Chemistry Commons^™

A Self-Supported Ru-Cu3P Catalyst Toward Alkaline Hydrogen Evolution, Zi-Xuan Wan, Chao-Hui Wang, Xiong-Wu Kang

Journal of Electrochemistry

Transition metal phosphide (TMP) is a kind of effective catalysts toward hydrogen evolution reaction (HER) in alkaline electrolytes. However, the performance of TMP catalysts is strongly limited by water splitting. In this work, we developed a method to prepare a copper foam (CF) supported Ru-doped Cu₃P catalyst (Ru-Cu₃P/CF) by a consecutive growth of Cu(OH)₂ nanoarrays, soaking in RuCl₃ solution and phosphorization. A large surface area was obtained by the self-supported catalysts with the appropriative Ru doping. As an excellent HER catalyst, it exhibited a low overpotential of 95.6 mV at a current density of …

Recent Advances In Computational Study And Design Of Mof Catalysts For Co2 Conversion, Haoyuan Chen

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Catalytic conversion of the greenhouse gas CO2 into value-added chemicals and fuels is highly beneficial to the environment, the economy, and the global energy supply. Metal–organic frameworks (MOFs) are promising catalysts for this purpose due to their uniquely high structural and chemical tunability. In the catalyst discovery process, computational chemistry has emerged as an essential tool as it can not only aid in the interpretation of experimental observations but also provide atomistic-level insights into the catalytic mechanism. This Mini Review summarizes recent computational studies on MOF-catalyzed CO2 conversion through different types of reactions, discusses about the usage of various computational …

Catalytic Effect Of Disordered Ru-O Configurations For Electrochemical Hydrogen Evolution, Xue Sun, Ya-Jie Song, Ren-Long Li, Jia-Jun Wang

Journal of Electrochemistry

Phase engineering is considered as an effective method for modulating the electronic structure and catalytic activity of catalysts. The disordered conformation of amorphous materials allows flexible reforming of the surface electronic structure, showing their attractiveness as catalysts for hydrogen evolution reaction (HER). Herein, we designed and developed an amorphous ruthenium dioxide (a-RuO₂) catalyst with a disordered Ru-O configuration. The conformational relationship between Ru-O ordering and HER performance is established by combining advanced electron microscopic techniques with detailed electrochemical tests. Specifically, the disordered Ru-O coordination significantly enhanced the HER catalytic activity in both acidic and alkaline media, ultimately leading …

Sialidase Inhibitors With Different Mechanisms, Joseph M. Keil, Garrett R. Rafn, Isaac M. Turan, Majdi A. Aljohani, Reza Sahebjam-Atabaki, Xue-Long Sun

Chemistry Faculty Publications

Sialidases, or neuraminidases, are enzymes that catalyze the hydrolysis of sialic acid (Sia)-containing molecules, mostly removal of the terminal Sia (desialylation). By desialylation, sialidase can modulate the functionality of the target compound and is thus often involved in biological pathways. Inhibition of sialidases with inhibitors is an important approach for under-standing sialidase function and the underlying mechanisms and could serve as a therapeutic approach as well. Transition-state analogues, such as anti-influenza drugs oseltamivir and zanamivir, are major sialidase inhibitors. In addition, difluoro-sialic acids were developed as mechanism-based sialidase inhibitors. Further, fluorinated quinone methide-based suicide substrates were reported. Sialidase product analogue …

Influence Of Surface Water Displacement On Solvation Thermodynamics, Mia Kim

Journal of the South Carolina Academy of Science

No abstract provided.

A Macrocyclic Molecule With Multiple Antioxidative Activities Protects The Lens From Oxidative Damage, Jinmin Zhang, Yu Yu, Magy A. Mekhail, Hongli Wu, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Growing evidence links oxidative stress to the development of a cataract and other diseases of the eye. Treatments for lens-derived diseases are still elusive outside of the standard surgical interventions, which still carry risks today. Therefore, a potential drug molecule ^OHPy₂N₂ was explored for the ability to target multiple components of oxidative stress in the lens to prevent cataract formation. Several pathways were identified. Here we show that the ^OHPy₂N₂ molecule activates innate catalytic mechanisms in primary lens epithelial cells to prevent damage induced by oxidative stress. This protection was linked to …

Measurement In Chemistry, Mathematics, And Physics Education: Student Explanations Of Organic Chemistry Reaction Mechanisms And Instructional Practices In Introductory Courses, Brandon J. Yik

USF Tampa Graduate Theses and Dissertations

The work in this dissertation is presented in two parts. The first part (Chapters 3 and 4) details work relating to students’ explanations of reaction mechanisms in organic chemistry. The second part (Chapters 5 and 6) details work relating to the evaluating the uptake of research-based instructional practices in introductory chemistry, mathematics, and physics courses.

To evaluate learning of organic chemistry reactions, instructors must ask students to construct written explanations of reaction mechanisms. Written assessments should focus on what is happening and why it is happening to promote deeper student understanding. However, for instructors to gain insight into students’ understanding, …

On Airborne Tire Wear Particles Along Roads With Different Traffic Characteristics Using Passive Sampling And Optical Microscopy, Single Particle Sem/Edx, And Μ-Atr-Ftir Analyses, Zhiqiang Gao, James V. Cizdziel, Kendall Wontor, Carly Clisham, Kaylea Focia, Juanita Rausch, David Jaramillo-Vogel

Faculty and Student Publications

Tire wear particles (TWPs) are a major category of microplastic pollution produced by friction between tires and road surfaces. This non-exhaust particulate matter (PM) is transported through the air and with runoff leading to environmental pollution and health concerns. Here, we collected airborne PM along paved roads with different traffic volumes and speeds using Sigma-2 passive samplers. Particles entering the samplers deposit onto substrates for analysis, or, as we modified it, directly into small (60 ml) separatory funnels, which is particularly useful with high particle loads, where a density separation aids in isolating the microplastics. We quantified putative TWPs (∼10–80 …

Synthesis Of Carbon Nanohoops And Macrocycles Via Alkyne Metathesis, Xin Zhou

LSU Doctoral Dissertations

Cycloparaphenyleneacetylene (CPPA) and cycloparaphenylene (CPP) are called carbon nanohoops; they are fully conjugated macrocycles with radially oriented aromatic groups. Though many syntheses of CPPA and CPP were reported, in the macrocyclization step, the yields were usually not satisfying, as the reactions were irreversible. Our group utilizes alkyne metathesis to address this problem. Chapter 1 provides backgrounds and an introduction to the carbon nanohoops and alkyne metathesis.

Chapter 2 details the synthesis of the [3]CPP⁴A and [3]CPP⁵A, with good macrocyclization yields via alkyne metathesis. This study showed the error-correction ability of alkyne metathesis, especially with nonsymmetric substrates. …

Spectroscopic Properties Of The Astrochemical Molecules [Al, O, Si]X (X = 0, +1), Jacqueline M. Friskey, Vincent J. Esposito, Tarek Trabelsi, Joseph S. Francisco

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aluminum and silicon are present in large quantities in the interstellar medium, making the triatomic species consisting of both elements intriguing with regard to the foundations of astrochemistry. Spectroscopic parameters have been calculated via high-level ab initio methods to assist with laboratory and observational detection of [Al, O, Si]^x(x = 0,+1). All [Al, O, Si]M^x(x = 0,+1) isomers exist in the linear geometry, with linear AlOSi (X ²Π) and linear AlOSi⁺ (X¹Δ) being the most stable neutral and cationic species, respectively. Formation of the neutral species most likely occurs via reaction of …

Effects Of Cannabinoids On Ligand-Gated Ion Channels, Murat Oz, Keun-Hang Susan Yang, Mohamed Omer Mahgoub

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Phytocannabinoids such as Δ⁹-tetrahydrocannabinol and cannabidiol, endocannabinoids such as N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol, and synthetic cannabinoids such as CP47,497 and JWH-018 constitute major groups of structurally diverse cannabinoids. Along with these cannabinoids, CB1 and CB2 cannabinoid receptors and enzymes involved in synthesis and degradation of endocannabinoids comprise the major components of the cannabinoid system. Although, cannabinoid receptors are known to be involved in anti-convulsant, anti-nociceptive, anti-psychotic, anti-emetic, and anti-oxidant effects of cannabinoids, in recent years, an increasing number of studies suggest that, at pharmacologically relevant concentrations, these compounds interact with several molecular targets including G-protein coupled receptors, ion …

Synthesis Of Novel Dna-Binding Polyamides To Prevent Cancer-Related Gene Overexpression, Huy Q. Nguyen

Dissertations

Pyrrole-imidazole polyamides (PIPs) are nanomolecular compounds designed to fit in the tight space of DNA minor grooves. As analogs of Netropsin and Distamycin A, PIPs are specifically designed to recognize the base pairs of DNA sequences. PIPs have many biological applications, such as regulating gene expression, biochemistry pathway regulations, and suppressing the development of cancer cells. SETMAR gene is the chimeric fusion of the SET domain with the mariner transposase. Its protein (Metnase) has functions involving DNA repairs in the NHEJ pathway, regulating gene expression, DNA decatenation, etc. Despite not having an active transposable element, SETMAR still has an unknown …

Fine Tuning The Pore Surface In Zirconium Metal−Organic Frameworks For Selective Ethane/Ethylene Separation, Yuchen Hu, Yanshu Shi, Yi Xie, Rebecca Shu Hui Khoo, Christian Fiankor, Xu Zhang,, Banglin Chen, Jian Zhang

Department of Chemistry: Faculty Publications

Ethylene is an important chemical feedstock for production of polymers and high-value organic chemicals, and yet its conventional purification process is plagued with high consumption of energy. Metal−organic frameworks (MOFs) provide a suitable adsorption platform for selective ethane/ ethylene separation thanks to their structural diversity, tunable pore characteristics, designable pore sizes, and high pore volumes. Although there are empirical design rules like avoiding open metal sites and creating nonpolar pore surfaces for development of adsorptive MOFs, it is still challenging to design robust MOFs that can realize direct ethane-selective separation. Herein, we systematically designed and synthesized three Zr-MOFs based on …

Origin Of The Second-Order Proton Catalysis Of Ferriin Reduction In Belousov-Zhabotinsky Reactions: Density Functional Studies Of Ferroin And Ferriin Aggregates With Outer Sphere Ligands Sulfate, Bisulfate, And Sulfuric Acid, Sara C. Mccauley, Rainer Glaser

Chemistry Faculty Research & Creative Works

The detailed mechanisms of Belousov-Zhabotinsky oscillating reactions continue to present grand challenges, even after half a century of study. The origin of the pH dependence of the oscillation pattern had never been rigorously identified. In our recent kinetic study of one of the key Belousov-Zhabotinsky reactions, the iron-catalyzed bromate oxidation of malonic acid, compelling agreement between experiments and kinetic simulations was achieved only with the inclusion of second-order proton catalysis of the reduction of the [Fe(phen)₃]³⁺ species. After exhausting all other avenues in search of an explanation of this proton catalysis, we considered the possibility that the …

2022 Scas Annual Meeting Program And Bulletin

Journal of the South Carolina Academy of Science

No abstract provided.

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

Environmental Bacteriophage Detection On Coastal Carolina University Campus, Madison Gentilo, Hailey Oldfield, Gavin Ockert, Paul E. Richardson

Journal of the South Carolina Academy of Science

Bacteriophages are viruses that infect bacteria. These viruses are found ubiquitously in the environment and are more abundant than any living organism on Earth, including bacteria. Eleven sites are designated for weekly sample collection on the campus of Coastal Carolina University. Water samples are filtered and amplified using strains of E. coli B and E. coli K12 to allow potential coliphages in the sample to proliferate to detectable levels. Plaque assays are used as a microbial screen for the presence of bacteriophage. Samples that test positively using the microbial test are analyzed through a molecular test using PCR to identify …

3,6-Dimethoxyxanthone From 2,2’,4,4’- Tetrahydroxy-Benzophenone Via Microwave-Assisted Annulation, Sarah E. Knisely, Faith R. Rosario, Salem F. Gebeyehu, Paige E. Heiple, Robert E. Lee Sr

Journal of the South Carolina Academy of Science

Xanthones are tricyclic aromatic compounds that have multiple pharmacological uses due to their anti-tumor, antioxidant, anti-inflammatory, anti-bacterial, and potentially chemopreventive properties. The target of this research was to optimize a two-step synthesis of 3,6-dimethoxyxanthone (3) from 2,2’,4,4’-tetrahydroxy-benzophenone (1) via microwave-assisted (200 °C, 30-40 min., 150 W) sodium acetate-catalyzed annulation. The product, 3,6-dihydroxyxanthone (2), was then methylated to (3) using dimethyl sulfate (DMS) and sodium carbonate in acetone at reflux. The product yields were 93% (>99% purity) for (2) and 94% (>99% purity) for (3). Characterization was accomplished using ¹H NMR, FTIR, melting point, TLC, HPLC, and GCMS. …

The Effects Of Human Behavioral Changes Due To The Covid-19 Pandemic On The Reservoir Of Lytic Escherichia Coli And Staphylococcus Aureus Bacteriophage On Humans At A South Carolina University, Korinne M. Swanson, Owen R. Smith, Paul E. Richardson

Journal of the South Carolina Academy of Science

Bacteriophages are viruses, whose unique ability to infect and lyse bacterial cells may provide valuable insight for evading the repercussions of a post-antibiotic era in medicine. This study isolated and characterized Escherichia coli and Staphylococcus aureus bacteriophage on students and faculty at Coastal Carolina University as a means to understand the viability of human bacteriophage reservoirs for bacteriophage therapy. From September 2021 to March 2022, nasal and postauricular swab samples and a behavioral survey were collected from ninety-three randomly selected participants. Additionally, sixteen participants contributed nasal and postauricular swab samples and a behavioral survey on a monthly basis in a …

Reconstruction Of Exchange–Correlation Potentials From Their Matrix Representations, Yan Oueis, Viktor N. Staroverov

Chemistry Publications

Within a basis set of one-electron functions that form linearly independent products (LIPs), it is always possible to construct a unique local (multiplicative) real-space potential that is precisely equivalent to an arbitrary given operator. Although standard basis sets of quantum chemistry rarely form LIPs in a numerical sense, occupied and low-lying virtual canonical Kohn–Sham orbitals often do so, at least for small atoms and molecules. Using these principles, we construct atomic and molecular exchange–correlation potentials from their matrix representations in LIP basis sets of occupied canonical Kohn–Sham orbitals. The reconstructions are found to imitate the original potentials in a consistent …

Interfacial Oxidative Oligomerization Of Catechol, Marcelo I. Guzman, Elizabeth A. Pillar-Little, Alexis J. Eugene

Chemistry Faculty Publications

The heterogeneous reaction between thin films of catechol exposed to O₃(g) creates hydroxyl radicals (HO^•) in situ, which in turn generate semiquinone radical intermediates in the path to form heavier polyhydroxylated biphenyl, terphenyl, and triphenylene products. Herein, the alteration of catechol aromatic surfaces and their chemical composition are studied during the heterogeneous oxidation of catechol films by O₃(g) molar ratios ≥ 230 ppbv at variable relative humidity levels (0% ≤ RH ≤ 90%). Fourier transform infrared micro-spectroscopy, atomic force microscopy, electrospray ionization mass spectrometry, and reverse-phase liquid chromatography with UV−visible and mass spectrometry detection …

Direct Measurement Of Stokes–Einstein Diffusion Of Cowpea Mosaic Virus With 19 Μs-Resolved Xpcs, Kacper Switalski, Jingyu Fang, Luxi Li, Miaoqi Chu, Erik Sarnello, Pete Jemian, Tao Li, Qian Wang, Qingteng Zhang

Faculty Publications

Brownian motion of Cowpea mosaic virus (CPMV) in water was measured using small-angle X-ray photon correlation spectroscopy (SA-XPCS) at 19.2 mu s time resolution. It was found that the decorrelation time tau(Q) = 1/DQ(2) up to Q = 0.091 nm(-1). The hydrodynamic radius R-H determined from XPCS using Stokes-Einstein diffusion D = kT/(6 pi eta R-H) is 43% larger than the geometric radius R-0 determined from SAXS in the 0.007 M K3PO4 buffer solution, whereas it is 80% larger for CPMV in 0.5 M NaCl and 104% larger in 0.5 M (NH4)(2)SO4, a possible effect of aggregation as well as …

Contra-Thermodynamic Halolactonization Of Lactam-Tethered 5-Aryl-4(E)-Pentenoic Acids For The Flexible And Stereocontrolled Synthesis Of Fused Lactam-Halolactones, Timothy K. Beng, Claire Borg, Morgan J. Rodriguez

All Faculty Scholarship for the College of the Sciences

Halolactonization of alkenoic acids enables the construction of oxygen-heterocycles via intramolecular halonium-induced nucleophilic addition. Although the literature is currently inundated with halolactonizations of 5-aryl-4(E)-pentenoic acids that predictably afford the 6-endo cyclization adducts, methods that reliably alter the innate regioselectivity bias to instead deliver the thermodynamically less favored 5-exo cyclization products are relatively rare. Here, we attempt to bridge this gap and have found mild conditions for contra-thermodynamic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids that lead to the formation of trans-fused lactam-γ-lactones. The natural proclivity for these 5-aryl-4(E)-pentenoic acids to undergo 6-endo cyclization is overridden and 5-exo-trig cyclization predominates. The success of …

Solvation Of Large Polycyclic Aromatic Hydrocarbons In Helium: Cationic And Anionic Hexabenzocoronene, Miriam Kappe, Florent Calvo, Johannes Schöntag, Holger F. Bettinger, Serge Krasnokutski, Martin Kuhn, Elisabeth Gruber, Fabio Zappa, Paul Scheier, Olof E. Echt

Faculty Publications

The adsorption of helium on charged hexabenzocoronene (Hbc, C₄₂H₁₈), a planar polycyclic aromatic hydrocarbon (PAH) molecule of D_6h symmetry, is investigated by a combination of high-resolution mass spectrometry and classical and quantum computational methods. The ion abundance of He_nHbc⁺ complexes versus size n features prominent local anomalies at n = 14, 38, 68, 82, and a weak one at 26, indicating that for these “magic” sizes the helium evaporation energies are relatively large. Surprisingly, mass spectra of anionic He_nHbc^– complexes feature a different set of anomalies, namely at …

Visualization For Better Learning In Chem 120, Ngoc (Valerie) Tran, Jeffrey A. Hansen

Annual Student Research Poster Session

Many concepts in organic chemistry relate to spatial reasoning and the ability to translate two-dimensional representations into a three-dimensional mental image. It is critical that students gain a thorough understanding of visualizing atoms, orbitals and their interactions in three dimensions. By developing an E-book with computer graphics, 3D animations, H5P films, and online apps, we hope to enhance Depauw students' learning experiences in the CHEM 120 course. In this project, we would like to demonstrate 3D representations of chemical concepts to help students form these 3D mental images from a 2D surface. The process includes concept developing, storyboarding, 2D and …

Method Development For The Analysis Of Pharmaceuticals Using High Performance Liquid Chromatography, To Uyen (Anita) Nguyen, Richard Martoglio

Annual Student Research Poster Session

Since 2013, there have been 1500 reports of counterfeit drugs to WHO, especially from African, American, and European regions 1. Tackling the problem of poor drug quality, the Distributed Pharmaceutical Analysis Lab (DPAL) provides a quality analysis to quantify active pharmaceutical ingredient contents with a goal to trigger a report to the MRA or WHO2. With the support of DPAL, we would like to perform a series of chromatography experiments using the HPLC in order to identify and quantify the active pharmaceutical ingredients (API) of Amoxicillin and Ciprofloxacin.

Chemweb: A 2d Molecular Builder Game, Suleman Bashir Baloch, Jeffrey A. Hansen

Annual Student Research Poster Session

The research is based on the development of a 2D molecular builder game for CHEM 120 students. The game allows students to draw and check their structures for a given formula against a database of possible correct structures. The game consists of 8 levels, each based on drawing the maximum possible isomers from a given chemical formula. It is created as a web-based application on React.js. The project shall allow greater liberty and ease to students in drawing structures. In addition, they shall be able to perform self-check for drawn structures which will significantly minimize the assistance required from instructors …

Impact Of Urea On Size And Red-Edge Emission Spectroscopy Of Reverse Micelles, Tran Nguyen, Nancy E. Levinger, Bridget Gourley Ph.D

Annual Student Research Poster Session

We use reverse micelles (RMs) as our model system to study the impact of osmolytes on water at the nanoscale. Reverse micelles are characterized by w0 = [polar component]/[surfactant]. In our experiment, we focus on 5 different w0 (w0 = 1, 5, 10, 20, 40) and 3 concentrations of urea (0.5M, 1M, 2M). The Dynamic Light Scattering (DLS) illustrates a linear relationship between reverse w0 (the ratio) and size. Additionally, the DLS data indicates that the impact of osmolytes on size for small reverse micelles is not significant. Furthermore, Red-Edge Emission Spectroscopy shows a bigger impact on emission for smaller …

High Performance Liquid Chromatography (Hplc) For Ampicillin And Cefuroxime, Patrick Mcinerney, Richard Martoglio

Annual Student Research Poster Session

Appropriate levels of an active pharmaceutical ingredient (API) in medicines must be present in a medical product for the patient to receive therapeutic value. High performance liquid chromatography (HPLC) was used to develop a methodology to test for the API in Ampicillin and Cefuroxime drugs. Following the regulations of the Distributed Pharmaceutical Analysis Lab (DPAL) out of Notre Dame system sustainability requirements linearity, precision, accuracy/range, spike/degraded spike, limit of detection /quantitation, tailing factor, and number of theoretical plates were experimentally determined to meet the excepted standards.

Development Of A Method For Evaluating Absorption Spectra Irregularities: 3-Methylcyclopentanol And 4-Methylcyclohexanol

Journal of Interdisciplinary Undergraduate Research

Accurate rate constant values are critical for understanding chemical reaction pathways involving cyclopentenyl and cyclohexenyl cation intermediates. One approach for determining this essential kinetic information follows the time rate of change of such cations using UV-visible spectrophotometry. However, the obtained absorption spectra often show asymmetric irregularities such as shoulders due to interfering side reactions. The aim of this exploratory study was to develop a method of interpreting UV-visible spectra that provides accurate rate constant values in addition to clarifying the cause of signal abnormalities. In this investigation, changes in spectra of the cation intermediates were followed over the course of …