Organic Chemistry Commons^™

Archean Phosphorus Liberation Induced By Iron Redox Geochemistry, Barry Herschy, Sae Jung Chang, Ruth Blake, Aivo Lepland, Heather Abbott-Lyon, Jacqueline Sampson, Zachary Atlas, Terence P. Kee, Matthew A. Pasek

Faculty Publications

The element phosphorus (P) is central to ecosystem growth and is proposed to be a limiting nutrient for life. The Archean ocean may have been strongly phosphorus-limited due to the selective binding of phosphate to iron oxyhydroxide. Here we report a new route to solubilizing phosphorus in the ancient oceans: reduction of phosphate to phosphite by iron(II) at low (<200 >°C) diagenetic temperatures. Reduction of phosphate to phosphite was likely widespread in the Archean, as the reaction occurs rapidly and is demonstrated from thermochemical modeling, experimental analogs, and detection of phosphite in early Archean rocks. We further demonstrate that the ...

Synthesis Of A Bipyridine Ligand For Metal-Triggered Supramolecular Polymers, Andrew D. Gould

DePaul Discoveries

Intermolecular forces, such as H-bonding, ionic interactions and metal chelation between small molecules, can lead to the assembly of higher-order supramolecular nanostructures. A metal chelator, 2-(Pyridin-2-yl) pyridine-5-carboxylic Acid (a bipyridine derivative), is expected to aid in the formation of supramolecular structures as part of amphiphilic molecules that self-assemble in solution in the presence of metal ions. The bipyridine ligand currently under synthesis can be prepared through a five-step synthesis scheme. The second reaction of this synthesis (the coupling of two pyridine rings) resulted in a combination of the desired 1,2,5-isomer, as well as an unforeseen 1,2 ...

Polymeric Hairy Nanoparticles With Helical Hairs: Synthesis And Self-Assembly, Md Hanif Uddin

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

Nanoscale particles based on the nature of building blocks often self-assemble into superstructures with distinctive spatial arrangements which can be used as functional materials for different application. Micro-phase separated hairy nanoparticle with helical hair can self-assemble to form supramolecular material which may mimic the properties and functions of the natural polymers such as protein and cellulose. Beside this hairy/core-shell nanoparticles also may find many applications such as in asymmetric catalysis, nano-fillers in tire and rubbers, model systems for biology, lithography and as sensors. In this work, we have successfully synthesized two hairy nanoparticles both of which has cross-linked polystyrene ...

Multi-Reference Systems In Chemistry; Unconventional Bonding In Organic Chemistry; Covalent Bonding In Transition Metal Clusters, Alan Wilfred Humason

Chemistry Theses and Dissertations

The geometries, chemical properties, and reactivities of molecules are determined by their electronic structure. The field of ab initio computational chemistry works to calculate the kinetic and potential energies between the nuclei and electrons of a molecule. These calculations usually begin with the determination the electronic ground state.

Molecules that cannot be adequately described with a single, ground state configuration are called \textit{multi-reference systems}, which require the calculation of a linear combination of all pertinent electronic configurations, with a corresponding increase in computational cost. This is not `black box' methodology, because solving these systems requires a good understanding of ...

Tumor-Targeting Fluorinated Phthalocyanines For Theranostic Applications, Erik Nathaniel Carrión

Seton Hall University Dissertations and Theses (ETDs)

Hydrocarbon-based therapeutics and imaging agents are prone to chemical oxidation and degradation resulting in loss of activity and limited functional utility. Thus, more material is required to achieve long-lasting therapeutic effects. Phthalocyanines (Pcs) and their metal complexes (PcMs) can be utilized as prodrugs requiring only renewable energy resources namely, air and light, for cancer therapy and diagnostic (theranostic) applications related to photodynamic therapy (PDT). Replacement of labile C-H bonds in the Pc scaffold with a combination of fluoro and perfluoroisopropyl groups has resulted in a stable yet reactive oxidation catalyst of biological significance and importance. For example, F₆₄PcZn ...

New Reactions Of Strained Allyl Silacycles, Elizabeth Cummins

Graduate Student Symposium

Ring-strained allylsilanes exhibit both electrophilic and nucleophilic characteristics, allowing for simultaneous activation and allylation of carbonyl compounds. Results are presented describing an optimized synthesis of certain allylsilacyclobutanes and their use in several selective carbon-carbon bond forming reactions.

Synthesis And Characterization Of Biodiesel Fuels From Furfuryl Alcohol And Spent Coffee Grounds, Amanda Raley

Electronic Theses and Dissertations

ABSTRACT

Biodiesel can be synthesized using several different triacylglycerides, alcohols, and catalysts. In this study, fatty acid methyl esters (FAMEs) and fatty acid ethyl esters (FAEEs) were produced from their respective alcohols and coffee oil, using either a basic (K₂CO₃) catalyst or an acidic catalyst (H₂SO₄). Fatty acid furfuryl esters (FAFurEs) were produced using commercially-purchased cooking oils (canola, olive, corn, sunflower, and peanut) with furfuryl alcohol, a basic (K₂CO₃) catalyst, a co-solvent (THF), and an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate). All samples were produced using either conventional heating methods (CH) or microwave-assisted ...

Investigations Into Ring-Opening Polymerization Of Functionalized Ε-Caprolactones, Danielle N. Coderre, Matthew K. Kiesewetter

Senior Honors Projects

Polymers are defined as large molecules constructed from small, repeating units (monomers) which make up everyday items, such as: plastic bags and bottles, waterproof coatings, pipes, etc. H-bonding urea (U) or thiourea (TU) catalysts paired with base cocatalysts used for organocatalytic ring-opening polymerization (ROP) of cyclic esters have been shown to exhibit fast rates of polymerization and result in polymers with controlled molecular weights (Mn) and low polydispersity indexes (PDI). Additionally, organocatalytic ring-opening polymerization (ROP) techniques have been shown to be tolerant of the incorporation of functional groups into the monomer feed, which is vital for the catalytic synthesis of ...

Size Exclusion Chromatography Based Liposomal Protein Extraction (Selpe), Carolyn Barnes

University of Tennessee Honors Thesis Projects

No abstract provided.

Treating Breast Cancer With Light: The Creation Of Two Photodynamic Therapy Agents, Victoria Lackey

Honors Theses

Photodynamic therapy (PDT) is a treatment for a wide display of diseases, including cancer, that has become gradually widespread. The procedure requires the usage of photosynthesizing agents, which are activated in the presence of light. One quite successful photodynamic therapy agent is an aromatic structure made up of four pyrrole rings called a porphyrin. This research focused on producing the water-soluble porphyrins, H2TPP-3-PEG-OH and H2TPP-PiperMe-OH, through the attachment of the starting porphyrin, H2TPPC, with 3-polyethyleneglycol and 3-piperidinemethanol, respectively. The novel, water-soluble agent was purified and characterized by infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), and UV-vis spectroscopy. Purity was ...

Cationic Ruthenium Complexes In Catalysis: The Activation Of Propargylic Alcohols Through Electronically Tuned Complexes, Matthew James Stark

Dissertations

With increasing complexity of metal complexes, it is of worthwhile interest to pursue systematic examinations of ligand modifications to study their impact on the reactivity of a catalyst. To that end, this study aimed to understand the effect electron-withdrawing ligands conveyed to catalytic activity in the etherification of propargylic alcohols and related reactions. A number of half-sandwich ruthenium complexes bearing ligands with varying electron–withdrawing properties were synthesized and structurally characterized. Their electronic and structural properties were investigated utilizing X-ray crystallography, revealing that the series of complexes did not vary significantly in structure. The complexes were studied electronically with cyclic ...

Intermolecular-Trapping Of 1,3-Dialkyl Diaziridines With Hdda-Derived Benzynes, Ramitha Rupasinghe

Undergraduate Research Symposium 2018

The extent to which benzynes react with various trapping agents is an important question in synthetic chemistry due to its versatility to produce products that can be used as pharmaceuticals, dyes and other complex molecules. The hexadehydro-Diels-Alder (HDDA) reaction allows the generation of benzynes in situ which then can be efficiently trapped to synthesize complex products in one step with high yields. Reactions of HDDA - derived benzynes with trapping agents such as thioamides, alcohols, pyrroles, silyl ethers and multifunctional natural products have been studied in previous research. In this research, the reactions of HDDA-derived benzynes with diaziridines is explored because ...

Evaluation Of Vaporization Enthalpies And Vapor Pressures Of Various Aroma And Pharmacologically Active Compounds By Correlation Gas Chromatography, Daniel Simmons

Theses

Scientists in the pharmaceutical, food, and aroma industries can benefit from reliable thermochemical data. Vaporization enthalpy and vapor pressure data are not available for all compounds. Furthermore, some literature data is conflicting. The goal of this work was to use a method called correlation gas chromatography (CGC) to generate reliable vaporization enthalpy data in instances where other experimental methods are not applicable. Vapor pressures of the targets were also calculated in cases where the required literature data on the standards used in this technique were available.

CGC involves making a standard cocktail that includes a mixture of standards and one ...

Secondary Electronic And Solvent Effects On Regiospecific P-Bromination Of Aromatic Systems, Selahaddin Gumus

Masters Theses & Specialist Projects

Bromoarenes are important aromatic building blocks that are commonly used to synthesize various functional compounds in pharmaceutical, agrochemical and related industries.^1,2 This great demand for bromoarenes makes their preparation a widely studied area of synthetic organic chemistry. However, further understanding of the reactivity and regiochemistry of aromatic functionalization reactions is still necessary, as much about the secondary substitution and solvent effects remain unknown.

Resonance Theory is a widely used theoretical model to predict the regiospecifity and reactivity of the bromination of various aromatic compounds.³ The reactivity and regiospecificity of many substituted aromatic compounds is well explained using ...

Photo-Controlled Release Of Zinc Ions In Aqueous Solution With Simultaneous Fluorescence Detection, Tyler Larson

Undergraduate Honors Theses

We created a system consisting of a highly fluorescent conjugated polymer nanoparticle paired with a photo-release dye. Upon irradiation at the maximum absorbance of the nanoparticle, it non-radiatively transfers its energy to the dye through the process of FRET (Fluorescence Resonance Energy Transfer), exciting the dye, which then releases a biologically relevant ion, zinc. This system enhances the photo-release process, making it kinetically faster and more efficient. The photo-event is accompanied by a change in fluorescence of the dye, allowing for simultaneous detection of photo-release. This thesis outlines nanoparticle synthesis using the reprecipitation method, synthesis of the zinc releasing dye ...

Organic Chemistry I & Ii (Ccga), Colleen Knight, Leon Gardner, Joseph Lodmell, Ernest Pascoe, Andrea Wallace, Lisa Mcneal

Chemistry Grants Collections

This Grants Collection for Organic Chemistry I & II was created under a Round Seven ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

• Linked Syllabus
• Initial Proposal
• Final Report

Photoremovable Protecting Groups Based On Electrocyclization With Leaving Group Expulsion Via A Proposed Zwitterion, Gilbert Ndzeidze

Dissertations (2009 -)

The triplet excited state of thioxanthone produced by photolysis undergoes reversible triplet energy transfer with a trimethylene - linked benzothiophene-2-carboxanilide ring system. The ensuing electrocyclic ring closure of the anilide moiety produces a putative zwitterionic intermediate that is capable of expelling leaving groups (LG-) from the C-3 position of the benzothiophene ring. Stern-Volmer quenching studies with cyclohexadiene as quencher furnish the rate constants for the triplet excitation transfer in the forward and reverse directions, which can be expressed as an equilibrium constant K = 0.058. Overall, the rate of triplet excited state reaction becomes K x kr = 5.7 x 104 ...

Discovery And Development Of A Three-Component Oxidopyrylium Cycloaddition And Its Application Towards Alpha-Hydroxytropolone Synthesis, Michael P. D'Erasmo

All Dissertations, Theses, and Capstone Projects

Historically, natural products have provided unique research opportunities and challenges for organic synthesis, chemical biology, and medicinal chemistry due to their molecular complexity and effects on physiological systems. The total synthesis of natural products has not only produced novel reaction methods and strategies capable of efficiently generating complex structural motifs but also granted access to sufficient quantities of otherwise scarce natural product material for clinical evaluation. These synthetic efforts have facilitated the formation of a transdisciplinary partnership between chemistry, biology, and medicine that has been paramount in elucidating the chemical and pharmaceutical utility of natural products. Chapter I of this ...

Comparison Of Processed And Non-Processed Biomass Digestion, Richard Bruce Clark

Graduate Theses – Chemistry and Biochemistry

Lignocellulosic ethanol is the main focus of second-generation biofuels [1]. Because cellulose is the most abundant organic material on earth, second-generation biofuels are a more sustainable option than the classical first-generation biofuels that use foodstuffs as the main feedstock in ethanol production [1]. Furthermore, biofuel can be produced not only from unprocessed biomass such as corn husks but also from processed material like paper [1]. Ionic liquids have shown to be quite effective in dissolving naturally occurring, and traditionally insoluble, polymers such as cellulose into solution, and cellulase enzymes have been shown to effectively digest cellulose into simple sugars [2 ...

Sphingomyelin And Gm1 Influence Huntingtin Binding To, Disruption Of, And Aggregation On Lipid Membranes, Maxmore Chaibva, Xiang Gao, Pranav Jain, Warren A. Campbell, Shelli L. Frey, Justin Legleiter

Chemistry Faculty Publications

Huntington disease (HD) is an inherited neurodegenerative disease caused by the expansion beyond a critical threshold of a polyglutamine (polyQ) tract near the N-terminus of the huntingtin (htt) protein. Expanded polyQ promotes the formation of a variety of oligomeric and fibrillar aggregates of htt that accumulate into the hallmark proteinaceous inclusion bodies associated with HD. htt is also highly associated with numerous cellular and subcellular membranes that contain a variety of lipids. As lipid homeostasis and metabolism abnormalities are observed in HD patients, we investigated how varying both the sphingomyelin (SM) and ganglioside (GM1) contents modifies the interactions between htt ...