Digital Commons Network^™

Novel Thermally Decomposable Cobalt Materials, Yu-Jui Chang

Master's Theses

Developing suitable material precursors of reduced metal films plays an important role inflexible electronics. We introduce a relatively low-temperature sintering liquid material that may be used to pattern a conductive layer. The liquid material is made of oxidized metal carboxylate salts along with liquid amines or carboxylic acids. When heated above ca. 220 C, this material spontaneously decomposes into reduced metal and various gas-phase products. Inideal (albeit not this) cases, this yields an adherent, electrically conducting perfect metal mirror.Such materials, inks if you will, conserve metal and plate only where deposited, thus meeting an important ecological goal of metal conservation. …

Initial Characterization Of Prna From Burkholderia Ambifaria: Developing An Nadph-Dependent Activity Assay For Tryptophan Halogenation, Mahmuda Akter

Theses and Dissertations

Some bacteria produce a potent antifungal agent (pyrrolnitrin) from tryptophan using four dioxygen dependent steps to outcompete other microbes. Each step of this process is catalyzed by an oxygenase encoded by the prnABCD cassette. The first enzymatic step in pyrrolnitrin biosynthesis is the regioselective chlorination of tryptophan to form 7-chlorotryptophan. This halogenation is catalyzed by PrnA, a Flavin dependent oxygenase, which has been isolated and characterized from P. fluorescens. The pyrrolnitrin biosynthesis pathway (prnABCD) has been also observed in the Burkholderia genus. This thesis comprises my studies on the expression, purification, and characterization of PrnA from Burkholderia ambifaria. Beyond the …

Quantum Mechanics-Based Computational Chemistry Has Become A Powerful Partner In The Scientific Research Of Nitrogen-Rich Compounds, Paving The Way For Important Advances In Biochemical, Pharmacological And Other Related Fields, Dobrushe Denburg

Student Theses and Dissertations

The Computational Chemistry of Nitrogen-Rich Compounds; Insight into Pioneering Research

Nitrogen-rich functional groups have long been studied for their diversity; nitrogen can form single, double and triple bonds with itself, and will therefore exist in a very broad range of molecular arrangements. Poly-nitrogen compounds are highly energetic and electron rich, and many compounds display unique properties that allow participation in very specialized chemical reactions. Of import is their ubiquity in biological systems, and throughout the past century and currently, their biological relevance is deeply and widely explored in biochemistry and biomedicine, from their involvement in natural biological processes and complex …

Proof Positive: Applications Of Chemical Analysis Techniques In Art Forgery Detection, Joseph Fryc

Museum Studies Theses

In response to the subjective nature of older forgery detection techniques, modern forgery detection methods rely heavily on chemical analysis of the materials utilized in a given piece of work in order to make authenticity determinations. Chemical methods of detection at their core provide an objective determination of facts regarding the composition of materials utilized in contested pieces and provide a relative date of production for those materials. In this way, chemical analysis helps service the field of modern forgery detection as a direct compliment to traditional stylistic analysis, by providing extra data on the piece that can often be …

Development Of Bioaffinity Based Assays For Forensic Applications, Juliana Maria Agudelo Cano

Legacy Theses & Dissertations (2009 - 2024)

In the field of forensic science, body fluids are a major contributor of evidence in investigations. However, body fluids are usually used only for their genetic content, overlooking its unique composition of proteins and low-molecular-weight compounds that often serve as biomarkers in clinical diagnostics. This investigation aimed to develop simple, effective, and economical models that can be used to identify different attributes of the originator. The focus of this research was to develop biocatalytic cascades that could analyze body fluids by using UV-Vis spectroscopy. These models could be implemented in forensic settings, as well as in biometric authentications. The central …

The Impact Of Project-Based Learning On Students In High School Chemistry In Rural Maine, Brianna Degone

Electronic Theses and Dissertations

Project-based learning (PBL) is an instructional strategy that is promoted throughout education for its use of active learning and ability to connect to real-world applications. Studies have been conducted on PBL ranging from early elementary grades through graduate courses, however little research considers the effectiveness of PBL at the secondary science level. This thesis considers the use of PBL and describes the implementation of a PBL unit in a rural Maine 11th grade chemistry classroom. The thesis aims to better understand the impact PBL has on students’ content learning and additional skills acquired through the PBL learning process. Along with …

Investigating The Effect Of Allostery On Downstream Biology Of The Epidermal Growth Factor Receptor, Deepto Mozumdar

Yale Graduate School of Arts and Sciences Dissertations

The Epidermal Growth Factor Receptor (EGFR) is a member of the receptor tyrosine kinase (RTK) family of human proteins with a critical role in transducing diverse extracellular chemical information to initiate multiple cellular signaling cascade in the cell that are essential for normal cell development. Aberrant activation of this receptor via mutation or overexpression misregulates this flow of information and is implicated in a multiple human carcinoma. Thus, understanding the molecular mechanisms by which chemical information is encoded and decoded in EGFR is imperative both from a basic cell biology and therapeutic standpoint. In this thesis consisting of four chapters, …

The Role Of Hydrogen Bonding And Hydrogen Migration In Different Environments, Nassim Beiranvand

Chemistry Theses and Dissertations

Hydrogen bonding is one of the most important topics in chemistry and has been a subject of many studies for years, using both experimental techniques and computational methods. My dissertation focuses on mechanistic studies of various types of intermolecu-lar and intramolecular hydrogen bonding in di˙erent systems based on quantum chemical calculations. In my work, I investigated the interplay of ring puckering and hydrogen bonding in DNA building blocks; hydrogen bonding in natural and unnatural base pairs and the nature of dihydrogen bonding by applying the Ring Puckering Analysis and the Local Vibrational Mode Theory (LVM). An additional aim of my …

From Small Molecules To Infinite Crystals: Probing Noncovalent Interactions Through Vibrational Spectroscopy, Sadisha Nanayakkara

Chemistry Theses and Dissertations

During my four years in the CATCO group supervised by Dr. Kraka, I have been exposed to various topics targeted to address a multitude of chemical problems, broadening our knowledge of modern chemistry research as we know it. In undertaking the age-old problem of understanding the nature of chemical bonding, I could modestly contribute with my work, using in-house tools based on vibrational spectroscopy.

First part of my dissertation is focused on inventing new methods and tools to efficiently investigate chemical bonding, followed by the study of some non-covalent interactions, imperative in catalysis and solid-state chemistry. This includes analysis of …

Synthesis Of P-Glycoprotein Inhibitor Compounds, Maha Aljowni

Chemistry Theses and Dissertations

SYNTHESIS OF P-GLYCOPROTEIN INHIBITOR COMPOUNDS Advisor: Professor Alexander R. Lippert Doctor of Philosophy conferred: August 4th, 2021 Dissertation completed: August 4th, 2021 A problem with cancer treatment is that many cancers develop resistance to chemotherapeutic agents, causing them to fail to accumulate in resistant cancer cells long enough to have any effect. This is due to the overexpression of a plasma membrane protein called P-glycoprotein (P-gp). Generally, the role of P-gp is to protect the cells from any toxins or foreign substances by pumping these toxins (including chemotherapeutic drugs) out of the cell. I am collaborating with the Wise-Vogel laboratory …

Application Of Artificial Intelligence And Machine Learning In Chemistry, Niraj Verma

Chemistry Theses and Dissertations

In the last four years, I have been exposed to various topics in scientific research under the supervision of Dr. Kraka in the CATCO group. Numerous involved chemistry projects were undertaken to gain an understanding of the basic laws of nature involving vibrational spectroscopy, molecular acidity, and catalysts based on transition metals for halogen chemistry. The insights from computational chemistry were then applied to model and predict various complicated problems in chemistry via artificial intelligence. With the help of classical artificial intelligence, the non-covalent interactions governing the properties of proteins and water properties were analyzed. Significant improvements were made in …

Quantum Chemical Investigation Of Novel Noncovalent Interactions Utilizing Vibrational Spectroscopy, Seth Francis Yannacone

Chemistry Theses and Dissertations

Theoretical/computational methods have been utilized to investigate a diverse array of questions currently at the forefront of modern chemistry research. The focus of this work is Local Vibrational Mode (LVM) Theory, originally formulated by Konkoli and Cremer, and under continuous development by the CaTcO research group. Derived from LVM theory, local stretching force constants (ka) represent physically meaningful measurements of chem- ical bond strength. Decomposition of normal vibrational modes into LVM contributions, also called characterization of normal modes (CNM), is another powerful manifestation of LVM theory; most notably when applied to the analysis of theoretical/experimental IR/Ra- man spectra. Recent developments …

Identification Of Chemical Structures And Substructures Via Deep Q-Learning And Supervised Learning Of Ftir Spectra, Joshua D. Ellis

MSU Graduate Theses

Fourier-transform infrared (FTIR) spectra of organic compounds can be used to compare and identify compounds. A mid-FTIR spectrum gives absorbance values of a compound over the 400-4000 cm^-1 range. Spectral matching is the process of comparing the spectral signature of two or more compounds and returning a value for the similarity of the compounds based on how closely their spectra match. This process is commonly used to identify an unknown compound by searching for its spectrum’s closes match in a database of known spectra. A major limitation of this process is that it can only be used to identify …

Structure And Reactivity Of The First Row Transition Metals Bearing Redox-Active Ligands And Tunable H-Bonding Interactions, Khashayar Rajabimoghadam

Chemistry Theses and Dissertations

Metalloenzymes, as natural catalysts, can break a reaction with high activation energy to multiple small reactions with lower activation energies; in these small reactions, multiple bonds form and dissociate rapidly, some metalloenzymes use redox-active ligands in their active site to provide the needed electrons for these multiple small reactions. Additionally, in the secondary coordination sphere in the vicinity of the metalloenzymes, the hydrogen bonding interactions facilitate the transfer and interaction of the substrates and the stabilization of the active intermediates. These unique features in metalloenzymes inspired chemists to design molecular models that can partially mimic the structure and reactivity of …

Ahr Expression On Rorc-Expressing Immune Cells Is Essential For I3c-Mediated Protection Against Colitis, Michal C. Williams

Senior Theses

Colitis is an inflammatory bowel disorder (IBD) whose etiology is attributed to modification in the luminal microbiota and dysregulation in the immune response. Indole is a signaling molecule which is naturally produced by gut luminal microbiota. Indole-3- carbinol (I3C) is a compound commonly found in vegetables and a ligand for the aryl hydrocarbon receptor (AhR). Previous studies have detected decreased expression and activation on the AhR receptor in colitis patients, thought to possibly alter gut microbiota metabolism, subsequently promoting colitis. 1 AhR, expressed in a variety of immune and epithelial cells, contributes to gut homeostasis by affecting vital mediators such …

Emergent Photophysics In Diketopyrrolopyrrole Superstructures, Andrew Levine

Dissertations, Theses, and Capstone Projects

Organic semiconductors have received substantial attention as active components in optoelectronic devices because of their processability and customizable electronic properties. Tailoring the organic active layer in these devices to exhibit desirable optoelectronic properties requires understanding the complex and often subtle structure-property relationships governing their photophysical response to light. Both structural organization and frontier molecular orbitals (FMO) play pivotal roles in energy relaxation processes, and complex interplay between organization and orbital energies are difficult to anticipate based upon the molecular structure of the components alone, especially in systems comprised of multiple components. In pursuit of design rules, there is a need …

The Synthesis Of Heterogeneous Catalysts: Transition Metal Nanoparticles Encapsulated In Halloysite And Applications In Organic Transformations, Jumanah Hamdi

University of New Orleans Theses and Dissertations

The natural scrolled clay, halloysite, was studied as a catalyst and solid support for the development of encapsulated transition metal nanoparticles (M@Hal). With the unique tubular nanostructure, raw halloysite exhibited remarkable chemical reactivity superior to other clays in the esterification of biomass-derived carboxylic acids. Raw halloysite was also effective in the esterification of various aromatic and non-aromatic carboxylic acids. These results indicated that halloysite has the potential utility as a “Green” heterogeneous catalyst for a broad scope of esterification applications. A novel Pd@Hal nanocomposite was synthesized under ambient conditions. The newly prepared catalyst was applied to the widely used Suzuki-Miyaura …

Cu-Promoted C-H Bond Hydroxylation Inspired By Cu-Dependent Metalloenzymes, Rachel Trammell

Chemistry Theses and Dissertations

From 2003 to 2015, Schӧnecker and Baran proposed a dinuclear Cu/O₂ species in their mechanistic proposal for the hydroxylation of sp³ C-H bonds within their systems (proposed based on yields). Inspired from the site selectivity of this methodology and poor analysis of the mechanism, the first project was inspired to re-examine the sp³ C-H bond hydroxylation by Schrӧnecker and Baran and perform an intensive investigation into understanding how Cu/O₂ interact which led us to propose a new mechanism based on the evidence collected (i.e., LCu^II-hydroperoxide species that undergoes homolytic O-O bond cleavage). From there …

Mechanistic Studies Of Catalysis Through Quantum Chemical And Machine Learning Approaches, Malgorzata Makos

Chemistry Theses and Dissertations

Chemical catalysis is one of the most important applications in chemistry and has been developed for years, using both experimental techniques and computational methods.

The first part of my dissertation focuses on mechanistic studies of various types of catalysts based on quantum chemical calculations. In my work, I investigated [NiFe] hydrogenase, [NHC]Au(I)-catalysts, and actinide sandwich complexes, by applying theoretical tools ranging from vibrational spectroscopy to all-electron relativistic methodologies. New comprehensive insights into the reaction mechanisms were obtained, forming the basis for the design of the next generation of catalysts.

An additional aim of my research included the development of innovative …

Investigations Involving Mononuclear And Dinuclear Transition Metal Catalysts For Photochemical Carbon Dioxide Reduction, Ansu Edwards

Honors Theses

There is currently a global energy crisis, which is in desperate need of solutions. New energy sources are required that will not pollute as much as our longstanding reliance on nonrenewable fossil fuels as an energy source. This pollution involves large amounts of greenhouse gas emissions, predominantly carbon dioxide (CO₂), that contribute to environmental problems such as climate change. In this context, a fairly recent research direction to address this problem is the development of transition metal catalysts that can convert CO₂ into reduced carbon products that can serve as chemical fuels. This work focuses on the …

Applications Of Sodium Azide In The Synthesis Of Tetrazines And Hydrolysis Reactions, My Le

Honors Theses

The inverse electron demand Diels−Alder cycloadditions of heterocyclic azadienes have provided a robust methodology for synthesizing highly substituted and functionalized heterocycles. It is widely used in organic synthesis and the pharmaceutical industry in the divergent construction of screening libraries and bioorthogonal conjugation. Each heterocyclic azadiene was found to possess a unique reactivity toward different classes of dienophiles, display predictable modes of cycloaddition, and exhibit substantial substituent electronic effects impacting their intrinsic reactivity and cycloaddition regioselectivity. Synthesis of 1,2,4,5-tetrazine has been reported in the literature since the late 19th century, showing scientists' tremendous interest in its application.

Herein we attempt to …

Small Molecule Activation By Transition Metal Complexes: Studies With Quantum Mechanical And Machine Learning Methodologies, Justin Kyle Kirkland

Doctoral Dissertations

One of the largest areas of study in the fields of chemistry and engineering is that of activation of small molecules such as nitrogen, oxygen and methane. Herein we study the activation of such molecules by transition metal compounds using quantum mechanical methods in order to understand the complex chemistry behind these processes. By understanding these processes, we can design and propose novel catalytic species, and through the use of data-driven machine learning methods, we are able to accelerate materials discovery.

Synthesis Of A Zinc Dipyrrin Complex For Photocatalytic Reduction Of Co2, Sylvia Meredith

Undergraduate Honors Theses

Zinc dipyrrin complexes have the potential to act as cheap, effective photosensitizers. Synthesizing and studying different types could lead to more efficient solar energy harvesting processes, especially the production of solar fuel. Here, two attempts to synthesize 1,3,7,9-tetraphenyl-5-mesityldipyrromethene are reported and discussed. According to ¹H NMR, the first synthesis attempt was not successful. The second synthesis attempt was not purified effectively, so ¹H NMR produced inconclusive results. Further purification strategies or alternate synthesis methods are required.

A Project To Dye For : Differentiation Of Dyed And Non-Dyed Human Hairs Using Atr Ft-Ir Spectroscopy, Joseph John Greco

Legacy Theses & Dissertations (2009 - 2024)

IR spectroscopy is widely utilized for forensic purposes due to the chemical fingerprint the method provides. ATR FT-IR spectroscopy is particularly advantageous because it allows for spectra to be collected quickly, accurately, and perhaps most importantly for forensics, non-destructively. Human hair is commonly collected at a crime scene, and further analyzed using DNA analysis and microscopy. However, these techniques have limitations. In the past ATR FT-IR spectroscopy has shown promise in the analysis of human hair for forensic purposes. In this study, the differentiation of undyed hair versus dyed hair classes of varying colors based on their IR spectra were …

Understanding The Non-Classical Secretion Mechanism Of Interleukin-1 Alpha, Clay Martin

Chemistry & Biochemistry Undergraduate Honors Theses

The Interleukin 1 family is a unique collection of cytokines in that they are primarily associated with both acute and chronic inflammation, which is associated with many diseases. In classical protein secretion, a protein, typically with an N-terminal signal peptide, is synthesized on a ribosome of a cell either in the cytoplasm or on the rough endoplasmic reticulum, transported to and merges with the Golgi apparatus, and is then sent to bind with either a lysosome or the cell membrane or is released from the cell via exocytosis. Thus, a non-classical secretion mechanism is any mechanism that differs from this. …

Synthesis Of A Dd-Π-Aa Organic Dye For Dye-Sensitized Solar Cells, Hope Lovell

Honors Theses

This project investigates the synthesis of a DD-π-AA (dual donor/dual acceptor) organic dye as a potential sensitizer for dye-sensitized solar cells (DSCs). The design of this dye was based off previous research that found dual donor/dual acceptor dyes exhibited promising results when used in a DSC. The donor groups, acceptor groups, and π-bridge were chosen for their stability, ability to absorb in the near-infrared (NIR) region, and intramolecular charge transfer (ICT) abilities.

While many components of the dye were synthesized, the final stages of the synthetic scheme were not completed due to the loss of time from COVID-19. Had the …

Synthesis And Conductivity Analysis Of A Methyl (Polyethylene Glycol) Comb Polymer, Olivia Fox

Honors Theses

The overall goal of work in this field is to improve materials for use in a variety of applications in fuel cell and battery production. This thesis specifically investigates the synthesis of two variations of a methyl (polyethylene glycol) comb polymer electrolyte (MePEG_nwhere n=7) to understand how the molecular structure of an ion-conducting polymer affects its electrochemical properties. The MePEG used in this synthesis contains seven ethylene glycol groups and was added to a poly (methylhydrosiloxane) comb polymer backbone. In the first sample, the polymer contained only the MePEG sidechain, and in the second sample, the polymer contained …

C-H Bond Activation And Cracking Of Cyclohexane Using Mass Spectrometry, Alyssa L. Mohr

Honors Capstones

Gas-phase mass spectrometry is used to study the C-H activation of cyclohexane by [(phen)M(X)]+ (where phen = 1,10-phenanthroline; M = Ni, Pd, or Pt; X = H or CH3), forming the cyclohexyl species [(phen)M(c-C6H11)]+. Collision-induced dissociation of this species and cyclohexane-induced ion molecule reactions result in ring opening followed by “cracking” of the hydrocarbon chain and dehydrogenation of the cyclohexyl ring. The catalytic nature of these processes enables the continual production of smaller hydrocarbons, such as ethylene and propylene, from ring opening/cracking as well as benzene, cyclohexene, and one, two, or three hydrogen molecules from dehydrogenation. The metal used largely …

Progress Towards Synthesis And Characterization Of Bay-Annulated Indigo Chromophores, Katherine Weiss, Denise Femia

HON499 projects

Through acetylation, N,N’-diacetylindigo was synthesized from indigo. N,N’-diacetylindigo and 2-thiopheneacetyl chloride were combined in an attempt to synthesize 7-thiophenyl bayannulated indigo (BAI). After 1H NMR characterization, it was found that the product was not 7-thiophenyl BAI. A previously synthesized sample of 7-phenyl BAI was purified. UV-VIS absorbance, fluorescence, IR, and 1H NMR were used to characterize the compounds.

Palladium-Catalyzed Cross-Coupling And Related Reactions Of Non-Classical Electrophiles Focusing On Esters, Amira Hanafi Dardir

Yale Graduate School of Arts and Sciences Dissertations

This thesis summarizes work related to the development of mild palladium-catalyzed cross- coupling reactions of phenyl- and benzyl- esters, which undergo different C-O bond cleavage selectivity, the scope of the reactions and applications, and mechanistic understanding of precatalyst activation and the oxidative addition steps. The first chapter of this thesis is an introduction summarizing palladium-catalyzed cross-coupling reactions of non-classical electrophiles. The second chapter focus on the development of mild palladium-catalyzed non- decarbonylative Suzuk-Miyuara and Buchwald Hartwig cross-coupling reactions of phenyl aryl- and alkyl-esters to generate ketenes and amides, respectively. The third chapter is the extension of the Suzuki-Miyuara reactions to …