in regulating gene expression, DNA replication, and DNA repair. Small molecule ligands were shown to alter GQ structure and stability and thereby serve as novel therapies, particularly against cancer. In this work, we investigate the interaction of a G-rich sequence, 5’-GGGTTGGGTTGGGTTGGG-3’ (T1), with a water-soluble porphyrin, N-methyl mesoporphyrin IX (NMM) via biophysical and X-ray crystallographic studies. UV-vis and fluorescence titrations, as well as a Job plot, revealed a 1:1 binding stoichiometry with an …

Synthesis, Characterization, Dna Binding, Topoisomerase Inhibition, And Apoptosis Induction Studies Of A Novel Cobalt(Iii) Complex With A Thiosemicarbazone Ligand, Stephen J. Beebe, Michael J. Celestine, Jimmie L. Bullock, Shayna Sandhaus, Jessa Faye Arca, Donald M. Cropek, Tekettay A. Ludvig, Sydney R. Foster, Jasmine S. Clark, Floyd A. Beckford, Criszcele M. Tano, Elizabeth A. Tonsel-White, Raj K. Gurung, Courtney E. Stankavich, Yuk-Ching Tse-Dinh, William L. Jarrett, Alvin A. Holder

Bioelectrics Publications

In this study, 9-anthraldehyde-N(4)-methylthiosemicarbazone (MeATSC) 1 and [Co(phen)₂(O₂CO)]Cl·6H₂O 2 (where phen = 1,10-phenanthroline) were synthesized. [Co(phen)₂(O₂CO)]Cl·6H₂O 2 was used to produce anhydrous [Co(phen)₂(H₂O)₂(NO₃)₃ 3. Subsequently, anhydrous [Co(phen)₂(H₂O)₂] (NO₃)₃ 3 was reacted with MeATSC 1 to produce [Co(phen)₂(MeATSC)](NO₃)₃·1.5H₂O·C₂ H₅OH 4. The ligand, MeATSC 1 and all complexes were characterized by elemental analysis, FT IR, UV–visible, and multinuclear NMR …

Synthesis And Characterization Of Starburst Pseudorotaxanes And Their Metallic Derivatives, Shalini D. Kadinappulige

Masters Theses

Mechanically Interlocked Molecules (MIMs) are interlocked molecular architectures, characterized by the fact that they are linked through a mechanical bond. Catenanes, rotaxanes, molecular knots, and Borromean rings are typical examples for these molecules. Since MIMs are not connected by covalent bonds, hydrogen bonding, π- π stacking, and/or electrostatic interactions help bring the components together. Dialkyl-ammonium centers, bis(pyridinium)ethane dications, viologen species, and naphthalenediimide π-deficient groups are well known as recognition motifs for crown ethers. In the research described here, we have synthesized several pseudorotaxanes and their tricyclohexyltin metallic derivatives, based on benzobis(imidazolium) (BBI) salts as axles, in combination with the 15DN38C10 …

Development Of Supported Pd-Based Catalysts For Carbon-Carbon Cross-Coupling And Oxidation Reactions, Mrinmoy Das

Theses and Dissertations

Heterogeneous catalysts are a crucial part of chemistry used for various chemical synthesis stages, pharmaceutical, and environmental applications. The use of nanoparticles or rather nanocatalysts enhances the heterogeneous catalytic applications. Both chemical and physical methods can be used to synthesize nanocatalysts. Chemical synthesis methods require comparatively fewer instruments and can easily synthesize a large amount of nanocatalysts. Nevertheless, chemical synthesis methods require reducing agents and solvents that can be toxic or harmful materials. They often need harsh reaction conditions as well, like high temperature and pressure. On the other hand, physical synthesis methods often require complex instrument setup, but their …

Discerning The Spectroscopic Properties And Chemical Reactivity Of Bioinspired Metallocomplexes, Ashley K. Forney

Theses and Dissertations

In Nature, metalloenzymes catalyze a variety of thermodynamically demanding reactions with remarkable performance under mild, physiological conditions. This innate ability is a driving force for the development of nature inspired, synthetic analogues that are robust and can catalyze a variety of organic transformations. This work involves the successful syntheses of four coordinate, bioinspired complexes, [M^II(n-DOB)] (M = Ni, Co, and Cu; n = 12 and 13), which have been characterized by NMR, ESI-MS, UV/Vis, EPR, and CV. Spectroscopic evidence presents the generation of reactive metal-(di)oxygen species that display amphoteric reaction behavior, making these rarities among inorganic oxidants. These …

Mixed-Valent Heterometallic Molecular Precursors : Expansion Into 4d Transition Metals, Jesse Caleb Carozza

Legacy Theses & Dissertations (2009 - 2024)

Hydrogen fuel can provide an ideal carbon-free energy carrier wherever water is available, be that on Earth or throughout the solar system. The use of water electrolysis to split water molecules into contaminant-free hydrogen gas, suitable for use in fuel cells, and oxygen gas allows also for storage of excess electrical energy during periods of high production and low demand, and an easy path to release that stored energy when demand is high and active supply is low. However, liberating hydrogen from water is an energy-intensive process, and effective electrocatalysts that reduce the amount of energy wasted by the reaction …

Reactions Of First-Row Transition Metal Complexes In Bis(Alkoxide) Ligand Environments With Diazoalkanes: Formation Of Carbenes Versus Reductive Coupling To Form Bridging Tetrazenes, Amanda Grass

Wayne State University Dissertations

This dissertation focuses on the design and reactions of novel late transition metal carbene complexes featuring alkoxide ligand environments. The high-valent cobalt carbene Co(OR)2(=CPh2) (OR = OCtBu2Ph), featuring short Co=C bond of 1.773(3) Å, was previously reported from the reaction of Co(OR)2(THF)2 with diphenyldiazoalkane. Magnetic and spectroscopic (EPR) studies demonstrated Co(OR)2(=CPh2) to be a low-spin S = ½ complex. Computational studies, in agreement with experimental data, suggested that the electronic structure of Co(OR)2(=CPh2) lies between intermediate spin Co(III) anti-ferromagnetically coupled to a carbene radical and a Co(IV) alkylidene. This dissertation began with investigation of this complex in carbene transfer reactivity. …

Greener Synthesis Of Chlorophosphazenes, Andrew Mcgee

Williams Honors College, Honors Research Projects

This project will attempt to synthesize chlorophosphazene molecules in the absence of solvents by using mechanochemical techniques in order to create a more environmentally friendly synthesis route. In this pursuit, various parameters will be changed including the milling ball to reagent ratios, the molar ratios of the reactants, and the addition of different catalysts. The products of each reaction will be characterized in order to determine success. This work builds upon existing efforts to utilize mechanochemical techniques in main group chemistry. The output of this project will be a report in ACS style and a poster to be presented for …

Design Of Pigments For Use In “Cool” Coatings, Tyler Laughorn

Williams Honors College, Honors Research Projects

This project was focused on the development and testing of several novel pigments that exhibit high NIR-reflectance and therefore show potential for use in “cool” coatings. A “cool” coating will reflect more solar radiation than other standard coatings, and so a coated structure would require less energy to keep cool. Four sets of pigments were synthesized: Co_1-xMg_xCr₂O₄ (teal), Co_0.25Mg_0.75Cr_2-yAl_yO₄ (blue), Ti_1-x-yNi_xSb_yO₂ (yellow), and Cr_2-xFe_xO₃ (black). NIR and TSR values were then measured …

Synthesis, Magnetic And Adsorption Of Dye Onto The Surface Of Nio Nanoparticles, Islam Gomaa, Nasser M. Hosny

Nanotechnology Research Centre

NiO was synthesized simply via thermal decomposition of nickel ascorbate, which resulted from semi-solid reaction of nickel acetate and ascorbic acid. The prepared precursor was characterized by elemental, thermal and spectral analyses. The precursor was decomposed at 700 °C producing cubic NiO with average size 50 nm as indicated from XRD and TEM. FESEM indicated the formation of macroporous NiO. Magnetic parameters (saturation magnetization (Ms), remanence (Mr) and coercivity (Hc)) of NiO nanoparticles and its precursor were determined and compared with the bulk nickel. Zeta potential measurements at different pH values indicated that NiO is negatively charged. Adsorption of ponceau …

Synthesis And Characterization Of Pyridine Dipyrrolide Iron Complexes Relevant To Nitrene And Carbene Group Transfer, Brett M. Hakey

Graduate Theses, Dissertations, and Problem Reports (ETD)

The synthesis and electronic structures of the square-planar high-spin Fe^II complexes (^MesPDP^Ph)Fe(OEt₂) and (^MesPDP^Ph)Fe(thf) were investigated. Analysis of these compounds using a combination of ¹H NMR and ⁵⁷Fe Mössbauer spectroscopies, in conjunction with computational analysis, has resulted in a rationalization for their unusual electronic structures, which arise from the unique coordination environment enforced by the pyridine dipyrrolide chelate ligand.

The reactivity of (^MesPDP^Ph)Fe(thf) with organic azides has been probed and resulted in the isolation of an array of products that are consistent with …

Cobalt-Catalyzed Aerobic Oxidative Cyclization Reactions Of Bisnucleophiles: New Methodologies And The Role Of Bisnucleophiles In O2 Activation, Jiaqi Liu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over the past few decades, transition metals have found wide applications in the development of selective oxidative transformations mediated by molecular oxygen. Due to the benign nature of molecular oxygen as an oxidant and an increasing awareness of green chemistry practice, tremendous progress has been made towards the development of Cu-and Pd-catalyzed aerobic oxidation reactions. As a first-row transition metal alternative to copper, cobalt has been employed in aerobic catalytic transformations for its cost-efficiency and earth abundance; however, redox-active mediators such as benzoquinone (BQ), N-hydroxyphthalimide (NHPI) or salen-type ligands are usually required. To date, reactions mediated by Co/O₂ catalytic …

Uncovering Structure-Property Relationships Of Inorganic Nanomaterials Via Transmission Electron Microscopy, Melonie Thomas

Theses and Dissertations--Chemistry

The rapid increase of research in nanoscale devices and nanotechnology in the past few decades has revealed that nanomaterials may possess exceptional properties that are significantly different from the bulk counterpart, due to local rearrangements of the atoms at surfaces and defects. Transmission electron microscopy (TEM) is an indispensable tool when it comes to the characterization of nanomaterials, primarily due to its ability to resolve the local-structure of materials at the atomic-scale. To study dynamic processes, however, regular TEM experiments are inadequate, as they provide only before and after information rather than the real-time data essential to understanding a reaction …

Synthesis Of Metal Oxide Surface And Interface Arrays By A Combined Solid-Liquid- Vapor/Vapor-Liquid-Solid Approach, Alexandra J. Riddle

Theses and Dissertations--Chemistry

This project was motivated by an in situ heating experiment in the transmission electron microscope (TEM) in which gold (Au) nanoparticles were observed to dissolve tin dioxide (SnO2) nanowires (NWs) under vacuum. The explanation for this observation was that the high-temperature and low-pressure environment of the TEM caused the reverse reaction of the well-known vapor-liquid-solid (VLS) method commonly used to grow NWs. In the VLS process, a metal catalyst absorbs reactant vapor until it becomes supersaturated. The precipitation of the NW occurs at the liquid-solid interface, which ceases when there is no longer reactant vapor, and the diameter of the …

Designing Metal-Halide Perovskites With Enhanced Optical Properties And Stability Using Surface Ligands, Md Aslam Uddin

Theses and Dissertations--Chemistry

Metal-halide perovskites (MHPs), with formula ABX₃ (A = methylammonium, formamidinium, or Cs⁺; B = Sn²⁺ or Pb²⁺; and X = Cl^-, Br^-, or I^-) are versatile and attractive materials because of their tunable optical and electronic properties. These optical and electronic properties include tunable direct band gaps, high absorption coefficients, low exciton binding energies, relatively high electron and hole mobilities, narrow emission line-widths, and high photoluminescence (PL) quantum yields (Φ_PL). Much of the initial excitement around organic metal-halide perovskites focused on their application in photovoltaics (PVs) …

Identification Of Adsorbate Ft-Ir Bands Using In-Situ Techniques: Pd Speciation And Adsorption Chemistry Of Pd-Zeolites For Passive Nox Adsorption, Robert Bruce Pace Iii

Theses and Dissertations--Chemistry

To meet increasingly stringent automotive emissions standards, further improvements in catalytic converter design are necessary. Current automotive catalyst systems are effective at eliminating emission of nitrogen oxides (NO_x) once the catalyst reaches operational temperature (~200 °C). NO_x emitted at lower catalyst temperatures now comprises most of the NO_x released during a typical test cycle. Referred to as “the cold start problem” this issue has come to the forefront of automotive catalyst development, as mitigating these emissions is necessary to further reduce automotive emissions. Passive NO_x adsorbers present an appealing solution to the cold start problem, …

Transition Metal Chalcogenide Hybrid Systems As Catalysts For Energy Conversion And Biosensing, Siddesh Umapathi

Doctoral Dissertations

"Generation of hydrogen and oxygen through catalyst-aided water splitting which has immense applications in metal air batteries, PEM fuel cells and solar to fuel energy production, has been one of the critical topics in recent times. The state of art oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER) catalysts are mostly comprised of precious metals. The current challenge lies in replacing these precious metal-based catalysts with non-precious earth-abundant materials without compromising catalytic efficiency.

This research explores mixed metal selenides containing Fe-Ni, Fe-Co and RhSe which were hydrothermally synthesized and/or electrodeposited and tested for OER and ORR …

Mechanistic Analysis Of Reductive Boracarboxylation Using Low Valent Copper And Co2, Notashia Nicole Baughman

Graduate Theses, Dissertations, and Problem Reports (ETD)

The synthesis of organoboron compounds is of contemporary importance in the chemistry community given their utility in subsequent functionalization reactions as well as their growing therapeutic potential in the treatment of human disease. This, coupled with the ubiquity of carboxylic acid functional groups in pharmaceuticals and fine chemicals, has led to interest in one-pot difunctionalization reactions using CO₂ and a boron source. An (ICy)copper(I)-catalyzed boracarboxylation reaction was recently developed wherein CO₂ and a pinacolboryl group is added across the double bond of vinyl arenes was recently developed, providing access to α-aryl-β-boryl propionic acid derivatives. A subsequent publication detailed …

Heparan Sulfate. A Ligand For Coordination Compounds., Eric Ginsburg

Theses and Dissertations

Heparan sulfate (HS), a type of glycosaminoglycan (GAG), has been identified as a ligand for interactions with polynuclear platinum complexes (PPCs). HS is involved in numerous biological processes, and often considered to be extracellular DNA. PPCs interact with HS through the formation of a “sulfate clamp”, where multiple anionic sulfate groups cluster around the cationic PPC. The masking of HS results in the inhibition of enzymatic activity, protein-HS interactions, and other biological processes. PPCs use HS proteoglycans as an method of cellular internalization. By targeting sulfated-GAGs, PPCs can offer precision medicine not currently observed with the FDA approved platinum therapies. …