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Full-Text Articles in Organic Chemistry

Du Undergraduate Showcase Abstracts: Research, Scholarship, And Creative Works, Kabe Aberle, Nadia Kako, Kateri Mcrae, Brooke Agulnek, Sky Palmon, Yasmine Ramirez, Francisca Aguirre Beltran, Ashley Juarez, Bridget Kim, Tessa Appel, Sterling Kerr, Spencer Ingley, Gabe Meyer, Robin Tinghitella, Dale Broder, Lily Baeza, Chloe Beers, Julia Coakley, Whitney Kelsey, Sydney Gainforth, Gabi Wing, Audrey Martin, Aaliyah Amore Berry, Brooke Watley, Kiruthika Venkatesan, Rachel Bienstock, Annabella Brotherston, Madison Bryant, Mia Burgener, Emma P. Lieb, Rachel A. Johnson, Jennifer L. Hoffman, Kania Campbell, Kiena Campbell, Courtney Cassidy, Sage Krzyzkowski, Maddox Jones, Skylar Abookire, Luke Hawkins, Sunnah Yoon, Andrea Chu, Yan Qin, Nyah Cubbison, Brian Gearity, Daniel Mcintosh, Mariely Cruz, Edward Garrido, Grady Dionne, Nicole Doris, Lyndsie Salvagio, Ann-Charlotte Granholm-Bentley, Anna Dymov, Hannah Eckert, Gabrielle Welsh, Erica Larson, Charlie Ernst, Anna Zhou, Sarah Watamura, Larissa Fedorovich-Klein, Georgie Fields, Kimberly A. Guevara, Aven Mccall, Ben Peltier, Feruz Yahia, Patrick Flores, Jadyn Floyd, Sophia Forcier, J. Von R. Monteza, Peter Sokol-Hessner, Gwendolyn Geiger, Scott Nichols, Camryn Gunter, Kendal Hengst, Charlie Bednarz, Issy Garside, Addison Baker, Rachel Mina, Brooke Hermanson, Amanda Klingler, William Highfill, Sydney Jaques, Kerstin Lewey, Allison Grossery, Daniel Linseman, Ethan Lim, Jagger Livengood, Owen Mantelli, Gabby Pappas, Abby Mcdonald, Madeleine Dierking, Eve Miller, Emma Loeber, Anna Marlow, Michael Kerwin, Ella Mathews, Hillary Hamann, Khadija Mohamed, Vivian Nguyen, Gabri Notov, Ifunayachi Ogbonna-Ukuku, Sunil Kumar, Charles Baysah, Sarah Olson, Don Sullivan, Anna Paradiso, Jay Parrish, Mira Pronobis, Alisha Pravasi, Kerstin Haring, Diego Ramirez, Christopher Reardon, Juliana Ramirez, Casey Doherty, Ella Kestner, Teagan Weindel, Cate Billings, Pablo Torre-Walter, Lucy Rand, Samantha Reynolds, Mark Siemens, Khadeeja Rashid, Laine Satterlee, Piper Heilbronner, Lily Pound, Ben Whitehurst, Anna Respet, Lizzie Lesoing, Sydney Hertel, Aya Saad-Masri, Brooke Ballenger, Max Proske, Hannah Rosenberg, Ellia Nakahara, Sophia Espinoza, Ivan Woolhouse, Simon Ruland, Gorkem Er, Timothy Sweeny, Melaku Saketa, Michela Schenk, Maren Lynch, Madi Hamm, Grace Schroeder, Michelle Rozenman, Rana Seif, Jackson Hall, Marisela Simental, Daniel Paredes, Aaron Mena, Preston Spaan, Evelyn Stovin, David Andrew Swartz, Anh Tran, Daniel Pittman, Luke Farchione, Emily Boyer, Ukari Verner, Lacey Conrad, Jonathan Velotta, James Weiner, Jagger Gossett, Noah Sherry, Sam Proud, Ben Block, Avi Narayana, Zoey Weiss, Alyssa Wilson, Gabrielle Walsh, David Zonana, Keely Wright, Kena Riveria, Lillybelle Deer, Jena Doom, Elysia Davis, Isabelle Yaremenko, Caitlyn Young Jul 2025

Du Undergraduate Showcase Abstracts: Research, Scholarship, And Creative Works, Kabe Aberle, Nadia Kako, Kateri Mcrae, Brooke Agulnek, Sky Palmon, Yasmine Ramirez, Francisca Aguirre Beltran, Ashley Juarez, Bridget Kim, Tessa Appel, Sterling Kerr, Spencer Ingley, Gabe Meyer, Robin Tinghitella, Dale Broder, Lily Baeza, Chloe Beers, Julia Coakley, Whitney Kelsey, Sydney Gainforth, Gabi Wing, Audrey Martin, Aaliyah Amore Berry, Brooke Watley, Kiruthika Venkatesan, Rachel Bienstock, Annabella Brotherston, Madison Bryant, Mia Burgener, Emma P. Lieb, Rachel A. Johnson, Jennifer L. Hoffman, Kania Campbell, Kiena Campbell, Courtney Cassidy, Sage Krzyzkowski, Maddox Jones, Skylar Abookire, Luke Hawkins, Sunnah Yoon, Andrea Chu, Yan Qin, Nyah Cubbison, Brian Gearity, Daniel Mcintosh, Mariely Cruz, Edward Garrido, Grady Dionne, Nicole Doris, Lyndsie Salvagio, Ann-Charlotte Granholm-Bentley, Anna Dymov, Hannah Eckert, Gabrielle Welsh, Erica Larson, Charlie Ernst, Anna Zhou, Sarah Watamura, Larissa Fedorovich-Klein, Georgie Fields, Kimberly A. Guevara, Aven Mccall, Ben Peltier, Feruz Yahia, Patrick Flores, Jadyn Floyd, Sophia Forcier, J. Von R. Monteza, Peter Sokol-Hessner, Gwendolyn Geiger, Scott Nichols, Camryn Gunter, Kendal Hengst, Charlie Bednarz, Issy Garside, Addison Baker, Rachel Mina, Brooke Hermanson, Amanda Klingler, William Highfill, Sydney Jaques, Kerstin Lewey, Allison Grossery, Daniel Linseman, Ethan Lim, Jagger Livengood, Owen Mantelli, Gabby Pappas, Abby Mcdonald, Madeleine Dierking, Eve Miller, Emma Loeber, Anna Marlow, Michael Kerwin, Ella Mathews, Hillary Hamann, Khadija Mohamed, Vivian Nguyen, Gabri Notov, Ifunayachi Ogbonna-Ukuku, Sunil Kumar, Charles Baysah, Sarah Olson, Don Sullivan, Anna Paradiso, Jay Parrish, Mira Pronobis, Alisha Pravasi, Kerstin Haring, Diego Ramirez, Christopher Reardon, Juliana Ramirez, Casey Doherty, Ella Kestner, Teagan Weindel, Cate Billings, Pablo Torre-Walter, Lucy Rand, Samantha Reynolds, Mark Siemens, Khadeeja Rashid, Laine Satterlee, Piper Heilbronner, Lily Pound, Ben Whitehurst, Anna Respet, Lizzie Lesoing, Sydney Hertel, Aya Saad-Masri, Brooke Ballenger, Max Proske, Hannah Rosenberg, Ellia Nakahara, Sophia Espinoza, Ivan Woolhouse, Simon Ruland, Gorkem Er, Timothy Sweeny, Melaku Saketa, Michela Schenk, Maren Lynch, Madi Hamm, Grace Schroeder, Michelle Rozenman, Rana Seif, Jackson Hall, Marisela Simental, Daniel Paredes, Aaron Mena, Preston Spaan, Evelyn Stovin, David Andrew Swartz, Anh Tran, Daniel Pittman, Luke Farchione, Emily Boyer, Ukari Verner, Lacey Conrad, Jonathan Velotta, James Weiner, Jagger Gossett, Noah Sherry, Sam Proud, Ben Block, Avi Narayana, Zoey Weiss, Alyssa Wilson, Gabrielle Walsh, David Zonana, Keely Wright, Kena Riveria, Lillybelle Deer, Jena Doom, Elysia Davis, Isabelle Yaremenko, Caitlyn Young

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Research Showcase.


A Study Of Ultrafast, Intense-Field Photodynamics In Carbon Dioxide, Carbon Disulfide, And Select Substituted Benzenes, Joshua Edwin Beck May 2025

A Study Of Ultrafast, Intense-Field Photodynamics In Carbon Dioxide, Carbon Disulfide, And Select Substituted Benzenes, Joshua Edwin Beck

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The study of the photodynamics of molecules in ultrashort pulses of intense radiation continues to be of interest. Electric field strengths in such pulses can approach or exceed the typical electric field strengths binding the electrons to the nuclear framework (ke/a20 ≈ 5 × 109 V/cm). The resulting excitation, ionization, and dissociation of molecular targets is of interest in many areas including attosecond science, femtochemistry, atmospheric science, high harmonic generation, and many other fields.

This dissertation investigates the photoionization and photofragmentation behavior of carbon dioxide, carbon disulfide, and the substituted benzenes nitrobenzene, aniline, as …


Characterization And Optimization Of Sand And Tung Oil-Based Resins For Binder-Jet 3d Printing, Daniel I. Ajiola Jan 2025

Characterization And Optimization Of Sand And Tung Oil-Based Resins For Binder-Jet 3d Printing, Daniel I. Ajiola

College of Graduate Studies: Theses & Dissertations

Binder-jet 3D printing as a transformative technology in additive manufacturing, offers the ability to fabricate complex structures with diverse materials. This thesis investigates the use of a sustainable tung oil-based resin to create composites, exploring the potential for an eco-friendly alternative to synthetic binders.

The aim of this research is to develop and characterize a bio-based resin formulation, using tung oil as the primary binder, for application in binder-jet 3D printing with sand as the reinforcement. The resin formulation was prepared by combining tung oil, n-butyl methacrylate, divinylbenzene, and di-tert-butyl peroxide in precise proportions, ensuring a balanced mixture that supports …


Mechanistic Investigation Of C—C Bond Activation Of Phosphaalkynes With Pt(0) Complexes, Roberto M. Escobar, Abdurrahman C. Ateşin, Christian Müller, William D. Jones, Tülay Ateşin Mar 2024

Mechanistic Investigation Of C—C Bond Activation Of Phosphaalkynes With Pt(0) Complexes, Roberto M. Escobar, Abdurrahman C. Ateşin, Christian Müller, William D. Jones, Tülay Ateşin

Research Symposium

Carbon–carbon (C–C) bond activation has gained increased attention as a direct method for the synthesis of pharmaceuticals. Due to the thermodynamic stability and kinetic inaccessibility of the C–C bonds, however, activation of C–C bonds by homogeneous transition-metal catalysts under mild homogeneous conditions is still a challenge. Most of the systems in which the activation occurs either have aromatization or relief of ring strain as the primary driving force. The activation of unstrained C–C bonds of phosphaalkynes does not have this advantage. This study employs Density Functional Theory (DFT) calculations to elucidate Pt(0)-mediated C–CP bond activation mechanisms in phosphaalkynes. Investigating the …


Thermocatalytic Plasma-Assisted Dry Reforming Of Methane Over Ni/Al2o3 Catalyst, Tyler Wong Dec 2023

Thermocatalytic Plasma-Assisted Dry Reforming Of Methane Over Ni/Al2o3 Catalyst, Tyler Wong

Seton Hall University Dissertations and Theses (ETDs)

Plasma catalysis is an advantageous approach that combines the effects of plasma with the enhancements of a catalyst. By utilizing a nickel catalyst in the plasma discharge zone of a dielectric barrier discharge (DBD), it can give an enhancement to the electrical field, boost microdischarges, and increase conversion and selectivity rates of CH4 and CO2 in the dry reforming of methane (DRM) reaction.

Industrial application of nickel catalysts in DBD Plasma DRM process are limited by poor stability, which is caused by the sintering of active metal particles and coke deposition on the catalyst surface. In this work, …


Contributions Of Tunneling In 8Π-6Π Electrocyclic Cascade Reactions Of Bicyclo[4.2.0]Octa-2,4-Diene Moieties, Ishika Jain, Claire Castro, William L. Karney Nov 2023

Contributions Of Tunneling In 8Π-6Π Electrocyclic Cascade Reactions Of Bicyclo[4.2.0]Octa-2,4-Diene Moieties, Ishika Jain, Claire Castro, William L. Karney

Featured Student Work

Six-electron electrocyclic reactions usually require relatively high temperatures; however recent research has shown that such reactions can occur at significantly lower temperatures in biosynthetic and biomimetic pathways. Pathways resulting in bicyclo[4.2.0]octa-2,4-diene moieties arise from thermally allowed 8π-6π electrocyclization cascade reactions of 1,3,5,7-octatetraenes, as in the biosynthesis of endiandric acids, elysiapyrones, and numerous other natural products. We report multidimensional tunneling calculations to explore the possible contribution of heavy-atom tunneling (e.g. by carbon) to biosynthetic pathways and biomimetic syntheses, and thus to provide a more complete picture of biochemical kinetics. M06-2X/cc-pVDZ calculations on the 8π-6π cascade cyclizations of methylated octatetraene model systems …


Non-Destructive Imaging Of Phytosulfokine Trafficking In Plants Using Fiber-Optic Fluorescence Microscopy, Bernard Abakah May 2023

Non-Destructive Imaging Of Phytosulfokine Trafficking In Plants Using Fiber-Optic Fluorescence Microscopy, Bernard Abakah

Electronic Theses and Dissertations

Plants secrete peptide ligands and use receptor signaling to respond to stress and control development. Understanding these phenomena is key to improving plant health and productivity for food, fiber, and energy applications. Phytosulfokine (PSK), a sulfated peptide hormone, regulates plant cell division, growth, and stress tolerance via specific phytosulfokine receptors (PSKRs). This study uses fiber-optic fluorescence microscopy to elucidate trafficking of PSK in live plants. The microscope features two-color optics and an objective lens connected to a 1-m coherent imaging fiber mounted on either a conventional upright microscope body or 5-axis positioning system (X–Y–Z plus pitch and yaw). PSK and …


Magnetic Interactions In Open-Shell Conjugated Polymers, Michael Steelman Jan 2023

Magnetic Interactions In Open-Shell Conjugated Polymers, Michael Steelman

Dissertations

Most materials are closed shell in which every electron participates in a bond, resulting in unremarkable magnetometry signatures and functionalities. While rare, modern technologies rely on magnetic materials in which unpaired electrons are localized to inorganic atomic centers. In recent decades, a collection of organic open-shell π-conjugated molecules have shown magnetic ordering, albeit at exceedingly low temperatures; a result of weak noncovalent intermolecular interactions limiting long range electronic exchange. Thus, practically applicable sp orbital magnetism that persists at or above room temperature remains a grand challenge for chemistry and physics. Despite the wide variety of chemical structures afforded by organic …


Architecture Of Heptagonal Metallo-Macrocycles Via Embedding Metal Nodes Into Its Rigid Backbone, A.M.Shashika D. Wijerathna, He Zhao, Qiangqiang Dong, Qixia Bai, Zhiyuan Jiang, Jie Yuan, Jun Wang, Mingzhao Chen, Markus Zirnheld, Rockwell T. Li, Yuan Zhang, Yiming Li, Pingshan Wang Jan 2023

Architecture Of Heptagonal Metallo-Macrocycles Via Embedding Metal Nodes Into Its Rigid Backbone, A.M.Shashika D. Wijerathna, He Zhao, Qiangqiang Dong, Qixia Bai, Zhiyuan Jiang, Jie Yuan, Jun Wang, Mingzhao Chen, Markus Zirnheld, Rockwell T. Li, Yuan Zhang, Yiming Li, Pingshan Wang

College of Sciences Posters

Metal-organic macrocycles have received increasing attention not only due to their versatile applications such as molecular recognition, compounds encapsulation, anti-bacteria and others, but also for their important role in the study of structure-property relationship at nano scale. However, most of the constructions utilize benzene ring as the backbone, which restricts the ligand arm angle in the range of 60, 120 and 180 degrees. Thus, the topologies of most metallo-macrocycles are limited as triangles and hexagons, and explorations of using other backbones with large angles and the construction of metallo-macrocycles with more than six edges are very rare.

In this study, …


High Figure Of Merit Spin Polarized Electron Sources Grown Via Mocvd, Benjamin Belfore, Adam Masters, Deewakar Poudel, Greg Blume, Stephen Polly, Erdong Wang, Seth M. Hubbard, Marcy Stutzman, Joseph M. Grames, Matt Poelker, Matt Grau, Sylvain Marsillac Jan 2023

High Figure Of Merit Spin Polarized Electron Sources Grown Via Mocvd, Benjamin Belfore, Adam Masters, Deewakar Poudel, Greg Blume, Stephen Polly, Erdong Wang, Seth M. Hubbard, Marcy Stutzman, Joseph M. Grames, Matt Poelker, Matt Grau, Sylvain Marsillac

Electrical & Computer Engineering Faculty Publications

Spin polarized photocathodes are key to the future operation of electron accelerators such as the ones at Thomas Jefferson National Accelerator Facility and Brookhaven National Laboratory. Currently, these photocathodes come in short supply due to limited production by molecular beam epitaxy. By developing a process to implement similar structures using metal organic chemical vapor deposition, the availability of these devices can be increased. In this paper, we detail the implementation of recent photocathode advancements via metal organic chemical vapor deposition process and show an improvement in both polarization and quantum efficiency of our devices compared to those fabricated via molecular …


Solvation Of Large Polycyclic Aromatic Hydrocarbons In Helium: Cationic And Anionic Hexabenzocoronene, Miriam Kappe, Florent Calvo, Johannes Schöntag, Holger F. Bettinger, Serge Krasnokutski, Martin Kuhn, Elisabeth Gruber, Fabio Zappa, Paul Scheier, Olof E. Echt Oct 2022

Solvation Of Large Polycyclic Aromatic Hydrocarbons In Helium: Cationic And Anionic Hexabenzocoronene, Miriam Kappe, Florent Calvo, Johannes Schöntag, Holger F. Bettinger, Serge Krasnokutski, Martin Kuhn, Elisabeth Gruber, Fabio Zappa, Paul Scheier, Olof E. Echt

Faculty Publications

The adsorption of helium on charged hexabenzocoronene (Hbc, C42H18), a planar polycyclic aromatic hydrocarbon (PAH) molecule of D6h symmetry, is investigated by a combination of high-resolution mass spectrometry and classical and quantum computational methods. The ion abundance of HenHbc+ complexes versus size n features prominent local anomalies at n = 14, 38, 68, 82, and a weak one at 26, indicating that for these “magic” sizes the helium evaporation energies are relatively large. Surprisingly, mass spectra of anionic HenHbc– complexes feature a different set of anomalies, namely at …


Development Of High Quantum Efficiency Strained Superlattice Spin Polarized Photocathodes Via Metal Organic Chemical Vapor Deposition, Benjamin Belfore Aug 2022

Development Of High Quantum Efficiency Strained Superlattice Spin Polarized Photocathodes Via Metal Organic Chemical Vapor Deposition, Benjamin Belfore

Electrical & Computer Engineering Theses & Dissertations

Spin polarized photocathodes are necessary to examine parity violations and other fundamental phenomena in the field of high energy physics. To create these devices, expensive and complicated growth processes are necessary. While integral to accelerator physics, spin polarized electrons could have other exciting applications in materials science and other fields of physics. In order to explore these other applications feasibly, the relative supply of spin polarized photocathodes with a high rate of both polarization and photoemission needs to be increased. One such way to increase this supply is to develop the means to grow them faster and at a larger …


Growth Kinetics Determine The Polydispersity And Size Of Pbs And Pbse Nanocrystals, Michael P. Campos, Jonathan De Roo, Matthew W. Greenberg, Brandon M. Mcmurtry, Mark P. Hendricks, Ellie Bennett, Natalie Saenz, Matthew Y. Sfeir, Benjamin Abecassis, Sanjit K. Ghose, Jonathan S. Owen Mar 2022

Growth Kinetics Determine The Polydispersity And Size Of Pbs And Pbse Nanocrystals, Michael P. Campos, Jonathan De Roo, Matthew W. Greenberg, Brandon M. Mcmurtry, Mark P. Hendricks, Ellie Bennett, Natalie Saenz, Matthew Y. Sfeir, Benjamin Abecassis, Sanjit K. Ghose, Jonathan S. Owen

Advanced Science Research Center

A library of thio- and selenourea derivatives is used to adjust the kinetics of PbE (E = S, Se) nanocrystal formation across a 1000-fold range (kr = 10−1 to 10−4 s−1), at several temperatures (80–120 °C), under a standard set of conditions (Pb : E = 1.2 : 1, [Pb(oleate)2] = 10.8 mM, [chalcogenourea] = 9.0 mM). An induction delay (tind) is observed prior to the onset of nanocrystal absorption during which PbE solute is observed using in situ X-ray total scattering. Density functional theory models fit to the X-ray pair distribution function (PDF) support a Pb2(μ2-S)2(Pb(O2CR)2)2 structure. Absorption spectra …


A Local Mode Study Of Ring Puckering Effects In The Infrared Spectra Of Cyclopentane, Edwin L. Sibert Iii, Peter F. Bernath Jan 2022

A Local Mode Study Of Ring Puckering Effects In The Infrared Spectra Of Cyclopentane, Edwin L. Sibert Iii, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

We report and interpret recently recorded high-resolution infrared spectra for the fundamentals of the CH2 scissors and CH stretches of gas phase cyclopentane at −26.1 and −50 ○C, respectively. We extend previous theoretical studies of this molecule, which is known to undergo barrierless pseudorotation due to ring puckering, by constructing local mode Hamiltonians of the stretching and scissor vibrations for which the frequencies, couplings, and linear dipoles are calculated as functions of the pseudorotation angle using B3LYP/6-311++(d,p) and MP2/cc-pVTZ levels of theory. Symmetrization (D5h) of the vibrational basis sets leads to simple vibration/pseudorotation Hamiltonians whose solutions …


Mechanism Of Action Of Dihydropteridine Reductase, Gabriela Arias De La Rosa Feb 2021

Mechanism Of Action Of Dihydropteridine Reductase, Gabriela Arias De La Rosa

Dissertations, Theses, and Capstone Projects

Human dihydropteridine reductase is an enzyme that transfers a hydride from NADH to reduce quinonoid 7,8-dihydropterin (qBH2) to 5,6,7,8-tetrahydropterin (BH4), which is a cofactor important in the production of neurotransmitters.DHPR deficiency causes a drastic form of the neurological genetic disease phenylketonuria (PKU) that does not benefit from a phenylalanine-free diet.From site-directed mutagenesis studies, mostly on Rat DHPR, we know that certain residues are important for cofactor binding, substrate binding, and hydride transfer; however, there are still some questions about how DHPR works, particularly, because there is not a crystal structure of the tertiary complex: What is …


Interactions Of Organic Fluorophores With Plasmonic Surface Lattice Resonances, Robert J. Collison Feb 2021

Interactions Of Organic Fluorophores With Plasmonic Surface Lattice Resonances, Robert J. Collison

Dissertations, Theses, and Capstone Projects

It is common knowledge that metals, alloys and pure elements alike, are lustrous and reflective, the more so when a metal surface is flat, polished, and free from oxidation and surface fouling. However, some metals reflect visible light, in the 380 nm to 740 nm range of wavelengths, much more strongly than others. In particular, some metals reflect wavelengths in certain portions of the ultraviolet (UV), visible, and near-infrared (NIR) regime, let us say 200 nm to 2000 nm, while absorbing light strongly in other segments of this range. There are several factors that account for this difference between various …


Using The Marcus Inverted Region And Artificial Cofactors To Create A Charge Separated State In De Novo Designed Proteins, Eskil Me Andersen Feb 2021

Using The Marcus Inverted Region And Artificial Cofactors To Create A Charge Separated State In De Novo Designed Proteins, Eskil Me Andersen

Dissertations, Theses, and Capstone Projects

To create an efficient de novo photosynthetic protein it is important to create long lived charge separated states. Achieving stable charge separation leads to an increase in the efficiency of the photosynthetic reaction which in turn leads to higher yields of end products, such as biofuels, electrical charge, or synthetic chemicals. In an attempt to create charge separated states in de novo proteins we hypothesized that we could engineer the free energy gaps in the proteins from excited primary donor (PD) to acceptor (A), and A back to ground state PD such that the forward electron transfer (ET) would be …


Nanopore Detection Of Long Time-Scale Single Metallic Cluster Conformational Changes And Surface Ligand Exchange, Bobby D. Cox Jan 2021

Nanopore Detection Of Long Time-Scale Single Metallic Cluster Conformational Changes And Surface Ligand Exchange, Bobby D. Cox

Theses and Dissertations

Single molecule nanopore spectroscopy serves as an emerging tool for studying small molecules in aqueous environments without the need for additional chemical labels. Recently it has been seeing increased use as a tool for investigating small metallic nanoparticles and clusters. These clusters consist of a handful of metallic atoms (e.g. Au18) and are regularly ‘passivated’ with organic ligands to provide functionality and protect against aggregation. There has been a widening gap in research studying the surface kinetics of these passivating ligands at the single molecule level as well as during the exchange process. In this work we investigated these surface …


Simulation Studies On The Interactions Of Electron Beam With Wastewater, X. Li, S. Wang, Helmut Baumgart, G. Ciovati, F. Hannon Jan 2021

Simulation Studies On The Interactions Of Electron Beam With Wastewater, X. Li, S. Wang, Helmut Baumgart, G. Ciovati, F. Hannon

Electrical & Computer Engineering Faculty Publications

The manufactured chemical pollutants, like 1,4 dioxane and PFAS (per- and polyfluroralkyl substances), found in the underground water and/or drinking water are challenging to be removed or biodegraded. Energetic electrons are capable of mediating and removing them. This paper utilizes FLUKA code to evaluate the beam-wastewater interaction effects with different energy, space and divergence distributions of the electron beam. With 8 MeV average energy, the electron beam exits from a 0.0127 cm thick titanium window, travels through a 4.3 cm distance air and a second 0.0127 cm thick stainless water container window with 2.43 cm radius, and finally is injected …


Pressure Driven Desalination Utilizing Nanomaterials, Fangyou Xie Sep 2020

Pressure Driven Desalination Utilizing Nanomaterials, Fangyou Xie

Master's Theses

Nanomaterials such as graphene oxide and carbon nanotubes, have demonstrated excellent properties for membrane desalination, including decrease of maintenance, increase of flux rate, simple solution casting, and impressive chemical inertness. Here, two projects are studied to investigate nanocarbon based membrane desalination. The first project is to prepare hybrid membranes with amyloid fibrils intercalated with graphene oxide sheets. The addition of protein amyloid fibrils expands the interlayer spacing between graphene oxide nanosheets and introduces additional functional groups in the diffusion pathways, resulting in increase of flux rate and rejection rate for the organic dyes. Amyloid fibrils also provide structural assistance to …


Monitoring And Identifying The Rhodamine 6g-Hydroxide Ion Reaction Using In-Situ, Surface-Enhanced Raman Spectroscopy, Ryan Lamb Apr 2020

Monitoring And Identifying The Rhodamine 6g-Hydroxide Ion Reaction Using In-Situ, Surface-Enhanced Raman Spectroscopy, Ryan Lamb

Masters Theses & Specialist Projects

An effective method for monitoring chemical reactions is necessary to better understand their mechanisms and kinetics. Effective reaction monitoring requires a spectroscopy technique with fast data acquisition, high sensitivity, structure-to-spectrum correlation, and low solvent interference. Surface-enhanced Raman spectroscopy (SERS) provides these features, which makes it a valuable tool for monitoring reactions. To obtain the Raman enhancement, metallic nanostructures typically made of silver or gold are aggregated using a salt. The nanoparticles aggregates must then be stabilized using a surfactant to use this method in situ due to eventual nanoparticle precipitation. In this study, gold nanoparticles stabilized with sodium dodecyl sulfate …


A Theoretical And Experimental Study Of Charge Transport In Organic Thermoelectric Materials And Charge Transfer States In Organic Photovoltaics, Ashkan Abtahi Jan 2020

A Theoretical And Experimental Study Of Charge Transport In Organic Thermoelectric Materials And Charge Transfer States In Organic Photovoltaics, Ashkan Abtahi

Theses and Dissertations--Physics and Astronomy

Applications of organic electronics have increased significantly over the past two decades. Organic semiconductors (OSC) can be used in mechanically flexible devices with potentially lower cost of fabrication than their inorganic counterparts, yet in many cases organic semiconductor-based devices suffer from lower performance and stability. Investigating the doping mechanism, charge transport, and charge transfer in such materials will allow us to address the parameters that limit performance and potentially resolve them. In this dissertation, organic materials are used in three different device structures to investigate charge transport and charge transfer. Chemically doped π-conjugated polymers are promising materials to be used …


Functional And Structural Studies Of Cytochromes P450 By Resonance Raman Spectroscopy, Yilin Liu Jul 2017

Functional And Structural Studies Of Cytochromes P450 By Resonance Raman Spectroscopy, Yilin Liu

Dissertations (1934 -)

Cytochrome P450 is a broad class of heme monooxygenase enzymes which catalyze various oxidative transformations. There are two main kinds of mammalian P450s: steroidogenic and drug metabolizing P450s. The first project involves a steroidogenic P450, CYP17A1, occupying a central role in the biosynthesis of steroid hormones. It catalyzes hydroxylation reaction on pregnenolone and progesterone, generating 17OH-pregnenolone and 17OH-progesterone, presumably utilizing a “Compound I” species. However, these hydroxylated products can be further processed in a second oxidative cycle to cleave the C17–C20 bond to form dehydroepiandrosterone or androstenedione, respectively, a crucial step in androgen production. Interestingly, it is well known that …


Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera Jan 2017

Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera

Honors Undergraduate Theses

In this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 μm in the lateral and 3.6 μm in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation while providing a strong signal from the contrast generated by the attenuation of propagating light due to absorption. This enables spatially resolved measurements of single …


Thermal Conductivities Of Organic Semiconductors, Yulong Yao Jan 2017

Thermal Conductivities Of Organic Semiconductors, Yulong Yao

Theses and Dissertations--Physics and Astronomy

Organic semiconductors have gained a lot of interest due to their ease of processing, low-cost and inherent mechanical flexibility. Although most of the research has been on their electronic and optical properties, knowledge of the thermal properties is important in the design of electronic devices as well. Our group has used ac-calorimetric techniques to measure both in-plane and transverse thermal conductivities of a variety of organic semiconductors including small-molecule crystals and polymer blends. For layered crystals composed of molecules with planar backbones and silylethynyl (or germylethynyl) sidegroups projecting between the layers, very high interplanar thermal conductivities have been observed, presumably …


Synthesis And Characterization Of Organic-Inorganic Hybrid Materials For Thermoelectric Devices, Paige M. Huzyak Apr 2016

Synthesis And Characterization Of Organic-Inorganic Hybrid Materials For Thermoelectric Devices, Paige M. Huzyak

Masters Theses & Specialist Projects

The development of organic-inorganic hybrid materials is of great interest in thermoelectrics for its potential to combine the desirable characteristics of both classes of materials. Thermoelectric materials must combine low thermal conductivity with high electrical conductivity, but in most materials, thermal and electrical conductivity are closely related and positively correlated. By combining the low thermal conductivity, flexibility, facile processing, and low cost of organic components with the high electrical conductivity and stability of inorganic components, materials with beneficial thermoelectric properties may be realized.

Here, we describe the synthesis and characterization of anthracene-containing organic-inorganic hybrid materials for thermoelectric purposes. Specifically, POSS-ANT …


Ultrafast Spectroscopy And Energy Transfer In An Organic/Inorganic Composite Of Zinc Oxide And Graphite Oxide, Jeff A. Secor Feb 2016

Ultrafast Spectroscopy And Energy Transfer In An Organic/Inorganic Composite Of Zinc Oxide And Graphite Oxide, Jeff A. Secor

Dissertations, Theses, and Capstone Projects

The energy transfers and nature of defect levels of an organic/inorganic composite of Zinc Oxide and Graphite are studied with multidimensional spectroscopy. The edge and surface states of each composite are uncovered using excitation emission experiments showing which defect states are mediating the energy transfer from the metal oxide to the graphite oxide. Multidimensional time resolved spectroscopy further describes the effect of the carbon phase on the energy transfer pathways in the material.


Proton-Electrostatic Localization: Explaining The Bioenergetic Conundrum In Alkalophilic Bacteria, James Weifu Lee Jan 2015

Proton-Electrostatic Localization: Explaining The Bioenergetic Conundrum In Alkalophilic Bacteria, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

The decades-longstanding energetic conundrum of alkalophilic bacteria as to how they are able to synthesize ATP has now, for the first time, been clearly solved using the proton-electrostatics localization hypothesis. This is a major breakthrough advance in understanding proton-coupling bioenergetics over the Nobel-prize work of Peter Mitchell’s chemiosmotic theory. The widespread textbook Mitchellian proton motive force (pmf) equation has now been significantly revised. Use of the newly derived equation results in an overall pmf value (215~233 mV) that is more than 4 times larger than that (44.3 mV) calculated from the Mitchellian equation for the alkalophilic bacteria growing at pH …


The Synthesis Of A Bisbenzothiophene (Bbt) Based Organic Semiconductor With Increased Function And Increased Solubility, Mary England Jan 2014

The Synthesis Of A Bisbenzothiophene (Bbt) Based Organic Semiconductor With Increased Function And Increased Solubility, Mary England

Senior Honors Theses

Organic semiconductors are growing in applications for use in modern technology.1 The main interest in these molecules can be attributed to their low cost (compared to silicon) and their ability to be used on flexible substrates. There are four features that make a good organic semiconductor. First, the molecule should be conjugated, having alternating single and double bonds (lone electron pairs act similarly to double bonds). Secondly, the molecule should be planar, or flat, in shape. Thirdly, the molecule should have a narrow band gap to increase the overall conductivity. Lastly, the molecule should be soluble to ease application. …


Experimenting With Polymer Blend Solar Cells And Active Layer Thickness, Ryan Blumenthal May 2013

Experimenting With Polymer Blend Solar Cells And Active Layer Thickness, Ryan Blumenthal

Physics

Bulk heterojunction organic photovoltaics utilize the electrical characteristics of semi-conductive polymers. These solution processable materials are beneficial because of their low material cost, light weight, and simple fabrication requirements. Our devices employ multiple photoactive polymers, P3HT and PCPDTBT, to absorb photons over a wide spectral range. We optimized various device characteristics including thickness and thermal anneal usage to reach a power conversion efficiency of 3.0% in AM1.5 sunlight. Device performance degrades over time due to atmospheric water and oxygen, prompting us to investigate device packaging to extend cell lifetime for additional testing.