Physical Sciences and Mathematics Commons^™

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 …

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 …

Organocatalyzed Synthesis Of Epoxides From Chalcones Utilizing Amino Acids, Sabrina N. Kegeler

Masters Theses

The epoxide functional group is important throughout the chemical and pharmaceutical industries, as well as in nature. In the chemical industry, epoxides are present in resins and fragrances. In the pharmaceutical industry, epoxide-containing compounds are used as intermediates in the manufacturing of drugs. In nature, many natural products contain epoxide groups and are used for medicinal purposes, and for models to create synthetic molecules.

One approach to epoxide synthesis involves the use of an alkene precursor, a base, and an oxidizing agent. This is where my investigations began. The first step was to optimize the epoxidation reaction, examining substrate scope, …

Development Of Bifunctional Thiourea Catalysts For Effective Direct Amidation Reactions, Alex Guzman

Summer Research

This research synthesized and analyzed novel catalysts that can effectively form amides. An amide is a chemical group commonly found in many pharmaceuticals and biochemicals, such as proteins. In fact, about 30% of pharmaceuticals contain an amide, and the formation of amides leads to corrosive and toxic by-products which are especially problematic on the large industrial scale. Green Chemistry has proven to be a critical tool in providing innovative solutions by making the industrial production of chemicals more sustainable and safe. The pharmaceutical industry has some of the most inefficient reactions in the chemical industry mainly due to the complexity …

Experiential Learning Activity: Biodiesel Inquiry Project, Ji Kim

Open Educational Resources

The activity described herein can be implemented in introductory chemistry and high school chemistry courses. The main goal of the project is to integrate a ubiquitous biodiesel production with experiential learning by providing a community-based project. The students work in groups, research the benefits of using biodiesel over petroleum-based diesel, collect waste cooking oil from home or restaurants, develop simple and cost-effective methods to produce biodiesel.

The Synthesis Of Highly Substituted Aromatics And The Reaction Of Alkene Pi Systems With Vinyl Cations, Nicholas Jarrod Dodge

Graduate College Dissertations and Theses

Aldol cyclotrimerizations have been used to achieve the rational chemical synthesis of both fullerenes and fullerene fragments in the past. Under certain conditions this reaction produces the corresponding cyclotetramer which has sometimes been regarded as an undesired byproduct. This work details efforts to synthesize and use these cyclotetramers toward a synthesis of a C240 fullerene fragment. One principal focus in this work is tridecacyclene, a cyclic tetramer of acenaphthylene given its name by our group for its thirteen rings. Relatively low yields for the synthesis of tridecacyclene and its derivatives drove us to investigate the mechanism of its formation and …

Surface Oxygenation Of Biochar Through Ozonization For Dramatically Enhancing Cation Exchange Capacity, Matthew D. Huff, Sarah Marshall, Haitham A. Saeed, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

Background

Biochar cation exchange capacity (CEC) is a key property that is central to biochar environmental applications including the retention of soil nutrients in soil amendment and removal of certain pollutants in water-filtration applications.

Results

This study reports an innovative biochar-ozonization process that dramatically increases the CEC value of biochars by a factor of 2. The ozonized biochars also show great improvement on adsorption of methylene blue by as much as a factor of about 5. In this study, biochar samples treated with and without ozone were analyzed by means of pH and CEC assays, water field capacity measurement, elemental …

Ion Separations: Achieving Selectivity Through Rational Design In Solvent Extraction And Crystallization Systems, Neil Justin Williams

Doctoral Dissertations

The selective separation of ions from aqueous solutions has been a difficult challenge to address in the separation sciences. The difficulties associated with selective separations of ions are due to a multitude of chemical and physical differences between them. Additionally, the term ions encompass both positively charged cations and their counter parts the negatively charge anions. The work covered in this dissertation discusses the difficulties encountered during the selective separation of both oxoanions and cations. Apart from the Introduction Chapter 1 and Conclusion Chapter 10, the selective separations oxoanions and cations will be discussed separately with the dissertation being …

Serendipitous Discovery Of A New Method For The Catalytic Synthesis Of Indole-Fused Benzazepanes, Edward Gluzman, Paul A. Vadola

DePaul Discoveries

We report here on our investigations into the application of 1,5-hydride transfer cyclization mechanisms to the synthesis of 2,3-disubstituted benzofurans and indoles. We found that PtI₄ in MeCN at 120 ºC was indeed capable of activating the alkyne, however, the expected 2,3-disubstituted indole product was not observed. Instead we isolated an indolyl-3-benzazepane via an unexpected intramolecular Steven’s rearrangement/ring expansion. While this transformation has been previously reported our method may prove to have increased substrate scope and more practical reaction conditions. Further studies are underway to optimize the reaction conditions and to fully explore the scope and mechanism of the …

Solvent Free Vanadium Mediated Organic Transformations, Garrett Oberst

Undergraduate Honors Thesis Collection

A mixture of vanadium(V) oxide and copper sulfate was used to catalyze oxidative transformations in a variety of organic compounds. Multiple functionalities were tested, including thiols, amines and alcohols. Various transformations were observed resulting in various oxidized products, including coupling reactions. Reactions were performed in a solvent-free environment due to the insoluble nature of vanadium(V) oxide in common organic solvents. Results were analyzed using HNMR and GCMS.

Substrate Specificity Of The Lipn Hydrolase From Mycobacterium Ulcerans, Stephanie Raynor

Undergraduate Honors Thesis Collection

Mycobacterium ulcerans is the causative agent of Buruli ulcer, a tropical skin disease that affects thousands of individuals annually. Recent studies have revealed that lipolytic enzymes are involved in the pathogenicity processes of mycobacterium and could be potential targets for novel antibiotics. LipN is one proposed serine hydrolase in Mycobacterium ulcerans that contains the conserved α/β hydrolase protein fold and utilizes the conserved catalytic traid of serine, histidine, and aspartate/glutamate. The physiological substrate and biological role of LipN from M. ulcerans have not yet been determined. In this study, LipN was cloned into a pET28a plasmid and overexpressed in an …

Structure-Property Relationships At The Nano-Bio Interface: Engineering The Nanoparticle Surface For Immunomodulation, Daniel Fernando Moyano Marino

Doctoral Dissertations

Each year, a variety of novel nanomaterials are being developed with the objective of treating different diseases. However, since nanomaterials are foreign to the human body, one of the principal factors that limit their use is the encounter with the first line of defense from the body: the immune system. If this interaction is not taken into account, an undesired recognition takes place and the efficiency of nanoparticle based therapies is dramatically reduced. As such, understanding the rules that govern this recognition is of prime importance in the field of nanomedicine. Following this line of thoughts (the driving force), the …

Metal-Ligand Cooperative Catalysis And Methods For Metal Removal From Organic Transformations, John-Paul J. Bow

Electronic Thesis and Dissertation Repository

Organometallic catalysis has revolutionized the synthesis of complex organic molecules. Methods for C-C, C-X and C-H bond formation and cleavage are exploited throughout the areas of fine chemicals synthesis, with major applications for pharmaceuticals. This situation raises duel challenges: 1) high-performance catalysts for environmentally and economically sustainable synthesis and 2) efficient methods of catalyst (i.e. metal) removal must be identified. This work tackles both of these areas. The highly tunable cooperative P^R₂N^R'₂ ligands have been implemented for the first time for catalytic organic transformations. I show that [Ru(Cp)(P^tBu₂N^Bn₂)(MeCN)][PF_{6 …}

Facile Method For Large Scale Alignment Of One Dimensional Nanoparticles And Its Biomedical Application, Sheng Feng

Theses and Dissertations

Topographical cues can profoundly affect cellular behaviors. This thesis investigate how to utilize the topographical cues generated by two techniques, flow assembly and electrospinning, to regulate cellular behaviors.

First of all, a facile and robust method to align one-dimensional (1D) nanoparticles (NPs) in large scale has been developed. Using flow assembly, representative rod-like nanoparticles, including tobacco mosaic virus (TMV), gold nanorods and bacteriophage M13, have been aligned inside capillaries by controlling flow rate and substrate surface properties. The properties of 1D NPs, such as stiffness and aspect ratio, play a critical role in the alignment. Furthermore, these hierarchically organized structures …

Impact Of Ocean Acidification On Aphotic Biogeochemical Production Of Reactive Oxygen Species, Sarah Ann Murphy

Theses and Dissertations

Reactive oxygen species (ROS) are critical to global maintenance of the global organic carbon cycle, sulfur cycle, oxygen cycle, and transition metal cycles. The primary source of ROS is commonly considered to be photolysis or photochemically driven reactions, however ROS also exist in aphotic zones. A geochemical mechanism for the same in dark environments based on the tidally driven, episodic movement of anoxic groundwaters through oxidized, Fe(III) rich sediments is shown. Predictive models were developed based on in vitro experiments and tested using sediment samples collected from a saline tidal creek in the estuary at Murrell’s Inlet, South Carolina. These …

Methodology Development In Green Chemistry: Oxoammonium Salt Oxidations And Fluoroform Incorporation, Rebecca J. Wiles

University Scholar Projects

Central to the advancement of small molecule synthesis is the ability to develop methodologies that reimagine well known chemistry in a new, environmentally friendly manner. In this thesis two central themes emerge: oxoammonium salt oxidations and trifluoromethyl incorporation using fluoroform gas. Several projects have been developed surrounding oxoammonium salt chemistry, which are featured by their mild conditions, ease of use, and the metal-free, recyclable nature of the oxidant. Trifluoromethylation using fluoroform gas finds its utility in the use of a potent greenhouse gas waste product as a benchtop reagent.

Methodology Development In Green Chemistry: Oxoammonium Salt Oxidations And Fluoroform Incorporation, Rebecca J. Wiles

Honors Scholar Theses

Central to the advancement of small molecule synthesis is the ability to develop methodologies that reimagine well known chemistry in a new, environmentally friendly manner. In this thesis two central themes emerge: oxoammonium salt oxidations and trifluoromethyl incorporation using fluoroform gas. Several projects have been developed surrounding oxoammonium salt chemistry, which are featured by their mild conditions, ease of use, and the metal-free, recyclable nature of the oxidant. Trifluoromethylation using fluoroform gas finds its utility in the use of a potent greenhouse gas waste product as a benchtop reagent.

Binding-Induced, Turn-On Fluorescence Of The Egfr/Erbb Kinase Inhibitor, Lapatinib, James N. Wilson

James N Wilson

We report the photophysical properties, binding-induced turn-on emission, and fluorescence imaging of the cellular uptake and distribution of lapatinib, an EGFR/ERBB inhibitor. Lapatinib, a type II, i.e. inactive state, inhibitor that targets the ATP binding pocket of the EGFR family of receptor tyrosine kinases. DFT calculations predict that the 6-furanylquinazoline core of lapatinib should exhibit an excited state with charge transfer character and an S0 to S1 transition energy of 3.4 eV. Absorption confirms an optical tran- sition in the near UV to violet, while fluorescence spectroscopy shows that photoemission is highly sensi- tive to solvent polarity. The hydrophobicity of …

Science Classics, Mark Masthay

Mark Masthay

An essay on the impact of the works in the Imprints and Impressions: Milestones in Human Progress, an exhibition of rare books from the collection of Stuart Rose. Exhibition was held Sept. 29-Nov. 9, 2014, at the University of Dayton.

Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk

Electronic Theses and Dissertations

This research sets out to build upon excited state o-azaxylylene cycloaddition. The mechanism behind the excitation and cycloaddition process of photogenerated o-azaxylylenes was determined experimentally. Time-correlated single-photon counting, steady-state spectroscopy, triplet quenching experiments, and quantum yield studies provided evidence suggesting that excited state intramolecular proton transfer is followed by intersystem crossing and stepwise addition to the tethered unsaturated pendant.

In keeping with the principles of diversity oriented synthesis, a modular approach was taken to gain access to a diverse array of N,O,S-Polyheterocycles which were modified postphotochemically via Suzuki coupling to yield fused biaryls. Cycloaddition products, outfitted with halogens …

Developing Catalysts For Improving Direct Amide Formation, Courtney Carley

Summer Research

The widespread occurrence of the amide functional group in the pharmaceutical industry and its prevalence in biological structures such as proteins illustrate the huge impact that amides have on our daily lives. Current methods of forming amides are expensive and harmful to the environment, so there is a need for the development of greener processes for the formation of amides. The first objective of this research is to synthesize catalysts for the direct formation of amides from carboxylic acids and amines. Previously developed catalysts for this transformation are not active enough, and are thus rarely used. The new catalysts to …

Investigating The Synthesis Of Heterocycles Via Gold Catalyzed Cyclizations And Cyclo-Dehydrating Reactions, Katherine L. Childers

Undergraduate Honors Thesis Projects

The goal of this project was to study novel synthetic procedures for heterocycles. This was achieved through a two-part investigation. In the first part, a variety of conditions for the gold catalyzed cyclization of allenes were studied. This work was focused on the lesser studied intermolecular reactions of allenes. A variety of allenes were synthesized, and then reacted with 1,3-dipoles and a gold catalyst. These reactions were determined to be unsuccessful through the analysis of nuclear magnetic resonance spectroscopy data. In the second part of this study, the synthesis of 1,3,4-oxadiazoles was investigated. Several cited procedures were examined to determine …

A Continuous Process Towards The Synthesis Of Quinolones, Stevara N. Clinton

Theses and Dissertations

Abstract

The development of quinolones is described from the first quinolone to the latest fluoroquinolones. Quinolones have generated considerable interest since their discovery because of their antibacterial capabilities. Analogs incorporating the 4-quinolone ring system comprise a largely expanding group of synthetic compounds. The development of antibacterial resistance has created the need for an efficient synthesis of quinolones that can be easily adapted toward the assembly of quinolone based antibacterial drugs.

There are several reported approaches to the 4-quinolone ring system. Many of these methods use expensive starting materials, require the removal of high boiling solvents, or use high temperature conditions …

Syntheses Of Precursors To Fluorine-18 Labeled Pet Imaging Agents, Lindsay B. Boling

Chancellor’s Honors Program Projects

No abstract provided.

Science Classics, Mark Masthay

Chemistry Faculty Publications

An essay on the impact of the works in the Imprints and Impressions: Milestones in Human Progress, an exhibition of rare books from the collection of Stuart Rose. Exhibition was held Sept. 29-Nov. 9, 2014, at the University of Dayton.

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

Senior Honors Theses

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

Organic Thin-Film Transistors And Tips-Pentacene, Zachary Stewart

Lewis Honors College Capstone Collection

TIPS-Pentacene, an organic semiconductor characterized by its good electronic properties, solubility, and stability, is used primarily in organic thin-film transistors (OTFT). This research seeks to create an OTFT by crafting a stencil, depositing the source and drain onto a substrate’s surface, and processing TIPS-Pentacene onto the channel between them. In addition, if time permits, the electronic properties of several OTFTs will be compared to determine how to optimize their production.

Boron And Metal Catalyzed C-C And C-H Bond Formation, Adam Barret Pippin

Doctoral Dissertations

Research efforts focused on the use of boron and metals to form new carbon-carbon and carbon-hydrogen bonds are summarized in this dissertation. Several novel reactions have been developed. These include: the deoxygenation of benzylic alcohols using chloroboranes; alkenylation of benzylic alcohols using boron trichloride; and dialkynlation of aryl aldehydes using dialkynylboron chloride. Numerous applications of these novel reactions have been developed. These include alternate routes to diphenylmethanes and 1,4-diynes from easily prepared dialkynylboron chlorides. In addition, E and Z alkenyl halides can now be prepared using boron trichloride without the use of butyllithium. The stereochemistry of the alkenyl halide can …

Ferrocene Constrained Helical Peptides Via On-Resin Cyclization, Thomas A. Mcteague

Senior Theses and Projects

Previous research within the Curran group has demonstrated that ferrocene may be used as an organometallic constraint to induce the formation of α-helices in short peptides which traditionally possess undefined conformations. Through strategic placement of lysine residues at the i and i+3 positions within the peptide, such a constraint was accomplished via the crosslinking of the lysine side chains to ferrocene dicarboxylic acid chloride in solution phase synthesis. The aim of this work was to develop a method for solid phase peptide synthesis (SPPS) for the synthesis of these ferrocene-constrained helices. In particular, we seek to develop a method in …

The Many Pharmaceutical Discoveries Of Gertrude B. Elion, Alayna Bonse

Natural Sciences Student Research Presentations

This poster discusses the contributions of Gertrude B. Elion to pharmaceutical science.