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Articles 4591 - 4620 of 33135

Full-Text Articles in Chemistry

An Imaging Mass Spectrometry Investigation Into The N-Linked Glycosylation Landscape Of Pancreatic Ductal Adenocarcinoma And The Development Of Associated Tools For Enhanced Glycan Separation And Characterization, Colin Mcdowell Dec 2022

An Imaging Mass Spectrometry Investigation Into The N-Linked Glycosylation Landscape Of Pancreatic Ductal Adenocarcinoma And The Development Of Associated Tools For Enhanced Glycan Separation And Characterization, Colin Mcdowell

MUSC Theses and Dissertations

The severity of pancreatic ductal adenocarcinoma (PDAC) is largely attributed to a failure to detect the disease before metastatic spread has occurred. CA19-9, a carbohydrate biomarker, is used clinically to surveille disease progression, but due to specificity challenges is not suitable for early discovery. As CA19-9 and other prospective markers are glycan epitopes, there is great clinical interest in understanding the glycobiology of pancreatic cancer. Unfortunately, few studies have been able to link glycosylation changes directly to pancreatic tumors and instead have focused on peripheral glycan alterations in the serum of PDAC patients. To address this gap in our understanding, …

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Groundwater Remediation Using Modified Biochar, Kers Ung-Watson, Ismail Abdulraheem, Nikki Tibayan, Suraj Pochampally Dec 2022

Groundwater Remediation Using Modified Biochar, Kers Ung-Watson, Ismail Abdulraheem, Nikki Tibayan, Suraj Pochampally

Undergraduate Research Symposium Posters

Biochar, a lightweight black residue made of carbon, has proved to be an effective adsorbent to remove TCE from groundwater. Not only is it an economical substitute for conventional adsorbents but it can be created by using a variety of organic materials. For this project, it will rely on walnut shell feedstock to create biochar as this had the best ability to adsorb TCE.

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Photocatalytic Anti-Markovnikov Hydroetherification Of Olefins, Kimberly A. Loyer Dec 2022

Photocatalytic Anti-Markovnikov Hydroetherification Of Olefins, Kimberly A. Loyer

Undergraduate Honors Theses

The development of olefin hydroetherification reactions via the addition of an alcohol nucleophile and hydrogen atom across an unsaturated carbon-carbon bond has remained a sought- after synthetic transformation. The formation of ethers via this methodology has traditionally required the use of transition metals and/or harsh conditions to catalyze the reaction and is challenging to make selective. However, the Nicewicz laboratory has since developed an anti- Markovnikov intramolecular hydroetherification of alkenols using photoredox catalysis. With the mechanism of this pivotal transformation—and of photoredox reactions in general—being largely unexplored mechanistically, the Hirschi lab implemented experimental 13C kinetic isotope effects (KIEs) and density …

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Development Of A Novel Ionic Liquid-Coated Adsorbent For Treating Emerging Contaminants In Recycled Water On The International Space Station, Madeline Carroll, Gabson Baguma, Savanna Vacek Dec 2022

Development Of A Novel Ionic Liquid-Coated Adsorbent For Treating Emerging Contaminants In Recycled Water On The International Space Station, Madeline Carroll, Gabson Baguma, Savanna Vacek

Undergraduate Research Symposium Posters

Synthesize at least 3 biobased ionic liquids. Optimize method for conducting liquid-liquid extractions. Analyze and quantify how much DMSO2 is removed by the ionic liquids. Coat biochar with the most effective biobased ionic liquids.

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Trapping And Cooling Of Ca+ For Cold Ion-Radical Collisions, Bernardo Gutierrez Dec 2022

Trapping And Cooling Of Ca+ For Cold Ion-Radical Collisions, Bernardo Gutierrez

Undergraduate Research Symposium Posters

Free radicals are molecules that contain an unpaired valence electron which induces high reactivity. Ion radical reactions are typically exothermic and have low (or zero) activation energy. It is for these reasons that ion-radical reactions are believed to dominate in interstellar clouds where temperatures hover around 3-10K. State-to-state measurements require precision control of both reactants.

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Molecular Insights Into The Redox Of Atmospheric Mercury Through Laser Spectroscopy, Rongrong Wu Cohen Dec 2022

Molecular Insights Into The Redox Of Atmospheric Mercury Through Laser Spectroscopy, Rongrong Wu Cohen

Theses and Dissertations

The widespread pollution of mercury motivates research into its atmospheric chemistry and transport. Gaseous elemental mercury (Hg(0)) dominates mercury emission to the atmosphere, but the rate of its oxidation to mercury compound (Hg(II)) plays a significant role in controlling where and when mercury deposits to ecosystems. Atomic bromine is regarded as the main oxidant for Hg(0) oxidation, known to initiate the oxidation via a two-step process in the atmosphere – formation of BrHg (R1) and subsequent reactions of BrHg with abundant free radicals Y, i.e., NO2, HOO, etc. (R2), where the reaction of BrHg +Y could also lead to the …

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The Chemistry And Catalytic Activity Of Dehydrogenative Silylation And Hydroboration Of Complexes Bearing Semirigid Ligands With Group 14 Elements, Niroshani S. Abeynayake Dec 2022

The Chemistry And Catalytic Activity Of Dehydrogenative Silylation And Hydroboration Of Complexes Bearing Semirigid Ligands With Group 14 Elements, Niroshani S. Abeynayake

Theses and Dissertations

Incorporation of silicon in the ligand backbone would yield electron-rich metal complexes upon coordination to transition metal complexes. The coordination chemistry of semirigid benzyl phosphines bearing a single or multiple phosphorus atoms and varying number of Si−H moieties has gained interest in recent years. This dissertation focuses on synthesizing silyl and germyl transition metal complexes of groups 9 and 10. Chapter II presents the synthesis of a family of four coordinated 14-electron rhodium complexes. The newly synthesized complexes were characterized in solution by multinuclear NMR spectroscopy and in the solid-state by single-crystal X-ray diffraction. These d6 complexes possess sawhorse …

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Enhanced Neurologic Concept Recognition Using A Named Entity Recognition Model Based On Transformers, Sima Azizi, Daniel B. Hier, Donald C. Wunsch Dec 2022

Enhanced Neurologic Concept Recognition Using A Named Entity Recognition Model Based On Transformers, Sima Azizi, Daniel B. Hier, Donald C. Wunsch

Chemistry Faculty Research & Creative Works

Although Deep Learning Has Been Applied to the Recognition of Diseases and Drugs in Electronic Health Records and the Biomedical Literature, Relatively Little Study Has Been Devoted to the Utility of Deep Learning for the Recognition of Signs and Symptoms. the Recognition of Signs and Symptoms is Critical to the Success of Deep Phenotyping and Precision Medicine. We Have Developed a Named Entity Recognition Model that Uses Deep Learning to Identify Text Spans Containing Neurological Signs and Symptoms and Then Maps These Text Spans to the Clinical Concepts of a Neuro-Ontology. We Compared a Model based on Convolutional Neural Networks …

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The Design, Synthesis, And Investigation Into Small Molecule Modulators Of The Src Homology 2 Domain-Containing Inositol 5’-Phosphatase (Ship), Shea Thomas Meyer Dec 2022

The Design, Synthesis, And Investigation Into Small Molecule Modulators Of The Src Homology 2 Domain-Containing Inositol 5’-Phosphatase (Ship), Shea Thomas Meyer

Dissertations - ALL

The PI3K pathway is a major cell signaling pathway that influences survival and longevity in eukaryotic cells. Abnormal signaling of this pathway has been implicated in a number of disorders, including Alzheimer's disease and cancer. The PI3K pathway utilizes the inositolphospholipid PI(3,4,5)P3 as a key secondary messenger in the transmission of signals from outside the cell to the nucleus. The SRC Homology 2 containing Inositol 5’-Phosphatase (SHIP) also plays a key role in the PI3K pathway, mediating hydrolysis of the inositol phospholipid PI(3,4,5)P3 to PI(3,4)P2. Early testing has shown modulation of SHIP activity through the use of small molecule modulators …

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Free Radical-Based Sequencing For Native Top-Down Mass Spectrometry, Carolina Rojas Ramírez, Rayan Murtada, Jinshan Gao, Brandon T. Ruotolo Dec 2022

Free Radical-Based Sequencing For Native Top-Down Mass Spectrometry, Carolina Rojas Ramírez, Rayan Murtada, Jinshan Gao, Brandon T. Ruotolo

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Native top-down proteomics allows for both proteoform identification and high-order structure characterization for cellular protein complexes. Unfortunately, tandem MS-based fragmentation efficiencies for such targets are low due to an increase in analyte ion mass and the low ion charge states that characterize native MS data. Multiple fragmentation methods can be integrated in order to increase protein complex sequence coverage, but this typically requires use of specialized hardware and software. Free-radical-initiated peptide sequencing (FRIPS) enables access to charge-remote and electron-based fragmentation channels within the context of conventional CID experiments. Here, we optimize FRIPS labeling for native top-down sequencing experiments. Our labeling …

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Computer Simulation Of The Light Absorption Band Of The Jumping Spider Isorhodopsin, Noah Zoldak Dec 2022

Computer Simulation Of The Light Absorption Band Of The Jumping Spider Isorhodopsin, Noah Zoldak

Honors Projects

In order to simulate the photoisomerization of the 9-cis Jumping Spider Isorhodopsin (JSiR-1) it is necessary to first simulate its light-absorption band. Here we report on the absorption band simulated using protein models constructed using the advanced Automatic Rhodopsin Modeling (a-ARM) program. A population of S0 models was created and the corresponding S0 to S1 transitions were determined for each member of the resulting population. The calculation resulted in a Gaussian plot showing that the wavelength of the absorption maximum of 560 nm (a violet color) that is consistent, but red-shifted, with respect the experimentally observed value.

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Standardization Of A Latent Blood Visualizer Based Upon Dna Degradation, Kailey M. Van 'T Hoff Dec 2022

Standardization Of A Latent Blood Visualizer Based Upon Dna Degradation, Kailey M. Van 'T Hoff

Honors Projects

Latent blood visualizers have been used in forensic science since 1937 beginning with Luminol. These visualizers through different types of reactions react with trace amounts of blood that cannot be seen with the naked human eye. These different reactions produce color that can then be seen by examiners. The four types of latent blood visualizers that were compared is luminol, leuco crystal violet, fluorescein, and bluestar. Luminol and bluestar use chemiluminescence, fluorescein uses florescent, and leuco crystal violet uses oxidation to react with iron in hemoglobin. At crime scenes when blood is detected which includes with the blood visualizers the …

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Partial Coalescence Of Cdse/Cds Core/Shell Nanocrystals, Jordyn Wray Dec 2022

Partial Coalescence Of Cdse/Cds Core/Shell Nanocrystals, Jordyn Wray

Honors Program Theses and Research Projects

Quantum dots are semiconductor nanocrystals that are a few nanometers in size that have different optical and electrical properties depending on size and shape. Some applications that quantum dots are used for, include, lasers, quantum computing, and solar cells. The goal of the research was to fuse cadmium selenide, cadmium sulfide (CdSe/CdS) core shells into dimers to increase the communication between particles in these applications. The CdSe were synthesized to 3 nm cores. Various procedures were used for CdSe/CdS synthesis, but the best performing sample contained 5 nm particles in diameter and a promising size for fusion. A metal salt …

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Hydrogen Bonding In Small Model Peptides; The Dft And Mp2 Study, Gracie Smith, Martina Kaledin Dec 2022

Hydrogen Bonding In Small Model Peptides; The Dft And Mp2 Study, Gracie Smith, Martina Kaledin

Symposium of Student Scholars

Formamide is a small model compound for the study of the peptide bond. The peptide bond links amino acids together, specifies rigidity to the protein backbone, and includes the essential docking sites for hydrogen-bond-mediated protein folding and protein aggregation, namely, the C=O acceptor and the N-H donor parts. Therefore, the infrared C=O (amide-I) and N-H (amide-A) vibrations provide sensitive and widely used probes into the structure of peptides. This computational chemistry work, we study hydrogen bonds in formamide dimer isomers. We evaluate the accuracy of the density functional theory (DFT) and many-body perturbation theory to the 2nd order (MP2) …

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Investigating The Electrochemical Behavior Of Dihydropyrrolopyroles For Use As Anodically Coloring Electrochromes, Perry Skiouris, Ally Kisiel, Valentino Sorto, Julia Mauro, Graham Collier Dec 2022

Investigating The Electrochemical Behavior Of Dihydropyrrolopyroles For Use As Anodically Coloring Electrochromes, Perry Skiouris, Ally Kisiel, Valentino Sorto, Julia Mauro, Graham Collier

Symposium of Student Scholars

Electrochromic materials have found widespread use in consumer electronics, energy saving windows, and military applications. They contain unique electronic properties allowing them to undergo a color change in a redox reaction. One classification of these molecules is known as anodically coloring electrochromes (ACEs). When in solution, these compounds are transmissive in the neutral (ground) state and absorb visible light upon oxidation, by the formation of a radical cation, thus making them colored. The focus of this study is the electronic transitions of this radical cation and how chemical modifications to the structures produce a variable color profile. To design prospective …

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Designing And Synthesizing A Warhead-Fragment Inhibitory Ligand For Ivyp1 Through Fragment-Based Drug Discovery, Samuel Moore Dec 2022

Designing And Synthesizing A Warhead-Fragment Inhibitory Ligand For Ivyp1 Through Fragment-Based Drug Discovery, Samuel Moore

Symposium of Student Scholars

Fragment-based drug discovery (FBDD) is a powerful tool for developing anticancer and antimicrobial agents. Within this, magnetic resonance spectroscopy (NMR) provides a comprehensive qualitative and quantitative approach to screening and validating weak and robust binders with targeted proteins, making NMR among the most attractive strategies in FBDD. Inhibitor of vertebrate lysozyme (Ivyp1) of P. aeruginosa serves as an excellent target because of its active cellular location and implications in clinical prognosis for cystic fibrosis and immunocompromised patients. This study uses current NMR and biophysical techniques to develop a covalent, fragment-linked warhead inhibitor for Ivyp1 through synthetic methods, warhead linking, and …

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The Spectral Features And Detectability Of Small, Cyclic Silicon Carbide Clusters, Christopher M. Sehring, C. Zachary Palmer, Brent R. Westbrook, Ryan C. Fortenberry Dec 2022

The Spectral Features And Detectability Of Small, Cyclic Silicon Carbide Clusters, Christopher M. Sehring, C. Zachary Palmer, Brent R. Westbrook, Ryan C. Fortenberry

Faculty and Student Publications

Rovibrational spectral data for several tetra-atomic silicon carbide clusters (TASCCs) are computed in this work using a CCSD(T)-F12b/cc-pCVTZ-F12 quartic force field. Accurate theoretical spectroscopic data may facilitate the observation of TASCCs in the interstellar medium which may lead to a more complete understanding of how the smallest silicon carbide (SiC) solids are formed. Such processes are essential for understanding SiC dust grain formation. Due to SiC dust prevalence in the interstellar medium, this may also shed light on subsequent planetary formation. Rhomboidal Si2C2 is shown here to have a notably intense (247 km mol−1) anharmonic vibrational frequency at 988.1 cm−1 …

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Efforts Towards The Asymmetric De Novo Synthesis Of Lanostanes And Euphanes, Htoo Tint Wai Dec 2022

Efforts Towards The Asymmetric De Novo Synthesis Of Lanostanes And Euphanes, Htoo Tint Wai

Dartmouth College Ph.D Dissertations

Tetracyclic triterpenoids are ubiquitous in nature and biology, with members displaying a wide range of medically relevant properties and occupying rather distinct regions of chemical space. Members of this large class include well-known steroid hormones and sterols as well as structurally interesting subclasses such as lanostanes and euphanes, among others. Comprised of the tetracyclic skeleton with three stereodefined quaternary centers at ring-junction positions, lanostanes and euphanes present synthetic challenges that are different from those encountered in efforts targeting the structurally less complex steroid hormones. Lanostanes, in particular, stand as a historically important class of compounds as significant attention has been …

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Probing Conformational Landscapes And Mechanisms Of Allosteric Communication In The Functional States Of The Abl Kinase Domain Using Multiscale Simulations And Network-Based Mutational Profiling Of Allosteric Residue Potentials, Keerthi Krishnan, Hao Tian, Peng Tao, Gennady M. Verkhivker Dec 2022

Probing Conformational Landscapes And Mechanisms Of Allosteric Communication In The Functional States Of The Abl Kinase Domain Using Multiscale Simulations And Network-Based Mutational Profiling Of Allosteric Residue Potentials, Keerthi Krishnan, Hao Tian, Peng Tao, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

In the current study, multiscale simulation approaches and dynamic network methods are employed to examine the dynamic and energetic details of conformational landscapes and allosteric interactions in the ABL kinase domain that determine the kinase functions. Using a plethora of synergistic computational approaches, we elucidate how conformational transitions between the active and inactive ABL states can employ allosteric regulatory switches to modulate intramolecular communication networks between the ATP site, the substrate binding region, and the allosteric binding pocket. A perturbation-based network approach that implements mutational profiling of allosteric residue propensities and communications in the ABL states is proposed. Consistent with …

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Pyridine Modifications Regulate The Electronics And Reactivity Of Fe–Pyridinophane Complexes, Magy A. Mekhail, Kristof Pota, Sugam Kharel, David M. Freire, Kayla N. Green Dec 2022

Pyridine Modifications Regulate The Electronics And Reactivity Of Fe–Pyridinophane Complexes, Magy A. Mekhail, Kristof Pota, Sugam Kharel, David M. Freire, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

12-Membered pyridinophanes are the focus of many studies as biological mimics, chelators, and catalytic precursors. Therefore, the desire to tune the reactivity of pyridinophanes to better control the applications of derivative metal complexes has inspired many structure–activity relationship studies. However, the separation of structural versus electronic changes imparted by ligand modification has made these structure–activity relationship studies of transition metal catalysts challenging to define. In this work we show that 4-substitution of the pyridine ring in 12-membered tetra-aza pyridinophanes successfully provides a regulatory handle on the electronic properties of the metal center and, therefore, the catalytic C–C coupling activity of …

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A Human Oral Fluid Assay For D- And L- Isomer Detection Of Amphetamine And Methamphetamine Using Liquid-Liquid Extraction, Brian Robbins, Rob E. Carpenter, Mary Long, Jacob Perry Dec 2022

A Human Oral Fluid Assay For D- And L- Isomer Detection Of Amphetamine And Methamphetamine Using Liquid-Liquid Extraction, Brian Robbins, Rob E. Carpenter, Mary Long, Jacob Perry

Human Resource Development Faculty Publications and Presentations

Medical providers are increasingly confronted with clinical decision-making that involves (meth)amphetamines. And clinical laboratories need a sensitive, efficient assay for routine assessment of D- and L-isomers to determine the probable source of these potentially illicit analytes. This paper presents a validated method of D- and L-isomer detection in human oral fluid from an extract used for determination of a large oral fluid assay (63 analytes) on an older AB SCIEX 4000 instrument. Taken from the positive extract, D- and L-analytes were added. The method for extraction included addition of internal standard and a 2-step …

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Wrack Lines Volume 22, Number 2, Fall-Winter 2022-2023, Nancy C. Balcom, Juliana Barrett, Judy Benson, Ben Crnic, Sto Len Dec 2022

Wrack Lines Volume 22, Number 2, Fall-Winter 2022-2023, Nancy C. Balcom, Juliana Barrett, Judy Benson, Ben Crnic, Sto Len

Wrack Lines

With the theme, "Looking Ahead: People and Projects Shaping the Future," the Fall-Winter 2022-2023 leads with the first in what will be a series of articles about offshore wind development impacting Connecticut. That is followed by the inspiring story of how a dying forest was replanted for climate resilience. Next, a profile of longtime marine educator Tim Visel tells about his lasting impact on Connecticut schools and students. Lastly, the complex challenge of dealing with Contaminants of Emerging Concern is examined, with descriptions of how Sea Grant is involved and the particularly troublesome group of substances called PFAS.

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Experimental Identification Of Aminomethanol (Nh2ch2oh)—The Key Intermediate In The Strecker Synthesis, Santosh K. Singh, Cheng Zhu, Jesse La Jeunesse, Ryan C. Fortenberry, Ralf I. Kaiser Dec 2022

Experimental Identification Of Aminomethanol (Nh2ch2oh)—The Key Intermediate In The Strecker Synthesis, Santosh K. Singh, Cheng Zhu, Jesse La Jeunesse, Ryan C. Fortenberry, Ralf I. Kaiser

Faculty and Student Publications

The Strecker Synthesis of (a)chiral α-amino acids from simple organic compounds, such as ammonia (NH3), aldehydes (RCHO), and hydrogen cyanide (HCN) has been recognized as a viable route to amino acids on primordial earth. However, preparation and isolation of the simplest hemiaminal intermediate – the aminomethanol (NH2CH2OH)– formed in the Strecker Synthesis to even the simplest amino acid glycine (H2NCH2COOH) has been elusive. Here, we report the identification of aminomethanol prepared in low-temperature methylamine (CH3NH2) – oxygen (O2) ices upon exposure to energetic electrons. Isomer-selective photoionization time-of-flight mass spectrometry (PI-ReTOF-MS) facilitated the gas phase detection of aminomethanol during the temperature …

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Carbon Cycling And Critical Zone Dynamics In An Urbanized Karst Groundwater System, Amy Hourigan Dec 2022

Carbon Cycling And Critical Zone Dynamics In An Urbanized Karst Groundwater System, Amy Hourigan

Masters Theses & Specialist Projects

Increasing atmospheric CO2 concentrations are correlated to rising global temperatures. Investigating the cumulative global carbon cycling processes is important to understand and quantify the global carbon cycle. By investigating basic geochemical parameters, EpCO2, DIC, and δ13CDIC, at four sites along Lost River Cave (LRC), in Bowling Green, Kentucky, concentrations, fluxes and sources of C dissolved in groundwater were determined. Urban karst groundwater systems, compared to more natural karst landscapes, typically exhibit widespread impervious, heat-absorbing surfaces, urban heat island effects, and increased anthropogenic groundwater inputs and localized CO2 emissions. Carbonate hydrogeochemical …

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Near-Infrared Dye-Glycogen Conjugates For Photodynamic And Photothermal Therapy, Farbod Shirinichi Dec 2022

Near-Infrared Dye-Glycogen Conjugates For Photodynamic And Photothermal Therapy, Farbod Shirinichi

Master's Theses

Near-Infrared (NIR) dyes are small organic molecules emerging as promising imaging agents and therapeutics for anticancer application. However, their small size inevitably resulted in several drawbacks, including low in vivo stability, inherent toxicity, and lack of targeting ability, which compromise their potential for clinical use. This project aims to address those issues by developing a novel “macromolecular” NIR dye. By covalently engineering the glycogen surface with indocyanine green (an FDA-approved NIR dye), we will create a series of glycogen-NIR dye conjugates with a size of 100-200 nm. In addition, this NIR dye is not stable in water for a long …

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Senstive Enantiomeric Analysis Of N-Acyl Homoserine Lactones In Bacterial Matrices, Abiud E. Portillo Dec 2022

Senstive Enantiomeric Analysis Of N-Acyl Homoserine Lactones In Bacterial Matrices, Abiud E. Portillo

Chemistry & Biochemistry Dissertations - Archive

Communication between unicellular organism has long been studied with many facets yet to be discovered. A specific type of communication in gram-negative bacteria is quorum sensing (QS). N-acyl homoserine lactones (N-HLs) are the molecular signals in this process. At a critical concentration of N-HLs, all bacteria of the same population stop behaving like individuals and in a concerted manner induce a specific gene expression which ultimately benefits the entire population in major. This phenomenon has been coined with the term quorum sensing with the main signaling molecules dubbed L-N-acyl homoserine lactones (L-N-HL). Quorum sensing signaling pathways have their influence in …

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A Continuously Renewed Copper Electrode For Constant-Potential Amperometry, Andrew T. Franklin Dec 2022

A Continuously Renewed Copper Electrode For Constant-Potential Amperometry, Andrew T. Franklin

Chemistry & Biochemistry Theses - Archive

Pulsed amperometric detection (PAD) is a well-established technique used for the detection of electroactive compounds following Ion Chromatography (IC). Target analytes, such as carbohydrates and amino acids, typically have no suitable chromophores and are not detectable by suppressed conductivity following IC separation. While direct current (DC) amperometry is simpler, the formation of oxidation products quickly fouls the electrode surface; PAD removes these products extending electrode longevity for up to ~2 weeks of operation. To further extend electrode lifespans, a new strategy is introduced herein using DC amperometry on a sacrificial copper wire anode. The wire face continually dissolves under oxidative …

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Turning Ligands On Their Side: Computational Investigation Into The Binding Of N2o And N2 In Transition Metal Complexes, Cole Donald Dec 2022

Turning Ligands On Their Side: Computational Investigation Into The Binding Of N2o And N2 In Transition Metal Complexes, Cole Donald

Electronic Theses and Dissertations

Common greenhouse gas nitrous oxide (N2O) is a thermodynamically potent and environmentally benign oxidant, making it a desirable target for metal center activation. Unfortunately, N2O is a poor ligand for transition metals due to its weak sigma-donating and pi-accepting properties; as a result, few transition metal complexes capable of interacting with N2O have been found. As the primary source of all nitrogen in organisms, abundant gas dinitrogen (N2) is a crucially important tiny molecule and an essential part of daily existence. However, due to its inertness, it has limited practical uses in …

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Unassisted Photoelectrochemical Solar-To-Hydrogen On Cubi2o4 Photocathodes Using Glycerol As A Sacrificial Oxidant, Caroline Eddy Dec 2022

Unassisted Photoelectrochemical Solar-To-Hydrogen On Cubi2o4 Photocathodes Using Glycerol As A Sacrificial Oxidant, Caroline Eddy

Chemistry & Biochemistry Undergraduate Honors Theses

The need to decarbonize society has driven the development of alternative energy technologies. Solar panels are capable of generating electricity at large scale and at competitive costs to fossil fuels, such as coal or natural gas. However, they are only capable of generating electricity when the sun is out. It is therefore necessary to understand how to store that energy for on-demand use. It is also desirable that the storage be portable, lightweight, and compatible with transportation infrastructure like fossil fuels are. A very desirable chemical fuel is H2 which can be produced simply by water electrolysis. Production of …

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Designing Single Molecule Diode, Tinsae Alem Dec 2022

Designing Single Molecule Diode, Tinsae Alem

Longwood Senior Theses

The field of single molecule electronics is based on using single molecule devices to control current in electronic circuits. One area of interest is to reproduce the functionality of traditional components such as wires, switches, and diodes using single molecule junctions. We used computational chemistry to design diodes to investigate what molecular features affect their performance including using different donors, acceptors, and connectors. A comparison of the diode's performance was made by comparing the rectification ratio. About 50 diodes were designed and tested, with rectification ratios ranging from 1.0 to 5.8. The results indicate that multiple factors have a significant …

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