Chemistry Commons^™

Contraction-Expansion Protocols., Nadine Katia Njoya

Electronic Theses and Dissertations

An approach to a new class of compounds known as bridgehead dienone is described. The route is based on a tandem contraction-expansion event in which the contraction triggers the expansion. The two steps involved are a palladium-catalyzed Favorskii contraction and a cis-divinyl cyclopropanone rearrangement. Progress towards these goals is reported.

Synthesis Towards Fulminic Acid And Its Derivatives In 1, 3-Dipolar Cycloaddition Reactions., Ophilia Ndi Toh

Electronic Theses and Dissertations

A new approach to fulminic acid cycloadditions has been developed. At reduced temperatures, fulminic acid is generated in situ and undergoes 1, 3-diploar cycloaddition reactions with dipolarophiles to form isoxazolines and/or its dimers. This procedure represents a novel, safe general method for the one-step generation of fulminic acid, which complements existing potentially explosive protocols.

Proposed Route To Cyclopenta[C]Thiophenes Via Activated Methylene, Vineet V. Karambelkar

Masters Theses & Specialist Projects

The synthesis of cyclopenta[c]thiophenes has been sparsely reported in the literature owing to several difficulties involved in their synthesis. The present work involves the proposed synthesis of cyclopenta[c]thiophenes and their precursors using activated methylene. Cyclopenta[c]thiophene compounds show promise in the field of polymer and catalysis chemistry. These substituted polythiophenes are potential organic semiconductors and anti-tumor agents. The research presented shows the successful and novel conversion of 3,4-bis(chloromethyl)-2,5-dimethylthiophene and 3,4-bis(bromomethyl)-2,5-dimethylthiophene to a fused 5,5'-fused membered ring which is the precursor to cyclopenta[c]thiophene the sulfone ester, 5-carbomethoxy-5- phenylsulfonyl-1,3-dimethyl-5,6-dihydro-4H-cyclopenta[c]thiophene, in just two steps as compared to four steps previously reported in the literature. …

Admicelle-Based Solid Phase Extraction Of Phenols Using Dialkylammonium Surfactant In The Hydroxide Form, Kali R. Pickering

Masters Theses & Specialist Projects

A technique for admicelle-based solid phase extraction is presented in which a dialkylammonium surfactant in the hydroxide form is immobilized on silica. By converting dihexadecyldimethylammonium bromide to the hydroxide form, the surfactant is allowed to have the property of a strong base, aiding in the extraction of acidic phenols which are difficult to extract because of their differing polarities. The surfactant-silica admicelle parameters were optimized for the efficient extraction of eight phenols. Adsorbed phenols were eluted from the sorbent using small volumes of methanol. The phenols were preconcentrated from drinking water samples and were determined using high performance liquid chromatography …

Inversion Symmetry And Local Vs. Dispersive Interactions In The Nucleation Of Hydrogen Bonded Cyclic N-Mer And Tape Of Imidazolecarboxamidines, Sihui Long, Venkatraj Muthusamy, Peter G. Willis, Sean Parkin, Arthur Cammers

Chemistry Faculty Publications

Substitutional changes to imidazolecarboxamidine that preserved intermolecular hydrogen bonding in the solid state were used to study the relationship between packing and the hydrogen bond motif. Various motifs competed, but the most common imidazolecarboxamidine crystalline phase was a C_i symmetric dimer that established inversion centers by associating enantiomeric tautomers. Counter to intuition, the calculated gas-phase energies per molecule of the solid state atomic coordinates of the C_i dimer motifs were higher than those of the C₁ dimer, trimer, tetramer and tape motifs, while the packing densities of C_i dimers were found to be higher. This result …

Optimization Of Microwave-Assisted Acid Digestion Method For Determination Of Trace Elements In Coal And Coal Fly Ash, Dejan Savic

Masters Theses & Specialist Projects

In most of the analytical and environmental laboratories today inductively coupled plasma (ICP) is a method of choice for analysis of trace metal elements present in coal and coal combustion products. This method requires use of liquid samples, so all coal and coal combustion products must be digested prior to analysis by ICP. Traditionally an open-air hot-plate acid digestion method published as ASTM D6357-04 was used to extract all trace metal elements into solution.

Recent development of microwave systems designed for digestions under extreme acidic conditions and high temperatures and pressures shifted focus toward more rapid and precise microwave-assisted digestion …

Preparation Of Halogenated Derivatives Of Thiazolo[5,4-D]Thiazole Via Direct Electrophilic Aromatic Substitution, Vladimir Benin, Alan T. Yeates, Douglas Dudis

Chemistry Faculty Publications

Chlorination and bromination reactions of thiazolo[5,4-d]thiazole led to the generation of its mono- and dihalogenated derivatives. These are the first instances of successful direct electrophilic aromatic substitution in the thiazolo[5,4-d]thiazole ring system. X-ray analysis demonstrates that both 2-bromothiazolo[5,4-d]-thiazole and 2,5-dibromothiazolo[5,4-d]thiazole are planar structures, with strongly manifested π-stacking in the solid state. Theoretical analysis of the pyridine-catalyzed halogenation (MP2/6-31+G(d) and B3LYP/6-31+G(d)calculations) reveals that introduction of one halogen actually leads to a slightly enhanced reactivity towards further halogenation. Several halogenation mechanisms have been investigated: 1) The direct C-halogenation with N-halopyridine as electrophile; …

Perfluorocyclobutyl Aryl Ether Polymers: A Modular Approach To Tailored Emission, Andrew Neilson

All Dissertations

Aryl trifluorovinyl ethers (TFVE) are versatile precursors to perfluorocyclobutyl aryl ether (PFCB) polymers. TFVE functionalized chromophores of a variety of colors have been synthesized for copolymerization to form PFCB polymers with tunable emissive properties. TFVE small molecule chromophores containing fluorene, benzothiadiazole, and bisthiophene show superb emissive properties and prove that the TFVE and PFCB structures have no effect on chromophore emission. Copolymerization of these chromophores with commercial TFVE monomers produced high molecular weight, thermally stable, emissive materials. With the use of trifunctional TFVE monomers these materials can be made into optical glasses. PFCB-phenylene vinylenes were prepared by Wittig polymerization and …

A Comparison Of The Surface Adsorption Characteristics Of Reduced And Oxidized Cytochrome C On A Fused Silica Surface Via Attenuated Total Internal Reflection Spectroscopy, Casey M. Kraning

Undergraduate Honors Thesis Collection

No abstract provided.

One-Pot Enol Silane Formation-Mukaiyama Aldol-Type Addition To Dimethyl Acetals Mediated By Tmsotf, C. Wade Downey, Miles W. Johnson, Kathryn J. Tracy

Chemistry Faculty Publications

Various ketones, esters, amides, and thioesters add in high yield to dimethyl acetals in the presence of silyl trifluoromethanesulfonates and an amine base. Acetals derived from aryl, unsaturated, and aliphatic aldehydes are all effective substrates. The reaction proceeds in a single reaction flask, with no purification of the intermediate enol silane necessary.

C–N Bond Rotation And E–Z Isomerism In Some N-Benzyl-N-Methylcarbamoyl Chlorides: A Dft Study, Michael Horwath, Vladimir Benin

Chemistry Faculty Publications

The current report presents the first theoretical study of the restricted CN bond rotation in carbamoyl chlorides. Several N-benzyl-N-methylcarbamoyl chlorides were investigated, with varying pattern of substitution in the aromatic ring. Optimizations and frequency calculations were conducted employing DFT at the B3LYP/6-31+G(d) level of theory. Each of the studied structures exhibits a pair of rotamers (s-Z and s-E), generated upon rotation around the C(O)N bond. The s-E isomer is the global minimum in every case, but the preference for it is usually less than 1 kcal/mol. Two possible transition state structures were identified …

Critically Evaluated Thermochemical Properties Of Polycyclic Aromatic Hydrocarbons, María Roux, Manuel Temprado, James Chickos, Yatsuhisa Nagano

Chemistry & Biochemistry Faculty Works

No abstract provided.

Singlet Oxygen Chemistry In Water:  A Porous Vycor Glasssupported Photosensitizer, David Aebisher, Nikolay S. Azar, Matibur Zamadar, Naveen Gandra, Harry D. Gafney, Roumei Gao, Alexander Greer

Faculty Publications

Singlet molecular oxygen [1O2 (1Δg)] is generated cleanly in aqueous solution upon irradiation of a heterogeneous complex, meso-tetra(N-methyl-4-pyridyl)porphine (1) adsorbed onto porous Vycor glass (PVG). The cationic photosensitizer 1 tightly binds onto PVG and gives a stable material, which does not dissociate 1 into the surrounding aqueous phase. The production of 1O2 was measured by monitoring the time-resolved 1O2 (1Δg) phosphorescence at 1270 nm. Indirect analysis of 1O2 generation was also carried out with the photooxidation oftrans-2-methyl-2-pentenoate anion, which afforded the corresponding hydroperoxide. Sensitizer-1-impregnated PVG gives rise to a new singlet …

Modeling The Physical Properties Of A Homologous Series On The Melting Temperatures And Densities Of N-Alkanes And Their Simple Alkyl-Derivatives, Antun Rubčić, Jasna Rubčić, James Chickos

Chemistry & Biochemistry Faculty Works

No abstract provided.

Synthesis Of Phenoxides With Pendant Amines And Catalytic Intramolecular Hydroaminations, Kenneth Awasung

Undergraduate Review

One core focus of my research project, (my 2007 summer research) is to make structural analogs of substituted phenols to support the titanium catalysis of organic compounds. The synthesis and study of these and related ligands, (pyrrolyls, aldimines, salens, and other nitrogen/oxygen heterocycles) is a major field of organometallic chemistry. Bulky phenols and their analogs serve as highly effective ligands to support catalysis due to their sterics and electronics. I have been designing and have begun synthesizing phenol analogs using a series of aldol condensations and michael additions and other organic chemistry methodology to generate new substituted phenols. Our method …

Using Azahetercyclic Electrophiles To Synthesize Novel Bicyclooxacalixarenes And Oxacalix[2]N-Hexylnaphthalimide[2]Naphthyridines, Doug Rooke

Honors Theses

Various bicyclooxacalixarenes, tricyclooxacalixarenes and oxacalix[2]N-hexylnapthalimide[2]naphthyridines are synthesized via SnAr condensation. This research has involved synthesis optimization. The oxacalix[2]N-hexylnaphthalimide[2]naphthyridines have exhibited host-guest binding in fluorescence experiments. These compounds have been characterized by NMR spectroscopy as well as single crystal X-ray diffraction.

Photochemical Generation And Intramolecular Chemistry Of Β-Alkoxycarbenes, Kimberly Graves

Honors Theses

The photolytic phenanthrene-based precursors for both β-methoxycarbene and β-ethoxycarbene were synthesized with and without a deuterium label attached to the a carbon. The incorporation of this deuterium label allowed distinction between a 1, 2-H shift and a 1, 2-O shift pathway to the respective alkyl vinyl ether, without the influence of a primary kinetic isotope effect. Photolyses of these precursors gave rearrangement products of the expected β-alkoxycarbenes. In the case of β-methoxycarbene, no methyl vinyl ether was observed due to its volatility. However, the appearance of aldehyde peaks in the NMR spectra, from an apparent further rearrangement to acetaldehyde through …

7Β-Hydroxy­Artemisinin, Paulo B. Carvalho, Bo Liu, Yunshan Wu, John S. Williamson, Mitchell A. Avery

Office for Research Publications and Presentations

Crystals of the title compound [systematic name: (3R,6R,7S,8aR,9R,12aR)-7-hydr­oxy-3,6,9-trimethyl­octa­hydro-3,12-ep­oxy[1,2]dioxepino[4,3-i]isochromen-10(3H)-one], C₁₅H₂₂O₆, were obtained from microbial transformation of artemisinin by a culture of Cunninghamella elegans. The stereochemistry of the compound is consistent with the spectroscopic findings in previously published works. A weak O—H⋯O hydrogen bond occurs in the crystal structure, together with intermolecular C—H⋯O hydrogen bonds.

Optimising Design Parameters Of Enzyme-Channelling Biosensors, Dana Mackey, Tony Killard

Conference Papers

Two mathematical models for an electrochemical biosensor are proposed and compared with a view to determining the ratio of two immobilized enzymes which maximizes the amperometric signal amplitude.

Environmentally Friendly Organic Synthesis Using Bismuth Compounds: Bismuth(Iii) Iodide Catalyzed Deprotection Of Acetals In Water, Ram Mohan, Aaron Bailey, Ashvin Baru, Kendall Tashe

Scholarship

The chemoselective deprotection of a wide range of acetals and ketals in water is catalyzed by bismuth(III) iodide. Bismuth(III) compounds are remarkably nontoxic and hence are attractive as environmentally friendly catalysts.

Adsorption Studies Of Cytochrome C On A Silica Nanoparticle Surface, Carrie Ann Hedge

Undergraduate Honors Thesis Collection

This honors thesis investigated the conformational changes in cytochrome c when it is adsorbed to silica nanoparticle surfaces before denaturant as well as when it is exposed to denaturant and then allowed to adsorb to silica nanoparticles.

Optical And Vibrational Spectroscopic Studies Of Synthetic Maya Pigments As A Function Of, Swati Kumar

Open Access Theses & Dissertations

Pigments developed by the Mayan civilization around 8th century, represent some of the most versatile pigments known to date. Several derivatives of these pigments are popular subjects of current research interest. This is due to the characteristic stability which is provided by a bonding mechanism between the dye and the clay. One such pigment "Maya Blue", a mixture of Indigo and Palygorskite, provides a dramatic background for murals and ceramics throughout Mesoamerica. Several research groups have devoted time and interest in unlocking its particular features.1-3

The work embodied in this Thesis is focused on the synThesis and characterization of three …

A Study Of The Interaction Of Thioindigo Dye, With Several Inorganic Host Materials, Alejandra Ramirez

Open Access Theses & Dissertations

Maya Blue has been the focus of numerous studies and is believed to be a mixture of palygorskite clay and indigo dye.^1,2 Several derivatives of this pigment have been developed with intriguing properties. For instance, the dye thioindigo reacts with the palygorskite clay to exhibit a broad range of colors from red to blue under UV-Vis excitation. Based on FT-Raman and computer simulation, previous work performed in our group could relate indigo and thioindigo interaction to the aluminum sites in the framework. super>3,4

The work performed with other inorganic host materials such as, layer structures and zeolites have …

Oligo(Vinylidene Fluoride) Langmuir-Blodgett Films Studied By Spectroscopic, Rafal Korlacki, J. Travis Johnston, Jihee Kim, Stephen Ducharme, Daniel W. Thompson, Vladimir M. Fridkin, Zhongxin Ge, James M. Takacs

Stephen Ducharme Publications

Thin films of amphiphilic vinylidene fluoride oligomers prepared by Langmuir–Blodgett deposition on silicone substrates were investigated by comparing experimental and theoretical mid-infrared (IR) spectra. The experimental spectra were obtained using infrared spectroscopic ellipsometry. Theoretical spectra were calculated using density functional theory. Excellent correspondence of major IR bands in both data sets shows that the molecular backbone is oriented with the long axis normal to the substrate plane. This is in contrast to poly vinylidene fluoride[1] LB films, in which the polymer chains are parallel to the substrate.

Unsymmetric Aryl–Alkyl Disulfide Growth Inhibitors Of Methicillin-Resistant Staphylococcus Aureus And Bacillus Anthracis, Edward Turos, Kevin D. Revell, Praveen Ramaraju, Danielle A. Gergeres, Kerriann Greenhalgh, Ashley Young, Nalini Sathyanarayan, Sonja Dickey, Daniel Lim, Mamoun M. Alhamadsheh, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

This study describes the antibacterial properties of synthetically-produced mixed aryl alkyl disulfide compounds as a means to control the growth of Staphylococcus aureus and Bacillus anthracis. Some of these compounds exerted strong in vitro bioactivity. Our results indicate that among the twelve different aryl substituents examined, nitrophenyl derivatives provide the strongest antibiotic activities. This may be the result of electronic activation of the arylthio moiety as a leaving group for nucleophilic attack on the disulfide bond. Small alkyl residues on the other sulfur provide the best activity as well, which for different bacteria appears to be somewhat dependent on …

Synthesis And Evaluation Of Cyclopropanated Carbohydrates For Cns Disorders, Jaime Talisman

Seton Hall University Dissertations and Theses (ETDs)

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Lignin Degradation In Wood-Feeding Insects, Scott M. Geib, Timothy R. Filley, Patrick G. Hatcher, Kelli Hoover, John E. Carlson, Maria Del Mar Jimenez-Gasco, Akiko Nakagawa-Izumi, Rachel L. Sleighter, Ming Tien

Chemistry & Biochemistry Faculty Publications

The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut …

Post-Production Separation And Functionalization Of Single-Walled Carbon Nanotubes, Kurukulasuriya Fernando

All Dissertations

ABSTRACT
Single-walled carbon nanotubes (SWNTs) are considered to have many potential applications due to their unique structural, physical, chemical and electronic properties. Because the rigid structure of carbon nanotube determines its toughness in dissolution, the processing capability of carbon nanotube is strongly limited. My carbon nanotube functionalization research was mainly focused on developing innovative methods to functionalize nanotubes with various polymers and large aromatic molecules to make them soluble to study their interesting properties and applications. In this dissertation, different methods for the functionalization and solubilization of carbon nanotubes are described. The co-existence of metallic and semiconducting carbon nanotubes has …

Spectral Data For "Synthesis Of Cyclopropanes Via Organoiron Methodology: Stereoselective Preparation Of Bi(Cyclopropyl)S", Rajesh K. Pandey, Sergey V. Lindeman, William A. Donaldson

Natural Products Synthesis via Organoiron Methodology

Spectral data created in the course of the research project. Supports specific findings in "Synthesis of Cyclopropanes via Organoiron Methodology: Stereoselective Preparation of Bi(cyclopropyl)s".

Cyclopropanation of [2-(alkenyl)pentenediyl]Fe(CO)₃ complexes (4) proceeds in a diastereoselective fashion to afford [2-(cyclopropyl)pentenediyl]Fe(CO)₃. The relative stereochemistry of the products was established by X-ray crystallography. The diastereoselectivity is rationalized on approach of the cyclopropanation reagent on the sterically more exposed face of 4. Oxidatively induced reductive elimination afforded stereodefined bi(cyclopropyl)s.

A Series Of Vertically Integrated Nanotechnology Experiments For The Undergraduate Curriculum, Kevin W. Kittredge, Lesley E. Russell, Michael C. Leopold

Chemistry Faculty Publications

We have designed three nanotechnology experiments that are vertically integrated for an undergraduate chemistry curriculum. They are an evolving set of experiments for sequential courses in an undergraduate chemistry program. These experiments are designed to match the student's level of understanding for each particular course. The participating student is involved in a "research" project that progresses in both theory and experimental technique. Students benefit from these vertically integrated experiments by being involved in multiple facets of a simulated research project. This mimics a traditional research project under an advisor's supervision without the undesired drawback of an unknown outcome.