Chemistry Commons^™

Thermosetting Polymers Via Azide Alkyne Cycloaddition, Richard H. Cooke Iii

Dissertations

This dissertation exploits properties inherent to azide-alkyne cycloaddition and applies practical solutions to difficult problems. Chapter II addresses structure-property relationships in glassy azido-alkyne matrices by varying the identity of the central linkage within tetrapropargyl bis-aniline-type crosslinkers, and by the addition or omission of Cu(I) catalyst. This systematic study showed that an ether or methylene linkage yielded lower melting tetrapropargyl crosslinkers that were soluble in, and produced homogeneous, networks when cured with, a standard azido resin, di(3-azido-2-hydroxypropyl) ether of bisphenol-A; in contrast, a sulfone linkage yielded a relatively insoluble crosslinker and poorly dispersed, heterogeneous networks when reacted with the same …

The Photodynamic And Structural Analyses Of Advanced Materials For Solar Fuel Conversion, Brian Pattengale

Dissertations (1934 -)

Mitigating the current and future climate and pollution issues that have been brought on by the combustion of fossil fuels is of utmost importance and will rely on, in part, the availability of renewable fuel sources. Of the possible sources of energy, solar is abundant, but must be harnessed efficiently and stored as a solar fuel to overcome the current storage issues that limit photovoltaic cells. One such fuel, H2(g), represents a carbon-neutral source of energy if it can be efficiently liberated from water via the water splitting reaction. Thus, much attention is focused on designing materials to perform the …

Design, Synthesis And Study Of Redox And Optoelectronic Properties Of Aromatic Oxidants And Polycyclic Aromatic Hydrocarbons, Mohammad Mosharraf Hossain

Dissertations (1934 -)

Organic materials play a significant role for the next generation photovoltaic devices that convert solar energy into usable forms of energy. In this regard, polycyclic aromatic hydrocarbons (PAHs) are fundamental tools in the developing area of molecular electronics and photovoltaics as they show excellent optical/electronic properties and are well-suited for applications in such developing areas as flexible display devices, field effect transistors and solar cell panels. Design and synthesis of novel materials for photovoltaics applications would require the proper understanding the mechanism of charge transport and identification of the structural features necessary in a particular molecular wire or PAH. To …

Advances In Amino Acid Analysis For Marine Related Matrices And Its Application To Coastal Shelf Settings In The Canadian Arctic, Rachel M. Mcmahon

OES Theses and Dissertations

Amino acids comprise up to 50% of organic matter in cellular material and are a major fraction of oceanic organic carbon. Amino acids are also considered highly labile during organic matter recycling, making them useful proxies for organic carbon cycling. Nevertheless, analysis of individual amino acids has been burdened by lengthy derivatization and complex analysis since the 1950s. In this thesis, I describe the modification of advanced analytical techniques, developed in the biomedical field, for analysis of marine matrices which allow the determination of at least 40 amino acids without the need for lengthy sample preparation and derivatization, twice the …

Rearrangements Of Fluorinated Cyclopropylamines As A Novel Approach Toward Fluoroalkene-Based Peptidomimetics, Igor Mezentsev, Vera Zaborova

The International Student Science Fair 2018

"Organofluorine molecules have been widely applied in various research fields because of the unique properties of fluorine atoms. One type of fluorinated compounds is fluoroalkene-based peptidomimetics which are structurally similar to amide-containing compounds. They have been prepared to improve the pharmaceutical properties such as bioactivity, target specificity, and metabolic stability of the bioactive amides.

We suggested a new way of synthesizing fluoroalkene-based peptidomimetics through 2-fluoro-2-halocyclopropylamines, which provides an effective way toward fluoroalkene-based peptidomimetics with increased functional group tolerance and possibility of convergent synthesis."

Reduction Of Nitro-Compounds By Iron Pentacarbonyl - New Approach To Drug Precursors, Alexander Sharipov, Maria Vladimirovna Galkina

The International Student Science Fair 2018

Reduction of nitro compounds lies at the center of most of the major areas of modern chemical industry, such as pharmacy and dye manufacturing. The precursors in these industrial processes predominantly possess multiple functional groups, including those highly susceptible to reduction by most of the currently used reducing agents. Therefore, the non-selective methods of reduction of precursors result in the loss of such functional groups. Furthermore, common reducing agents can potentially trigger the undesired intramolecular interactions between the substrate molecules and in turn make it impossible to obtain the end product. The rising demand for a cheap and efficient approach …

Rearrangements Of Fluorinated Cyclopropylamines As A Novel Approach Toward Fluoroalkene-Based Peptidomimetics, Igor Mezentsev, Vera Zaborova

The International Student Science Fair 2018

Organofluorine molecules have been widely applied in various research fields because of the unique properties of fluorine atoms. One type of fluorinated compounds is fluoroalkene-based peptidomimetics which are structurally similar to amide-containing compounds. They have been prepared to improve the pharmaceutical properties such as bioactivity, target specificity, and metabolic stability of the bioactive amides.

We suggested a new way of synthesizing fluoroalkene-based peptidomimetics through 2-fluoro-2-halocyclopropylamines, which provides an effective way toward fluoroalkene-based peptidomimetics with increased functional group tolerance and possibility of convergent synthesis.

Steric Effects Of Alkyl Ammonium Salts On The Combustion Of Exchanged Smectite Clays, Celeste A. Keith

Electronic Theses and Dissertations

Bomb calorimetry was explored as a new method for determining the cation exchange capacity (CEC) of clays. Smectite clays were modified with several alkyl ammonium salts varying in number of carbons and the spatial orientation of the carbons about the central nitrogen atom. The clays used, standards purchased from the Source Clay Repository, have CECs of 44, 80, 88, and 120 meq/100 g. Theoretically, the combustion energy of the organo-clays should be approximately the same for each salt. Any differences in energy would be due to the different structures of the salts and how they are oriented in the interlamellar …

New Platinum(Ii) And Rhenium(I) Complexes Of "Linear" Chelate Ligands Terminated With Pyridyl Or Imidazolyl N-Donor Groups, Himali Kokila Ranasinghe Pilana Vithanage

LSU Doctoral Dissertations

The overall goal of this dissertation research is to design, synthesize, and study new Pt(II) and Re(I) complexes relevant to biomedical applications. One of the projects involves the assessment of the interactions of bulky tridentate carrier ligands with a bound guanine nucleobase derivative (G) in platinum complexes, with a goal of developing chemistry potentially relevant to active anti-cancer Pt drugs. In another project, the fac-[Re^I(CO)₃]⁺ core is used to prepare novel Re(I) complexes with the purpose of developing new linking chemistry relevant to ^99mTc and ¹⁸⁷Re radiopharmaceuticals. This research explores …

Sulfonamide Synthesis Via Calcium Triflimide Activation Of Sulfonyl Fluorides, Nicholas Ball, Paramita Mukherjee, Cristian P. Woroch, Leah Cleary, Mark Rusznak, Ryan W. Franzese, Matthew R. Reese, Joseph W. Tucker, John M. Humphrey, Sarah M. Etuk, Sabrina C. Kwan, Christopher W. Am Ende

Pomona Faculty Publications and Research

A method using calcium triflimide [Ca(NTf₂)₂] as a Lewis acid to activate sulfonyl fluorides toward nucleophilic addition with amines is described. The reaction converts a wide array of sterically and electronically diverse sulfonyl fluorides and amines into the corresponding sulfonamides in good yield.

Oxidation Of N-Doped Multiwalled Carbon Nanotubes And Formation Of Discontinuous Spiraled Carbon Nanoribbons, Aman Preet Kaur, Mark S. Meier, Rodney Andrews, Dali Qian

Chemistry Faculty Publications

The effects of five commonly used wet chemical oxidations were studied for the extent of oxidation of graphitized nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs). KMnO₄/ H₂SO₄ was the most potent oxidant, as it produced the highest fraction of oxygen-containing functional groups. Electron microscopy studies showed that the treatment of annealed N-MWCNTs (G-N-MWCNTs) with H₂SO₄/HNO₃ and H₂SO₄/KMnO₄ mixtures leads to interesting spiraled ribbon textures. A structural model, involving the stacking of coiled subunits to form a discontinuous carbon nanoribbon rather than a continuous ribbon is proposed to …

Deciphering The Mechanism Of O2 Reduction With Electronically Tunable Non-Heme Iron Enzyme Model Complexes, Roshaan Surendhran, Alexander A. D'Arpino, Bao Y. Sciscent, Anthony F. Cannella, Alan E. Friedman, Samantha N. Macmillan, Rupal Gupta, David C. Lacy

Publications and Research

A homologous series of electronically tuned 2,20,200-nitrilotris(N-arylacetamide) pre-ligands (H3LR) were prepared (R ¼ NO2, CN, CF3, F, Cl, Br, Et, Me, H, OMe, NMe2) and some of their corresponding Fe and Zn species synthesized. The iron complexes react rapidly with O2, the final products of which are diferric mu-oxo bridged species. The crystal structure of the oxidized product obtained from DMA solutions contain a structural motif found in some diiron proteins. The mechanism of iron mediated O2 reduction was explored to the extent that allowed us to construct an empirically consistent rate law. A Hammett plot was constructed that enabled …

Synthesis And Characterization Of (Pyno−)2gacl: A Redox-Active Gallium Complex, Jacob M. Kirsh , '17, Audra J. Woodside , '19, B. C. Manor, P. J. Carroll, Paul R. Rablen, Christopher R. Graves

Chemistry & Biochemistry Faculty Works

We report the synthesis of a gallium complex incorporating redox-active pyridyl nitroxide ligands. The (pyNO−)2GaCl complex was prepared in 85% yield via a salt metathesis route and was characterized by 1H and 13C NMR spectroscopies, X-ray diffraction, and theory. UV–Vis absorption spectroscopy and electrochemistry were used to access the optical and electrochemical properties of the complex, respectively. Our discussion focuses primarily on a comparison of the gallium complex to the corresponding aluminum derivative and shows that although the complexes are very similar, small differences in the electronic structure of the complexes can be correlated to the identity of the metal.

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 1,2,3-isomer. Future research will therefore …

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 the …

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, …

A Detailed Study Of Novel High-Performance Bromine And Phosphorus Based Reactive Flame Retardants In High-Quality Bio-Polyol Based Rigid Polyurethane Foams, Sanket Bhoyate

Electronic Theses & Dissertations

Structural fire is one of the most catastrophic issues related to human safety observed from reports of National Fire Protection Association of United States in past years. Polyurethanes are one of the important structural material used as thermal insulation in housing. They are also used in automotive, construction, medical, packaging, furniture, thermal, electrical, and vibration insulation. Considering this, we have synthesized bio-based polyurethane foams using limonene-based polyol, isocyanates, and other compounds. Flame retardancy was imparted using reactive flame retardant polyols. Firstly, flame retardancy test was performed on the foams using two novel aliphatic and two novel aromatic bromine-based synthesized reactive …

Flame Retardancy Of Ferrocene Incorporated Epoxide, Sultan Alanazi

Electronic Theses & Dissertations

Epoxy resins are thermosetting resins that are used in a variety of applications such as electrical and electronic devices. However, epoxy resins can be inherently flammable. To circumvent this problem, epoxy resins were prepared by incorporating ferrocene carboxylic acid into the epoxy prior to thermal setting, as a flame retardant. Ferrocene carboxylic acid was prepared by condensing o-chlorobenzoyl chloride with ferrocene followed by hydrolysis. The synthesized ferrocene carboxylic acid was characterized by ¹H-NMR spectroscopy, ¹³C-NMR spectroscopy, and FT-IR spectroscopy. Epoxy films were then prepared by reacting ferrocene carboxylic acid (10, 15, and 20% by wt) with bisphenol A …

The Preparation Of Palladium Complexes Of N-Pyrazolylpropanamide Derivatives, Tyler Palombo 5275714

Senior Honors Projects, 2010-2019

The reaction of 3,5-dimethylpyrazolyl-N-isopropylpropanamide (L1) with dichloro(1,5-cyclooctadiene)palladium(II) displaces cyclooctadiene forming Cl₂Pd(L1)₂. This complex has been characterized by NMR and IR spectroscopy, single crystal X-Ray diffraction, and elemental analysis. It is composed of a square planar Pd with trans L1 ligands attached through a pyrazolyl nitrogen and intramolecular hydrogen bonding between the amide and chloride. Similar reactions were carried out with 3,5-dimethylpyrazolylpropanamide (L2), pyrazolyl-N-isopropylpropanamide (L3), 3-(1H-benzotriazol-1-yl)-N,N-dimethylpropanamide (L4), 3-methylpyrazolylpropanamide (L5), 3-(1H-benzotriazol-1-yl)-2-methylpropanamide (L6), and N-pyrazolypropanamide (L7) presumably forming analogous complexes. This formulation for …

Discovery Of A Novel Inhibitory Compound Produced By The Soil Bacterium Rhodococcus Sp. Mtm3w5.2, Patrick South

Undergraduate Honors Theses

Due to increases in antibiotic resistance stemming from the overuse of commercial antibiotics, the need to discover novel antibacterial compounds is becoming more urgent. A species of Rhodococcus, MTM3W5.2, has been discovered and was found to produce a metabolite with inhibitory activity against closely related species. The aim of this study is to elucidate the structure of the inhibitory metabolite by isolating and purifying it; then characterizing it using spectroscopic techniques. The compound was isolated from MTM3W5.2 RM broth cultures using n-butanol extraction, which yielded an active crude extract. The crude extract was then subjected to fractionation using a Sephedex …

Imide Arylation With Aryl(Tmp)Iodonium Tosylates, Souradeep Basu, Alexander H. Sandtorv, David R. Stuart

Chemistry Faculty Publications and Presentations

Herein, we describe the synthesis of N-aryl phthalimides by metal-free coupling of potassium phthalimide with unsymmetrical aryl(TMP)iodonium tosylate salts. The aryl transfer from the iodonium moiety occurs under electronic control with the electronrich trimethoxyphenyl group acting as a competent dummy ligand. The yields of N-aryl phthalimides are moderate to high and the coupling reaction is compatible with electron-deficient and sterically encumbered aryl groups.

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 …

An Exploration Of Pyrrole Groups On The Enantioselectivity Of Pig Liver Esterase, Brian Long

Honors Theses

Pig Liver Esterase (PLE) is a serine protease enzyme that can interact with one side of a diester to hydrolyze the ester to a carboxylic acid, and research has found that the level of hydrophobicity of side groups can impact the enantioselectivity of PLE hydrolysis.1, 2 The Jones Model is what current researchers use to model the active site of PLE, but the nature of its binding pockets, namely the Hydrophobic Long (HL) pocket, has been called into question.3 Dimethyl 2-((pyrrole-2-yl)methyl)-2-methylmalonate was prepared to be subjected to PLE hydrolysis to see whether enantioselectivity was found. Chiral HPLC revealed 25.32% enantiomeric …

Diastereoselective Synthesis Of 2,4,6-Trisubstituted Piperidines Via Aza-Prins Cyclization, John A. Hood

Honors Theses

The nitrogen heterocycles are shared amongst 59% of Food and Drug Administration (FDA) approved small molecule pharmaceuticals with the six-membered piperidine representing the most common moiety. Given the versatility and potential to yield derivatives with broad biological activities, the discovery of new chemical methods to generate these heterocycles in a more time and cost-efficient manner is desired. While there are existing racemic methods to access this class of molecule, the objective of this research is to pioneer a new novel six-step method to generate 2,4,6-trisubstituted piperidines with stereoselective control.

The first step is a condensation between a nonenolizable aldehyde and …

Long-Range Electrostatic Interactions In Gold Catalysis And Fluorinating Reagent Development., Zhichao Lu

Electronic Theses and Dissertations

Our research focus is on applying two long range electrostatic interactions--coulombic interaction between ion pairs and hydrogen bonding—to two tasks: exploring counterion effects in gold catalysis and utilizing hydrogen bonding for fluorinating reagent development. Cationic gold catalysis is considered one of the most important breakthroughs in organic synthesis over the past two decades. A wealth of empirical information on counterion effects is now available regarding homogeneous gold catalysis. However, the rational understanding of the counterion effect on reactivity is still elusive. We proposed a widely applicable model to rationalize the kinetic effect in gold catalyzed reaction. We first solved the …

Computational Study Of Lawesson’S Reagent Mediated Fluorenone Dimerization Forming 9,9’-Bifluorenylidene, Andrew Jourdan Eckelmann

Graduate Theses/Dissertations

The ambition of this work is to start a path to the a priori rational design of high yield production for electron acceptors with finely tuned band gaps, from the comfort of an armchair. To this end, organic photovoltaics offer a cheap and sustainable means of manufacture using readily available materials and avoids the toxicity of some of the heavy metals used in first and second-generation solar cells such as cadmium. The microwave assisted Lawesson’s reagent mediated one-pot one-step solventless synthesis takes less than 3 minutes and results in an 84% yield of 9,9’-bifluorenylidene from two equivalents of fluorenone. While …

Highly Flame Retardant And Bio-Based Rigid Polyurethane Foams Derived From Orange Peel Oil, Chunyang Zhang

Electronic Theses & Dissertations

Polyurethane is an important class of polymer which is being used for various industrial applications in the form of rigid foams, flexible foams, thermoplastic, elastomer, coating, and adhesive. Especially there is a huge market for rigid polyurethane foams for their applications as thermal insulating material in building and housing. In general, polyurethanes are prepared using polyols and diisocyanates. Most of the polyols used by industries are petrochemical based. In this project, a novel polyol from an orange peel oil-based derivative, limonene dimercaptan, was synthesized using one step photochemical thiol-ene reaction. The synthesized polyol was used to prepare flame retardant polyurethane …

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 …

Conformational Studies Of Gram-Negative Bacterial Quorum Sensing Acyl Homoserine Lactone (Ahl) Molecules: The Importance Of The N→* Interaction, Fintan Kelleher, Goar Sánchez-Sanz, Darren Crowe, Alan Nicholson, Adrienne Fleming

Articles

A ¹H NMR study shows the presence of intermolecular hydrogen bonds for AHLs in CDCl₃ solution. A detailed computational study of the structure of AHLs and the relative stability between the extended conformations (X) and those showing n→p* interactions (np) have been carried out by means of DFT calculations. Solvent effects have been shown to be very important when stabilising np conformations, particularly with polar solvents. This was shown by the shortening of C···O intramolecular distances and the increase in the relative energies favouring the np conformation with the dielectric constant of the solvent. …

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 voltammetry, …