Chemistry Commons^™

Structural, Spectroscopic, And Computational Insights From Canavanine-Bound And Two Catalytically Compromised Variants Of The Ethylene-Forming Enzyme, Shramana Chatterjee, Matthias Fellner, Joel A. Rankin, Midhun George Thomas, Simahudeen Bathir Jaber Sathik Rifayee, Christo Christov, Jian Hu, Robert P. Hausinger

Michigan Tech Publications

The ethylene-forming enzyme (EFE) is an Fe(II), 2-oxoglutarate (2OG), and l-arginine (l-Arg)-dependent oxygenase that either forms ethylene and three CO2/bicarbonate from 2OG or couples the decarboxylation of 2OG to C5 hydroxylation of l-Arg. l-Arg binds with C5 toward the metal center, causing 2OG to change from monodentate to chelate metal interaction and OD1 to OD2 switch of D191 metal coordination. We applied anaerobic UV-visible spectroscopy, X-ray crystallography, and computational approaches to three EFE systems with high-resolution structures. The ineffective l-Arg analogue l-canavanine binds to the EFE with O5 pointing away from the metal center while promoting chelate formation by 2OG …

Thermal Frontal Polymerization – Applications In Coatings And Composites, Maria Martinez

LSU Doctoral Dissertations

Thermal frontal polymerization has long been used as a method to cure composites and coatings. However, this is the first time these applications have been used without the use of a catalyst, for the case of composites and coatings.

Chapter 2 discusses how to optimize cure-on-demand, thin layer coatings, using frontal polymerization. Previously, for the use of curing thin layer coating using thermal FP, it was known to just make the formulation viscous enough, as this would prevent premature quenching caused by heat loss. It was discovered that for a given layer thickness, a minimum viscosity and initiator concentration were …

Two New Catalysts For Oxidation Of Water To Oxygen, Takia Sultana

LSU Master's Theses

If fuels, such as hydrogen or methanol, are to be produced from renewable energy (solar or wind) in the future, efficient catalysts will be needed, not only for fuel production reactions but for the essential simultaneous oxidation of water to O₂. Ruthenium complexes are among the more promising water oxidation catalysts (WOCs). Two new isomeric ruthenium WOCs have been prepared based on the benzylpyridyltriazole ligand (Figure 3); trans-py-[Ru(tpy)(bpt)(H₂O)]²⁺ (trans-py-1) and trans-trz-[Ru(tpy)(bpt)(H₂O)]²⁺ (trans-trz-1) (tpy = 2,2’:6’,2’’-terpyridine, bpt = benzylpyridyltriazole). Ceric ammonium nitrate [(CAN)/Ce(IV)] oxidants were …

Applied Depositional Geosystems Of The Coos Bay Basin, Oregon: Organic Geochemistry, Maturation, Paleoenvironmental Reconstruction And Biostratigraphy Of The Coaledo Delta During The Middle Eocene Climatic Optimum (Meco), Allison K. Barbato

LSU Doctoral Dissertations

The Coos Bay Basin on the southwestern coast of Oregon is a forearc basin that contains exceptionally preserved Eocene to Miocene, tidal to wave-dominated, shallow deltaic to deep marine sediments of the Coaledo Delta. Coastal depositional environments are known to host source, reservoir, and seal rocks. Climate, topographic relief, and geographical position all play an important role in regional vegetation development and oceanic setting. This study assesses 84 outcrop and 12 core samples from Coos Bay for their organic geochemical characteristics and microfossil assemblage to provide source rock characterization information, organofacies descriptions, environmental reconstructions, and age control.

Results indicate the …

Green Oxidation Of Aromatic Hydrazide Derivatives Using An Oxoammonium Salt, Nidheesh Phadnis, Jessica A. Molen, Shannon M. Stephens, Shayne M. Weierbach, Kyle M. Lambert, John A. Milligan

College of Life Sciences Faculty Papers

Aromatic diazenes are often prepared by oxidation of the corresponding hydrazides using stoichiometric quantities of nonrecyclable oxidants. We developed a convenient alternative protocol for the oxidation of aromatic hydrazides using Bobbitt's salt (1), a metal-free, recyclable, and commercially available oxoammonium reagent. A variety of aryl hydrazides were oxidized within 75 min at room temperature using the developed protocol. Computational insight suggests that this oxidation occurs by a polar hydride transfer mechanism.

Broad-Spectrum Lignin-Based Adhesives Using Thiol–Silyl Ether Crosslinkers, Yishayah Bension, Siteng Zhang, Tristan Menninger, Ting Ge, Chuanbing Tang

Faculty Publications

Lignin is a renewable feedstock that is abundant and inexpensive but still presents challenges for its valorization. In this work, we converted functionalized lignin into broad-spectrum adhesives using thiol–silyl ether crosslinkers. The curing behavior of adhesives was investigated via rheology of their resin forms. These materials exhibit good adhesion on diverse substrates, including wood, glass, steel, aluminium, carbon fiber, and different plastics, with the most adhesion strength in the range of 1–3 MPa. These adhesives were also explored for applications, ranging from wet conditions to different mechanically responsive materials. The mechanism of adhesion was further examined to understand the bonding …

Advanced Electroanalysis For Electrosynthesis, Monica Brachi, Wassim El Housseini, Kevin Beaver, Rohit Jadhav, Ashwini Dantanarayana, Dylan G. Boucher, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Electrosynthesis is a Popular, Environmentally Friendly Substitute for Conventional Organic Methods. It Involves using Charge Transfer to Stimulate Chemical Reactions through the Application of a Potential or Current between Two Electrodes. in Addition to Electrode Materials and the Type of Reactor Employed, the Strategies for Controlling Potential and Current Have an Impact on the Yields, Product Distribution, and Reaction Mechanism. in This Review, Recent Advances Related to Electroanalysis Applied in Electrosynthesis Were Discussed. the First Part of This Study Acts as a Guide that Emphasizes the Foundations of Electrosynthesis. These Essentials Include Instrumentation, Electrode Selection, Cell Design, and Electrosynthesis Methodologies. …

Chiral Recognition Of Chiral (Hetero)Cyclic Derivatives Probed By Tetraaza Macrocyclic Chiral Solvating Agents Via ¹H Nmr Spectroscopy, Yu Wang, Hongmei Zhao, Chunxia Yang, Lixia Fang, Li Zheng, Hehua Lv, Pericles Stavropoulos, Lin Ai, Jiaxin Zhang

Chemistry Faculty Research & Creative Works

In the Field of Chiral Recognition, Chiral Cyclic Organic Compounds, Especially Heterocyclic Organic Compounds, Have Attracted Little Attention and Have Been Rarely Studied as Chiral Substrates by Means of 1H NMR Spectroscopy. in This Paper, Enantiomers of Thiohydantoin Derivatives, Representing Typical Five-Membered N,N-Heterocycles, Have Been Synthesized and Utilized for Assignment of Absolute Configuration and Analysis of Enantiomeric Excess. All Enantiomers Have Been Successfully Differentiated with the Assistance of Novel Tetraaza Macrocyclic Chiral Solvating Agents (TAMCSAs) by 1H NMR Spectroscopy. Surprisingly, Unprecedented Nonequivalent Chemical Shift Values (Up to 2.052 Ppm) of the NH Proton of Substrates Have Been Observed, a New …

Group Iv Topological Quantum Alloy And The Role Of Short-Range Order: The Case Of Ge-Rich Ge1–XPbX, Yunfan Liang, Shunda Chen, Xiaochen Jin, Damien West, Shui-Qing Yu, Tianshu Li, Shengbai Zhang

Electrical Engineering and Computer Science Faculty Publications and Presentations

Despite the explosion of interest in topological materials over the last decades, their applications remain limited due to challenges in growth and incorporation with today’s microelectronics. As a potential bridge to close this gap, we investigate the group-IV alloy Ge_1–xPb_x, in the Ge-rich condition using density functional theory and show that relatively low concentrations of Pb (~9.4%) can lead to a topological phase transition. Furthermore, the calculation of the Z₂ invariant for both the random alloy and the alloy with short-range order (SRO) indicate that the topological phase of the material can be directly modified …

Activated Carbon Derived From Cucumber Peel For Use As A Supercapacitor Electrode Material, Meruyert Nazhipkyzy, Gulim Kurmanbayeva, Aigerim Seitkazinova, Esin Apaydın Varol, Wanlu Li, Balaussa Dinistanova, Almagul Issanbekova, Togzhan Mashan

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Biowaste conversion into activated carbon is a sustainable and inexpensive approach that relieves the pressure on its disposal. Here, we prepared micro-mesoporous activated carbons (ACs) from cucumber peels through carbonization at 600 °C followed by thermal activation at different temperatures. The ACs were tested as supercapacitors for the first time. The carbon activated at 800 °C (ACP-800) showed a high specific capacitance value of 300 F/g at a scan rate of 5 mV/s in the cyclic voltammetry and 331 F/g at the current density of 0.1 A/g in the galvanostatic charge–discharge analysis. At the current density of 1 A/g, the …

Finding The Perfect Purple: An Exploration Of Glaze Making And Chemical Safety In The Pottery Studio, Kara Eppard, Michael Hough

ASPIRE 2024

This project was undertaken as an IDS-100H course linkage between ceramics and chemistry. Through time spent reviewing literature and time in the studio, a project was developed that allowed the application of technical skills of each discipline in a creative fashion. The creative focus of the project was to find a suitable purple glaze to utilize on a previously thrown pottery collection. During the project techniques in glaze making were explored. Over 25 glazes were tested, and two firing techniques were explored. Additionally, safety within the pottery studio was increased through aspects such as the development of an MSDS, and …

Chemistry Matters Spring 2024, Otterbein University Chemistry Department

Chemistry Matters Department Newsletter

In this Issue:

Letter from the Chair; Johnston Receives National Science Foundation Grant; Students and Faculty Travel to National Scientific Meetings; Department Acquires New Instrument; Chemistry Educators; Faculty Publish Book Chapters; Farewell to our Spring 2023 Graduates and Farewell to the Grote Family; Science Lecture Series Brings Dr. Diana Aga to Campus; Faculty Receive Recognition; A Wide Range of Undergraduate Chemistry Research Projects are Ongoing on Campus During 2023-24; High School Teachers Explore Art and Chemistry; The Cardy Chemistry Cluster; Students in the Department Earned Awards for Excellence.

Comparison Of Atmospheric Pressure Chemical Ionization And Electrospray Ionization Mass Spectrometry For The Direct Analysis Of Hops Bittering Compounds, Chhiring Sherpa

Masters Theses

Hops acids are essential components in the beer brewing process containing alpha acids (α-acids) and beta acids (β-acids) as the major hops bittering compounds. Quantifying these acids is vital for quality control and determining bitterness levels and hops variety profiles. Current industry standards, like High-Performance Liquid Chromatography with Ultraviolet detection (HPLC-UV) and Ultraviolet Spectroscopy (UV-Vis), though effective, are time-consuming and solvent-intensive, providing incomplete information.

This research introduces a novel method using mass spectrometry with atmospheric pressure chemical ionization (APCI-MS) to analyze hops bittering acids without chromatographic separations. This approach offers rapid analysis, high throughput, and eco-friendliness.

Comparison with direct electrospray …

Molecular Geometry Changes In Some Carbonyls And Aromatic Rings Upon Electronic Excitation: Herzberg-Teller Vibronic Coupling And Unitary Duschinsky Rotation, Maryam Yahya Al-Sakkaf

Theses

The common assumption in probing the dynamical motion of molecules is that the molecular electronic activity depends weakly on vibrational coordinates on electronic excitation. Therefore, electron-vibration interaction, which is known as Vibronic Coupling (VC), may be ignored. The Herzberg-Teller theory of Vibronic Coupling (HTVC) is a breakdown of the Born-Oppenheimer Approximation (BOA) since nuclear and electronic degrees of freedom can no longer be separated. The inclusion of a single quantum of a non-totally symmetric vibrational mode changes the overall symmetry of the state and permits the transition. Often, this assumption may be invalid, especially in carbonyl and aromatic compounds. This …

Theoretical And Computational Astrochemistry: A Variational Quantum Monte Carlo (Vqmc) Study Of The Trihydrogen Molecule Cation (H3+), Ahmad Saeed Alsaed

Theses

H₃⁺ is the simplest Three-Center Two-Electron molecule and it is of much interest in astrochemistry due to its high occurrence in the outer space, high reactivity, and strong acidic properties. In addition,H₃⁺ is involved in many chemical reactions in the interstellar medium (ISM) and its significant ability to absorb energy contributed to the cooling of the Universe during its early stages.

The main objective of this thesis is to approximate the ground state electronic energy of H₃⁺ by using a simple trial wavefunction consisting of a doubly occupied molecular orbital multiplied by a Jastrow …

Synthesis And Characterization Of Heavy-Metal Oxoanion- And Phosphonate-Binding Nanojars, Pooja Singh

Dissertations

Nanojars are an emerging class of anion-binding and extraction agents. These supramolecular coordination complexes (2 nm wide) exhibit exceptional anion binding strength that points to their possible application in the recovery of toxic or valuable anions from water bodies. Nanojars of the formula (TBA)2[XO3/42−⸦{CuII(μ-OH)(μ-pyrazolate)}n] (TBA = tetrabutylammonium cation; XO3/42− = anion; X = Se, Te, Cr, Mo, W, HP, HAs, HV; n = 26 – 36) are synthesized from Cu2+, OH−, pyrazole and the TBA salts of various anions. Nanojars possess hydrophobic exteriors with an array of pyrazolate ligands and hydrophilic interiors with a …

Exploring Cation Exchange: Unveiling Its Significance In Biochar And Bioenergetics Applications, Gyanendra Kharel

Chemistry & Biochemistry Theses & Dissertations

Cation exchange, a cornerstone of soil chemistry and nutrient cycling, is a fundamental chemical process that occurs in soils, sediments, membranes, and other solid materials. It involves the interchange of positively charged ions, or cations, between a solid matrix and a surrounding solution. This process is crucial in various natural and engineered systems, leading to a range of applications across different fields.

This dissertation presents an extensive investigation into the applications of cation exchange in the fields of biochar and bioenergetics, encompassing three distinct aims. The first aim concentrates on the surface oxygenation of biochar through ozonization, aiming to achieve …

Broadband Dielectric Spectroscopic Detection Of Volatile Organic Compounds With Zinc Oxide And Metal-Organic Frameworks As Solid-State Sensor Materials, Papa Kojo Amoah

Electrical & Computer Engineering Theses & Dissertations

The industrial revolution drove technological progress but also increased the release of harmful pollutants, posing significant risks to human health and the environment. Volatile organic compounds (VOCs), which have various anthropogenic and natural sources, are particularly concerning due to their impact on public health, especially in urban areas. Addressing these adverse effects requires comprehensive strategies for mitigation as traditional gas sensing techniques have limitations and there is a need for innovative approaches to VOC detection.

VOCs encompass a diverse group of chemicals with high volatility, emitted from various human activities and natural sources. These compounds play a crucial role in …

Spectroscopy Of Atmospheres, Randika Dodangodage

Physics Theses & Dissertations

Spectroscopic methods are used to study planetary and stellar atmospheres. The information obtained from spectroscopic studies provides insight into atmospheric compositions and dynamics, which can be used to model and characterize atmospheres and climates. Laboratory-recorded absorption cross-sections are needed to interpret the recorded spectra of planets and stars. High resolution ethane, neopentane, propene, and n-butane spectra have been recorded, and absorption cross-sections have been provided for different temperatures and total pressures with different broadening gases, including hydrogen, helium, and nitrogen. The Atmospheric Chemistry Experiment (ACE) satellite orbits Earth and records spectra through solar occultation limb observations. HOCl is a chlorine …

Physical And Chemical Methods To Assess Performance Of Tpo-Modified Asphalt Binder, Rebecca M. Herndon, Jay Balasubramanian, Klaus Woelk, Magdy Abdelrahman

Chemistry Faculty Research & Creative Works

The Demand for Effective Asphalt Additives is Growing as Road Infrastructure Ages and More Sustainable Pavement Solutions Are Needed. Tire Pyrolysis Oil (TPO) is an Example Material that Has Been Gaining Attention as a Potential Asphalt Additive. While Physical Performance Grade (PG) Temperatures Are the Predominant Performance Requirements for Asphalt Binders, Chemical Properties Are Also Significant in the Evaluation of Asphalt Performance. There is a Need to Chemically Characterize the Aging of Asphalt Binders Modified with TPO and Link Chemical Changes in Binder Components to Binder Performance. This Study Compares 2%, 4%, and 8% TPO and Asphalt Binder Blends Via …

Impact Of Pulsed Electric Field Treatment On Barley Germination For Malting, Rose Saxton, Caitlin Lahey, Brianna Smith, Emily Hibberd, Joshua Bevan, Cini Baumhoff, Ashley Galant, Jerry Young, Brian Meyer, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

The malting process takes one week to steep, germinate, and kiln barley to make malt. Making quality malt is critically important to achieve the desired attributes of the finished beer, and the process is time-intensive and costly. Malt quality is assessed by indicators including β-glucan quantity, α-amylase activity, Free Amino Nitrogen (FAN) content, and overall extract concentration in the finished malt. Here, we report Pulsed Electric Field (PEF) treatment of barley to accelerate malt production. A small-scale trial of 250 g to 1.00 kg barley, was evaluated for germination at two PEF treatment conditions, generically referred to as “low” and …

Computational Study Of Substituent Effects On The Diels-Alder Reaction Involving Furan And Maleimide For Hydrogel Synthesis, Matthew Phillips

Honors Theses

This research utilized a computational study with SPARTAN’20 software to analyze the energetics of the Diels-Alder (DA) reaction between substituted furan and maleimide. The products of this type of reaction can lead to the production of hydrogels. Hydrogels are used in multiple biomedical applications, such as controlled drug delivery systems, wound dressings (liquid bandages), contact lenses, and more. The DA reaction involves a diene (a hydrocarbon with two conjugated π bonds) and a dienophile (a hydrocarbon with one π bond). Research on the placement of electron withdrawing and electron donating groups onto the dienophile and diene has been completed in …

Decoding Molecular Recognition Mechanism Of Small Molecule Ligand-Rna Binding Pocket Systems Using Molecular Dynamics And Metadynamics, Zhixue Bai

Legacy Theses & Dissertations (2009 - 2024)

From my PhD research, under Amber99-Chen-Garcia force field, umbrella sampling and MD simulation helped us found that the 2’-5’ phosphodiester RNA backbone linkage modification on in vitro selected neomycin RNA aptamer can transfer it to ‘amikacin RNA aptamer’ by changing the conformation and backbone rigidity of the RNA binding pocket, which further influenced the binding mode and binding pathway of amikacin. Furthermore, under the same force field, metadynamics was found more powerful for simulating the binding pathway, binding mechanism and predicting binding modes of small molecule ligand recognizing its RNA target by filling up all energy basins on free energy …

Hydrophobic Deep Eutectic Solvents: Liquid-Liquid Extraction Of Organic Water Pollutants, Abigail Louise Maletta

Masters Theses

Pollution is a topic of significant research within the scientific community. The massive demand for industrial processes to deliver the technology and resources we rely on has opened numerous avenues for pollutants to enter the environment, affecting air, water, soil, and the food chain. Oftentimes, these pathways are intertwined, and the interplay between water and air currents spreads pollution globally, creating a cascade of environmental impacts. Water, a vital resource for all forms of life, is particularly susceptible to industrial pollution. Among the most prevalent water pollutants are heavy metals, such as lead and mercury, and organic compounds, often released …

Efforts Toward Difunctionalization Of (Hetero)Arenes Enabled By Visible Light, Eric Allen

Master's Theses (2009 -)

Functionalized arenes and heteroarenes are ubiquitous motifs in natural products, pharmaceuticals, and functional materials. As such, methods to place multiple functionalities on (hetero)arenes in one synthetic step create molecular complexity quickly and are highly valued. The vast majority of current strategies are metal-mediated, although others such as utilizing aryne intermediates and cycloadditions have also been reported. The premier challenge in this research area is the difficulty in controlling regioselectivity. Strategies of controlling regioselectivity have included tuning the electronic nature of the substrate, the use of directing groups (DGs), steric influences, ligand control, and photochemically initiated methods. Certain strategies tend to …

Structure, Dynamics, And Redox Reactivity Of An All-Purpose Flavodoxin, Sharique Khan, Ahmadullah Ansari, Monica Brachi, Debarati Das, Wassim El Housseini, Shelley Minteer, Anne Frances Miller

Chemistry Faculty Research & Creative Works

The Flavodoxin Of Rhodopseudomonas Palustris CGA009 (Rp9Fld) Supplies Highly Reducing Equivalents To Crucial Enzymes Such As Hydrogenase, Especially When The Organism Is Iron-Restricted. By Acquiring Those Electrons From Photodriven Electron Flow Via The Bifurcating Electron Transfer Flavoprotein, Rp9Fld Provides Solar Power To Vital Metabolic Processes. To Understand Rp9Fld's Ability To Work With Diverse Partners, We Solved Its Crystal Structure. We Observed The Canonical Flavodoxin (Fld) Fold And Features Common To Other Long-Chain Flds But Not All The Surface Loops Thought To Recognize Partner Proteins. Moreover, Some Of The Loops Display Alternative Structures And Dynamics. To Advance Studies Of Protein–protein Associations …

Development Of On-The-Fly Quasi-Steady State Approximation For Chemical Kinetics In Cfd, Abhinav Balamurugan

Doctoral Dissertations and Master's Theses

This study analyzes the feasibility of On-The-Fly Quasi-Steady-State Approximation (OTF-QSSA) application for solving chemical kinetics within Computational Fluid Dynamics (CFD) simulations, aiming to reduce the computational demand of detailed mechanisms. An algorithm that dynamically identifies and designates Quasi-Steady-State (QSS) species at specific grid locations and instances during the simulation was developed. With this information, our method pseudo-delays the advancement of concentrations for these QSS species—effectively setting their rate of concentration change to zero for a set number iteration before updating using the detailed mechanism and thereby omitting the computationally intensive processes typically required for their calculation during those skipped iteration. …

Efficient Photocatalytic Core–Shell Synthesis Of Titanate Nanowire/Rgo, Xiaofang Ye, Yang Tian, Mengyao Gao, Fangjun Cheng, Jinshen Lan, Han Chen, Mark Lanoue, Shengli Huang, Z. Ryan Tian

Chemistry & Biochemistry Faculty Publications and Presentations

Wide bandgap semiconductor-based photocatalysts are usually limited by their low solar energy conversion efficiency due to their limited absorption solar wavelength, their rapid surface recombination of the photogenerated electron–hole pairs, and their low charge-carrier mobility. Here, we report a novel stepwise solution synthesis for achieving a new photocatalytic core–shell consisting of a titanate nanowire/reduced graphene oxide shell (or titanate/rGO) 1D-nanocomposite. The new core–shell nanocomposite maximized the specific surface area, largely reduced the charge transfer resistance and reaction energy barrier, and significantly improved the absorption of visible light. The core–shell nanocomposites’ large on/off current ratio and rapid photo-responses boosted the photocurrent …

Tripodal Naphthalene Mono Imide Chemosensor For Detection Of Metal Ions, Joshua Do, Rosanna Jees

Posters - 2024

1,8-Naphthalimide is an excellent fluorophore (fluorescent compound) with long emission wavelength band (400-600 nm), a large stokes shift, insensitive to pH and synthetic versatility. Triazole functional group has been used as binding sites for various metal ions in particular Zn(II), Cu(II) and Fe(III) metal ions. Based on naphthalimide as fluorophore and triazole as binding site, a new tripodal chemosensors has been designed and synthesized by copper catalyzed Huisgen Azide Alkyne cycloaddition reaction (known as click reaction). Its photophysical properties with various metal ions were investigated by fluorescence spectroscopy. Binding studies with various metal ions such as Zn(II), Cd(II) and Fe(III) …

Attendance At Virginia Academy Of Science Meetings: A Report Of The Panel Discussion Held By The Chemistry Section Of The Virginia Academy Of Science, Tom Devore

Virginia Journal of Science

Since the attendance in the Chemistry Section at the Virginia Academy of Science (VAS) spring meetings has not returned to the numbers attending prior to the cancellation of the 2020 meeting due to the Covid pandemic, a roundtable discussion was held as part of the 2023 VAS Annual Meeting at the College of William and Mary on May 25, 2023 to discuss possible ways to increase attendance at future meetings. This is a report of the topics discussed and the suggestions made.