Chemistry Commons^™

Synthesis And Characterization Of Humic/Melanin-Like Compounds By Oxidative Polymerization Of Simple Aromatic Precursors, Nastaran Khademimoshgenani, Sarah A. Green

Michigan Tech Publications, Part 1

Dissolved organic matter (DOM) is a complex mixture of naturally occurring organic molecules originating from multiple marine and terrestrial sources. DOM plays a significant role in water quality by affecting the photochemistry, trace metal transport, and acidity in aquatic systems. Understanding the chemical composition of DOM helps interpret the links between its optical properties and molecular structures. Currently, the molecular origins of the optical properties of DOM are not well-defined. In this study, we oxidize and initiate the polymerization of melanin precursors 1,8-dihydroxy naphthalene and 5,6-dihydroxy indole by the addition of hydrogen peroxide and/or with ultraviolet irradiation. Our goal is …

Synthesis And Characterization Of Semi-Interpenetrating And Double Networks Of Sulfonimide- And Imidazolium-Containing Poly(Ionic Liquids), Jeremiah Coughlon, Seth Taylor, Jason Bara, Kevin Miller, Sourav Chatterjee

Scholars Week

In recent years, there has been increased research interest in creating electrically conductive polymer membranes with materials that are widely available and environmentally safe. Herein, we report how polymeric membranes comprised of unique combinations of ionenes and poly(ionic liquids), including a recently developed sulfonimide- and imidazolium-containing methacryloxy-based monomer, were produced via UV photopolymerization. These membranes were specifically tailored to exhibit both ionic conductivity and an affinity for carbon dioxide, which are both crucial characteristics in such applications as electron transport in lithium-ion batteries and gas sorbency in separation techniques. Monomers, such as the aforementioned methacryloxy-based ionic liquid (IL) and C4VIm, …

Synthesis And Properties Of Bio-Based 3d Printable Resins, Cameron Woods, Seth Taylor, Jeremiah Coughlon, Turner Perdue, Sourav Chatterjee, Jason E. Bara

Scholars Week

A photopolymer resin is a monomer that, when introduced to light of a certain wavelength, starts to polymerize into a solid. This has become a growing part of the 3D printing industry. There have been many advancements in the field of 3D printing, however, a lot of these resins are not environmentally friendly and even harmful if not handled in the correct manner. Plant based resins are becoming more and more popular because of their biodegradability and for the possibility of using renewable resources. Glycerol is a plant-based compound that is produced in excess in industry. Glycerol obtained from bioethanol …

Physiochemical Properties Of Urethane-Containing Ionic Liquids And Ionenes From A Non-Isocyanate Synthetic Approach, George Timmermann

Scholars Week

Ionic polymers that are designed to contain ionic liquids (ILs) in their backbones have been shown to exhibit a high degree of variability through changing the type of ionic character and the location of the ionic region within the molecule. This large amount of variability in both the structure and characteristics of ILs allows researchers to design task-specific ionic polymers and ILs for a variety of applications including gas separation membranes and solid polymer electrolytes. The synthesis of a specific class of ILs and ionenes through the incorporation of urethane groups with imidazolium rings by reacting carbonyl diimidazole with various …

Coarse-Grained Molecular Simulations And Ensemble-Based Mutational Profiling Of Protein Stability In The Different Functional Forms Of The Sars-Cov-2 Spike Trimers: Balancing Stability And Adaptability In Ba.1, Ba.2 And Ba.2.75 Variants, Gennady M. Verkhivker, Mohammed Alshahrani, Grace Gupta

Mathematics, Physics, and Computer Science Faculty Articles and Research

Evolutionary and functional studies have suggested that the emergence of Omicron variants can be determined by multiple fitness tradeoffs including immune escape, binding affinity, conformational plasticity, protein stability, and allosteric modulation. In this study, we embarked on a systematic comparative analysis of the conformational dynamics, electrostatics, protein stability, and allostery in the different functional states of spike trimers for BA.1, BA.2, and BA.2.75 variants. Using efficient and accurate coarse-grained simulations and atomistic reconstruction of the ensembles, we examined the conformational dynamics of the spike trimers that agree with the recent functional studies, suggesting that BA.2.75 trimers are the most stable …

Optimization Of Adsorption Of Methylene Blue Dye On Activated Charcoal, Abigail Seputro

Research and Creativity Symposium

Methylene blue and crystal violet are cationic dyes of high intensity that are commonly discharged in wastewater. The colored compounds in this environment inhibit sunlight penetration in waterways, resulting in the destruction of aquatic ecosystems. Activated carbon offers an attractive option for the efficient removal of dyes from wastewater due its excellent adsorption ability, highly porous structure, and large thermal/chemical stability. This study was conducted in order to investigate the adsorption of methylene blue dye from aqueous solution by various types of activated charcoal using UV-Vis spectroscopy. The effects of temperature and adsorbent quantity were studied to optimize the efficiency …

Using Transition State Theory To Understand The Kinetics For The Gas-Phase Synthesis Of Ammonia, Chloe Boyd, Stephen Case, Abigail Seputro

Research and Creativity Symposium

To identify the rate-determining step and the most stable transition state for the Haber-Bosch synthesis of gas-phase ammonia, electronic structure calculations for the reactants (N2, H2, NNH2, H2NNH2, HNNH3), intermediates, and transition states were found using the program GAMESS and the basis sets 6-31G*, 6-311G**, and STO-3G (1). The basis set 6-31G* revealed N2(g) + 3H2(g) ⇌ TS1 ⇌ NNH2(g)+ 2H2(g) as the rate-determining step because it had the smallest equilibrium constant (Keq) of 4.2085*10-36. The reaction coordinate diagram showed the most stable transition state was TS4 from the step HNNH3(g) + H2(g) ⇌ TS4 ⇌ 2NH3(g), which had the …

The Coastal Monitor: Vol. 10 No. 1, John Tanacredi Ph.D.

The Coastal Monitor

New Year’s Day has always been, for me, a time to reflect and project into the near future. Nature’s influence on us all certainly tops my listing with several environmental concerns. For example, the frequency and intensity of hurricanes to Long Island. A decade has passed since Superstorm Sandy re-opened the “Old Inlet” on Long Island which now has mostly naturally closed. So, the new year immediately prompts me to assess the previous year’s Hurricane Ian, a Category 4 system, with winds exceeding 150 mph, which had considerable impact in Florida, and then proceeded north resulting in over 2 inches …

Stem Club, Rohan Tatineni, Kevin Prososki

Honors Program: Expanded Learning Clubs

The goal of STEM club is to teach the students various basic scientific principles and relate them to experiments and the real world. In addition, the scientific method will be taught and be a main focus of the club along with the engineering design process.

Synthesis And Characterization Of Terbium(Iii) Complexes: Can We Manipulate The Emission Signature?, Ryan Gagnon

[Archive] Belmont University Research Symposium (BURS)

Successful Lewis acid/base reactions of terbium(III) nitrate with 2,2’-bipyrdine (22’bpy), 1,10-phenanthroline (phen), and 2,6-pyridine dimethanol (pydm) have yielded the products: Tb(22’bpy)₂(NO₃)₃, Tb(phen)₂(NO₃)_3, and [Tb(pydm)₃](NO₃)₃, respectively. In accord with the well-known antenna-effect, the absorption spectrum of each complex is similar to the spectrum of the free ligand, while the emission spectrum of the complex is identical for the free terbium(III) ion. In contrast, the substitution of a ligand containing a third-row nonmetal strategically placed near the terbium may force interaction between the 3p nonmetal …

Crystal Structure Of Dihydrofolate Reductase From The Filarial Nematode W. Bancrofti In Complex With Nadph And Folate, Keith Lange, Kathleen M. Frey, Tyler Eck, Cheryl A. Janson, Ueli Gubler, Nina M. Goodey

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Lymphatic filariasis is a debilitating illness with an estimated 50 million cases as of 2018. The majority of cases are caused by the parasitic worm W. bancrofti and additional cases by the worms B. malayi and B. timori. Dihydrofolate reductase (DHFR) is an established target in the treatment of cancer, bacterial, and protozoal infections and may be a potential target for drugs targeting parasitic worm infections, including filariasis. Recent studies have shown that known antifolate compounds, including methotrexate, inhibit the activity of W. bancrofti DHFR (WbDHFR). However, the absence of structural information for filarial DHFRs has limited the study of …

Using Cyclic-Step Chronopotentiometry To Explore Electron Mobility In Dye-Sensitized Solar Cells, Jasmine Hopson, Ian Mcneil

Honors Projects

In this project, we are making dye-sensitized solar cells using titanium dioxide and the dye from raspberries. We are exploring how electrons diffuse through these systems. To do this, we perform cyclic chronopotentiometry where we cycle between periods of applying a voltage to achieve a certain current and periods where the current is stopped. We focus on the time-dependent decay of the voltage when the current is stopped and fit these decays with a bi-exponential model. We compare the results of devices with and without lithium perchlorate in the electrolyte solution since lithium lowers the energies of the acceptor states …

Investigation Of Cofactor Activities Of Endothelial Microparticle- Thrombomodulin With Liposomal Surrogate, Valentinas Gruzdys, Lin Wang, Dan Wang, Rachel Huang, Xue-Long Sun

Chemistry Faculty Publications

Thrombomodulin (TM) is a type I transmembrane glycoprotein mainly expressed on the endothelial cells, where it binds thrombin to form the thrombin-TM complex that can activate protein C and thrombin-activable fibrinolysis inhibitor (TAFI) and induce anticoagulant and anti-fibrinolytic reactions, respec-tively. Cell activation and injury often sheds microparticles that contain membrane TM, which circulate in biofluids like blood. However, the biological function of circulating microparticle-TM is still unknown even though it has been recognized as a biomarker of endothelial cell injury and damage. In comparison with cell membrane, different phospholipids are exposed on the microparticle surface due to cell membrane "flip-flop"upon …

Modeling Excited State Processes In Molecular Aggregates By Constructing An Adaptive Basis For The Hierarchy Of Pure States, Leonel Varvelo

Chemistry Theses and Dissertations

Simulating excitation energy transfer (EET) in molecular materials is of crucial importance for the development of and understanding of materials such as organic photovoltaics and photosynthetic systems and further development of novel materials. The Hierarchy of Pure States (HOPS) is an exact framework for the time evolution of an open quantum system in which a hierarchy of stochastic wave functions are propagated in time. The adaptive HOPS (adHOPS) method achieves size-invariant scaling with the number of simulated molecules for sufficiently large aggregates by using an adaptive basis that moves with the excitation through the material. To demonstrate the power of …

Nitric Oxide As A Signaling Molecule For Biofilm Formation And Dispersal In Mediated Electron Transfer Microbial Electrochemical Systems, Kevin Beaver, Ashwini Dantanarayana, Ana Bonizol Zani, Danielle L. Lehto, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

With applications in bioremediation, biosensing, and bioenergy, microbial electrochemical systems are a rapidly growing, multidisciplinary field within biological, chemical, and materials science. Since these systems use living microorganisms as biocatalysts, it is important to understand how microbial physiology, namely biofilm formation, affects these electrochemical systems. Specifically, the literature lacks research that assesses the effects of biofilm on metabolic current output in mediated electron transfer systems. in this study, Rhodobacter capsulates and Pseudomonas putida GPo1 were used as model, nonpathogenic strains that facilitate electron transfer via diffusible redox mediators. Nitric oxide has gained attention in biomedicine as a gaseous signaling molecule, …

Microscale Chemical Manipulation And Imaging Using Photoactive Molecules And Light, Uroob Haris

Chemistry Theses and Dissertations

Chemical manipulation with light has been an active and growing area of research with important implications in materials science, biotechnology, and environmental science. From early investigations of light sensitive materials for photography in the 19^th century, to printing billions of transistors on a semiconductor chip in present day, scientists have gained a deep understanding of photochemistry and the processes that allow us to harness light for everyday applications. In this work, we explore microscale fabrication and molecular imaging using light and photoactive molecules as foundational tools. We develop a visible-light mediated technique for high resolution microscale chemical lithography comprising …

Biophysical And Structural Characterization Of Non-Canonical Dna Structures, Paul C. Seth , '23

Senior Theses, Projects, and Awards

G-quadruplex (GQ) and i-motif (iM) non-canonical DNA structures can be formed by G- and C-rich sequences within the genome, respectively. GQ and iM DNA play important roles in different biological processes and are promising therapeutic targets. Recently, the first left-handed GQ (LHGQ) was discovered and much remains to be learned about the structure and function of LHGQ DNA.

In this thesis, we investigate the biophysical and structural behavior of two LHGQ-forming sequences from the human genome, from the Human Solute Carrier 1 (SLC) and nuclear receptor binding SET domain (NSD) genes. We found that flanking bases play an important role …

Computational Investigation Of Porphyrin-Based Host Design For Anions And Ion Pairs, Symphony Hill

Honors Theses

Little research has heretofore been devoted to studying the binding interactions between porphyrin-based molecular hosts and anions or ion pairs. Such interactions could be important in synthesizing molecules capable of detecting, binding, extracting, and transporting ions of biological, environmental, and industrial significance. With this in mind, computational studies of nine different porphyrin hosts were performed to examine the structural and binding properties of each molecule and potential ion guests. Using the Spartan computational chemistry software, each porphyrin was modeled and binding was tested with a number of ions of different shapes and sizes. Data was then collected regarding the distances …

Substituent Effect Analysis On Halogen Bonding Interactions, Summer Hanson

Honors Theses

This study was used to determine the significance of substituents placed on aromatic molecules and how electron-donating groups (EDG) and electron-withdrawing groups (EWG) affect the strength of the halogen bond. Each study involved the same substituents, each differing in electron-withdrawing and electron-donating capability. Five different systems were created on computational software to evaluate the distance between the halogen bond donor and halogen bond acceptor. In two studies, the goal was to find the best electron-donor on the halogen bond acceptor (donor of electron density) while the halogen bond donor remained constant. For one study, the goal was to determine the …

Rage Inhibitors In Neurodegenerative Diseases, V. Prakash Reddy, Puspa Aryal, Pallavi Soni

Chemistry Faculty Research & Creative Works

Nonenzymatic Reactions of Reducing Sugars with Primary Amino Groups of Amino Acids, Proteins, and Nucleic Acids, Followed by Oxidative Degradations Would Lead to the Formation of Advanced Glycation Endproducts (AGEs). the AGEs Exert Multifactorial Effects on Cell Damage Leading to the Onset of Neurological Disorders. the Interaction of AGEs with the Receptors for Advanced Glycation Endproducts (RAGE) Contribute to the Activation of Intracellular Signaling and the Expression of the Pro-Inflammatory Transcription Factors and Various Inflammatory Cytokines. This Inflammatory Signaling Cascade is Associated with Various Neurological Diseases, Including Alzheimer's Disease (AD), Secondary Effects of Traumatic Brain Injury (TBI), Amyotrophic Lateral Sclerosis …

Molecular Cluster Complex Of High-Valence Chromium Selenide Carbonyl As Effective Electrocatalyst For Water Oxidation, Ibrahim Munkaila Abdullahi, Manashi Nath

Chemistry Faculty Research & Creative Works

Developing Simple, Affordable, and Environmentally Friendly Water Oxidation Electrocatalysts with High Intrinsic Activity and Low overpotential Continues to Be an Area of Intense Research. in This Article, a Trichromium Diselenide Carbonyl Cluster Complex (Et₄N)₂[Se₂Cr₃(CO)₁₀], with a Unique Bonding Structure Comprising Bridging Se Groups, Has Been Identified as a Promising Electrocatalyst for Oxygen Evolution Reaction (OER). This Carbonyl Cluster Exhibits a Promising overpotential of 310 MV and a Low Tafel Slope of 82.0 MV Dec⁻¹ at 10 MAcm⁻², with Superior Durability in an Alkaline Medium, for a Prolonged …

Development And Validation Of A Liquid Chromatography-Tandem Mass Spectrometry Method For The Determination Of Temozolomide In Mouse Brain Tissue, Raghavi Kakarla, Kimberly Yacoub, Rebecca L. Bearden, Aimin Zhou, Sanjib Mukherjee, Frank Y. Shan, Baochuan Guo

Chemistry Faculty Publications

Temozolomide is a Food and Drug Administration-approved anticancer drug that has poor drug delivery via oral or intravenous routes. A potential strategy to combat this problem is investigating alternative routes of administration, requiring quantitation of the drug in the brain tissues by liquid chromatography-mass spectrometry. However, current methods used to extract the drug from brain tissues resulted in poor recovery and substantial matrix effects. Herein, we reported a new two-step extraction method that involves the use of Proteinase K to lyse tumor tissues to efficiently release the drug, followed by ethanol protein precipitation. The extracts were then separated on a …

Dipole Cooperativity And Polarization Frustration Determine The Secondary Structure Distribution Of Short Alanine Peptides In Water, Ying Yuan, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

The physical driving forces for secondary structure preferences of hydrated alanine peptide are investigated with B3LYP-D3(BJ) and the adaptive force matching (AFM) method. The AFM fit to the DFT surface, ALA2022, provides excellent agreement with the nuclear magnetic resonance scalar coupling constants from experiments. In turn, the model is used to gain insight into the physical driving forces behind secondary structure preferences of hydrated peptides. DFT calculations with and without the Conductor-like Screening Model (COSMO) show that the α helix is stabilized by solvent polarization due to dipole cooperativity. The two adjacent amide groups in β strand form a near-planar …

Simulating A Flexible Water Model As Rigid: Best Practices And Lessons Learned, Raymond Weldon, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

Two ways to create rigid versions of flexible models are explored. The rigid model can assume the Model’s Geometry (MG) as if the molecule is not interacting with any other molecules or the ensemble averaged geometry (EG) under a particular thermodynamic condition. Although the MG model is more straightforward to create, it leads to relatively poor performance. The EG model behaves similarly to the corresponding flexible model (the FL model) and, in some cases, agrees even better with experiments. While the difference between the EG and the FL models is mostly a result of flexibility, the MG and EG models …

Sustainable Approaches To Photo-, Thermo-, And Electro-Chemical Reactions Of Amines, James David Sitter

Theses and Dissertations

In recent years, sustainable routes for chemical synthesis have garnered renewed interest. As the world continues to fight pollution and rising costs, it is imperative that new routes of synthesis that continuously fight the issues of pollution and waste are discovered, defined and explored. While traditional synthesis routes that require energy input typically require the burning of fossil fuels to produce heat, the amount of resources that go into the production of these fossil fuels and the sequestration of its waste to minimize its impact on the carbon footprint is enormous. Furthermore, sustainable chemistry research aims to decrease and minimize …

Structural And Immunological Characterization Of Inhaled Allergens And Their Complexes With Antibodies, Kriti Khatri

Theses and Dissertations

Allergy is an outcome of an allergen-antibody reaction (1). Potent airborne allergens from dust mites and pets are major causative factors for allergic conditions among predisposed individuals. Group-2 allergen Der p 2 from Dermatophagoides pteronyssinus is a major allergen which causes allergic conditions in more than 80% of mite-allergic subjects (2). Similarly, airborne allergen Can f 1 from dog (Canis familiaris) is also a major risk allergen which affects 10-20% of the population worldwide (3). Considering the increasing prevalence of inhalant allergens in the environment, antigenic characterization is crucial for improving allergy diagnostics and management. This study focuses …

The Kinetic Control Of Polymer Micelles; Chemical Functionality, Material Interactions, And Equilibration, Taylor Larison

Theses and Dissertations

Polymer micelles have found significant uses in areas such as, energy storage devices, catalysis, opto-electronics, drug-delivery, oil additives, and nanoreactors. In many of these applications the overall micelle size (aggregation number) and chemical functionalization determines performance. To progress towards more advanced materials synthesized from the facile bottom-up approach with polymeric micelles the implementation and study of thermodynamic handles were investigated. Here the kinetic control of micelles was studied across a range of applications; independent control over micelle functionality, the spatial orientation of multiple metal oxide nanoparticles in mesoporous materials via self-assembly, and the use of small-angle neutron scattering (SANS) to …

A Microscopic Investigation Of Chemically Modified Membranes For Potential Oil Water Separation Applications, Latifa Rashed Al Nuaimi

Theses

Oil spills can have catastrophic impacts on both the environment and human society, an enormous oil spill known as the Deepwater Horizon Disaster happened in the Gulf of Mexico in April 2010 caused by an explosion of oil rig which started the catastrophe. It is achievable to reduce oil spills by developing and advancing technologies including gravity settling, centrifugation, gas flotation, coagulation, electrochemical, adsorption, and membrane filtration. There are many materials that can be used to form membranes, and each one has unique properties and advantages. The current study used the 3D printing porous membrane which is manufactured with an …

Exploring New Techniques For Precision Deuteration Of Alkenes And Alkynes, Zoua Pa Vang

Dissertations (1934 -)

Deuterium labeled compounds are often utilized in chemical research as internal standards in mass spectrometry, to study reaction mechanisms and in the pharmaceutical industry to slow the rate of metabolism. With the increase interest for deuterium labeled molecules, there is a renewed interest in selective methods for the installation of deuterium atoms into small organic molecules. However, current methods to incorporate deuterium atoms into organic molecules can lead to isotopic mixtures such as isotopologues and isotopomers. These isotopic species are indistinguishable due to their similar physical properties, leading to inseparable products by common purification techniques. Furthermore, common spectroscopic techniques to …

Using Capillary Electrophoresis To Quantify Competitive Binding Of Adsorbates To Silver Nanoparticles, Christopher D. Chung , '23

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are increasingly used commercially and medically due to their antimicrobial and antibacterial properties. With increased use comes increased release of AgNPs into the environment, and once released, AgNPs can form coronas with molecules ranging from biomolecules to proteins to natural organic matter (NOM). The molecules in the corona adsorb to the surface of the AgNPs, drastically altering their innate properties such as cytotoxicity and binding behavior. In this study, we characterize and quantify model AgNP-adsorbate systems by obtaining their relevant reaction parameters through three different affordable analytical techniques, including dynamic light scattering (DLS), UV-vis spectroscopy, and capillary …