Chemistry Commons^™

Squaramide Structure And Interactions With Benzene, Serina Tressler

Undergraduate Research and Scholarship Symposium

The chemical industry’s continued reliance on expensive and toxic metal catalysts has driven the search for greener and more sustainable alternatives. One such option is hydrogen bonding organocatalysts, a group of inexpensive compounds made from renewable feedstocks. However, the interactions of these compounds with aryl groups is not currently understood, limiting their overall effectiveness. Dual hydrogen bond donors such as squaramide and thiourea have been a focus of study for some time, but the structure and interactions of unsubstituted squaramide have not been thoroughly reported and present an unknown in catalyst design. This study seeks to understand the structure of …

Development Of A Rapid Drug Detection Method For Insects Using Paper Spray Ionization Mass Spectrometry (Psi-Ms), Alexandria Plyler

Undergraduate Research and Scholarship Symposium

Insects have the ability to reflect the chemical environment that they have developed in. Thus, necrogenous insects can reflect the chemical environment of cadavers they have fed on. Forensic scientists can potentially utilize insect larvae as an alternate biological matrix to detect drugs in cadavers that are skeletonized, burned, or otherwise badly damaged. Analysis of insects using paper spray ionization mass spectrometry (PSI-MS), an analytical method requiring little to no sample preparation, could prove a rapid, cost-effective, and non-destructive alternative form of toxicological analysis. Traditional tissue analysis via GC and LC-MS often require lengthy sample preparation, use expensive reagents, and …

The Supercam Instrument Suite On The Mars 2020 Rover: Science Objectives And Mast-Unit Description, S. Maurice, R. C. Wiens, P. Bernardi, P. Caïs, S. Robinson, T. Nelson, O. Gasnault, J. -M. Reess, M. Deleuze, F. Rull, J. -A. Manrique, S. Abbaki, R. B. Anderson, Y. André, Stanley M. Angel, G. Arana, T. Battault, P. Beck, K. Benzerara, S. Bernard, Et. Al.

Faculty Publications

On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2–7 m, while providing data at sub-mm to mm scales. We report …

Gcn5-Related N-Acetyltransferases (Gnats) With A Catalytic Serine Residue Can Play Ping-Pong Too, Jackson T. Baumgartner, Thahani S. Habeeb Mohammad, Mateusz P. Czub, Karolina A. Majorek, Xhulio Arolli, Cillian Variot, Madison Anonick, Wladek Minor, Miguel A. Ballicora, Daniel P. Becker Ph.D., Misty L. Kuhn

Chemistry: Faculty Publications and Other Works

Enzymes in the Gcn5-related N-acetyltransferase (GNAT) superfamily are widespread and critically involved in multiple cellular processes ranging from antibiotic resistance to histone modification. While acetyl transfer is the most widely catalyzed reaction, recent studies have revealed that these enzymes are also capable of performing succinylation, condensation, decarboxylation, and methylcarbamoylation reactions. The canonical chemical mechanism attributed to GNATs is a general acid/base mechanism; however, mounting evidence has cast doubt on the applicability of this mechanism to all GNATs. This study shows that the Pseudomonas aeruginosa PA3944 enzyme uses a nucleophilic serine residue and a hybrid ping-pong mechanism for catalysis instead …

Kathmandu Nepal - 1993

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Thessaloniki Greece - 1992

World Data - Europe

Relevant Publications

Environmental Science & Technology Publication (1995)

3rd International Symposium: Transport and Air Pollution (1994)

Synthesis And Characterization Of Regioregular Cross-Conjugated Poly(Thienylene Vinylene)S, Yousef M. Katba Bader

Chemistry and Chemical Biology ETDs

Poly(thienylene vinylene)s (PTVs) is special a class of conjugated polymers (CPs) that show remarkable optoelectronic properties and promising applications. The main reason that hinders their application, is the lack of synthetic methodologies for preparing new derivatives with various functionality. Developing new PTVs with improved structures based on structure-property relationships increases the potential of utilizing this type of polymers in advanced applications. Most available preparation methods lead to regio-random PTVs (ra-PTVs) structures due to the different placement of the sidechain in the polymer backbone, which results in reduced crystallinity. In this study, we developed a novel strategy that produces a series …

Theoretical Investigation Of In2h2 And Tl2h2 And Their Relationship To Other Group 13 Metal Dihydrides, Caroline Sargent

Student Scholarship

Four constitutional isomers{ dibridged, monobridged, vinylidene-like, and trans{ of group 13 metal dihydrides have been reviewed and studied by theoretical methods. Equilibirum structures, relative enthalpies, and vibrational spectroscopic information is presented for isomers of Al2H2, Ga2H2, In2H2, and Tl2H2. Properties of the isomers of Al2H2 and Ga2H2 were obtained from previous studies.1{3 Properties of In2H2 and Tl2H2 were calculated using rigorous ab initio theory, and the results are presented. …

Broken-Hearted” Carbon Bowl Via Electron Shuttle Reaction: Energetics And Electron Coupling, Gabrielle A. Leith, Allison M. Rice, Brandon J. Yarbrough, Preecha Kittikhunnatham, Abijai Mathur, Nicholas A. Morris, Megan J. Francis, Anna A. Berseneva, Poonam Dhull, Richard D. Adams, M. Victoria Bobo, Aaron A. Vannucci, Mark D. Smith, Sophya Garashchuk, Natalia B. Shustova

Faculty Publications

Unprecedented one-step CC bond cleavage leading to opening of the buckybowl (π-bowl), that could provide access to carbon-rich structures with previously inaccessible topologies, is reported; highlighting the possibility to implement drastically different synthetic routes to π-bowls in contrast to conventional ones applied for polycyclic aromatic hydrocarbons. Through theoretical modeling, we evaluated the mechanistic pathways feasible for π-bowl planarization and factors that could affect such a transformation including strain and released energies. Through employment of Marcus theory, optical spectroscopy, and crystallographic analysis, we estimated the possibility of charge transfer and electron coupling between “open” corannulene and a strong electron acceptor such …

Anion–Anion Interactions In Aerogen-Bonded Complexes. Influence Of Solvent Environment, Anna Grabarz, Mariusz Michalczyk, Wiktor Zierkiewicz, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Ab initio calculations are applied to the question as to whether a AeX₅− anion (Ae = Kr, Xe) can engage in a stable complex with another anion: F−, Cl−, or CN−. The latter approaches the central Ae atom from above the molecular plane, along its C₅ axis. While the electrostatic repulsion between the two anions prevents their association in the gas phase, immersion of the system in a polar medium allows dimerization to proceed. The aerogen bond is a weak one, with binding energies less than 2 kcal/mol, even in highly polar aqueous solvent. The complexes are …

Exploring The Effects Of Various Growth Conditions On Gene Expression Of Mechanosensitive Ion Channels In Escherichia Coli, Sarah C. Johnson, Hannah R. Malcolm

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

In rapidly changing environmental conditions, bacterial mechanosensitive ion channels are responsible for ensuring cell survival. Bacterial mechanosensitive channels gate in response to membrane tension in order to relieve intracellular pressure, prior to cell lysis. The most well-studied bacterial mechanosensitive channels include the mechanosensitive channel of large (MscL) and small (MscS) conductance from Escherichia coli (E. coli), both of which gate in response to tension. In E. coli, there are seven mechanosensitive ion channel genes: MscL, MscS, and five additional genes that are members of the MscS superfamily. Of these seven genes, six have been shown to gate directly in response …

Synthesis And Validation Of Substrates For Prmt1 Using Plate-Based Screening Assay, Tina Sawatzky, Sarah Mann, Bryan Knuckley

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

PRMT (Protein Arginine Methyltransferase) is a mammalian enzyme that catalyzes methylation of arginine residues in a polypeptide chain. PRMT is categorized as 3 different types. The methylation can occur as asymmetric dimethylation (ADMA, PRMT 1, 2, 3, 4, 6, and 8), symmetric dimethylation (SDMA, PRMT 7, 5 and 9) or monomethylation (MMA, PRMT 7), Type I, II and III respectively. PRMT1 generates ADMA on arginine residues of the Histone H4 N-terminal tail, which can lead to transcription of cancer-related genes. Alternatively, PRMT5 can modify the same arginine residue to produce SDMA, which represses the development of those same cancer-related genes. …

Determination Of The Traits In Leguminous Crops Under Saline Condition, Tojiddin Kuliev, Karomat Ismailova

Karakalpak Scientific Journal

In this study, the variability and determination of genetic traits for winter legume crop varieties the Vostok-55 (Pisum arvense L) and Mirzachul-1 (Vicia villoza Roth L) were investigated under moderate saline soil condition. Results show that the weight of the bean was marked as variable and highly deterministic, and the height of the plants was the most stable. The selection of plants based on these traits is the most effective way of salinity. Both variety the forage pea Vostok-55 and vetch Mirzachul-1 is highly recommended as a sideration and forage crop in saline lands.

Synthesis Of The Microbial Polysaccharide Gellan From Dairy And Plant-Based Processing Coproducts, Thomas P. West

Faculty Publications

The purpose of this review is to provide both background about the microbial polysaccharide gellan and, more specifically, to examine bacterial gellan synthesis on dairy and plant-based processing coproducts. The anionic heteropolysaccharide gellan is known to be synthesized by Sphingomonas elodea strain ATCC 31461 [1,2]. Although originally classified as Pseudomonas elodea, this strain was reclassified as a species of Sphingomonas [3,4]. Structurally, the water-soluble gum gellan exists as a tetrasaccharide composed of 20% glucuronic acid, 60% glucose and 20% rhamnose [5–7]. The native form of gellan has been shown to contain acetyl and L-glyceryl groups. These substituents need to be …

Ratiometric Near-Infrared Fluorescent Probes Based On Hemicyanine Dyes Bearing Dithioacetal And Formal Residues For Ph Detection In Mitochondria, Yunnan Yan, Yibin Zhang, Shuai Xia, Shulin Wan, Tara Vohs, Marina Tanasova, Rudy Luck, Haiying Lui

Michigan Tech Publications, Part 1

Ratiometric near-infrared fluorescent probes (AH+ and BH+) have been prepared for pH determination in mitochondria by attaching dithioacetal and formal residues onto a hemicyanine dye. The reactive formyl group on probe BH+ allows for retention inside mitochondria as it can react with a protein primary amine residue to form an imine under slightly basic pH 8.0. Probes AH+ and BH+ display ratiometric fluorescent responses to pH changes through the protonation and deprotonaton of a hydroxy group in hemicyanine dyes with experimentally determined pKa values of 6.85 and 6.49, respectively. Calculated pKa values from a variety of theoretical methods indicated that …

Protonation Of Methyl Phenyl Porphyrin Isomers Using Uv Spectroscopy, Mamiko Swanson, Isabel De Angelis, Harsh Chheda, Rushi Patel, Raahil Shah, Shreya Patel, Maria Ballester Ph.D.

Chemistry and Physics Faculty Proceedings, Presentations, Speeches, Lectures

The protonation of methyl phenyl porphyrin isomers was studied through UV vis spectroscopy using trifluoroacetic acid (TFA), a strong organic acid. Protonation was achieved by titration of the porphyrin in toluene and toluene/methanol (90:10). A wavelength shift from the free base Soret to the protonated Soret confirms the formation of the dication. The resulting UV spectra was used to calculate an apparent pKa value of each free base porphyrin isomer. Addition of methanol to the porphyrin solution decreased the average pKa values of the Soret and Q-bands for each porphyrin. This could be an indication of a stabilizing monocation, not …

Comparisons Of Silver Nanoparticle Synthesis Methods By Microwave And Non-Microwave Using Hydrogen Gas As A Reducing Agent, Sofia Erech Hanapin

Honors Theses

Synthesis and characterization of silver nanoparticles are of current interest. This research project describes a simple and rapid synthesis of silver nanoparticles upon reduction of Silver (I) oxide (Ag2O) by molecular hydrogen (H2) at elevated temperature (70 – 100 °C) and a pressure of > 1 atmosphere by heating the aqueous mixture using a common kitchen microwave. This reaction generates naked silver colloids that contain no foreign stabilizers other than metal particles in aqueous media. Its application of an antibacterial effect was monitored by using biological cultures using the Kirby-Bauer Test.

Thermodynamic Analysis Of Pamam Dendrimer Synthesis, Ryutaro Einar Jacobson

Honors Theses

The objective of this research was to determine kinetic and thermodynamic data about the reaction between ethylene diamine and methyl acrylate which is used in the production of PAMAM dendrimers. Establishing a rate law and finding values such as rate constant, activation energy, and Arrhenius coefficient will help in determining the best possible conditions for the reaction. A rate law was established through the method of initial rates, comparing the rates of reactions with different initial concentrations to one another. Additional reactions were run with active cooling to observe the effects on rate and reaction progress, and finally reactions were …

Finding Optimal Opa-Iblc Derivatized Amino Acid Analysis Parameters With Three-Dimensional Fluorometric Scans For Hplc Method Validation, Aaron Jacobs

Honors Theses

Three-dimensional fluorometric scans of OPA-IBLC derivatized glutamic acid and histidine solutions revealed that decreasing concentration maintained maximum λem but produced different maximum λex. In pH 0.4 M sodium borate buffer (pH 10.4), 50 μM derivatized amino acid solutions had maxima around 350- to 450-nm λex-λem where 12.5 μM solutions had maxima around 230- to 450-nm λex- λem. In the lower concentration, the λex peak at 230 nm was about 80% higher than 350 nm. Thus, collecting spectra with 230 nm λex would provide better LOD and LOQ. Results inform HPLC standard concentrations since differential quenching effects may produce non-linear calibration …

Tulsa - Wb Us64 To Sb Us169

United States Data - Oklahoma

Relevant Publications

Environmental Science & Technology Publication (2006)

Environmental Science & Technology Publication (2008)

Environmental Science & Technology Publication (2014)

Environmental Science & Technology Publication (2015)

Environmental Science & Technology Publication (2021)

2003 Final Report

2013 Final Report

2015 Final Report

2017 Final Report

2019 Final Report

Fort Mchenry Tunnel - 1991

United States Data - Maryland

Relevant Publications

Air & Waste Management Association Publication (1994)

Atmospheric Environment Publication (1996)

Detection Of Gold Cysteine Thiolate Complexes On Gold Nanoparticles With Time-Of-Flight Secondary Ion Mass Spectrometry, Yolanda Hedberg, Jonas Hedberg, Valentin Romanovski, Elena Romanovskaia, Heng-Yong Nie

Chemistry Publications

Gold (Au) nanoparticles (NPs) are widely used in nanomedical applications as a carrier for molecules designed for different functionalities. Previous findings suggested that biological molecules, including amino acids, could contribute to the dissolution of Au NPs in physiological environments and that this phenomenon was size-dependent. We, therefore, investigated the interactions of L-cysteine with 5-nm Au NPs by means of time-of-flight secondary ion mass spectrometry (ToF-SIMS). This was achieved by loading Au NPs on a clean aluminum (Al) foil and immersing it in an aqueous solution containing L-cysteine. Upon rinsing off the excessive cysteine molecules, ToF-SIMS confirmed the formation of gold …

Polymer Particles For The Intra-Articular Delivery Of Drugs To Treat Osteoarthritis, Xueli Mei, Ian J. Villamagna, Tony Nguyen, Frank Beier, C. Thomas Appleton, Elizabeth R. Gillies

Chemistry Publications

Osteoarthritis (OA) is a leading cause of chronic disability. It is a progressive disease, involving pathological changes to the entire joint, resulting in joint pain, stiffness, swelling, and loss of mobility. There is currently no disease-modifying pharmaceutical treatment for OA, and the treatments that do exist suffer from significant side effects. An increasing understanding of the molecular pathways involved in OA is leading to many potential drug targets. However, both current and new therapies can benefit from a targeted approach that delivers drugs selectively to joints at therapeutic concentrations, while limiting systemic exposure to the drugs. Delivery systems including hydrogels, …

Chapter 2.1: Visualization Of Metal Ion Buffering Via 3-D Topo Surfaces Of Complexometric Titrations, Garon C. Smith, Md Mainul Hossain

Water Topos: A 3-D Trend Surface Approach to Viewing and Teaching Aqueous Equilibrium Chemistry

This chapter examines 1:1 metal-ligand complexometric titrations in aqueous media. It presents surfaces that plot computed equilibrium parameters above a composition grid with titration progress (mL of ligand) as the x-axis and overall system dilution (log C ) as the y-axis. The sample systems in this chapter are restricted to EDTA as a ligand. Other chelating ligands that form exclusively 1:1 complexes could also be modeled with this software. The surfaces show the quality of the equivalence point break under various conditions. More importantly, they develop the phenomenon of metal ion buffering. They clearly distinguish the difference between …

Influence Of Monovalent And Divalent Ions In The Conformational Change Of Caspase-Cleaved Par-4 (Cl-Par-4) Tumor Suppressor Protein, Krishna K. Raut, Komala Ponniah, Steven M. Pascal

College of Sciences Posters

Prostate apoptosis response-4 (Par-4) is a pro-apoptotic tumor suppressor protein. We have shown that this 38 kDa full-length Par-4 (Fl-Par-4) protein is predominantly intrinsically disordered in vitro. In vivo, Par-4 is cleaved by caspase-3 at Asp-131 to generate a 24 kDa functionally active cleaved Par-4 (cl-Par-4) fragment. The cl-Par-4 protein inhibits the NF-κB-mediated cell survival pathway and causes selective apoptosis in various tumor cells. Our laboratory is interested in how the disorder-order balance within Fl-Par-4 and cl-Par-4 may be related to the balance between cell survival and cell death. Currently, we are using biophysical techniques such as circular …

Anodic Dissolution Of Copper In The Acidic And Basic Aluminum Chloride 1-Ethyl-3-Methylimidazolium Chloride Ionic Liquid, Lorlyn Reidy, Chen Wang, Charles L. Hussey

Faculty and Student Publications

The anodic dissolution of copper was investigated at a copper RDE in the Lewis acidic and basic composition regions of the room-temperature AlCl3-EtMeImCl ionic liquid (IL) to assess the utility of chloroaluminate liquids as solvents for the electrochemical machining and electropolishing of copper. In the Lewis acidic IL (60 mol % AlCl3), the dissolution of Cu0 proceeds under mixed kinetic-mass transport control with an exchange current density of 7.00 mA cm-2 at 306 K and an apparent activation free energy of 19.7 kJ mol-1. A formal potential of 0.843 V was obtained for the Cu+/Cu0 reaction from potentiometric measurements. In …

Visible Light Generation And Mechanistic Investigation Of High-Valent Metal-Oxo Species Supported By Different Ligands, Seth Ellis Klaine

Masters Theses & Specialist Projects

Numerous transition metal catalysts have been designed as biomimetic model compounds for the active site of metalloenzymes found throughout Nature, most notably cytochrome P450 monooxygenases that carry out the oxidative transformations of organic substrates with near-perfect chemo-, regio-, and stereo-selectivity. The primary active oxidants in catalytic and enzymatic cycles are fleeting high-valent metal-oxo intermediates where the oxo ligand can transfer to an organic substrate in a process known as oxygen atom transfer (OAT).

In the present work, porphyrin-manganese(III), salen-chromium(III), and salenmanganese( III) derivatives were successfully synthesized and spectroscopically characterized using 1H NMR and UV-Vis spectroscopies. A facile photochemical approach was …

Synthesis And Catalytic Oxidation Of Organic Substrates By Light-Harvesting Metalloporphyrins, Christian Alcantar

Masters Theses & Specialist Projects

note: Some notation in this abstract may not appear exactly as formatted in the thesis.

In this work, ruthenium, iron, and manganese light-harvesting metalloporphyrins have been successfully synthesized to serve as biomimetic models of the active site of Cytochrome P450 for the development of a green and efficient oxidation catalyst. The covalent introduction of light-harvesting boron-dipyrrin (BODIPY) fluorophores on the porphyrin macrocycle allows for the absorption of a broader range of visible light in addition to that captured by the porphyrin aromatic system alone. It is expected that this core-antenna system will increase the absorbed light energy and transfer it …

Ph-Sensitive Chitosan Nanoparticles For Salivary Protein Delivery, Yi Zhu, Lina M. Marin, Yizhi Xiao, Elizabeth R. Gillies, Walter L. Siqueira

Chemistry Publications

Salivary proteins such as histatins (HTNs) have demonstrated critical biological functions directly related to tooth homeostasis and prevention of dental caries. However, HTNs are susceptible to the high proteolytic activities in the oral environment. Therefore, pH-sensitive chitosan nanoparti-cles (CNs) have been proposed as potential carriers to protect proteins from enzymatic degradation at physiological salivary pH. Four different types of chitosan polymers were investigated and the optimal formulation had good batch to batch reproducibility, with an average hydrodynamic diame-ter of 144 ± 6 nm, a polydispersity index of 0.15 ± 0.04, and a zeta potential of 18 ± 4 mV at …

College Of Natural Sciences Newsletter, April 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 4

Page 1 Dean's Message
Page 2 & 3 Awards & Recognition
Page 4 Student Spotlight: Allsion Bjornstad
Page 5 Research Spotlight: Dr. Vondruska & Students
Page 6 Department Head Interviews
Page 7 Media Coverage of CNS
Page 8 Open PRAIRIE Data
Page 9 Student Club Spotlight: BMGSA
Page 10 Then & Now: Urban Geography