Other Chemistry Commons^™

Using Molecular Dynamics To Study Qs21 Interactions And Penetration Of Lipid-Cholesterol Bilayers, Sarai Guerrero, Mikko Karttunen

Western Research Forum

Saponins have been used as adjuvant agents for decades in vaccines and therapies, but none are as well studied or heavily used as QS-21. This achievement is notwithstanding the fact that QS-21 usage is limited by its stability, toxicity, and scarcity. These shortcomings have only pushed researchers to develop and experiment with artificial recreations of the saponin to harness its unique benefits. A considerable number of research hours have been poured into this topic, but like QS-21 there is a shortcoming here as well. The number of articles that look at QS-21 interactions with the bilayer or the conditions under …

Drug Improvement And Design Involving G-Protein Coupled Receptors, Gabriel Saliba

Chemistry & Biochemistry Student Projects

No abstract provided.

A Chemical Overview Of Opioid Receptors And Their Agonists, Noah Kuszak

Chemistry & Biochemistry Student Projects

This work is a brief overview of the three main opioid receptors and some current research of the ways we can change the agonists and how they affect the opioid receptor pathway.

Dentin Biomodification Potency Of Proanthocyanidins, David J. Ryker

Chemistry & Biochemistry Student Projects

No abstract provided.

Characterization Of Hydrogen Bonding, Halogen Bonding And Argyrophilic Interactions Using Computational Modeling, Sarah Nicole Arradondo

Electronic Theses and Dissertations

Non-covalent interactions govern multiple important chemical processes throughout nature from those within the human body to the complex environment of the atmosphere. Quantum mechanical electronic structure modeling of these relatively weak interactions can provide molecular level insight that can further our understanding of specific macroscopic properties. In the present work different non-covalent interactions are computationally evaluated within four systems. A small prototypical hydrogen bonded system and the various structural motifs that promoted proton transfer within concentrated acid and water clusters are characterized with sophisticated wavefunction based methods and large robust basis sets in order to accurately predict the structures energies …

Photoluminescent Zirconium Complexes For Visible Light Photoredox Catalysis, Yu Zhang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Early transition metals like zirconium are attractive candidates for the design of luminescent molecules based on earth-abundant elements. Here, a series of zirconium complexes carrying two pyrrolyl-based ligands have been synthesized and characterized. These complexes are photoluminescent upon excitation with visible light and exhibit remarkably long emission lifetimes of hundreds of μs in solution at room temperature. Computational studies using time-dependent density functional theory (TD-DFT) were conducted to identify the nature of the luminescent excited states as mixed intra-ligand/ligand-to-metal charge-transfer (ILCT/LMCT) states. The electrochemistry studies revealed multiple reversible redox events for each zirconium complex. Furthermore, the excited state of the …

Atom-Specific Activation In Co Oxidation, Simon Schreck, Elias Diesen, Jerry Larue, Hirohito Ogasawara, Kess Marks, Dennis Nordlund, Matthew Weston, Martin Beye, Filippo Cavalca, Fivos Perakis, Jonas Sellberg, André Eilert, Kyung Hwan Kim, Giacomo Coslovich, Ryan Coffee, Jacek Krzywinski, Alex Reid, Stefan Moeller, Alberto Lutman, Henrik Öström, Lars G. M. Pettersson, Anders Nilsson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report on atom-specific activation of CO oxidation on Ru(0001) via resonant X-ray excitation. We show that resonant 1s core-level excitation of atomically adsorbed oxygen in the co-adsorbed phase of CO and oxygen directly drives CO oxidation. We separate this direct resonant channel from indirectly driven oxidation via X-ray induced substrate heating. Based on density functional theory calculations, we identify the valence-excited state created by the Auger decay as the driving electronic state for direct CO oxidation. We utilized the fresh-slice multi-pulse mode at the Linac Coherent Light Source that provided time-overlapped and 30 fs delayed pairs of soft …

Nanoparticles And Their Use In Cancer Imaging, Prevention And Treatment, George Gray

Chemistry & Biochemistry Student Projects

No abstract provided.

Tomatine And Furocoumarins: Toxins In Commonly Consumed Plants, Julia Noonan

Chemistry & Biochemistry Student Projects

No abstract provided.

Development Of Chemistry Activities For Local Outreach In Stem, Emily Knight

Chemistry & Biochemistry Student Projects

Introduction: This research project was started because of an increase in outreach opportunities for the Department of Chemistry and Biochemistry. For similar opportunities, we now have bins of content that are simple to use, encouraging more students to participate in volunteer research.

Purpose: to find, modify, and/or create grade-level appropriate labs and demonstration activities for 5th-8th graders, with a specific focus on activities hat involve easily available components. These activities are intended to be used for outreach to local schools by chemistry student volunteers and released online to act as a resource for teachers.

Educational Resources: Polymers, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

This document contains 3 polymer-based activities demonstrating different properties of polymers - the physical characteristics, possible absorbency, and elasticity. These activities can be abbreviated and used in rotating stations, planned over multiple days, or you can pick on that fits best with the classroom environment.

Educational Resources: Ionic Matching, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

The entire point of this piece is simply to introduce balancing charges in ionic compounds. This is a simpler method to get students thinking about the idea, which also makes it suitable for pre-high school students. It gives a visual representation of how charges balance and cow cations pair with anions. At this level, it is very similar to least common denominator calculations.

Educational Resources: Homemade Fluorometer, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

Educational Resources: Exchange Rates And Unit Conversion, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

Students might have experience in 3rd-6th grade with converting basic ideas such as volume and measurements. This is intended to expand that idea and introduce the mole. It's also a general interactive conversion/exchange activity. All items in here are just based on what we had available and convenient, so feel free to swap out items such as rubber stoppers with something more easily available …

Educational Resources: Curie Point Engine, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

The Curie point of a metal is the temperature at which it loses its magnetic characteristics. Heat can cause magnets to stop being magnetic, which is why heating up magnets is not advised. The engine works because the Curie point of nickel is 354 degrees Celsius, a temperature that can be reached with a simple candle flame. Included are instructions about how to build …

Educational Resources: Magnets, Emily Knight

Chemistry & Biochemistry Student Projects

No abstract provided.

Photoelectrochemical Studies On Non-Noble Metal Based Catalysts Towards Tandem Solar Water Splitting, Arun Siddarth Sridhar

Dissertations

Photoelectrochemical (PEC) water splitting makes direct use of solar energy incident on semiconductor photoelectrodes, and it is a convenient, economic option to produce high purity hydrogen at low temperatures. The use of multiple light absorbers can increase overall solar energy utilization and provide a solution to the trade-off between overall band gap and band edge positioning of photoelectrodes specific to solar water oxidation and water reduction. The study of non-noble metal based catalysts for hydrogen evolution reaction (HER) and oxygen evolution reactions (OER) are essential for economic practical commercialization of photo-electrolyzers. This dissertation focuses on the use of a variety …

Secondary Electronic And Solvent Effects On Regiospecific P-Bromination Of Aromatic Systems, Selahaddin Gumus

Masters Theses & Specialist Projects

Bromoarenes are important aromatic building blocks that are commonly used to synthesize various functional compounds in pharmaceutical, agrochemical and related industries.^1,2 This great demand for bromoarenes makes their preparation a widely studied area of synthetic organic chemistry. However, further understanding of the reactivity and regiochemistry of aromatic functionalization reactions is still necessary, as much about the secondary substitution and solvent effects remain unknown.

Resonance Theory is a widely used theoretical model to predict the regiospecifity and reactivity of the bromination of various aromatic compounds.³ The reactivity and regiospecificity of many substituted aromatic compounds is well explained using resonance …

Organic Photochemistry: Remote Delivery Of Reactive Oxygen Intermediates Via A Heterogeneous Approach, Niluksha Walalawela Abeykoon

Dissertations, Theses, and Capstone Projects

Photosensitized oxidation reactions produce a number of intermediates species, which are generated in varying amounts over time. This complexity presents major challenges in the study of oxidation processes. Mechanistic efforts to separate and deliver reactive oxygen intermediates enable their controlled use in processes such as bacterial inactivation. This thesis describes a heterogeneous reaction approach taken to control the generation and delivery of reactive oxygen intermediates. The mechanistic details of photosensitized reactions were elucidated via synthetic, materials, and physical organic techniques to optimize the delivery of reactive oxygen intermediates. This thesis contains six chapters as described below.

Chapter 1 gives a …

Gas-Phase Studies Of Nucleophilic Substitution Reactions: Halogenating And Dehalogenating Aromatic Heterocycles, Leah L. Donham

Theses and Dissertations

Halogenated heterocycles are common in pharmaceutical and natural products and there is a need to develop a better understanding of processes used to synthesize them. Although the halogenation of simple aromatic molecules is well understood, the mechanisms behind the halogenation of aromatic heterocycles have been more problematic to elucidate because multiple pathways are possible. Recently, new, radical-based mechanisms have been proposed for heterocycle halogenation. In this study, we examine and test the viability of possible nucleophilic substitution, S_N2@X, mechanisms in the halogenation of anions derived from the deprotonation of aromatic heterocycles. All the experiments were done in a …

Development Of Photocatalysts Supported On Graphitic Carbon Nitride For The Degradation Of Organic Water Pollutants, Atanu Giri

Theses and Dissertations

Graphitic carbon nitride (g-C₃N₄) heterojunction composites with the semiconducting metal oxides, CeO₂, ZnO and TiO₂ are prepared in situ by co-calcination of the precursor materials or by a solvothermal method. The structural, morphological and the optical properties of the prepared materials are studied using various microscopy and spectroscopy techniques. The synthesized composite materials, CeO₂/g-C₃N₄, ZnO/g-C₃N₄ and TiO₂/g-C₃N₄ are more efficient in the photocatalytic degradation of the water pollutants indigo carmine (IC) and atrazine than the pure metal oxide, g-C …

Eigenstate–Specific Temperatures In Two–Level Paramagnetic Spin Lattices, Mark Masthay, Calley N. Eads, Amber N. Johnson, R. Gerald Keil, Phillip Miller, Ross E. Jones, Joe D. Mashburn, Harry B. Fannin

Chemistry Faculty Publications

Increasing interest in the thermodynamics of small and/or isolated systems, in combination with recent observations of negative temperatures of atoms in ultracold optical lattices, has stimulated the need for estimating the conventional, canonical temperature Tconvc of systems in equilibrium with heat baths using eigenstate-specific temperatures (ESTs). Four distinct ESTs—continuous canonical, discrete canonical, continuous microcanonical, and discrete microcanonical—are accordingly derived for two-level paramagnetic spin lattices (PSLs) in external magnetic fields. At large N, the four ESTs are intensive, equal to Tconvc, and obey all four laws of thermodynamics. In contrast, for N < 1000, the ESTs of most PSL eigenstates are non-intensive, differ from Tconvc, and violate each of the thermodynamic laws. Hence, in spite of their similarities to Tconvc at large N, the ESTs …

The Autophagy-Related Beclin-1 Protein Requires The Coiled-Coil And Bara Domains To Form A Homodimer With Submicromolar Affinity, Matthew J. Ranaghan, Michael A. Durney, Michael F. Mesleh, Patrick R. Mccarren, Colin W. Garvie, Douglas S. Daniels, Kimberly L. Carey, Adam P. Skepner, Beth Levine, Jose R. Perez

Chemistry Faculty Publications

Beclin-1 (BECN1) is an essential component of macroautophagy. This process is a highly conserved survival mechanism that recycles damaged cellular components or pathogens by encasing them in a bilayer vesicle that fuses with a lysosome to allow degradation of the vesicular contents. Mutations or altered expression profiles of BECN1 have been linked to various cancers and neurodegenerative diseases. Viruses, including HIV and herpes simplex virus 1 (HSV-1), are also known to specifically target BECN1 as a means of evading host defense mechanisms. Autophagy is regulated by the interaction between BECN1 and Bcl-2, a pro-survival protein in the apoptotic pathway that …

Phase Behavior Of Binary And Polydisperse Suspensions Of Compressible Microgels Controlled By Selective Particle Deswelling, A. Scotti, U. Gasser, E. S. Herman, Jun Han, A. Menzel, L. Andrew Lyon, A. Fernandez-Nieves

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We investigate the phase behavior of suspensions of poly(N-isopropylacrylamide) (pNIPAM) microgels with either bimodal or polydisperse size distribution. We observe a shift of the fluid-crystal transition to higher concentrations depending on the polydispersity or the fraction of large particles in suspension. Crystallization is observed up to polydispersities as high as 18.5%, and up to a number fraction of large particles of 29% in bidisperse suspensions. The crystal structure is random hexagonal close-packed as in monodisperse pNIPAM microgel suspensions.We explain our experimental results by considering the effect of bound counterions. Above a critical particle concentration, these cause deswelling of the largest …

Controlled Electrochemical Synthesis Of Single One-Dimensional Metal Nanochains Across Microgap Electrodes., Amareshwari Konutham

Electronic Theses and Dissertations

This study mainly focuses on the fabrication of single one dimensional (1D) NP chains across the 5-micron gap of Au two electrode devices (TED). This has been achieved by electrochemical deposition of Ag onto the two electrodes, soaking the TED in 0.1 M Cetyltrimethyl ammonium bromide for 2-3 hours, and then close monitoring of the current as a function of time while a voltage across the two Ag coated Au electrodes in air. One dimensional Ag nanoparticle chain formation occurred by oxidation of Ag to Ag⁺ at the positive electrode followed by movement of Ag⁺ ions to the …

Ab Initio Methyl Linoleate Bond Dissociation Energies: First Principles Fishing For Wise Crack Products, Zachary Ryan Wilson

Graduate Theses/Dissertations

With the prices of petroleum reflecting demand for this finite resource, attention has been turned to alternative sources of energy. Biodiesel, defined as fatty acid methyl esters (FAMEs), exhibits many of the same properties as conventional diesel but is derived from biological sources. FAMEs are subsequently thermally cracked to form more light-weight petrochemical products. I aim to further understand the thermal cracking procedure, at an atomic-level, in hopes that this may aid in future engineering of viable fuels. I studied the effective computational modeling of bond disassociations in the FAME methyl linoleate. Bond dissociation in a 44-reaction database with known …

Application Of Bottlebrush Block Copolymers As Photonic Crystals, Allegra L. Liberman-Martin, Crystal K. Chu, Robert H. Grubbs

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Brush block copolymers are a class of comb polymers that feature polymeric side chains densely grafted to a linear backbone. These polymers display interesting properties due to their dense functionality, low entanglement, and ability to rapidly self-assemble to highly ordered nanostructures. The ability to prepare brush polymers with precise structures has been enabled by advancements in controlled polymerization techniques. This Feature Article highlights the development of brush block copolymers as photonic crystals that can reflect visible to near-infrared wavelengths of light. Fabrication of these materials relies on polymer self-assembly processes to achieve nanoscale ordering, which allows for the rapid preparation …

Ab Initio And Semi-Empirical Calculations Of Cyanoligated Rhodium Dimer Complexs, Yazeed Asiri

Electronic Theses and Dissertations

Molecular modeling, using both ab initio and semi-empirical methods has been undertaken for a series of dirhodium complexes in order to improve the understanding of the nature of the chemical bonding in this class of homogeneous catalysts. These complexes, with carboxylamidate and carboxylate ligands, are extremely functional metal catalysts used in the synthesis of pharmaceuticals and agrochemicals. The X-ray crystallography shows anomalies in the bond angles that have potential impact on understanding the catalysis. To resolve these issues, minimum energy structures of several examples (e.g. Rh₂(NHCOCH₃)₄, Rh₂(NHCOCH₃)₄NC, Rh …

Analyzing The Kinetics Of A Bromophenol Blue Fading Reaction In Basic Conditions For An Undergraduate Lab, Zeljka Popovic

Georgia College Student Research Events

Bromophenol blue is a common pH indicator and dye used in many different industries. Once a solution of bromophenol blue is placed in a concentrated basic solution, the color fades from a blue/violet color to clear solution with a pH of 4.6 or greater. The rate law of the reaction is analyzed through the use of a small footprint visible-near-infrared spectrometer (Vis-NIR) with a diode array detector. An absorbance wavelength of 590 nm as a function of time was collected using Ocean Optics OceanView software. The results contained in the data collection file are exported to a spreadsheet for further …

Catalysis In Real Time Using X-Ray Lasers, A. Nilsson, Jerry L. Larue, H. Öberg, H. Ogasawara, M. Dell’Angela, M. Beye, H. Öström, J. Gladh, J. K. Nørskov, W. Wurth, F. Abild-Pedersen, L. G. M. Pettersson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We describe how the unique temporal and spectral characteristics of X-ray free-electron lasers (XFEL) can be utilized to follow chemical transformations in heterogeneous catalysis in real time. We highlight the systematic study of CO oxidation on Ru(0001), which we initiate either using a femtosecond pulse from an optical laser or by activating only the oxygen atoms using a THz pulse. We find that CO is promoted into an entropy-controlled precursor state prior to desorbing when the surface is heated in the absence of oxygen, whereas in the presence of oxygen, CO desorbs directly into the gas phase. We monitor the …