Chemistry Commons^™

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

Soft Lithographic Replication Of High Length-Scale Micropillars From Laser-Ablated Fused-Silica Templates, Jason Pitts

University Honors Theses

Soft lithography is a well-established route to wafer-scale reproduction of micro- and nanoscale features in a wide variety of materials. Nevertheless, micron length scales have yet to be explored, despite the potential utility of such structures. Here, polymer micropillars of 6-12 μm length, approximately 0.5-1.5 μm wide at 10 μm spacing are reproduced from a polydimethylsiloxane (PDMS) mold made from patterned cellulose acetate (CA). The patterned CA was cast from a rigid fused silica template machined by a pulsed femtosecond laser. Pore topographic features were successfully reproduced in Norland Optical Adhesive (NOA), polycaprolactone (PCL), Nafion, acrylonitrile butadiene styrene (ABS), and …

Donnan Potential Across The Outer Membrane Of Gram-Negative Bacteria And Its Effect On The Permeability Of Antibiotics, Olaniyi Alegun, Ankit Pandeya, Jian Cui, Isoiza Ojo, Yinan Wei

Chemistry Faculty Publications

The cell envelope structure of Gram-negative bacteria is unique, composed of two lipid bilayer membranes and an aqueous periplasmic space sandwiched in between. The outer membrane constitutes an extra barrier to limit the exchange of molecules between the cells and the exterior environment. Donnan potential is a membrane potential across the outer membrane, resulted from the selective permeability of the membrane, which plays a pivotal role in the permeability of many antibiotics. In this review, we discussed factors that affect the intensity of the Donnan potential, including the osmotic strength and pH of the external media, the osmoregulated periplasmic glucans …

Dataset For Characterization Of ‘Cool’ And ‘Warm’ White Leds, Edward Navarre

SIUE Faculty Research, Scholarship, and Creative Activity

The emission properties of “cool” and “warm” white LEDs were studied. The suitability of pulse-width modulation as a method to control LED brightness was examined. Both types of LED demonstrated emission standard deviation minima at a PWM frequency greater than 2000 Hz. The functional wavelength ranges of the LEDs were approximated using the linearity of brightness as a function of pulse-width modulation duty-cycle and the root mean squared deviation from mean for absorbance measurements. Both LED types demonstrated good stability in absorbance measurements over long operation times. The “warm” LED demonstrated a broader range of wavelengths useful for spectrophotometry. This …

Efficacy Of Ryr2 Inhibitor El20 In Induced Pluripotent Stem Cell-Derived Cardiomyocytes From A Patient With Catecholaminergic Polymorphic Ventricular Tachycardia., Tarah A. Word, Ann P. Quick, Christina Y. Miyake, Mayra K. Shak, Xiaolu Pan, Jean J. Kim, Hugh D. Allen, Martha Sibrian-Vazquez, Robert M. Strongin, Andrew P. Landstrom, Xander H T Wehrens

Chemistry Faculty Publications and Presentations

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited cardiac arrhythmia syndrome that often leads to sudden cardiac death. The most common form of CPVT is caused by autosomal-dominant variants in the cardiac ryanodine receptor type-2 (RYR2) gene. Mutations in RYR2 promote calcium (Ca ) leak from the sarcoplasmic reticulum (SR), triggering lethal arrhythmias. Recently, it was demonstrated that tetracaine derivative EL20 specifically inhibits mutant RyR2, normalizes Ca handling and suppresses arrhythmias in a CPVT mouse model. The objective of this study was to determine whether EL20 normalizes SR Ca handling and arrhythmic events in induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) …

Total Synthesis And Antimalarial Activity Of 2-(-Hydroxybenzyl)-Prodigiosins, Isoheptylprodigiosin, And Geometric Isomers Of Tambjamine Myp1 Isolated From Marine Bacteria., Papireddy Kancharla, Yuexin Li, Monish Yeluguri, Rozalia A. Dodean, Kevin A. Reynolds, Jane X. Kelly

Chemistry Faculty Publications and Presentations

Highly efficient and straightforward synthetic routes toward the first total synthesis of 2-(-hydroxybenzyl)-prodigiosins (-), isoheptylprodigiosin (), and geometric isomers of tambjamine MYP1 ((/)-) have been developed. The crucial steps involved in these synthetic routes are the construction of methoxy-bipyrrole-carboxaldehydes (MBCs) and a 20-membered macrocyclic core and a regioselective demethylation of MBC analogues. These new synthetic routes enabled us to generate several natural prodiginines - in larger quantity. All of the synthesized natural products exhibited potent asexual blood-stage antiplasmodial activity at low nanomolar concentrations against a panel of parasites, with a great therapeutic index. Notably, prodiginines and - provided curative in …

Β -Technetium: An Allotrope With A Nonstandard Volume-Pressure Relationship, Emily Siska, Dean Smith, Christian Childs, Daniel Koury, Paul M. Forster, Keith V. Lawler, Ashkan Salamat

Chemistry and Biochemistry Faculty Research

We report the synthesis and structure of the second allotrope of technetium, β-Tc. Transformative pathways are accessed at extreme conditions using the laser-heated diamond anvil cell and confirmed with in situ synchrotron x-ray diffraction and Raman spectroscopy. β-Tc is fully recoverable to ambient conditions, although counter to our DFT calculations predicting a face-centered-cubic lattice, we observe a tetragonal structure (I4/mmm) that exhibits further tetragonal distortion with pressure. β-Tc has an expanded volume relative to the hcp ground state phase, that when doped with nitrogen has an unexpected volume lowering. Such anomalous behavior is possibly indicative of a rare electronic phase …

Engineered Nanostructured Nitrogen-Doped Carbon Network (Ndc) Electrodes With Unprecedented Cycling Stability For Water Capacitive Deionization In Harsh Conditions, Soha Essam Anwar

Theses and Dissertations

Capacitive deionization (CDI) is a feasible low-cost desalination technique for low-to-medium (brackish) salinity water. However, cycling stability and regeneration of the CDI electrodes are the bottlenecks hindering the practical application of the technology on large scale. Oxidation of the electrodes during the sequential adsorption-desorption processes is one of the most challenging problems hindering their long-term cycling performance. Herein, we demonstrated the ability to design and fabricate exceptionally stable CDI electrodes via a one-pot pyrolysis protocol. The optimized pyrolysis of nitrogen-carbon precursors at different temperatures enabled the fabrication of carbon materials with a controlled amount nitrogen dopant (NDCs) with exceptional cycling …

Fullerene And Tungsten Oxide Nanostructures-Based Electrocatalysts For All-Vanadium Redox Flow Batteries, Farah Ahmed El Diwany

Theses and Dissertations

The vanadium redox flow battery (VRFB) is one of the most promising long-term energy storage solutions mainly due to its long service life and the independence of its energy capacity on power rating and vice versa. However, its relatively high capital cost limits its widespread deployment. Economic analysis reveals that a high-power density VRFB with decreased cell stack size can dramatically reduce the cost. The energy efficiency of a VRFB primarily depends on the kinetics of vanadium redox reactions that take place in the stack. Therefore, studying the effect of surface chemistry of electrodes on the kinetics of each …

Complexes With Atomic Gold Ions: Efficient Bisligand Formation, Felix Duensing, Elisabeth Gruber, Paul Martini, Marcelo Goulart, Michael Gatchell, Bilal Rasul, Olof E. Echt, Fabio Zappa, Masoomeh Mahmoodi-Darian, Paul Scheier

Faculty Publications

Complexes of atomic gold with a variety of ligands have been formed by passing helium nanodroplets (HNDs) through two pickup cells containing gold vapor and the vapor of another dopant, namely a rare gas, diatomic molecule (H₂, N₂, O₂, I₂, P₂), or various polyatomic molecules (H₂O, CO₂, SF₆, C₆H₆, adamantane, imidazole, di-cyclopentadiene, and fullerene). The doped HNDs were irradiated by electrons; ensuing cations were identified in a high-resolution mass spectrometer. Anions were detected for benzene, di-cyclopentadiene, and fullerene. For most …

Assessing Competitive Reaction Rates In The Nitration Of 2-Methylbiphenyl, Biphenyl, And Toluene To Determine Steric Restriction In Resonance-Stabilized Planarization Of The Carbocation Intermediates, Victor A. Hanson, Tristan Wine, Kevin Bartlett, Joshua Padilla, Alessandro Rizzi

Honors Projects

Electrophilic aromatic substitution (EAS) reactions have long been a fundamental addition to sophomore-level organic chemistry classes, allowing students the opportunity to explore the electron donating and withdrawing effects of electrons contained in the substituents of the aromatic reactant. In this paper we present preliminary findings on the nitration of methylated biphenyls using kinetic and regioselective assessments to analyze steric influences on the planarization of 2-methylbiphenyl after EAS nitration. Our preliminary findings show that nitration favors the methylated phenyl ring of 2-methylbiphenyl, indicating that the steric influence of the methyl group restricts planarization of the carbocation intermediate. Furthermore, a competition nitration …

Tellurorhodamine Photocatalysts In Aerobic Oxidation Reactions: Development Of Synthetic Methods And Reaction Mechanisms, Irving D. Rettig

Dissertations and Theses

Aerobic oxidation photocatalysis involves the use of oxygen as an oxidant species, coupled to a light driven catalyst to achieve useful chemical transformations. Catalytic aerobic oxidation reactions can be defined as either oxidase-like, in which O₂ acts as an electron donor/acceptor but is not incorporated into the reaction products, or oxygenase-like where O₂ acts as an electron donor/acceptor and is incorporated into the reaction products. A multitude of inorganic catalysts have been developed that can achieve a wide scope of oxidase-like or oxygenase-like reactivity, however, it is rare for a catalyst to be capable of both. We report …

Analytical Survey Of Tattoo Inks—A Chemical And Legal Perspective With Focus On Sensitizing Substances, Xuying Wang, Leila Josefsson, Silvia Meschnark, Marie-Louise Lind, Åsa Emmer, Walter Goessler, Yolanda S. Hedberg

Chemistry Publications

Background

Tattoo inks have been reported to elicit allergic contact dermatitis.

Objectives

To investigate the labels and the contents of metals and pigments in tattoo inks, considering restrictions within the European Union.

Methods

Seventy-three tattoo inks currently available on the market, either bought or donated (already used), were investigated for trace metals and pigments by inductively coupled plasma mass spectrometry and by matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry.

Results

Ninety-three percent of the bought tattoo inks violated European, legal requirements on labeling. Fifty percent of the tattoo inks declared at least one pigment ingredient incorrectly. Sixty-one percent …

Assessment Of The Chemical Mechanism Of Staphylococcus Aureus 5’-Methylthioadenosine/S-Adenosylhomocysteine Nucleosidase, A Novel Target For Drug Design, Kumari Vaijayanti Karn

Theses and Dissertations

Staphylococcus aureus 5’-methylthioadenosine/S-adenosylhomocysteine nucleosidase (SaMTAN), a multiple substrate-specific enzyme that catalyzes the irreversible hydrolytic reaction by cleaving the glycosidic bond in different adenosine based metabolites and plays a key role in biofilm production regulated by bacterial quorum sensing (Mishra & Ronning, 2012). The reaction mechanism of SaMTAN has been suggested to be acid-base catalyzed hydrolysis. The active site of SaMTAN has five amino acid residues that are candidates for the general acid residues or the general base residues. It has been suggested that Glutamic acid 11, 171 and 173 (E11,E171 and E173) may play as the general base while Aspartic …

Colossal Density-Driven Resistance Response In The Negative Charge Transfer Insulator Mns2, Dylan Durkee, Nathan Dasenbrock-Gammon, G. Alexander Smith, Elliot Snider, Dean Smith, Christian Childs, Simon A.J. Kimber, Keith V. Lawler, Ranga P. Dias, Ashkan Salamat

Chemistry and Biochemistry Faculty Research

A reversible density driven insulator to metal to insulator transition in high-spin MnS2 is experimentally observed, leading with a colossal electrical resistance drop of 108 ω by 12 GPa. Density functional theory simulations reveal the metallization to be unexpectedly driven by previously unoccupied S22- σ3p∗ antibonding states crossing the Fermi level. This is a unique variant of the charge transfer insulator to metal transition for negative charge transfer insulators having anions with an unsaturated valence. By 36 GPa the emergence of the low-spin insulating arsenopyrite (P21/c) is confirmed, and the bulk metallicity is broken with the system returning to an …

Evaluation Of A Photosensitizer Redox Couple For Oxide Removal Rate Tunability In Shallow Trench Isolation Chemical Mechanical Planarization, Abigail N. Linhart, Katherine M. Wortman-Otto, Jason J. Keleher

Chemistry Department Faculty Articles

As technology continues to expand beyond that predicted by Moore's Law the need to alter chemical mechanical planarization (CMP) processes to meet consumer demands is critical. To achieve higher oxide material removal rates (MRR), slurry formulations have become more complex by implementing rate enhancing additives to increase the slurry's chemical activity. However, the modulation of MRR in situ requires changes in mechanical parameters, such as downforce, platen speed, and flow rate. These parameters effectively increase the chemical activity of the slurry; however, they can result in greater defectivity due to increased shear force. Therefore, this work employs the use of …

Investigations Into Size And Surface Control Of Silicon Nanocrystals For Improved Optical Properties, James Donald Barnes

Dissertations and Theses

The discovery of visible photoluminescence (PL) from nanocrystalline porous silicon in 1990 led to extensive research into the mechanisms of the emergent properties, and optimization of these properties, for use in applications. The widespread use of silicon nanoparticles (Si NPs) in commercial applications is currently limited by three main factors: 1) poor radiative recombination efficiency of the interband transition, 2) instability of the interband photoluminescence, and 3) a lack of scalable methods for producing Si NPs that are both highly crystalline and size monodisperse.

To address these limitations, this dissertation correlates changes in the photoluminescence properties of hydrogen passivated silicon …

Linear Discriminant Analysis Based On Gas Chromatographic Measurements For Geographical Prediction Of Usa Medical Domestic Cannabis, Ramia Z. Al Bakain, Yahya S. Al-Degs, James V. Cizdziel, Mahmoud A. Elsohly

Faculty and Student Publications

Fifty four domestically produced cannabis samples obtained from different USA states were quantitatively assayed by GC-FID to detect 22 active components: 15 terpenoids and 7 cannabinoids. The profiles of the selected compounds were used as inputs for samples grouping to their geographical origins and for building a geographical prediction model using Linear Discriminant Analysis. The proposed sample extraction and chromatographic separation was satisfactory to select 22 active ingredients with a wide analytical range between 5.0 and 1,000 μg/mL. Analysis of GC-profiles by Principle Component Analysis retained three significant variables for grouping job (Δ9-THC, CBN, and CBC) and the modest discrimination …

Quantum Transport Of The 2d Surface State In A Nonsymmorphic Semimetal, Xue Liu, Jin Hu, Jiang Wei, Chunlei Yue, Sergey V. Erohin, Yanglin Zhu, Abin Joshy, Jinyu Liu, Ana M. Sanchez, David Graf, Pavel B. Sorokin, Zinqiang Mao

Physics Faculty Publications and Presentations

In a topological semimetal with Dirac or Weyl points, the bulk-boundary correspondence principle predicts a gapless edge mode if the essential symmetry is still preserved at the surface. The detection of such topological surface state has been considered as the fingerprint prove for crystals with nontrivial topological bulk band. On the contrary, it has been proposed that even with symmetry broken at the surface, a new surface band can emerge in nonsymmorphic topological semimetals. The symmetry reduction at the surface lifts the bulk band degeneracies and produces an unusual “floating” surface band with trivial topology. Here, we first report quantum …

The Effect Of Reaction Conditions On The Nucleation And Particle Growth Of A Colloidal Covalent Organic Framework, Brendan Posson

Master's Theses

Covalent organic frameworks (COFs) are a novel class of crystalline materials with regular porosity, high specific surface area, and various linkage chemistries. Conventional chemical syntheses of these materials lead to the formation of bulk powders characterized as polycrystalline aggregates. Synthesizing these materials as colloidal systems is an effective means to prevent aggregation and achieve larger single-crystalline domain sizes. In this thesis, I describe the effect of temperature and transimination catalyst strength on COF particle nucleation and particle growth. Morphology and crystallinity of the COF-300 particles were confirmed using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The onset of colloidal …

Repurposing Drugs To Treat Heart And Brain Illness, Maranda S. Cantrell, Alejandro Soto-Avellaneda, Jackson D. Wall, Aaron D. Ajeti, Brad E. Morrison, Lisa R. Warner, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Drug development is a complicated, slow and expensive process with high failure rates. One strategy to mitigate these factors is to recycle existing drugs with viable safety profiles and have gained Food and Drug Administration approval following extensive clinical trials. Cardiovascular and neurodegenerative diseases are difficult to treat, and there exist few effective therapeutics, necessitating the development of new, more efficacious drugs. Recent scientific studies have led to a mechanistic understanding of heart and brain disease progression, which has led researchers to assess myriad drugs for their potential as pharmacological treatments for these ailments. The focus of this review is …

Tailored Porous Carbons Enabled By Persistent Micelles With Glassy Cores, Eric R. Williams, Paige L. Mcmahon, Joseph E. Reynolds Iii, Jonathan L. Snider, Vitalie Stavila, Mark Allendorf, Morgan Stefik

Faculty Publications

Porous nanoscale carbonaceous materials are widely employed for catalysis, separations, and electrochemical devices where device performance often relies upon specific and well-defined regular feature sizes. The use of block polymers as templates has enabled affordable and scalable production of diverse porous carbons. However, popular carbon preparations use equilibrating micelles which can change dimensions in response to the processing environment. Thus, polymer methods have not yet demonstrated carbon nanomaterials with constant average template diameter and tailored wall thickness. In contrast, persistent micelle templates (PMTs) use kinetic control to preserve constant micelle template diameters, and thus PMT has enabled constant pore diameter …

The Impact Packaging Type Has On The Flavor Of Wine, Katherine A. Thompson-Witrick, Eric R. Pitts, John L. Nemenyi, Drew Budner

Chemistry

This is a literature review of the most commonly available wine packaging categories. This includes glass bottles, polyethylene terephthalate bottles (PET), bag-in-box (BIB), aluminum cans, and Tetra Pak. This review includes a description and history of each category. In addition, the market share and environmental impacts of each category are discussed. Special attention is paid to the reported impact on packaged wine flavor and aroma for each packaging type. Finally, the potential impacts on consumer preference are discussed. While glass is still the dominant packaging material within the wine industry and by consumer demand, economic and environmental concerns are driving …

College Of Natural Sciences Newsletter, June 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 6.

Page 1 Dean's Message
Page 2-6 Remembering the Life of Dr. Pengra and Celebrating His legacy for Entire Generations to Come.

Formulating 3-Chloropropyltriethoxysilane Modified Silica Nanoparticle Sprays As Hydrophobic Transparent Coatings Onto Cotton Textiles, Mikaela C. S. Mendoza, Gilbert U. Yu

Chemistry Faculty Publications

Cotton textiles were transformed into hydrophobic fabrics via the application of 3-chloropropylthriethoxysilane-functionalized silica nanoparticle spray coatings. Silica particles were measured to be < 50 nm, as determined by dynamic light scattering (DLS). The incorporation of hexadecyltrimethylammonium bromide (HTAB), a surfactant, into the nanosilica alcohol-based sprays resulted in a suspension that was stable for at least a week. Stability and turbidity tests of samples point to smaller particle size (silica nanoparticles = 24.3 ± 8.5 nm) as the main contributor to possibly providing transparency, as evidenced when sprayed in colored (black) textiles, while still contributing to hydrophobicity/ superhydrophobicity of the cloth.

Design, Synthesis And Evaluation Of Molecules With Selective And Poly-Pharmacological Actions At D1r, D3r And Sigma Receptors, Pierpaolo Cordone

Dissertations, Theses, and Capstone Projects

The dopamine D3 receptor (D3R) is one of the most studied receptors involved in drug addiction. One of the most common strategies to treat substance use disorders is via D3R antagonism. The majority of the D3R antagonists synthesized so far have poor pharmacokinetic properties and/or lack selectivity toward D3R. In this thesis, the design, synthesis and biological evaluation of novel molecules that target the dopamine D1 receptor (D1R), D3R and the serendipitous discovery of molecules that target s receptors will be described.

Chapter 1 presents a survey of the fundamental pharmacology of D1R, D3R and s receptors and the therapeutic …

Mechanistic And Synthetic Studies Of Oxidopyrylium Cycloaddition Reactions, Lauren P. Bejcek

Dissertations, Theses, and Capstone Projects

Cycloaddition chemistry has historically served as a robust route to stereo-rich and highly functionalized cyclic and heterocyclic compounds. Herein we describe our examination of 3-hydroxy-4-pyrone-derived oxidopyrylium cycloadditions in both mechanistic considerations as well as the unique synthetic advancements of their corresponding cycloadducts. Chapter 1 is a literature review where we specifically outline the use of oxidopyrylium cycloadditions in the synthesis of natural products. This includes the mention of previous syntheses prior to 2008, and a more thorough examination of the natural products synthesized from 2008 to present. The work exploits this chemistry as a facile route to highly complex 7-membered …

Synthetic And Biological Studies On Benzazepine Derivatives As Dopamine Receptor Ligands, Rajan Giri

Dissertations, Theses, and Capstone Projects

Dopamine (DA) receptors, members of the G-protein coupled receptors (GPCRs) family, are divided in two groups based on their transmembrane structural homology domains: D1R-like (D1R, D5R sub-types) and D2R-like DA receptors (D2R, D3R and D4R sub-types). Disturbances in dopaminergic neurotransmission are associated with several CNS disorders. Hence, DA receptor selective ligands have been sought as pharmacological agents to normalize perturbations in the dopaminergic system. Despite several notable efforts, the discovery of highly selective ligands for dopamine receptor sub-types has proved challenging due to close transmembrane structural similarity, especially between DA receptor sub-types within the same group.

The 1-phenylbenzazepine scaffold is …

Emergent Photophysics In Diketopyrrolopyrrole Superstructures, Andrew Levine

Dissertations, Theses, and Capstone Projects

Organic semiconductors have received substantial attention as active components in optoelectronic devices because of their processability and customizable electronic properties. Tailoring the organic active layer in these devices to exhibit desirable optoelectronic properties requires understanding the complex and often subtle structure-property relationships governing their photophysical response to light. Both structural organization and frontier molecular orbitals (FMO) play pivotal roles in energy relaxation processes, and complex interplay between organization and orbital energies are difficult to anticipate based upon the molecular structure of the components alone, especially in systems comprised of multiple components. In pursuit of design rules, there is a need …

Iron And Iodine-Mediated Reactions, Xiaochen Liu

Dissertations, Theses, and Capstone Projects

This thesis work focuses on developing facile, low-cost, and environmentally friendly reactions, specifically the iron and iodine-mediated reactions, including (1) iron-catalyzed reductive ring-opening of 3,5-disubstituted isoxazoles and isoxazolines in aged N-methyl-2-pyrrolidone (NMP*), (2) iodine-mediated C-N bond cross-coupling reactions between amides and aldehydes, and (3) ICl-mediated functionalization of β-alkoxy alkynes – synthesis of α-iodo-γ-chloro-ketones.

Chapter I provides a background introduction on previous synthesis and applications of β-enaminones and 1,3-diketones that play as synthons or ligands. Ring-openings of heterocycles, such as isoxazoles and isoxazolines have attracted great attentions. A newly developed iron-catalyzed reductive system was established upon our previous palladium-catalyzed research. …