Chemistry Commons^™

Immobilization Of Electrocatalytically Active Gold Nanoparticles On Nitrogen-Doped Carbon Fiber Electrodes, Daniel Mawudoku

Electronic Theses and Dissertations

Studies of single, isolated nanoparticles provide better understanding of the structure-function relationship of nanoparticles since they avoid complications like interparticle distance and nanoparticle loading that are typically associated with collections of nanoparticles distributed on electrode supports. However, interpretation of results obtained from single nanoparticle immobilization studies can be difficult to interpret since the underlying nanoelectrode platform can contribute to the measured current, or the immobilization technique can adversely affect electron transfer. Here, we immobilized ligand-free gold nanoparticles on relatively electrocatalytically inert nitrogen-doped carbon ultramicroelectrodes that were prepared via a soft nitriding method. Sizes of the particles were estimated by a …

Simple Photochemical Reduction Of Carbon Dioxide To Formate, Ovuokenye Omadoko

Electronic Theses and Dissertations

There is a need to develop techniques for conversion of carbon dioxide to other useful products such as methanol, formaldehyde, formic acid, formate, methane, and hydrocarbons. Carbon dioxide can be converted into these products using different methods such as photochemical, electrochemical, thermochemical and hydrogenation by bacteria. Formate is of interest due to its wide industrial applications which include it’s use in direct liquid fuel cells, as an additive in pyrolysis vapors, a precursor for biological fuels, and it is a key intermediate in methanogenesis breaking down complex organic compounds. In this work, conversion of carbon dioxide to formate was accomplished …

Development Of A Ground-Based Aerial-Tracking Instrument For Open-Path Spectroscopy To Monitor Atmospheric Constituents, Haden Hodges

Civil Engineering Undergraduate Honors Theses

A ground-based aerial-tracking instrument, known as the Ground Tracker, designed to provide spectral data to quantify greenhouse gases is under development. The Ground Tracker includes an Optical System including a high power rifle scope, video camera, and spectrometer used to locate an active light source from the Emitter, and collect spectral data by utilizing an actuating mirror. The implementation of this instrument could be made low cost by utilizing existing weather balloon infrastructure to allow the Emitter to be placed into the lower stratosphere. The recovery of the emitter will be possible by tracking the GPS coordinates. Weather balloon instrument …

Electronic Transmutation: An Aid For The Rational Design Of New Chemical Materials Using The Knowledge Of Bonding And Structure Of Neighboring Elements, Katie A. Lundell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Everything in the universe is made up of elements from the periodic table. Each element has its own role that it plays in the formation of things it makes up. For instance, pencil lead is graphite. A series of honeycomb-like structures made up of carbon stacked on top of one another. Carbon’s neighbor to the left, boron doesn’t like to form such stacked honeycomb-like structures. But, what if there was a way to make boron act like carbon so it did like to form such structures? That question is the basis of the electronic transmutation concept presented in this dissertation. …

Computational And Experimental Studies On Energy Storage Materials And Electrocatalysts, Jared B. Moss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the growing global population comes the ever-increasing consumption of energy in powering cities, electric vehicles, and portable devices such as cell-phones. While the power grid is used to distribute energy to consumers, the energy sources needed to power the grid itself are unsustainable and inefficient. The primary energy sources powering the grid, being fossil fuels, natural gas, and nuclear, are unsustainable as the economically-accessible reserves are continually depleted in exchange for detrimental emissions and air-pollutants. Cleaner, renewable sources, such as solar, wind, and hydroelectric, are intermittent and unreliable during the peak hours of energy usage, that is dawn and …

Synthesis And Biological Studies Of Amphiphilic Compounds Derived From Saccharides And Aminoglycosides, Madher N. Alfindee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Adjacent cells communicate through gap junctions (GJs). These GJs are formed by head to head docking of two hemichannels (HCs) from two adjacent cells. HCs are connexin hexamer proteins. Connexin mutation is the most frequent cause of childhood hearing loss. This hearing impairment affects 2 in every 2000 children. Inhibition of the HCs might be the key factor to treat such disorders. A library of amphiphilic kanamycins was synthesized to be tested as HC inhibitors. These compounds showed excellent inhibition activity in comparison with the parent compound (kanamycin A) with less toxicity.

A library of monosaccharide esters with varying carbon …

Computational Study Of The Ro-Vibrational Spectrum Of Co-Co₂, Eduardo Castro-Juarez, Xiao-Gang Wang, Tucker Carrington Jr., Ernesto Quintas-Sánchez, Richard Dawes

Chemistry Faculty Research & Creative Works

An accurate ab initio ground-state intermolecular potential energy surface (PES) was determined for the CO-CO₂ van der Waals dimer. The Lanczos algorithm was used to compute rovibrational energies on this PES. For both the C-in and O-in T-shaped isomers, the fundamental transition frequencies agree well with previous experimental results. We confirm that the in-plane states previously observed are geared states. In addition, we have computed and assigned many other vibrational states. The rotational constants we determine from J = 1 energy levels agree well with their experimental counterparts. Planar and out-of-plane cuts of some of the wavefunctions we compute …

Enhanced Flocculation Using Drinking Water Treatment Plant Sedimentation Residual Solids, Sandhya Rao Poleneni, Enos Inniss, Honglan Shi, John Yang, Bin Hua, Joseph Clamp

Chemistry Faculty Research & Creative Works

Inefficient removal of total organic carbon (TOC) leads to the formation of carcinogenic disinfection by-products (DBPs) when a disinfectant is added. This study is performed in an effort to develop a simple, non-invasive, and cost-effective technology that will effectively lower organic precursors by having water utilities reuse their treatment residual solids. Jar tests are used to simulate drinking water treatment processes with coagulants-aluminum sulfate (alum), poly-aluminum chloride (PACl), and ferric chloride and their residual solids. Ten coagulant-to-residual (C/R) ratios are tested with water from the Missouri River at Coopers Landing in Columbia, MO versus alluvial ground waters. This treatment results …

Phosphonate-Directed Catalytic Asymmetric Hydroboration: Synthesis Of Functionalized Chiral Secondary And Tertiary Boronic Esters And Mechanistic Insights, Suman Chakrabarty

Department of Chemistry: Dissertations, Theses, and Student Research

Over the past 30 years, catalytic asymmetric hydroboration (CAHB) of alkenes has emerged as a leading methodology to access chiral primary and secondary boronic esters. However, it wasn’t until 2015 that directed-CAHB was for the first time shown to efficiently access chiral tertiary boronic esters. The latter are excellent precursors to synthetically challenging structural motifs such as chiral tertiary alcohols, carbinamines and all-carbon quaternary stereocenters via stereospecific C-B bond substitutions. This dissertation focuses on phosphonate-directed CAHB of diverse alkene substrates, including challenging stereodefined trisubstituted alkenes, to efficiently access multifunctional chiral secondary and tertiary boronic esters. Mechanistic insights obtained via deuterium …

Current-Use Pesticides In New Zealand Streams: Comparing Results From Grab Samples And Three Types Of Passive Samplers, Kimberly J. Hageman, Christopher H.F. Aebig, Kim Hoang Luong, Sarit L. Kaserzon, Charles S. Wong, Tim Reeks, Michelle Greenwood, Samuel Macaulay, Christoph D. Matthaei

Chemistry and Biochemistry Faculty Publications

New Zealand uses more than a ton of pesticides each year; many of these are mobile, relatively persistent, and can make their way into waterways. While considerable effort goes into monitoring nutrients in agricultural streams and programs exist to monitor pesticides in groundwater, very little is known about pesticide detection frequencies, concentrations, or their potential impacts in New Zealand streams. We used the ‘Polar Organic Chemical Integrative Sampler’ (POCIS) approach and grab water sampling to survey pesticide concentrations in 36 agricultural streams in Waikato, Canterbury, Otago and Southland during a period of stable stream flows in Austral summer 2017/18. We …

Highly Active Nanostructured Cos2/Cos Heterojunction Electrocatalysts For Aqueous Polysulfide/Iodide Redox Flow Batteries, Dui Ma, Bo Hu, Wenda Wu, Xi Liu, Jiantao Zai, Chen Shu, Tsegaye Tadesse Tsega, Liwei Chen, Xuefeng Qian, T. Leo Liu

Chemistry and Biochemistry Faculty Publications

Aqueous polysulfide/iodide redox flow batteries are attractive for scalable energy storage due to their high energy density and low cost. However, their energy efficiency and power density are usually limited by poor electrochemical kinetics of the redox reactions of polysulfide/iodide ions on graphite electrodes, which has become the main obstacle for their practical applications. Here, CoS₂/CoS heterojunction nanoparticles with uneven charge distribution, which are synthesized in situ on graphite felt by a one-step solvothermal process, can significantly boost electrocatalytic activities of I⁻/I₃⁻ and S²⁻/S_x²⁻redox reactions by improving absorptivity of …

Self-Assembly, Integration, Characterizations And Applications Of Plasmonic And Excitonic Nanomaterials, Bijesh Kafle

Chemistry and Chemical Biology ETDs

Plasmon on metal nanoparticles can efficiently confine, amplify light at the nanoscale. This property is beneficial for different applications such as harvesting energy of the broad solar spectrum, highly sensitive spectroscopy, photocatalysis, and many other optoelectronic applications. For plasmonic applications, it is necessary to understand the fundamental physical properties of the individual, coupled plasmonic nanomaterials, and their interaction with the surrounding environment, which is not fully understood yet. In this dissertation, the chemical and optical interaction in plasmonic interfaces has been investigated. Plasmon-enhanced photochemistry of p-aminothiophenol as a model molecule is investigated using highly sensitive surface-enhanced Raman spectroscopy (SERS). The …

Stereodynamical Control Of A Quantum Scattering Resonance In Cold Molecular Collisions, Pablo G. Jambrina, James F.E. Croft, Hua Guo, Mark Brouard, Balakrishnan Naduvalath, F. Javier Aoiz

Chemistry and Biochemistry Faculty Research

Cold collisions of light molecules are often dominated by a single partial wave resonance. For the rotational quenching of HD (v=1, j=2) by collisions with ground state para-H2, the process is dominated by a single L=2 partial wave resonance centered around 0.1 K. Here, we show that this resonance can be switched on or off simply by appropriate alignment of the HD rotational angular momentum relative to the initial velocity vector, thereby enabling complete control of the collision outcome.

Capabilities And Limitations Of The Spin Hamiltonian Formalism In Single Molecule Magnets, Philip Ferko

Dissertations

The rational design of molecular magnetic materials is an ongoing effort involving physics, materials science, and chemistry. A common approach to design of complexes and interpretation of magnetic data is the spin Hamiltonian formalism. In this approach, magnetic data is interpreted through constants extracted from the parameterization of data. In design, certain structural motifs are pursued, rationalized by the minimization or maximization of terms in the spin Hamiltonian. In this work, monometallic complexes were prepared to simplify magnetic behavior and allow the examination of specific factors that influence single molecule magnetism like coordination geometry, ligand identity, symmetry, and spin-orbit coupling. …

Optical Gas Imaging Survey Of Oil And Gas Wells In The Uinta Basin, Utah, Seth Lyman, Trang Tran, Marc L. Mansfield

Browse all Datasets

This is a dataset of oil and gas well pads which were surveyed for hydrocarbon emissions with an optical gas imaging camera deployed from the ground at pad edges. The data are described thoroughly in a peer-reviewed paper: Lyman S., Tran, T., Mansfield, M. Ravikumar, A., 2019. Aerial and Ground-Based Optical Gas Imaging Survey of Uinta Basin Oil and Gas Wells.

These are example videos collected during a hydrocarbon emissions survey of oil and gas well pads in Utah.

ExampleGroundVideo.mp4 is a video created with an optical gas imaging camera of an emission plume from well pad equipment. The video …

Small Angle X-Ray Scattering Study Of Conformational Changes In Steroid Responsive Activator (Sra) Rna Upon Binding With Suppressor Protein Sharp, Diane Diatta

Master of Science in Chemical Sciences Theses

ABSTRACT

Differentiation and proliferation are known to be influenced by steroid stimulation. The steroid receptor activator (SRA) RNA is a large RNA transcript indicated to be an epigenetic regulatory component in the steroid receptor coactivator-1 (SRC-1) acetyltransferase complex. It is needed for a response to steroid hormones by tumor cells. However, this activity is hindered by suppressive RNA binding proteins like the SMRT/HDAC1-associated repressor protein (SHARP), which binds the STR7 domain of SRA RNA through its four RNA recognition motifs (RRMs); it is not fully understood how SHARP executes this role as there are no SRA RNA-SHARP structures available for …

60th Annual Rocky Mountain Conference On Magnetic Resonance

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 60th annual meeting of the Rocky Mountain Conference on Magnetic Resonance, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Denver, Colorado, July 21-25, 2019.

Improving Performance Of The Smd Solvation Model: Bondi Radii Improve Predicted Aqueous Solvation Free Energies Of Ions And PkA Values Of Thiols, Saber Mirzaei, Maxim Vadimovich Ivanov, Qadir K. Timerghazin

Chemistry Faculty Research and Publications

Calculation of the solvation free energy of ionic molecules is the principal source of errors in the quantum chemical evaluation of pK_a values using implicit polarizable continuum solvent models. One of the important parameters affecting the performance of these models is the choice of atomic radii. Here, we assess the performance of the solvation model based on density (SMD) implicit solvation model employing SMD default radii (SMD) and Bondi radii (SMD-B), a set of empirical atomic radii developed based on the crystallographic data. For a set of 112 ions (60 anions and 52 cations), the SMD-B model showed …

Calculation Of Molecular Vibrational Spectra On A Quantum Annealer, Alexander Teplukhin, Brian K. Kendrick, Dmitri Babikov

Chemistry Faculty Research and Publications

Until recently molecular energy calculations using quantum computing hardware have been limited to gate-based quantum computers. In this paper, a new methodology is presented to calculate the vibrational spectrum of a molecule on a quantum annealer. The key idea of the method is a mapping of the ground state variational problem onto an Ising or quadratic unconstrained binary optimization (QUBO) problem by expressing the expansion coefficients using spins or qubits. The algorithm is general and represents a new revolutionary approach for solving the real symmetric eigenvalue problem on a quantum annealer. The method is applied to two chemically important molecules: …

The Chemistry And Biology Of Cyclophostin, The Cyclipostins And Related Compounds, Christopher Spilling

Chemistry & Biochemistry Faculty Works

Cyclophostin, the cyclipostins and the salinipostins are structurally related cyclic enolphosphate natural products. This mini review describes their isolation, synthesis and biological activities. In addition, the synthesis and biological activities of monocyclic enolphosphate and mono and bicyclic enolphosphonate analogs are presented.

Development Of Ni-Catalyzed Alkene Dicarbofunctionalization Reactions, Shekhar Kc

Chemistry and Chemical Biology ETDs

Alkenes serve as one of the most important feedstocks for organic synthesis, having two vicinal sites for bond formation. In alkenes, both vicinal sites can be functionalized with two reagents in a process commonly known as alkene difunctionalization, which results in the formation of two new bonds. A number of alkenes difunctionalization reactions, such as diamination, dioxygenation, carboamination and carbooxygenation, are known. However, difunctionalization of alkenes with two carbon-based entities, termed alkene dicarbofunctionalization, is relatively less common. Development of such a process could provide a powerful method to introduce two different carbon fragments across an alkene in a regioselective manner, …

Optimization Of Protein Entrapment In Affinity Microcolumns Using Hydrazide-Activated Silica And Glycogen As A Capping Agent, John Vargas-Badilla, Saumen Poddar, Shiden Azaria, Chenhua Zhang, David S. Hage

David Hage Publications

Several approaches were compared for the entrapment of proteins within hydrazide-activated silica for use in affinity microcolumns and high performance affinity chromatography. Human serum albumin (HSA) and concanavalin A (Con A) were used as model proteins for this work. Items considered in this study included the role played by the solution volume, amount of added protein, and use of slurry vs. on-column entrapment on the levels of solute retention and extent of protein immobilization that could be obtained by means of entrapment. The levels of retention and protein immobilization were evaluated by injecting warfarin or 4-methylumbellipheryl α-D-mannopyranoside as solutes with …

More Homogeneous Capillary Flow And Oxygenation In Deeper Cortical Layers Correlate With Increased Oxygen Extraction, Baoqiang Li, Tatiana V. Esipova, Ikbal Sencan, Kıvılcım Kılıç, Buyin Fu, Michele Desjardins, Mohammad Moeini, Sreekanth Kura, Mohammad A. Yaseen, Frederic Lesage, Leif Østergaard, Anna Devor, David A. Boas, Sergei A. Vinogradov, Sava Sakadžić

Chemistry: Faculty Publications and Other Works

Our understanding of how capillary blood flow and oxygen distribute across cortical layers to meet the local metabolic demand is incomplete. We addressed this question by using two-photon imaging of resting-state microvascular oxygen partial pressure (PO2) and flow in the whisker barrel cortex in awake mice. Our measurements in layers I-V show that the capillary red-blood-cell flux and oxygenation heterogeneity, and the intracapillary resistance to oxygen delivery, all decrease with depth, reaching a minimum around layer IV, while the depth-dependent oxygen extraction fraction is increased in layer IV, where oxygen demand is presumably the highest. Our findings suggest that more …

Acid-Mediated N-Iodosuccinimide-Based Thioglycoside Activation For The Automated Solution-Phase Synthesis Of Α-1,2-Linked-Rhamnopyranosides, Victoria R. Kohout, Alyssa L. Pirinelli, Nicola L.B. Pohl

Chemistry Publications

Carbohydrate structures are often complex. Unfortunately, synthesis of the range of sugar combinations precludes the use of a single coupling protocol or set of reagents. Adapting known, reliable bench-chemistry reactions to work via automation will help forward the goal of synthesizing a broad range of glycans. Herein, the preparation of di- and tri-saccharides of alpha 1→2 rhamnan fragments is demonstrated using thioglycoside donors with the development for a solution-phase-based automation platform of commonly used activation conditions using N-iodosuccinimide (NIS) with trimethylsilyl triflate. Byproducts of the glycosylation reaction are shown to be compatible with hydrazine-based deprotection conditions, lending broader functionality …

Use Of Pope Engagement Index To Measure Cognitive Load Of Physical Modeling Activities In Organic Chemistry, Jenifer Calvert

Master of Science in Chemical Sciences Theses

Understanding how students learn and process information is critical to developing physical modeling activities that facilitate student learning by decreasing cognitive load in the working memory. Optimizing cognitive load during physical modeling activities in organic chemistry is the key to effective and efficient learning. Using EEG (electroencephalogram) and eye tracking technologies, researchers measured and recorded the cognitive processing of participants while they completed a chiral physical modeling activity. Analysis of the data using the Engagement Index developed by Pope et al provided information necessary to develop curriculum that does not undermine student learning due to excessive cognitive load.

Comparison Of Halogen With Proton Transfer. Symmetric And Asymmetric Systems, Jia Lu, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The transfer of the halogen atom X within (A⸳⸳X⸳⸳A)+ systems was calculated for A = NH3, OH2, and CH3, and where X=Cl, Br, and I. These potentials are similar to those computed for equivalent proton transfers. Each contains a single symmetric well for short R(A⸳⸳A) distances. As R is stretched a second minimum appears, separated from the first by a transfer barrier E† which climbs quickly as R is elongated. The central X prefers association with the N in asymmetric systems (H3NX⸳⸳OH2)+, but a second (H3N⸳⸳XOH2)+ minimum, albeit less stable than the first, can appear if R(N⸳⸳O) is stretched.

Unconventional Anticancer Metallodrugs And Strategies To Improve Their Pharmacological Profile, Maria Contel

Publications and Research

No abstract provided.

A Molecular Reconstruction Approach To Sitebased 3d-Rism And Comparison To Gist Hydration Thermodynamic Maps In An Enzyme Active Site, Crystal Nguyen, Takeshi Yamazaki, Andriy Kovalenko, David A. Case, Michael K. Gilson, Tom Kurtzman, Tyler Luchko

Publications and Research

Computed, high-resolution, spatial distributions of solvation energy and entropy can provide detailed information about the role of water in molecular recognition. While grid inhomogeneous solvation theory (GIST) provides rigorous, detailed thermodynamic information from explicit solvent molecular dynamics simulations, recent developments in the 3D reference interaction site model (3D-RISM) theory allow many of the same quantities to be calculated in a fraction of the time. However, 3D-RISM produces atomic-site, rather than molecular, density distributions, which are difficult to extract physical meaning from. To overcome this difficulty, we introduce a method to reconstruct molecular density distributions from atomic site density distributions. Furthermore, …

Synthesis Of New Aliphatic Pseudo-Branched Polyester Co-Polymers For Biomedical Applications, Zachary Shaw

Electronic Theses & Dissertations

In this study, a hyperbranched polyester co-polymer was designed using a proprietary monomer and diethylene glycol or triethylene glycol as monomers. The synthesis was carried out using standard melt polymerization technique and catalyzed by p-Tolulenesulfonic acid. The progress of the reaction was monitored with respect to time and negative pressure, with samples being subjected to standard characterization protocols. The resulting polymers were purified using the solvent precipitation method and characterized using various chromatographic and spectroscopic methods including GPC, MALDI-TOF, and NMR. We have observed polymers with a molecular weight of 29,643 kDa and 33,996 kDa, which is ideal to be …

Effects Of Ionic Liquid Alkyl Chain Length On Denaturation Of Myoglobin By Anionic, Cationic, And Zwitterionic Detergents, Joshua Y. Lee, Katherine M. Selfridge, Eric M. Kohn, Timothy Vaden, Gregory A. Caputo

College of Science & Mathematics Departmental Research

The unique electrochemical properties of ionic liquids (ILs) have motivated their use as solvents for organic synthesis and green energy applications. More recently, their potential in pharmaceutical chemistry has prompted investigation into their effects on biomolecules. There is evidence that some ILs can destabilize proteins via a detergent-like manner; however, the mechanism still remains unknown. Our hypothesis is that if ILs are denaturing proteins via a detergent-like mechanism, detergent-mediated protein unfolding should be enhanced in the presence of ILs. The properties of myoglobin was examined in the presence of a zwitterionic (N,N-dimethyl-N-dodecylglycine betaine (Empigen BB®, EBB)), cationic (tetradecyltrimethylammonium bromide (TTAB)), …