Chemistry Commons^™

Photocathodes From Aerobic Oxidation Of Tellurorhodamines, Amelia Jellison

Dissertations and Theses

Growing environmental concerns have facilitated an increased need for renewable energy. Solar energy is an excellent source of renewable energy, however current dye-sensitized solar cells are not efficient enough for commercial use. This thesis attempts to create a novel dye-sensitized cathode to increase the efficiency of dye-sensitized solar cells.

Dye-sensitized cathodes could lower the energy level on the cathode and thereby increase the overall efficiency of the solar cell, however until now it has not been attempted. A tellurorhodamine dye with a mesityl ring was chosen as the dye for its ability to aerobically oxidize in the presence of light. …

Quantitative Characterization And Prediction Of The Binding Determinants And Immune Escape Hotspots For Groups Of Broadly Neutralizing Antibodies Against Omicron Variants: Atomistic Modeling Of The Sars-Cov-2 Spike Complexes With Antibodies, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Nishank Raisinghani, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

A growing body of experimental and computational studies suggests that the cross-neutralization antibody activity against Omicron variants may be driven by the balance and tradeoff between multiple energetic factors and interaction contributions of the evolving escape hotspots involved in antigenic drift and convergent evolution. However, the dynamic and energetic details quantifying the balance and contribution of these factors, particularly the balancing nature of specific interactions formed by antibodies with epitope residues, remain largely uncharacterized. In this study, we performed molecular dynamics simulations, an ensemble-based deep mutational scanning of SARS-CoV-2 spike residues, and binding free energy computations for two distinct groups …

Epr Imaging Workshop: From Theory And Practice To Applications, Arthur H. Heiss, Ralph T. Weber, Sandra S. Eaton, Gareth R. Eaton

TeachEPR Submissions

Methods of imaging and insights from imaging are described. Practical aspects of sample type and dimensions are described.

Workshop presented at the 27th International EPR Symposium, sponsored by Bruker BioSpin EPR Division and the University of Denver, in Denver, Colorado on August 1, 2004.

Workshop On The Epr Of Aqueous Samples, Gareth R. Eaton

TeachEPR Submissions

The problem with water and other materials that absorb microwave energy are described. Dielectric properties are described as a function of frequency.

Workshop presented at the 25th International EPR Symposium on July 28, 2002.

Electro-Oxidative Deoxyfluorination Of Arenes With Net3·3hf, En Chih Liu, Sabrina M. Reich, Mayank Tanwar, Matthew Neurock, Long Luo, Melanie S. Sanford

Chemistry Faculty Research & Creative Works

This report describes the design, development, and optimization of an electrochemical deoxyfluorination of arenes using a tetrafluoropyridine-derived leaving group. NEt₃·3HF serves as the fluoride source, and the reactions are conducted using either constant potential or constant current electrolysis in an undivided electrochemical cell. Mechanistic studies support a net oxidative pathway, in which initial single-electron oxidation generates a radical cation intermediate that is trapped by fluoride. The resulting radical undergoes a second oxidation reaction, followed by the loss of the leaving group to yield the fluoroarene product.

Special Purpose Epr Resonators, Gareth R. Eaton

TeachEPR Submissions

Many types of EPR resonators are described.

Special applications that use various resonators are mentioned.

Lab Practical: Cw Basics, Gareth R. Eaton

TeachEPR Submissions

1. How do you position the sample in the resonator?
2. How do you select the center field for a spectrum?
3. How do you select the modulation amplitude?
4. How do you select the microwave power?

Lab Practical: Transition Metals: Epr Of A Vanadyl Complex, Gareth R. Eaton

TeachEPR Submissions

1. What information can you obtain from a spectrum of one orientation of a single crystal that is wide enough to encompass all of the vanadium hyperfine lines?

2. How does the spectrum change when you rotate the crystal? Look at both the position of the center of the spectrum and the hyperfine splitting.

How To Measure B1, Gareth R. Eaton

TeachEPR Submissions

• CW Methods
• Pulsed EPR Methods

Lab Practical: Nitroxides, Gareth R. Eaton

TeachEPR Submissions

1. How do you fill a capillary tube with an aqueous solution? How are capillaries positioned in the resonator?
2. How does the spectrum of a nitroxide change when the viscosity of a solution is increased?
3. How do you determine the concentration of the radical in the solution?

Lab Practical: Pulse Epr, Gareth R. Eaton

TeachEPR Submissions

1. How do you over-couple the resonator for a pulse experiment?
2. How do you find a 2-pulse echo?
3. How do you select the microwave attenuation?

How To Measure Q, Gareth R. Eaton

TeachEPR Submissions

•Frequency bandwidth
–Using spectrometer frequency sweep
–Using a network analyzer

•Ring down following a pulse

Advances In Pyrazolo[1,5-A]Pyrimidines: Synthesis And Their Role As Protein Kinase Inhibitors In Cancer Treatment, Terungwa H. Iorkula, Osasere Jude Kelly Osayawe, Daniel A. Odogwu, Latifat Oluwatobi Ganiyu, Emmanuel Faderin, Raymond Femi Awoyemi, Busayo Odunayo Akodu, Ikhazuagbe Hilary Ifijen, Omowunmi Rebecca Aworinde, Peter Agyemang, Odo Lovelyn Onyinyechi

Michigan Tech Publications

Pyrazolo[1,5-a]pyrimidines are a notable class of heterocyclic compounds with potent protein kinase inhibitor (PKI) activity, playing a critical role in targeted cancer therapy. Protein kinases, key regulators in cellular signalling, are frequently disrupted in cancers, making them important targets for small-molecule inhibitors. This review explores recent advances in pyrazolo[1,5-a]pyrimidine synthesis and their application as PKIs, with emphasis on inhibiting kinases such as CK2, EGFR, B-Raf, MEK, PDE4, BCL6, DRAK1, CDK1 and CDK2, Pim-1, among others. Several synthetic strategies have been developed for the efficient synthesis of pyrazolo[1,5-a]pyrimidines, including cyclization, condensation, three-component reactions, microwave-assisted methods, and green chemistry approaches. Palladium-catalyzed crosscoupling …

Motion Of Nitroxide Radicals, Gareth R. Eaton

TeachEPR Submissions

A brief outline is presented of how motion of a nitroxide radical can be estimated from the continuous wave (CW) EPR line shape.

Lab Practical: Rapid Scan Epr, Gareth R. Eaton

TeachEPR Submissions

• To develop an understanding of the rapid scan experiment relative to other EPR methods.
• To observe the effects of scan rate on samples with differing T₂ relaxation times.

Infrared Cooling In An Anharmonic Cascade Framework: 2-Cyanoindene, The Smallest Cyano-Pah Identified In Tmc-1, Mark H. Stockett, Vincent J. Esposito, Eleanor K. Ashworth, Ugo Jacovella, James N. Bull

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Infrared (IR) cooling of polycyclic aromatic hydrocarbon (PAH) molecules is a major radiative stabilization mechanism of PAHs present in space and is the origin of the aromatic infrared bands (AIBs). Here, we report an anharmonic cascade model in a master equation framework to model IR emission rates and emission spectra of energized PAHs as a function of internal energy. The underlying (simple harmonic cascade) framework for fundamental vibrations has been developed through the modeling of cooling rates of PAH cations and other carboneaous ions measured in electrostatic ion storage ring experiments performed under “molecular cloud in a box” conditions. The …

Discovery And Functional Characterization Of Biomarkers In Clear Cell Renal Cell Carcinoma, Wagma Caravan

Arts & Sciences Graduate Student Theses and Dissertations

Not all tumors are created equally, nor should they be treated as such. Modern research has uncovered a multitude of genetic aberrations, genomic dysregulation, and epigenetic modifications that contribute to cancer. While cancers are classified based on their tissue of origin and may share common features or pathways, the tumor microenvironment is far from uniform. It comprises a dynamic network of cell populations with divergent genomic profiles, all of which collectively drive tumor progression—with some tumors more efficient and aggressive than others. The heterogeneity within these tumors makes it notoriously harder to treat, as standard therapies fail to address the …

Workshop On Quantitative Epr, Dave Barr, Sandra S. Eaton, Gareth R. Eaton, Ralph T. Weber, Patrick Carl, Peter Höfer, Richard W. Quine, George A. Rinard, Colin Mailer

TeachEPR Submissions

Presentations on quantitative EPR at the workshop that preceded the writing of our text, Quantitative EPR.

Presented at the 31^st Annual EPR Symposium in Breckenridge, Colorado on July 27, 2008.

Types Of Epr Resonators, Gareth R. Eaton

TeachEPR Submissions

Fundamental properties of resonators are described with photographs of a variety of actual EPR resonators.

Distances Between Spins, Gareth R. Eaton

TeachEPR Submissions

• Distance measurement by measuring T₁ and T_2.
• Relation to DEER and CW simulation and half-field intensity.
• Dipolar and exchange interactions.
• The dynamic NMR spectral collapse picture.

Epr Workshop: Lab Practicals Summary, Gareth R. Eaton

TeachEPR Submissions

• Basics – nitroxide and trityl
• Nitroxides
• Metals - vanadyl
• Pulse
• Rapid scan

Vanadium Line Shapes, Gareth R. Eaton

TeachEPR Submissions

VO²⁺ complexed with water, acetylacetonate, and/or other ligands yields a well-resolved 8-line spectrum (I = 7/2 for V) in solution. Powder spectra show that the hyperfine couplings are anisotropic.

Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter

Engineering Faculty Articles and Research

With the expanding use of polymers in additive manufacturing, sustainable resins for use in vat photopolymerization are required to reduce their environmental impact. One promising approach to achieve this is to incorporate biobased fillers that replace the acrylates in photopolymer resins as ‘green’ alternatives. In this study, photopolymer composites consisting of a methacrylate resin with varying calcium carbonate powder content between 0 and 50 wt.% were investigated. A digital light processing technique was used to fabricate tensile test specimens for mechanical testing. Good printability, dimensional accuracy, and good interlayer adhesion were observed for composite resin formulations that incorporated calcium carbonate …

Effective Learning Strategies In Stem, Muzammil Arshad, Rebecca R. Romatoski, Mamoona Muzammil

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Effective learning strategies were developed, implemented, and applied at five separate institutions of higher education in the United States, and one in the Middle East. The research has been dedicated to determining effective learning strategies for student learning and success. The research series developed grading rubric for homework and exams, developed a course structure for hybrid and face-to-face courses in STEM, and studied the impact of the syllabus design on student learning and motivation. A pedagogical methodology constituting the designed course structure was utilized to use various activity-based modules. Course lectures were designed to utilize PowerPoint presentations and/or OneNote as …

Analysis Of 26 Studies Of The Impact Of Coconut Oil On Lipid Parameters: Beyond Total And Ldl Cholesterol, Mary T. Newport, Fabian M. Dayrit

Chemistry Faculty Publications

Coconut oil (CNO) is often characterized as an “artery-clogging fat” because it is a predominantly saturated fat that ostensibly raises total cholesterol (TChol) and LDL cholesterol (LDL-C). Whereas previous analyses assessed CNO based on the relative effects on lipid parameters against other fats and oils, this analysis focuses on the effects of CNO itself. Here, we review the literature on CNO and analyze 984 lipid profile data sets from 26 CNO studies conducted over the past 40 years. This analysis shows considerable heterogeneity among CNO studies regarding participant selection, the amount consumed, and the study duration. The analysis reveals that, …

Dft Study Of The Mechanism Of Selective Hydrogenation Of Acetylene By Rhodium Single-Atom Catalyst Supported On Hy Zeolite, Melisa Su Yordanlı, Roberto Escobar, Jessica Meza, Deniz Akgül, Yuxin Zhao, Alper Uzun, Fatma Ahu Akin, Viktorya Aviyente, Abdurrahman Cagri Atesin, Tülay A. Ateşin

School of Earth, Environmental, & Marine Sciences Faculty Publications

The selectivity of acetylene hydrogenation by the Rh single-atom catalyst (SAC) supported on HY zeolite was investigated using density functional theory (DFT) and a 5/83T quantum mechanics/molecular mechanics (QM/MM) embedded cluster model. The calculated activation barrier (ΔG‡) for the oxidative addition of dihydrogen to the Rh metal center (15.9 kcal/mol) is lower in energy than that for the σ-bond metathesis of dihydrogen to the Rh—C bond (22.7 kcal/mol) and the Rh—O bond (28.4 kcal/mol). The activation barriers of the oxidative addition of subsequent dihydrogen molecules are significantly higher than that of the oxidative addition of the first dihydrogen molecule. These …

Consequences Of Oxidative Dna Damage: Base-Pair Dissociation, Singlet Oxygenation And Dna-Protein Crosslinking, May Myat Moe

Dissertations, Theses, and Capstone Projects

8-Oxo-2′-deoxyguanosine (OG) is a common DNA lesion resulting from oxidatively generated damage and pairs with complementary cytidine (C) in Watson Crick base-pairing within duplex DNA. The WC-OG·C lesion, if not recognized or repaired, not only leads to G⋅C→T⋅A transversion mutations (through Hoogsteen (HG) base pairing of OG⋅A), but also renders the base pair being more vlunerable to ionizing radiation and singlet oxygen (1O2) damage. Leveraging on our previous accomplishments on the study of gas-phase reactions of 1O2 with 2′-deoxyguanosine radical cations, my research thesis expanded to the investigation of reaction dynamics of 9-methyl-8-oxoguanine (9MOG) radical cations. The experiments of following …

Investigating Dna Damage Caused By Reactive Oxygen And Nitrogen Species Via Guided-Ion-Beam Scattering And Computational Techniques, Jonathan Benny

Dissertations, Theses, and Capstone Projects

Among DNA nucleobases, guanine (G) is the primary target for one-electron ionization and oxidation, generating G●+ through various processes, including photooxidation, electrocatalytic oxidation, DNA-binding transition metals, ionizing radiation, and photolysis. This is due to the low adiabatic ionization potential and oxidation potential of guanine. Electron holes from other nucleobases can move to guanine, proving that G●+ production traps oxidative DNA damage. G●+ formation can exacerbate DNA damages and cause secondary reactions from reactive oxygen species (ROS) and reactive nitrogen species (RNS) during pathological processes. The following three projects were conducted using a customized electrospray ionization (ESI) guided-ion-beam tandem mass spectrometer, …

Studies On The Synthesis, Function, And Properties Of Troponoids, John-Charles A. Baucom

Dissertations, Theses, and Capstone Projects

Troponoids are a unique class of non-benzenoid aromatic compounds with a wide range of demonstrated applications in pharmaceuticals and molecular sensing. The cycloheptatrienone scaffold possesses a noteworthy degree of tunability as a function of ring oxygenation. This manuscript describes our efforts toward a better understanding of the physical consequences of the scaffold to better utilize the motif. Chapter the first discusses our efforts at elucidating the mechanism of troponoid inhibition of the Hepatitis B virus reverse transcriptase RNAse H enzymatic domain. Using homology modeling in conjunction with traditional in vitro assays we were able to establish the likely mechanism of …

Tracing The Sources Of Nitrogen In Submarine Groundwater Discharge And Primary Producers In The Great South Bay Estuary, Nia H. Rene

Dissertations, Theses, and Capstone Projects

The primary aim of this research was to elucidate the impact of submarine groundwater discharge (SGD) and septic effluent on coastal primary producers in the Great South Bay (GSB). The study focused on three main objectives: assessing the impact of precipitation patterns on SGD, tracing nitrogen sources into the GSB, and determining the impact of these nitrogen sources on coastal primary producers. The research revealed that current precipitation patterns significantly influence SGD across different seasons, highlighting the seasonal variability in groundwater discharge and its implications for nutrient loading in coastal waters. A suite of tracers was employed to identify and …