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The Role Of Sugars In Aggregation Of The Protein Kassinin, Lillie G. Waldron Jan 2024

The Role Of Sugars In Aggregation Of The Protein Kassinin, Lillie G. Waldron

Student Summer Scholars Manuscripts

The aggregation of proteins to form amyloids is implicated in several diseases such as Alzheimer’s Disease, Parkinson’s Disease, and many others. This aggregation has several stages, progressing from isolated protein molecules (monomers) to small aggregates (oligomers), which are toxic to cells, and finally to large, string-like mature aggregates. Despite this association with disease, functional amyloids, which have normal biological functions, also result from protein aggregation. Kassinin, an amphibian peptide involved in nerve signal transmission, is a model system for functional amyloid study. To compare the aggregation of functional and disease-causing amyloids, we previously synthesized a fluorine-labeled kassinin through solid-phase peptide …

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A Spectrophotometric Determination Of Strontium Complexation With Methylthymol Blue, Adebayo Comlan Djanman Jan 2024

A Spectrophotometric Determination Of Strontium Complexation With Methylthymol Blue, Adebayo Comlan Djanman

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This study examines the complexation behavior of methylthymol blue (MTB) with strontium, particularly focusing on its application in addressing environmental concerns related to radiotoxic 90Sr. Using spectrophotometric techniques, the binding interactions were analyzed at pH = 7.50, 9.60, and 12.20. Results indicate that MTB forms a 1:1 complex with strontium at pH = 7.50, while at pH = 9.60 and 12.20 were assumed to influence complexation due to changes in ligand deprotonation and electrostatic interactions. Equilibrium constants (K1) = 22 (± 2) and molar absorptivities, ε1 = 6.3 x 10^3 (± 0.0008) L·mol⁻¹·cm⁻¹, and ε2 = 9.73 x (± 0.2)10^3 …

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Corrosion Inhibitors: Mitigating The Degradation Of Rebar, Jake R. Hughes Jan 2024

Corrosion Inhibitors: Mitigating The Degradation Of Rebar, Jake R. Hughes

Williams Honors College, Honors Research Projects

Our conjecture was twofold: first, that two compounds historically used as food preservatives could act as environmentally friendly inhibitors against rebar corrosion, and second, that molecular properties have a quantifiable influence on inhibition efficiency (%IE). To evaluate the two compounds, cyclic potentiodynamic polarization was used to determine corrosion current density (icorr) and %IE. The “green” inhibitor candidates included sodium metabisulfite and ascorbic acid, which yielded maximum %IE values of -123900% and 91%, respectively. Results indicated that sodium metabisulfite is not a suitable inhibitor, while ascorbic acid showed potential to extend reinforced concrete’s design life without posing health or …

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Novel Re-Crosslinkable Preformed Particle Gels (Rppg) For Parent- And Infill-Well-Fracture Interactions Mitigation, Xiaojing Ge, Adel Alotibi, Ahmed Al-Hlaichi, Yanbo Liu, Tao Song, Junchen Liu, Baojun Bai, Thomas P. Schuman Jan 2024

Novel Re-Crosslinkable Preformed Particle Gels (Rppg) For Parent- And Infill-Well-Fracture Interactions Mitigation, Xiaojing Ge, Adel Alotibi, Ahmed Al-Hlaichi, Yanbo Liu, Tao Song, Junchen Liu, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Hydraulic fracturing treatments in unconventional infill (or "child") wells can be significantly affected by depletion from existing parent-well, resulting in asymmetrical fracture growth. These issues may lead to excessive load-water production, proppant deposition, casing deformation in the parent well, and unbalanced stimulation of infill wells. To mitigate these effects, various strategies have been proposed, including the use of far-field diverters in child wells and repressurization of parent wells. Additionally, an increasingly popular strategy involves injecting near-wellbore diverters to temporarily plug entry points into the parent wellbores during frac operations on infill wells. To achieve better application, a novel low-cost, self-degradable, …

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Tracking The Reaction Networks Of Criegee Intermediates Formed In The Ozone-Assisted Oxidation Reactions Of C5 Acyclic And Endocyclic Alkenes, Arden M. Floyd Jan 2024

Tracking The Reaction Networks Of Criegee Intermediates Formed In The Ozone-Assisted Oxidation Reactions Of C5 Acyclic And Endocyclic Alkenes, Arden M. Floyd

Honors Undergraduate Theses

Uni- and bi-molecular reactions involving Criegee intermediates (CIs), characteristic to alkene-ozone reactions, play an important role in synthetic organic, atmospheric, and combustion chemistry. However, difficulty in detecting key intermediates has prevented a thorough understanding of the details of the ozonolysis mechanism. To gain new insights into how alkene structure affects the CI network, the ozone assisted oxidation reactions of trans-2-pentene and cyclopentene are investigated between 320 K and 760 K in an atmospheric pressure jet stirred reactor (JSR). Molecular-beam mass spectrometry in conjunction with single photon tunable synchrotron VUV radiation is used to identify elusive intermediates by means of …

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A Comparative Study Of Cationic Copper(I) Reagents Supported By Bipodal Tetramethylguanidinyl-Containing Ligands As Nitrene-Transfer Catalysts, Suraj Kumar Sahoo, Brent Harfmann, Himanshu Bhatia, Harish Singh, Srikanth Balijapelly, Amitava Choudhury, Pericles Stavropoulos Jan 2024

A Comparative Study Of Cationic Copper(I) Reagents Supported By Bipodal Tetramethylguanidinyl-Containing Ligands As Nitrene-Transfer Catalysts, Suraj Kumar Sahoo, Brent Harfmann, Himanshu Bhatia, Harish Singh, Srikanth Balijapelly, Amitava Choudhury, Pericles Stavropoulos

Chemistry Faculty Research & Creative Works

The Bipodal Compounds [(TMG2biphenN-R)CuI-NCMe](PF6) (R = Me, Ar (4-CF3Ph-)) And [(TMG2biphenN-Me)CuI-I] Have Been Synthesized With Ligands That Feature A Diarylmethyl- And Triaryl-Amine Framework And Superbasic Tetramethylguanidinyl Residues (TMG). The Cationic Cu(I) Sites Mediate Catalytic Nitrene-Transfer Reactions Between The Imidoiodinane PhI = NTs (Ts = Tosyl) And A Panel Of Styrenes In MeCN, To Afford Aziridines, Demonstrating Comparable Reactivity Profiles. The Copper Reagents Have Been Further Explored To Execute C-H Amination Reactions With A Variety Of Aliphatic And Aromatic Hydrocarbons And Two Distinct Nitrene Sources PhI = NTs And PhI = NTces (Tces = 2,2,2-Trichloroethylsulfamate) In Benzene/HFIP (10:2 V/v). Good Yields …

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Perfect Polar Alignment Of Parallel Beloamphiphile Layers: Improved Structural Design Bias Realized In Ferroelectric Crystals Of The Novel “Methoxyphenyl Series Of Acetophenone Azines”, Harmeet Bhoday, Nathan Knotts, Rainer Glaser Jan 2024

Perfect Polar Alignment Of Parallel Beloamphiphile Layers: Improved Structural Design Bias Realized In Ferroelectric Crystals Of The Novel “Methoxyphenyl Series Of Acetophenone Azines”, Harmeet Bhoday, Nathan Knotts, Rainer Glaser

Chemistry Faculty Research & Creative Works

An Improved Design Is Described For Ferroelectric Crystals And Implemented With The "Methoxyphenyl Series" Of Acetophenone Azines, (MeO−Ph, Y)-Azines With Y=F (1), Cl (2), Br (3), Or I (4). The Crystal Structures Of These Azines Exhibit Polar Stacking Of Parallel Beloamphiphile Monolayers (PBAMs). Azines 1, 3, And 4 Form True Racemates Whereas Chloroazine 2 Crystallizes As A Kryptoracemate. Azines 1–4 Are Helical Because Of The N−N Bond Conformation. In True Racemates The Molecules Of Opposite Helicity (M And P) Are Enantiomers A(M) And A*(P) While In Kryptoracemates They Are Diastereomers A(M) And B*(P). The Stacking Mode Of PBAMs Is Influenced …

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Solar Enhanced Oxygen Evolution Reaction With Transition Metal Telluride, Harish Singh, Taishi Higuchi-Roos, Fabrice Roncoroni, David Prendergast, Manashi Nath Jan 2024

Solar Enhanced Oxygen Evolution Reaction With Transition Metal Telluride, Harish Singh, Taishi Higuchi-Roos, Fabrice Roncoroni, David Prendergast, Manashi Nath

Chemistry Faculty Research & Creative Works

The Photo-Enhanced Electrocatalytic Method of Oxygen Evolution Reaction (OER) Shows Promise for Enhancing the Effectiveness of Clear Energy Generation through Water Splitting by using Renewable and Sustainable Source of Energy. However, Despite Benefits of Photo electrocatalytic (PEC) Water Splitting, its Uses Are Constrained by its Low Efficiency as a Result of Charge Carrier Recombination, a Large overpotential, and Sluggish Reaction Kinetics. Here, We Illustrate that Nickel Telluride (NiTe) Synthesized by Hydrothermal Methods Can Function as an Extremely Effective Photo-Coupled Electrochemical Oxygen Evolution Reaction (POER) Catalyst. in This Study, NiTe Was Synthesized by Hydrothermal Method at 145°C within Just an Hour …

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Polar Stacking Of Dipole Parallel-Aligned Monolayers Of Unsymmetrical 1,4-Diphenyl-1,3-Butadienes Creates Nonlinear Optical Materials: Insights From Experiments Guide Structure Assignments, Harmeet Bhoday, Justin Nulsen, Steven P. Kelley, Rainer Glaser Jan 2024

Polar Stacking Of Dipole Parallel-Aligned Monolayers Of Unsymmetrical 1,4-Diphenyl-1,3-Butadienes Creates Nonlinear Optical Materials: Insights From Experiments Guide Structure Assignments, Harmeet Bhoday, Justin Nulsen, Steven P. Kelley, Rainer Glaser

Chemistry Faculty Research & Creative Works

A series of 1-(4′-halophenyl)-4-(4″-methoxyphenyl) buta-1,3-dienes, (H, MeO, Y)-1,4-diphenylbutadienes with halogens Y = F (1), Cl (2), Br (3), and I (4) are described. Crystal structure analysis establishes that 1-4 present a new class of highly dipole parallel-aligned polar organic molecular materials for nonlinear optics (NLO). Building on previous studies of polar crystals of unsymmetrical acetophenone azines, (R, X, Y)-azines, X-Ph-CR═N-N═CR-Ph-Y (R = Me; X = R'O, PhO, R'OPh; Y = F, Cl, Br, I), we suspected that the all-carbon analogs (R, R'O, Y)-1,4-diphenylbutadienes, R'O-Ph-CR═CH-CH═CR-Ph-Y, could crystallize with polar lattices and feature stronger NLO effects because of their improved conjugation and …

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Dna Origami-Assisted Regioselective Organization Of Anisotropic Gold Nanotriangle Clusters, Wenyan Liu, Prashant Gupta, Yuwei Zhang, Krishna Thapa, Srikanth Singamaneni, Risheng Wang Jan 2024

Dna Origami-Assisted Regioselective Organization Of Anisotropic Gold Nanotriangle Clusters, Wenyan Liu, Prashant Gupta, Yuwei Zhang, Krishna Thapa, Srikanth Singamaneni, Risheng Wang

Chemistry Faculty Research & Creative Works

The manipulation of anisotropic nanoparticles, such as gold nanorods and nano prisms, has attracted great attention in nanotechnology due to their sensitive geometry-dependent properties. However. traditional synthesis and assembly methods for these particles face challenges in size uniformity and higher-order structuring. To address these limitations, this study presents a strategy using DNA origami triangles, not just as templates, but as encapsulating agents for gold nanotriangles (AuNTs). This method enables the construction of diverse nanoparticle clusters with precisely controlled distance and orientation. The formed clusters exhibit unique optical characteristics, demonstrated by UV-visible spectroscopy and supported by finite-difference time domain (FDTD) simulations. …

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Selected Trace Element Uptake By Rice Grain As Affected By Soil Arsenic, Water Management And Cultivar -A Field Investigation, Eric M. Farrow, Jianmin Wang, Honglan Shi, John Yang, Bin Hua, Baolin Deng Jan 2024

Selected Trace Element Uptake By Rice Grain As Affected By Soil Arsenic, Water Management And Cultivar -A Field Investigation, Eric M. Farrow, Jianmin Wang, Honglan Shi, John Yang, Bin Hua, Baolin Deng

Chemistry Faculty Research & Creative Works

Accumulation of arsenic (As) in rice grain was reported in many regions of the world, including the United States, which has been a threat to human health. This field research investigated the grain As accumulation and its relationship with the uptake of selenium (Se), molybdenum (Mo), and cadmium (Cd) in soils with and without monosodium methane arsonate (MSMA) amended, as effects of selected rice cultivars and water management. Results indicated that MSMA increased the accumulation of As and Se but decreased Mo for all six cultivars under four irrigation management. MSMA also increased grain-Cd in some cultivars. In no MSMA-amended …

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High-Capacity Anode For Sodium-Ion Batteries Using Hard Carbons Derived From Polyurea-Cross-Linked Silica Xerogel Powders, Santhoshkumar Sundaramoorthy, Rushi U. Soni, Stephen Yaw Owusu, Sutapa Bhattacharya, A. B.M.Shaheen Ud Doulah, Vaibhav A. Edlabadkar, Chariklia Sotiriou-Leventis, Amitava Choudhury Jan 2024

High-Capacity Anode For Sodium-Ion Batteries Using Hard Carbons Derived From Polyurea-Cross-Linked Silica Xerogel Powders, Santhoshkumar Sundaramoorthy, Rushi U. Soni, Stephen Yaw Owusu, Sutapa Bhattacharya, A. B.M.Shaheen Ud Doulah, Vaibhav A. Edlabadkar, Chariklia Sotiriou-Leventis, Amitava Choudhury

Chemistry Faculty Research & Creative Works

In this article, we demonstrated carbon aerogel-silica composites derived from polyurea-cross-linked silica xerogel powders (C-PUA@silica) as anodes for Na-ion batteries. These xerogel-derived hard carbons with embedded silica showed a stable high capacity. Of the several hard carbon samples derived at different temperatures, the pyrolyzed sample at 800 °C (C-PUA@silica-800) showed a high capacity of 236 mAh/g at a current density of 10 mA/g and a stable cycle-life at 200 mAh/g. The galvanostatic charge-discharge curves displayed a sloping voltage profile reminiscent of the adsorption mechanism of Na+ storage. On the other hand, higher temperature-pyrolyzed samples at 1300 °C (C-PUA@silica-1300) displayed a …

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Boosting The Microbial Electrosynthesis Of Formate By Shewanella Oneidensis Mr-1 With An Ionic Liquid Cosolvent, Ashwini Dantanarayana, Wassim El Housseini, Kevin Beaver, Monica Brachi, Timothy P. Mcfadden, Shelley D. Minteer Jan 2024

Boosting The Microbial Electrosynthesis Of Formate By Shewanella Oneidensis Mr-1 With An Ionic Liquid Cosolvent, Ashwini Dantanarayana, Wassim El Housseini, Kevin Beaver, Monica Brachi, Timothy P. Mcfadden, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Microbial electrosynthesis (MES) is a rapidly growing technology at the forefront of sustainable chemistry, leveraging the ability of microorganisms to catalyze electrochemical reactions to synthesize valuable compounds from renewable energy sources. The reduction of CO2 is a major target application for MES, but research in this area has been stifled, especially with the use of direct electron transfer (DET)-based microbial systems. The major fundamental hurdle that needs to be overcome is the low efficiency of CO2 reduction largely attributed to minimal microbial access to CO2 owing to its low solubility in the electrolyte. With their tunable physical …

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Assessing Fixed-Node Diffusion Monte Carlo For Radical Polymerization Reaction Energetics, Timothy Brian Huber Jan 2024

Assessing Fixed-Node Diffusion Monte Carlo For Radical Polymerization Reaction Energetics, Timothy Brian Huber

Graduate Research Theses & Dissertations

The art of quantum chemistry is grounded to the discovery of a time efficient computational method that can capture the essential physics. Historically, the Hartree-Fock method, where an electron moves in the mean field of the other electrons, has provided the orbitals used to construct a single-reference Slater determinant and thus formed the basis for molecular orbital calculations. Kohn-Sham density functionals have become overwhelmingly popular among the chemistry community due to their low computational cost. However, their prediction of thermodynamic properties important in free radical polymerization has shown difficulty due to an artificial delocalization of electron density and spin contamination …

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Excited State Proton Transfer From Acidic Alcohols To A Quinoline Photobase Can Be Solvated By Non-Acidic Alcohol Solvents, Jonathan Ryan Hunt, Joseph Hecht, Clara Goolsby, Jade Hagihara, Monique Loza, Samantha Del Pozo Jan 2024

Excited State Proton Transfer From Acidic Alcohols To A Quinoline Photobase Can Be Solvated By Non-Acidic Alcohol Solvents, Jonathan Ryan Hunt, Joseph Hecht, Clara Goolsby, Jade Hagihara, Monique Loza, Samantha Del Pozo

Chemistry and Biochemistry Faculty Works

Photobases are a type of molecule that become more basic upon photoexcitation and can therefore be used to control proton transfer reactions with light. The solvation requirements for excited state proton transfer (ESPT) in photobase systems is poorly understood, which limits their applicability. Here, we investigate the solvation of the ESPT reaction using 5-methoxyquinoline (MeOQ), a well-studied photobase with an excited state pKa (pKa*) of approximately 15.1, as a model system. Previous studies have shown that, in addition to the acidic donor that donates a proton to the photoexcited MeOQ, an additional “auxiliary donor” is necessary to solvate the resulting …

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Investigation Of Ion Pairing And Clustering Leading To The Nucleation Of Fluorite Using Ion Selective Electrode Potentiometry, Courtney L. Crone Jan 2024

Investigation Of Ion Pairing And Clustering Leading To The Nucleation Of Fluorite Using Ion Selective Electrode Potentiometry, Courtney L. Crone

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Previously, mineral nucleation was described by Classical Nucleation Theory (CNT), a theory based on the thermodynamic properties of bulk materials. However, an alternative model, known as the Prenucleation Cluster Pathway, has been increasingly used to describe nucleation of minerals. This model considers the presence of thermodynamically stable ion clusters known as “prenucleation clusters” (PNCs). In the present research, the nucleation mechanism of calcium fluoride was investigated to identify evidence of PNCs by means of the ion-selective electrode (ISE) method, where a CaCl2 solution was titrated into a NaF solution while investigating the effects of saturation level and the aqueous ratio …

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Photoluminescence Of Beryllium-Related Defects In Gallium Nitride, Mykhailo Vorobiov, Mykhailo Vorobiov Jan 2024

Photoluminescence Of Beryllium-Related Defects In Gallium Nitride, Mykhailo Vorobiov, Mykhailo Vorobiov

Theses and Dissertations

This study explores the potential of beryllium (Be) as an alternative dopant to magnesium (Mg) for achieving higher hole concentrations in gallium nitride (GaN). Despite Mg prominence as an acceptor in optoelectronic and high-power devices, its deep acceptor level at 0.22 eV above the valence band limits its effectiveness. By examining Be, this research aims to pave the way to overcoming these limitations and extend the findings to aluminum nitride and aluminum gallium nitride (AlGaN) alloy. Key contributions of this work include. i)Identification of three Be-related luminescence bands in GaN through photoluminescence spectroscopy, improving the understanding needed for further material …

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Effects Of Geometric Isomerism On Benzothiazole-Carbazole Based Tadf Emitters In Poly(Arylene Ether)S, Grace Olive Jan 2024

Effects Of Geometric Isomerism On Benzothiazole-Carbazole Based Tadf Emitters In Poly(Arylene Ether)S, Grace Olive

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Thermally activated delayed fluorescence (TADF) small molecules have dominated the literature for their use in OLED devices. The use of TADF polymers has been employed to correct for processing issues that small molecules face, providing increased thermal stability and supportive electronic structures. A TADF chromophore based on a 2-(2,6-difluorophenyl)-benzothiazole-carbazole donor-acceptor pair was synthesized via a copper (I) catalyzed reaction. The chromophore exhibited peak absorption at 340 nm and emission at 477 nm. The resulting chromophore was incorporated into a poly(arylene ether) (PAE) backbone via nucleophilic aromatic substitution (NAS) with 4,4’-biphenol, 4,4’-difluorodiphenyl sulfone, and 2-(2,6-difluorophenyl)-benzothiazole as comonomers. UV/Vis analysis of the …

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Hybridization Kinetics Of Four-Way Junctions Localized On A Dna Scaffold, Katherine N. Taylor Jan 2024

Hybridization Kinetics Of Four-Way Junctions Localized On A Dna Scaffold, Katherine N. Taylor

Honors Undergraduate Theses

DNA computing is an ever-growing field with scientists trying to design structures that optimize logic gate communication to develop fast, biologically compatible, computational structures. We hypothesize that by using the principles of DNA computing, it is possible to design a DNA tile capable of studying localized DNA hybridization that can differentiate between oligonucleotides of different structural conformations. This includes synthetically manipulating DNA into a nanostructure that can perform Boolean logic functions to calculate the different rates of hybridization. To test our hypothesis, we designed a DNA Tile that incorporated a 4WJ using YES logic. Linear and hairpin single-stranded (ss) DNA …

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Mapping The Reaction Networks Of Cis Formed In The Ozone-Assisted Oxidation Of C₆ Acyclic And Endocyclic Alkenes, Zachary Clarke Jan 2024

Mapping The Reaction Networks Of Cis Formed In The Ozone-Assisted Oxidation Of C₆ Acyclic And Endocyclic Alkenes, Zachary Clarke

Honors Undergraduate Theses

Criegee intermediates (CIs) are highly reactive species generated during the ozonolysis of alkenes, exerting a critical influence on atmospheric oxidation, combustion chemistry, and synthetic processes. Their reactivity, encompassing unimolecular and bimolecular pathways, shapes oxidation mechanisms and product distributions in these environments. A key determinant of CI behavior is the structural nature of the parent alkene. Acyclic alkenes typically yield intermediates with minimal steric hindrance, facilitating rapid reactions, whereas endocyclic alkenes produce geometrically constrained CIs with enhanced internal stabilization, redirecting reaction pathways and reducing overall reactivity. Despite their importance, mechanistic understanding remains limited due to experimental challenges in detecting CIs and …

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Use Of Interlaboratory Studies For The Development Of Consensus-Based Criteria For The Elemental Analysis Of Electrical Tapes, Lacey M. Leatherland Jan 2024

Use Of Interlaboratory Studies For The Development Of Consensus-Based Criteria For The Elemental Analysis Of Electrical Tapes, Lacey M. Leatherland

Graduate Theses, Dissertations, and Problem Reports (ETD)

Tape evidence is often used in criminal cases involving violent crimes, kidnappings, improvised explosive devices (IEDs), and drug trafficking. This evidence can reveal potential links between suspects, items, or scenes. The forensic examination of electrical tape can provide investigative leads or offer support to alternative hypotheses evaluated in the courtroom. A conventional analytical scheme includes microscopic examination, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy Energy Dispersive Spectrometry (SEM-EDS), and Pyrolysis Gas Chromatography Mass Spectrometry (Py-GC/MS). Elemental analysis of electrical tapes is commonly achieved using SEM-EDS; however, recent scientific literature suggests that this analysis can evolve from using SEM-EDS to …

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Experimental And Chemical Modeling Of Applied Dc Electric Field Induced H2 – Air Axisymmetric Laminar Co-Flow Diffusion Flames With Low Carbon Impurities, Susith Dilshan Pathmasiri Gunamuni Halowitage Jan 2024

Experimental And Chemical Modeling Of Applied Dc Electric Field Induced H2 – Air Axisymmetric Laminar Co-Flow Diffusion Flames With Low Carbon Impurities, Susith Dilshan Pathmasiri Gunamuni Halowitage

Graduate Theses, Dissertations, and Problem Reports (ETD)

The effect of externally applied DC electric fields on flame structure was investigated in a stationary atmospheric axisymmetric laminar H2–Air flame with less than 100 ppm carbon equivalent impurities. Flame OH chemiluminescence signals were recorded using a UV-sensitive CCD array as a function of voltage (+10 to -10 kV) applied to a stainless-steel ring electrode placed around the burner nozzle. Changes in chemiluminescence signal are reported as a function of electrode height above the burner, airflow, and fuel composition. Significant changes in OH* distributions were observed for voltages below -5 kV. Under optimum conditions, the height of the …

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Room Temperature Decarboxylative Amination Reactions Of Carboxylic Acids, Rabina Basnet Jan 2024

Room Temperature Decarboxylative Amination Reactions Of Carboxylic Acids, Rabina Basnet

Graduate Theses, Dissertations, and Problem Reports (ETD)

Anilines are important structural motifs present in numerous natural products and pharmaceutically relevant compounds. Among the various synthetic strategies that have been developed, transition-metal-catalyzed cross-coupling reactions represent one of the most commonly employed methods for the formation of anilines. However, these approaches generally require pre-functionalized aryl coupling partners, and the utilization of more readily available, and structurally diverse coupling partners, such as carboxylic acids, would be desirable. Decarboxylative coupling reactions have garnered significant attention as an alternative approach to form new C-N bonds, and substantial progress has been made in this area. Nevertheless, these methods remain limited, with a predominant …

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Photoinduced Alpha-Hydroxy C–H Alkylation Of Mono-Alcohols Via Hydrogen Atom Transfer (Hat) Of An Activated Boron-Containing Complex, Courtney Deanna Glenn Jan 2024

Photoinduced Alpha-Hydroxy C–H Alkylation Of Mono-Alcohols Via Hydrogen Atom Transfer (Hat) Of An Activated Boron-Containing Complex, Courtney Deanna Glenn

Graduate Theses, Dissertations, and Problem Reports (ETD)

Hydroxy (-OH) groups are one of the most abundant functional groups found in natural products and pharmaceuticals with many of these compounds containing multiple alcohol classes. The ability to selectively functionalize a specific α-OH C–H bond in the presence of other competitive sites would provide straightforward access to new, potentially bioactive compounds. In recent literature, photoredox catalysis has been implemented to perform site and stereoselective α-OH C–H functionalization of cis-diol containing substrates. Incorporating an organoboron cocatalyst into these systems have proven to be crucial in decreasing the bond dissociation energy (BDE) and increasing hydricity of the α-OH C–H bond …

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Investigation Of Deoxyfluorination Of Alkyl Alcohols Using Pentafluoropyridines Through A Covalent Intermediate, Christopher Allen Bias Jan 2024

Investigation Of Deoxyfluorination Of Alkyl Alcohols Using Pentafluoropyridines Through A Covalent Intermediate, Christopher Allen Bias

Graduate Theses, Dissertations, and Problem Reports (ETD)

Organofluorines are an omnipresent class of organic molecules, especially in pharmaceuticals. Selective fluorination of drug molecules allows for the influence of properties including metabolic activity, solubility, and intrinsic potency. Deoxyfluorinations are typically performed via generation of nucleophilic fluoride from a deoxyfluorination agent. Traditionally, diethylaminosulfur trifluoride (DAST) is the reagent of choice for these reactions, and it remains a popular reagent today. However, it has a propensity to form elimination side products and explode. Several research groups have recently developed new classes of deoxyfluorination agents including imidazole-based reagents (PhenoFluor) and sulfonyl fluorides (PyFluor) that exhibit better functional group tolerance and much …

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Conformational Investigation Of Biopolymers Through Molecular Dynamics (Md) Simulations And In-Droplet Hdx-Ms Utilizing Cvssi, Samira Hajian Foroushani Jan 2024

Conformational Investigation Of Biopolymers Through Molecular Dynamics (Md) Simulations And In-Droplet Hdx-Ms Utilizing Cvssi, Samira Hajian Foroushani

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over the last two decades, mass spectrometry (MS) has received significant interest in biological study platforms, especially in the areas of proteomics and metabolomics. With the development of soft ionization methods like electrospray ionization (ESI), mass spectrometry has emerged as a potent method for directly characterizing proteins in their native state. The recent invention of capillary vibrating sharp-edge spray ionization has opened new avenues for the study of biopolymer native structure including the usage of droplet charge tuning and in-droplet hydrogen-deuterium exchange (HDX) labeling. With this new technique comes the opportunity to study biopolymer ion structure preservation with molecular dynamics …

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Α-Hydroxy C–H Functionalization Of Alcohols Via Boronic Acid, Hat, Photoredox Triad Catalytic System, Seth Christopher Cowan Jan 2024

Α-Hydroxy C–H Functionalization Of Alcohols Via Boronic Acid, Hat, Photoredox Triad Catalytic System, Seth Christopher Cowan

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation explores the research that I have conducted in my time at West Virginia University. Most of my work has focused on the development of methods and studies to further understand the α-OH C–H functionalization of alcohols. This work involves a system of catalysts including photocatalysts, HAT catalysts, and boronic acid catalysts. Chapter 1 highlights a background for each of these areas. Photoredox catalysis has been an increasing area of chemistry over the past two decades as this technique can be used to design conditions to form new bonds in a selective manner through the utilization of light energy. …

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Synthesis, Characterization, And Reactivity Studies Of Pyridine Dipyrrolide Iron-Carbene Complexes With Electronically Distinct Carbene Moieties, Jose G. Rodriguez Jan 2024

Synthesis, Characterization, And Reactivity Studies Of Pyridine Dipyrrolide Iron-Carbene Complexes With Electronically Distinct Carbene Moieties, Jose G. Rodriguez

Graduate Theses, Dissertations, and Problem Reports (ETD)

First, three (MesPDPPh) iron carbene complexes with electronically distinct carbene moieties were synthesized. These transitional iron carbene complexes were first characterized by 1H nuclear magnetic resonance (NMR) spectroscopy as their spectra showed paramagnetically shifted resonances. Additionally, their respected solid state structures were collected via X-ray diffraction. The two donor/acceptor iron carbene complexes [(MesPDPPh)Fe(C(CO2Me)(4-FPh) and (MesPDPPh)Fe(C(CO2Me)(4-MeOPh)] demonstrated a weak Fe-O interaction between the iron center and ester function group while the (MesPDPPh)Fe(IMe) displayed a C2v symmetric structure in the …

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A Portable, Digital Nucleic Acid Amplification Test For Use At The Point Of Care, Bethany J. Fike Jan 2024

A Portable, Digital Nucleic Acid Amplification Test For Use At The Point Of Care, Bethany J. Fike

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nucleic acid tests are key tools for the detection and diagnosis of many diseases. In many cases, the amplification of nucleic acids is required to reach a detectable level. Although nucleic acid tests have great success, there is a need to make nucleic acid amplification tests more accessible to a point-of-care (POC) setting for diagnosis, prognosis, and monitoring of infectious diseases. Traditionally, these tests are performed through bulk Polymerase Chain Reaction (PCR) and are monitored in real time with a change in fluorescence intensity. With these bulk testing methods, only a qualitative or semi-quantitative result is possible. For more exact …

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Extended Conformations Of Bifurcating Electron Transfer Flavoprotein Constitute Up To Half The Population, Possibly Mediating Conformational Change, Sharique A. Khan, Alan Hicks, Wellington C. Leite, James Byrnes, Biswajit Gorai, Maria-Andrea Mroginski, Hugh O'Neill, Anne-Francis Miller Jan 2024

Extended Conformations Of Bifurcating Electron Transfer Flavoprotein Constitute Up To Half The Population, Possibly Mediating Conformational Change, Sharique A. Khan, Alan Hicks, Wellington C. Leite, James Byrnes, Biswajit Gorai, Maria-Andrea Mroginski, Hugh O'Neill, Anne-Francis Miller

Markey Cancer Center Faculty Publications

Electron transfer bifurcation enables biological systems to drive unfavourable (endergonic) electron transfer by coupling it to favourable (exergonic) transfer of a second electron. In electron transfer flavoproteins (ETFs), a domain-scale conformational change is believed to sever the favourable pathway after a single electron has used it, thereby preventing the energy dissipation that would accompany exergonic transfer of the second electron. To understand the conformation change that participates in turnover, we have deployed small-angle neutron scattering (SANS) and computational techniques to characterize the bifurcating ETF from Acidaminococcus fermentans (AfeETF). SANS data reveal an overall radius of gyration (Rg) of 30.1 ± …

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