Chemistry Commons^™

Differential Binding Of Tetrel-Bonding Bipodal Receptors To Monatomic And Polyatomic Anions, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Previous work has demonstrated that a bidentate receptor containing a pair of Sn atoms can engage in very strong interactions with halide ions via tetrel bonds. The question that is addressed here concerns the possibility that a receptor of this type might be designed that would preferentially bind a polyatomic over a monatomic anion since the former might better span the distance between the two Sn atoms. The binding of Cl⁻ was thus compared to that of HCOO⁻, HSO₄⁻, and H₂PO₄⁻ with a wide variety of bidentate receptors. A pair …

Disruption Of The Hippocampal And Hypothalamic Blood-Brain Barrier In A Diet-Induced Obese Model Of Type Ii Diabetes: Prevention And Treatment By The Mitochondrial Carbonic Anhydrase Inhibitor, Topiramate, Therese S. Salameh, William G. Mortell, Aric F. Logsdon, D. Allan Butterfield, William A. Banks

Chemistry Faculty Publications

Background: Type II diabetes is a vascular risk factor for cognitive impairment and increased risk of dementia. Disruption of the blood–retinal barrier (BRB) and blood–brain barrier (BBB) are hallmarks of subsequent retinal edema and central nervous system dysfunction. However, the mechanisms by which diet or metabolic syndrome induces dysfunction are not understood. A proposed mechanism is an increase in reactive oxygen species (ROS) and oxidative stress. Inhibition of mitochondrial carbonic anhydrase (mCA) decreases ROS and oxidative stress. In this study, topiramate, a mCA inhibitor, was examined for its ability to protect the BRB and BBB in diet-induced obese type II …

Examination Of The Structures, Energetics, And Vibrational Frequencies Of Small Sulfur-Containing Prototypical Dimers, (H2s)2 And H2o/H2s, Katelyn M. Dreux, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

The optimized geometries, vibrational frequencies, and dissociation energies from MP2 and CCSD(T) computations with large correlation consistent basis sets are reported for (H₂S)₂ and H₂O/H₂S. Anharmonic vibrational frequencies have also been computed with second-order vibrational perturbation theory (VPT2). As such, the fundamental frequencies, overtones, and combination bands reported in this study should also provide a useful road map for future spectroscopic studies of the simple but important heterogeneous H₂O/H₂S dimer in which the hydrogen bond donor and acceptor can interchange, leading to two unique minima with very similar energies. …

Toward The Impact Of Particulate Matter On Human Health: Evaluation Of Fluorescent Environmentally Persistent Free Radical (Epfr) Surrogates, Ansonia Badgett

LSU Doctoral Dissertations

Environmentally persistent free radicals (EPFRs)—a newly discovered pollutant associated with particulate matter (PM)—form during combustion and thermal processes, such as the incineration of hazardous waste. Various chlorine- and hydroxy-substituted benzenes chemisorb on the surface of metal oxides (e.g., NiO, CuO, and Fe₂O₃) and then form EPFRs, stabilized radical species, as the result of the transfer of electrons between the adsorbate and the metal ion of the metal oxide. Previous studies have shown direct correlations between ultra-fine (d < 0.1 mm) particulate matter (PM_0.1) exposure and adverse pulmonary health effects. PM_0.1 has the potential …

Facile Synthesis Of A Tailored-Designed Au/Pt Nanoanode For Enhanced Formic Acid, Methanol, And Ethylene Glycol Electrooxidation, Yaser M. Asal Mr., Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof

Chemical Engineering

The recent revolution in nanoscience and global energy demand have motivated research in liquid fuel cells (LFCs) due to their enhanced efficiency, moving flexibility, and reduced contamination. In line with this advancement, a glassy carbon (GC) electrode was modified with platinum (PtNPs) and gold (AuNPs) nanoparticles to fabricate a nanosized anode for formic acid, methanol, and ethylene glycol electrooxidation (abbreviated, respectively, to FAO, MO, and EGO), of the key anodic reactions of LFCs. The deposition sequence of the catalyst’s layers was important where the Au/Pt/GC electrode (in which PtNPs were directly deposited onto the GC surface followed by AuNPs—surface coverage …

Photo-Induced Remote C-H Functionalization And New Thioglycoside Donor Development For O-Glycosylation, Shaofu Du

LSU Doctoral Dissertations

This dissertation focuses on the method development of C-H functionalization using photo-redox catalysis and the synthesis of new thioglycoside donors towards O-glycosylation. Chapter 1 describes the remote Csp³-H functionalization using photo-redox catalysis. The site-selective and high-yielding conversion of unreactive aliphatic C-H bonds has been a challenge for organic chemists for many years. In this work, inert C-H bonds were successfully converted to more useful C-C, C-N, and C-O bonds via hydrogen atom transfer (HAT), radical translocation and polar crossover. This mechanistic manifold was enacted by visible-light irradiation of o-diazoniaphenyl alkyl sulfones in the presence of Ru(bpy) …

One-Step Femtosecond Laser Ablation Synthesis Of Sub-3 Nm Gold Nanoparticles Stabilized By Silica, Mallory G. John, Katharine M. Tibbetts

Chemistry Publications

No abstract provided.

Conserved Vibrational Coherence In The Ultrafast Rearrangement Of 2-Nitrotoluene Radical Cation, Derrick Ampadu Boateng, Mi'kayla D. Word, Lavrenty Gutsev, Puru Jena, Katharine M. Tibbetts

Chemistry Publications

2-Nitrotoluene (2-NT) is a good model for both photolabile protecting groups for organic synthesis and the military explosive 2,4,6-trinitrotoluene (TNT). In addition to the direct C−NO2 bond-cleavage reaction that initiates detonation in TNT, 2-NT undergoes an H atom attack reaction common to the photolabile 2-nitrobenzyl group, which forms the aci-nitro tautomer. In this work, femtosecond pump−probe measure- ments with mass spectrometric detection and density functional theory (DFT) calculations demonstrate that the initially prepared vibrational coherence in the 2-NT radical cation (2- NT+) is preserved following H atom attack. Strong-field adiabatic ionization is used to prepare 2-NT+, which can overcome a …

Single-Step Fret-Based Detection Of Femtomoles Dna, Kumar Sapkota, Anisa Kaur, Caleb Donkoh-Moore, Soma Dhakal

Chemistry Publications

Sensitive detection of nucleic acids and identification of single nucleotide polymorphism (SNP) is crucial in diagnosis of genetic diseases. Many strategies have been developed for detection and analysis of DNA, including fluorescence, electrical, optical, and mechanical methods. Recent advances in fluorescence resonance energy transfer (FRET)-based sensing have provided a new avenue for sensitive and quantitative detection of various types of biomolecules in simple, rapid, and recyclable platforms. Here, we report single-step FRET-based DNA sensors designed to work via a toehold-mediated strand displacement (TMSD) process, leading to a distinct change in the FRET efficiency upon target binding. Using single-molecule FRET (smFRET), …

Anisotropic Structure And Dynamics Of Water Under Static Electric Fields, M. Shafiei, M. Von Domaros, D. Bratko, A. Luzar

Chemistry Publications

We study the structure and dynamics of water subject to a range of static external electric fields, using molecular dynamics simulations. In particular, we monitor the changes in hydrogen bond kinetics, reorientation dynamics, and translational motions of water molecules. We find that water molecules translate and rotate slower in elec- tric fields, because the tendency to reinstate the aligned orientation reduces the prob- ability of finding a new hydrogen bond partner and hence increases the probability of reforming already ruptured bonds. Furthermore, dipolar alignment of water mole- cules with the field results in structural and dynamic anisotropies even though the …

Computational Analysis Of The Structural Importance Of The Conserved Glycine Residues At Positions 31, 33, And 35 In The Chromophore Formation And Folding Of Green Fluorescent Protein, Franceine Welcome

Chemistry Honors Papers

Green fluorescent protein, initially cloned and expressed from the bioluminescent jellyfish, Aequorea victoria (avGFP), has a wide range of uses in cellular biology, one of which includes uses as a biological marker1. Variants of GFP exist, but some residues are highly conserved and necessary for appropriate chromophore formation. Some of these conserved residues are the glycine residues at positions 31, 33 and 35, though it they are not part of the tripeptide that forms the chromophore2 .

The objective of this honors study and 3 related independent studies was to use computational methods to find out why the glycines at …

Palladium Complexes Bearing Κ²-N,N And Κ³-N,N,O Pendant Amine Bis(Phenolate) Ligands, Brendan J. Graziano, Eric M. Collins, Nathaniel C. Mccutcheon, Claire L. Griffith, Nicole M. Braunscheidel, Trilisa M. Perrine, Bradley M. Wile

Chemistry and Biochemistry Faculty Scholarship

The synthesis and characterization of ten new palladium(II) amine bis(phenolate) complexes is reported. Solution and single-crystal X-ray diffraction studies reveal the presence of both κ²-N,N and κ³-N,N,O binding modes in these square planar complexes. For complexes with sterically less demanding phenolate donors, addition of external acidic or basic reagents allows for the selective masking of a coordination site at Pd. Complexes bearing bulky cumyl substituents on phenolate donors exhibited unusual ¹H NMR spectroscopic features that are consistent with an anagostic interaction with the palladium center. Computational analysis …

Synthesizing Polyhydroxylated Indolizidines From D-Glucopyranoside, Stephanie Bryson

SURE (Stonehill Undergraduate Research Experience)

The individual sugars that constitute more complex carbo-hydrates are joined together by glycosidic bonds. Glycosidase enzymes catalyze the hydrolysis of these glycosidic bonds. The action of glycosidases plays an important role in viral infections, cancer, and diabetes. Iminosugars are nitrogen containing sugar analogs that are known to inhibit glycosidase function. The main objective of this research is to synthesize four of the possible 32 stereoisomers of a tetrahydoxylated indolizidine iminosugar (Figure 1) starting from a commercially available D-glucopyranoside. After synthesizing pyrrolidine 6 (39.3%), a ring-closing metathesis was performed to generate the indolizidine 7. A ruthenium catalyzed dihydroxylation followed by acetylation …

Snowpack Measurements Suggest Role For Multi-Year Sea Ice Regions In Arctic Atmospheric Bromine And Chlorine Chemistry, Peter K. Peterson, Mark Hartwig, Nathaniel W. May, Evan Schwartz, Ignatius Rigor, Wendy Ermold, Michael Steele, James H. Morison, Son V. Nghiem, Kerri A. Pratt

Chemistry

As sources of reactive halogens, snowpacks in sea ice regions control the oxidative capacity of the Arctic atmosphere. However, measurements of snowpack halide concentrations remain sparse, particularly in the high Arctic, limiting our understanding of and ability to parameterize snowpack participation in tropospheric halogen chemistry. To address this gap, we measured concentrations of chloride, bromide, and sodium in snow samples collected during polar spring above remote multi-year sea ice (MYI) and first-year sea ice (FYI) north of Greenland and Alaska, as well as in the central Arctic, and compared these measurements to a larger dataset collected in the Alaskan coastal …

An Overview Of Capillary Electrophoresis (Ce) In Clinical Analysis, David S. Hage

David Hage Publications

The development and general applications of capillary electrophoresis (CE) in the field of clinical chemistry are discussed. It is shown how the early development of electrophoresis was closely linked to clinical testing. The rise of gel electrophoresis in clinical chemistry is described, as well as the eventual developments that lead to the creation and the use of modern CE. The general principles of CE are reviewed and the potential advantages of this method in clinical testing are examined. Finally, an overview is presented of several areas in which CE has been developed and is currently being explored for use with …

Coordination Chemistry Of N,N’- Azodoxides, Lakshmi Balaraman

ETD Archive

The coordination chemistry of nitric oxide (NO) with transition metals has been extensively investigated, but that of organic NO derivatives as ligands less so. Some nitrosoalkanes RNO and nitrosoarenes ArNO are in equilibrium with dimeric species known as N,N'–azodioxides, R(O)NN(O)R or Ar(O)NN(O)Ar. The cis diastereomers of azodioxides have been proposed to act as bidentate chelating ligands for both main-group and transition metals, but only three azodioxide complexes, a dicationic iron (II) complex, a neutral scandium (III) complex, and a dicationic calcium (II) complex, have thus far been structurally characterized before our work in this area. The delocalized π system of …

The Relationship Between Rock Climbing And Total Body Strength And Endurance, Madison Gamma, Alexa Bruce, Madison Massey, Ashlee Cordero

The Corinthian

Purpose: The purpose of our study was to assess the relationship between muscular strength and endurance and time to complete a rock wall climb.

Methods: The researchers of this study tested 22 participants ranging from 19-25 years of age. An informed consent and a Physical Activity Readiness Questionnaire (PARQ+) form were completed by each individual before being cleared to participate in this study. Data collection was completed on two separate days. On the first day, participants completed four fitness tests which consisted of a hand grip strength assessment, a 10-repetition maximum (RM) leg press, a flexed arm hang test, and …

Refinement Of Production Grade Biodiesel, Campbell Axt, Robert B. Hughley Jr., Sydney Ninneman, Jillian Turner

The Corinthian

The modified Burton method for the thermal hydrogen-cracking of peanut oil has been investigated in McGill Research Group since 2009. The successful and reliable production of biodiesel has been achieved since 2014. A hydrocarbon with a viscosity similar to Production Grade Diesel will work in modern diesel engines. The current product has a viscosity significantly lower than production grade diesel. The starting material has a viscosity significantly higher than Production Grade Diesel. Current research is investigating methodologies to mix starting material and product to achieve target viscosity.

Synthesis Of 1,3-Di(4-Pyridinyl)Acetone, Zachary Tyler Boggs

Theses, Dissertations and Capstones

Although isoelectronic to benzene, the reactivity of pyridine-derived compounds can be quite different. Notably, routes to prepare pyridyl analogs to known phenyl compounds can be very different from how the phenyl compounds are made, even when the nitrogen atom would appear to play an insignificant role in the reaction. This is the case for 1,3-di-4-pyridylacetone. Its phenyl analog has been known for over 90 years and is easily prepared, while the only reported synthesis of 1,3-di-4-pyridylacetone occurs in very low yield. We report a preliminary synthesis from common starting materials, albeit in low yield, and offer an explanation for why …

Identifying C-Mannosylatedproteins In Raw264.7 Cells Via In Vitro Hsc70 Co-Immunoprecipitation Strategies, Nicholas Ryan Kegley

Theses, Dissertations and Capstones

C-mannosylation is a specific type of glycosylation in which α-mannose is covalently bound to the C2 atom of a tryptophan via a carbon-carbon bond. Presently, it is known to occur on proteins that contain the W-x-x-W-x-x-W/C motif found within the Thrombospondin Type-1 Repeat (TSR), with ‘x’ denoting any amino acid. C-mannosylation has been implicated in a number of cellular functions, including protein secretion and type I cytokine receptor function. Previous research has shown that exogenous C-mannosylated peptides derived from TSR-containing proteins upregulate the production of the pro-inflammatory cytokine Tumor Necrosis Factor alpha (TNF-α) in RAW264.7 macrophage cells. This upregulation is …

Characterizing The Effects Of Environmental Stressors On The Photosynthetic Capacity Of Chlorella Vulgaris, Amanda Louise Smythers

Theses, Dissertations and Capstones

Chlorella vulgaris is a unicellular green algae grown throughout the world. Due to its multiple trophic modes as well as its ability to maintain high rates of growth under adverse conditions, it has been of global interest for use in ecological contamination studies, biofuel feedstock optimization, and studies of photosynthetic electron transfer. Using a wide-range of methods for physiological and photosynthetic characterization, the studies within seek to further extend the usefulness of C. vulgaris in a variety of environmentally important studies. Once the protocols were optimized specifically for this alga, they could be applied in both ecologically relevant and biodiesel …

Isolation And Identification Of Hsc70 Conjugates In Raw264.7 Murine Macrophage-Like Cells, Michael Arland Parsons

Theses, Dissertations and Capstones

IL12R- β2 is a Type I cytokine receptor and contains the WXXW (WSNWS) sequence that often predicates the post-translational addition of mannose to a tryptophan residue via a carbon-carbon bond. This study will stimulate expression of IL12R- β2 in RAW 264.7 Macrophage-Like Cells by shutting down the extracellular signal kinase (ERK) pathway and introducing inflammatory agents lipopolysaccharide and CpG DNA in order to collect a concentrated sample of IL12R- β2. These samples will be analyzed for the presence of C-mannosyltryptophan residue

Novel Dna Origami Based Lateral Flow Assay Development, Adrienne Walker

Theses, Dissertations and Capstones

Lateral flow assays (LFA) are used for point-of-care qualitative diagnostics of an analyte of interest, often in non-laboratory environments. Traditionally, the format of a lateral flow assay is to utilize immobilized antibodies on a membrane as the capture probe in conjunction with a reporting immunological recognition system for an analyte captured between them in a sandwich format. However, there are several shortcomings of antibodies which recommend their replacement with other recognition elements, if possible. The research described in this thesis was directed toward using several of the inherent properties of DNA based Origami nanostructures to enable the construction of DNA …

3d-Qsar, Molecular Docking, And Dynamics Simulation Of Quinazoline-Phosphoramidate Mustard Conjugates As Egfr Inhibitor, Ruslin Ruslin, Amelia Resky, Yamin Yamin, Sandra Megantara, Chun Wu, Muhammad Arba

College of Science & Mathematics Departmental Research

To develop novel and more potent quinazoline–phosphoramidate mustard conjugates as epidermal growth factor receptor (EGFR) inhibitor, three-dimensional quantitative structure-activity relationship [comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA)] combined with molecular docking were performed. A series of 13 compounds in the training set gave q2 values of 0.577 and 0.537, as well as r2 values of 0.926 and 0.921 for CoMFA and CoMSIA models, respectively. The contour maps that were produced by the CoMFA and CoMSIA models revealed that steric, electrostatic, and hydrophobic fields were crucial in the inhibitory activity of quinazoline–phosphoramidate derivatives. Based on the …

Nanomole Silver Detection In Chloride-Free Phosphate Buffer Using Platinum And Gold Micro- And Nanoelectrodes, Prabhakar Sidambaram, John Colleran

Articles

The electrochemical determination of ultra-low concentrations of silver requires reliable, reproducible measurements using sensitive analytical techniques. To date, the electrochemical determination of silver in biological buffers and pH neutral media has not been successful in terms of reproducibility. In this work, we report on the determination of ultra-low concentrations of silver in chloride-free phosphate buffer solution (PB, pH 7.4). Detection was conducted at gold and platinum micro and nanoelectrodes using anodic stripping voltammetry (ASV). The micro and nanoelectrodes were fabricated using a Sutter P-2000 laser puller, with physical and electrochemical characterization revealing flat disk-shaped working surfaces of 10–15 μm (microelectrode) …

Homologous Recombination Under The Single-Molecule Fluorescence Microscope, Dalton R. Gibbs, Soma Dhakal

Chemistry Publications

Homologous recombination (HR) is a complex biological process and is central to meiosis and for repair of DNA double-strand breaks. Although the HR process has been the subject of intensive study for more than three decades, the complex protein–protein and protein–DNA interactions during HR present a significant challenge for determining the molecular mechanism(s) of the process. This knowledge gap is largely because of the dynamic interactions between HR proteins and DNA which is difficult to capture by routine biochemical or structural biology methods. In recent years, single-molecule fluorescence microscopy has been a popular method in the field of HR to …

Conformations Of Tricyanofuran-Type Metastable-State Photoacids, Juan E. Arias

Honors Undergraduate Theses

Tricyanofuran-type metastable-state photoacids, relative newcomers to the field of photochromism, outperform traditional light-controlled molecular switches in regards to applicability in biological systems. In a preliminary attempt to understand the underlying processes that govern these compounds, this thesis project establishes the isomeric identity of an unsubstituted tricyanofuran-type metastable-state photoacid, referred to as TCF 1 in this work. Two-dimensional nuclear magnetic resonance experiments are employed to experimentally determine the presence and identity of the open-form TCF 1 isomers. Electronic structure calculations are then used to provide quantitative insight into the experimental results. Experiment and theory show that four out of eight possible …

Implication Of Inorganic Nitrogen And Phosphorous Species As A Cause Of A Harmful Algal Bloom Event In Caesar Creek Lake, Ohio And Its Tributaries, Baxter Jeffrey Foskuhl

Browse all Theses and Dissertations

Agricultural runoff poses a threat to the Wilmington, Ohio municipal water supply and its source waters. A harmful algal bloom (HAB) was documented in June 2019 in Caesar Creek Lake, Waynesville, Ohio. This study seeks to establish baseline nutrient concentrations in Caesar Creek Lake (Warren County, Ohio) and its tributaries, and to identify potential non-point sources of excess nitrogen and phosphorous that contributed to the HAB event. In collaboration with the Wilmington Water Department, dissolved inorganic nitrogen DIN-[N] (sum of NH3-[N], NH4+-[N], NO2--[N], NO3--[N] concentrations), dissolved phosphorous DP-[P], particulate phosphorous PP-[P], total phosphorous TP-[P] (total sum of DP-[P] and PP-[P] …

Cis/Trans Energetics In Epoxide, Thiirane, Aziridine And Phosphirane Containing Cyclopentanols: Effects Of Intramolecular Oh···O,S,N And P Contacts, Ben E. Smith, Jeremy M. Carr, Gregory S. Tschumper

Faculty and Student Publications

c 2019 by the authors A recent computational analysis of the stabilizing intramolecular OH···O contact in 1,2-dialkyl-2,3-epoxycyclopentanol diastereomers has been extended to thiiriane, aziridine and phosphirane analogues. Density functional theory (DFT), second-order Møller-Plesset perturbation theory (MP2) and CCSD(T) coupled-cluster computations with simple methyl and ethyl substituents indicate that electronic energies of the cis isomers are lowered by roughly 3 to 4 kcal mol−1 when the OH group of these cyclopentanol systems forms an intramolecular contact with the O, S, N or P atom on the adjacent carbon. The results also suggest that S and P can participate in these stabilizing …

Assessing The Recyclability Of Stainless-Steel Powder Used In Selective Laser Melting-3d Printing, Alexis I. Keaton

Theses

Additive manufacturing (AM) is becoming one of the most distinctively growing versatile technologies. In most AM techniques that requires the use of powder, the powder that is not fused into the 3D print can be replenished and used for another build. Unfused powder is generally collected on the powder-bed after an AM build is complete. In most cases, the ability to replenish unfused powder with virgin powder aids in limiting any significant change in powder’s properties that may cause compromising the quality of the 3D prints. If no powder is added to the recycled powder it is likely to shift …