Chemistry Commons^™

Preparation And Characterization Of Macroporous Electrodes For Electrochemical Bioassays, Ashwin Rao

All Dissertations

Applications such as point-of-care medical diagnosis and in-the-field biological warfare agent detection require portable bioassays which are less laborious yet cost effective. Conventional sandwich bioassays see limited use for such applications as it involves time consuming steps of reagent treatment and washings, and are restricted to use inside laboratories. We explore new platforms for sandwich bioassays required by such applications. The platform we have developed is based on electrochemical methods of detection. Flow-through three-dimensional electrodes suitable for use in electrochemical sandwich bioassays were fabricated. A composite of superporous agarose and reticulated vitreous carbon (SPA-RVC) material was used for the fabrication …

Proteomic Strategies For Investigation Of Protein/Ligand And Peptide/Ligand Non-Covalent Interactions By Electrospray Ionization Mass Spectrometry, Abraham H. Lo

Chemistry & Biochemistry Theses - Archive

Through universal proteomic methods and electrospray ionization-mass spectrometry (ESI-MS), multiple molecular recognition strategies were investigated as a prospective complementary tool for investigating protein-ligand interactions. Three model protein-ligand systems: bovine serum albumin/naproxen, cytochrome c/ATP & ADP, and integrin/RGD peptide were probed based on the categorical difference in the nature of each ligand. It was found that screening for protein binding sites from proteolytic digests was feasible for one of three models. Three different proteolytic digests of cytochrome c featured several examples of binding interaction with the ligands ATP and ADP. The detection of binding between intact cytochrome c and ATP/ADP was …

Synthetic Studies And Biological Evaluation Of Imidazole-Containing Marine Alkaloids, Lesley Ann Schmid

Chemistry & Biochemistry Dissertations - Archive

This dissertation discusses the synthetic methods towards and the preliminary biological studies of an unnamed, imidazole-containing alkaloid, derived from the marine species Oceanapia. This alkaloid was first discovered in 1996 by researchers at the NIH as a possible inhibitor of the key enzyme in the detoxification cycle of Mycobacterium tuberculosis. Chapter 1 provides an overview of tuberculosis, which is currently the second highest cause of death worldwide, with one third of the world's population infected. In recent years, the emergence of multi-drug resistant strains has created new interest and funding for tuberculosis research. New treatments like the alkaloid described above …

A Structural, Magnetic, And Mössbauer Spectral Study Of The Dyco₄₋ₓfeₓb Compounds, With X=0-3, Hervé Mayot, Olivier Isnard, Fernande Grandjean, Gary J. Long

Chemistry Faculty Research & Creative Works

The DyCo_4-xFe_xB compounds, with x=0, 1, 1.5, 2, 2.5, and 3, have been investigated by x-ray diffraction, magnetic measurements, and iron-57 Mössbauer spectroscopy. The substitution of cobalt by iron induces both an anisotropic increase in the unit-cell volume and a large increase in the Curie temperature. The 4.2 K magnetization decreases with increasing iron content. The Mössbauer spectra of the DyCo_4-xFe_xB compounds with x=1, 1.5, and 2 reveal rather small iron hyperfine fields of approximately 16 T and large quadrupole interactions of +1.0 and -1.0 mms, for the 6i and 2c sites, …

Semifluorinated Polymers Via Cycloaddition And Nucleophilic Addition Reactions Of Aromatic Trifluorovinylethers, Scott Iacono

All Dissertations

This dissertation encompasses the synthesis, characterization, and properties of semifluorinated polymers derived from thermal polymerization of aryl trifluorovinyl ether (TFVE) monomers. This work is divided into two parts based on the methodology of thermal polymerization using aryl TFVE monomers. The first part of this work involves the thermal [2 + 2]cyclodimerization of aryl TFVE monomers affording perfluorocyclobutyl (PFCB) aryl ether polymers. Chapter 1 provides an overview of PFCB aryl ether polymers as a next-generation class of high performance fluoropolymers that have been successfully employed for a myriad of technologies. PFCB aryl ether polymers are highly desired because of their high …

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; …

Palladium Nanoparticles Supported By Alumina Nanofibers Synthesized By Electrospinning, S. J. Park, S. Bhargava, E. T. Bender, George G. Chase, R. D. Ramsier

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Palladium nanoparticles supported by alumina nanofibers have been successfully synthesized by electrospinning using palladium chloride incorporated into a solution of polyvinyl pyrrolidone and aluminum acetate. Palladium agglomerate sizes and the surface morphology of the electrospun nanofibers were determined by transmission electron microscopy. Palladium nanoparticles appeared to be well dispersed within the electrospun nanofiber structure. X-ray diffraction, x-ray photoelectron spectroscopy, and Raman scattering spectroscopy techniques were used to identify the crystalline form and distinguish between oxidized and metallic palladium particles after heating and hydrogenation.

The Determination Of The Electronic Structure And Geometries Of Boron And Boron Mononitrogen Clusters Using An Adaptive, Kink-Based Path Integral Approach To Quantum Mechanics, Shawn Wilkinson

Honors Capstones

No abstract provided.

Optimization Of Expression And Purification Of Acetoacetyl-Coa Thiolase From Sunflower, Anthony Muriithi Maina

Theses, Dissertations and Culminating Projects

The [beta]-oxidation system in sunflower (Helianthus annuus L.) cotyledons is distinguished by the existence of two different thiolase isoforms, Thiolase I (acetoacetyl-CoA thiolase, EC 2.3.1.9 AACT) and Thiolase II (3-oxoacyl-CoA thiolase, EC 2.3.1.16 OACT). Glyoxysomal AACT is the last enzyme in the p-oxidation of fatty acids in plant glyoxysomes. Glyoxysomal AACT has been successfully cloned, expressed and purified from sunflower cotyledons (Dyer et al., 2006). In this paper we investigate the optimal conditions for both expression and purification. These include the choice of vector, the growth conditions and the purification parameters for the maximum possible yield of AACT protein.

The Effects Of Physical And Chemical Modulating Agents On The Induction Of Vaccine-Induced Immune Responses, Andrea Nicole Ryan

Honors Scholar Theses

After the development of the viral-based prostate cancer vaccine, Ad5-PSA, much research has been orientated to help enhance the induced immune response by combining the vaccine with physical and chemical modulating agents, more specifically the polymers polyethylenimine (PEI), chitosan, and chitosan coated with CD3 complex antibodies; all previously shown to stimulate an immune response as isolated gene carriers. To compare the vaccine-induced immune responses between the naked vaccine and the polymer-vaccine combinations, a mouse model using the ovalbumin- specific Ad-OVA vaccine was tested using intracellular cytokine staining (ICS), tetramer staining, and cytotoxic T-cell lymphocyte assays to measure the activation of …

The Ligand Effects In The Rhodium Catalyzed 1,4-Addition Reaction Of Terminal Alkynes To -Unsaturated Ketones, Jocellie Marquez

Renée Crown University Honors Thesis Projects - All

Ligand effects play an important role in reactivity and selectivity in many transition metal catalyzed processes. The role of the phosphine ligand is critical to the product ratio in rhodium-catalyzed reaction of methyl vinyl ketone and terminal alkynes. For a ligand with a hemilabile oxygen on the phosphine, smaller ligands shift the product ratio in favor of the 1,4-addition product while with bulky oxygen ligands a dimerization/addition product manifold is dominant. Ligand screen results show that tri-o-tolylphosphine (TOTP) provided the best yields and highest selectivity for dimer-addition product.

Light-Triggered Proton And Electron Transfer In Flavin Cofactors, Guifeng Li, Ksenija D. Glusac

Chemistry Faculty Publications

The pH dependent behavior of two flavin cofactors, flavin-adenine dinucleotide (FAD) and flavin mononucleotide (FMN), has been characterized using femtosecond transient absorption spectroscopy for the first time. The flavin excited state was characterized in three states of protonation (Fl(-), Fl, and FlH(+)). We found that Fl and Fl(-) exhibit the same excited state absorption but that the lifetime of Fl(-) is much shorter than that of Fl. The transient absorption spectrum of FlH(+) is significantly different from Fl and Fl(-), suggesting that the electronic properties of the flavin chromophore become appreciably modified by protonation. We further studied the excited state …

Structure And Dynamics Of Poly (Para-Phenyleneethynylene)S In Solutions And Thin Films, Yunfei Jiang

All Dissertations

This research focuses on the structure and dynamics of a family of rigid polymers, poly(para-phenyleneethynylene)s (PPEs) in solutions and thin films using small angle neutron scattering, neutron spin echo, nuclear magnetic resonance, X-ray scattering, atomic force microscopy and fluorescence spectroscopy. The effects of the solvent and the side chain on the molecular conformation and the association of PPEs have been investigated.
In dilute solutions, the phase diagram of dinonyl PPE in toluene and cyclohexane exhibits three distinct phases. At higher temperatures, PPEs form molecular solutions with extended conformations in toluene and worm-like chains in cyclohexane. With decreasing temperatures, PPEs associate …

Synthesis And Characterization Of Polymeric Materials Derived From Multifunctional Alkyl A-Hydroxymethylacrylates, Jean-Francois Morizur

Dissertations

The research presented in this dissertation covers the investigation of new materials derived from alkyl a-hydroxymethylacrylates (RHMA). The first project exposed in Chapter II involves the synthesis, characterization of RHMA-based reactive surfactants and their successful incorporation in acrylic latexes. The amphiphilic monomers testify of a good copolymerization behavior with other acrylic monomers such as methyl methacrylate and butyl acrylate although their extensive bulkiness. They led to the formation of well-defined polymeric particles via a seeded emulsion polymerization process and permitted decreasing significantly the water sensitivity of the resulting films as compared to film incorporating conventional emulsifier such as sodium dodecyl …

Targeted Drug Delivery Systems For Cancer Therapy, Antonio Clementi, Christine O'Connor, Mary Mcnamara, A. Mazzaglia, M. C. Aversa, A. Giuffrida

Conference Papers

The role of cyclodextrin’s (CD) in drug delivery has advanced in recent years and this may be attributed to its biocompatibility and well established synthesis. Chemical modification of CDs has shown to extend the physicochemical properties and the host capacity for a variety of drugs. β-CD has been widely used in the early stages of pharmaceutical applications because of its ready availability and its cavity size suitability for a wide range of drugs. Chemical modification of β-CD has proven to enhance aqueous solubilisation, microbiological stability and reduced toxicity in previous studies.1 Folate Receptors are over-expressed in several human cancers including …

Photopolymerization And Characterization Of Crosslinked Thiol-Ene Networks And Poss/Thiol-Ene Nanocomposites, Tolecia Sharonda Shaunee Clark

Dissertations

Interests in the area of thiol-ene photopolymerization are rapidly expanding due to the numerous advantages over the polymers produced by traditional solvent based polymerizations. Although current research of photoinitiated thiol-ene polymerization is diverse, numerous opportunities are available for investigating structure/property and structure/reactivity relationships and novel material applications. This research in this dissertation includes a fundamental study of the effect of monomelic thiol functionality on thiol-ene polymerization kinetics and formation of the thiol-ene network structure, and an investigation of the development of novel silicate based thiol-ene nanocomposites. The first fundamental study investigates the effect of thiol functionality on the kinetics and …

The Design, Synthesis, And Controlled Polymerization Of Cationic And Zwitterionic Norbornene Derivatives, David Allen Rankin

Dissertations

Ring-opening metathesis polymerization (ROMP) has been exploited for the controlled polymerization of cationic and zwitterionic norbornene-based monomers and employed in the preparation of homo- and block-copolymer systems in homogeneous organic media without the use of post-polymerization modification or protecting group chemistries. Relying on previous knowledge of certain halogenated alcoholic organic solvents capable of solubilizing hydrophilic monomers, the first study, describes the synthesis and controlled polymerization of a series of new permanently cationic ammonium exo-7- oxanorbornene derivatives M31 via ROMP, with the first generation Grubbs catalyst 17, in a novel solvent mixture comprised of 1:1 vol/vol 2,2,2-trifluoroethanol (TFE)/methylene chloride (CH2CI2). This …

Raft Synthesis Of Water-Soluble, Stimuli-Responsive Ab Diblock Copolymers, Ran Wang

Dissertations

A series of water-soluble, stimuli-responsive AB diblock copolymers were synthesized via the reversible addition-fragmentation chain transfer (RAFT) polymerization technique employing 2-(2- carboxyethylsulfanylthiocarbonylsulfanyl)propionic acid (CTA26) as the RAFT mediating agent.

First, a series of diacid functional trithiocarbonate chain transfer agents (CTA's) were synthesized and examined for their effectiveness as mediating agents in controlling the polymerization of «-butyl acrylate (nBA). Overall, CTA26 demonstrated good control in the homopolymerization of nBA with respect to the molecular weight and the molecular weight distribution, as well as its ability to form block copolymers with high reinitiating efficiency, and thus was chosen as the CTA for …

Simpol.1: A Simple Group Contribution Method For Predicting Vapor Pressures And Enthalpies Of Vaporization Of Multifunctional Organic Compounds, James F. Pankow, William E. Asher

Physics Faculty Publications and Presentations

The SIMPOL.1 group contribution method is developed for predicting the liquid vapor pressure p^o_L (atm) and enthalpy of vaporization Δ H_vap (kJ mol^-1) of organic compounds as functions of temperature (T). For each compound i, the method assumes log₁₀p^o_L,i (T)=∑_kν_k,ib_k(T) where ν_k,i is the number of groups of type k, and b_k (T) is the contribution to log₁₀p^o_L,i (T) by each group of type k. A …

Identification Of Metallo-Ss-Lactamase Inhibitors Via Enzyme Assay And Hplc-Ms Monitoring, Peggy Ann Sanchez

Theses, Dissertations and Culminating Projects

The vast overuse of antibiotics along with extrachromosomal gene insertion between different bacterial species has led to the Darwinian consequence of antibiotic resistance. Amongst the contributing factors to the rise of bacterial resistances are the production of ß-lactamases, which pose a major impediment to treatment with ß-lactam drugs such as penicillins and carbapenems. SPM-1 is a metallo-ß-lactamase (MBL) that confers antibiotic resistance to bacteria through zinc-mediated hydrolysis of ß-lactams. Bacteria that express the SPM-1 metalloenzyme show reduced sensitivity to ß-lactam drugs. One method to defeat this form of resistance is to administer a ß-lactam antibiotic with a potent ß-lactamase inhibitor …

Perfluorocyclobutyl Aryl Ether Polymers For Proton Exchange Membranes, Raul Hernandez

All Theses

Over the last decades Nafion¨ has emerged as the polymer of choice for the fabrication of Proton Exchange Membranes (PEM)s, due to its excellent proton conductivity and long-term stability. However, high temperatures and low relative humidity decrease fuel cell efficiency, due to the highly hydrated conditions required for proton conductivity. To overcome these issues, different types of sulfonated polymers have been proposed as promising substitutes for Nafion ¨, these include; Poly(arylene ether sulfones) (PAES) and Perfluorocyclobutyl (PFCB) aryl ether polymers among others.
Chapter 2 of this thesis describes the synthesis of a new class of sulfonated PAESs containing the perfluorocyclobutyl …

Iron(Iii)-Salophene: An Organometallic Compound With Selective Cytotoxic And Anti-Proliferative Properties In Platinum-Resistant Ovarian Cancer Cells, Thilo S. Lange, Kyu Kwang Kim, Rakesh K. Singh, Robert M. Strongin, Carolyn Mccourt, Laurent Brard

Chemistry Faculty Publications and Presentations

Background: In this pioneer study to the biological activity of organometallic compound Iron(III)-salophene (Fe-SP) the specific effects of Fe-SP on viability, morphology, proliferation, and cell-cycle progression on platinum-resistant ovariancancer cell lines were investigated.

Methodology/Principal Findings: Fe-SP displayed selective cytotoxicity against SKOV-3 and OVCAR-3 (ovarian epithelial adenocarcinoma) cell lines at concentrations between 100 nM and 1 μM, while the viability of HeLa cells (epithelial cervix adenocarcinoma) or primary lung or skin fibroblasts was not affected. SKOV-3 cells in contrast to fibroblasts after treatment with Fe-SP revealed apparent hallmarks of apoptosis including densely stained nuclear granular bodies within fragmented nuclei, highly condensed …

Carbon Nanotubes And Nanocomposites For Thermal And Electrical Applications, Wei Wang

All Dissertations

The known electrical and thermal properties of carbon nanotubes have prompted many predictions on their extraordinary potentials for ultimately performing polymeric nanocomposites. In this dissertation, chemical modification and functionalization of carbon nanotubes have been demonstrated as being effective for high-quality polymeric carbon nanotube composites, especially with our approach of using polymers that are structurally identical or maximally similar to the matrix polymers in the nanotube functionalization. For example, a poly(N-vinyl carbazole) (PVK) copolymer containing pendant hydroxyl groups was synthesized for the functionalization of single-walled carbon nanotubes (SWNTs). The shared solubility of the functionalized nanotube samples with PVK matrix polymer enabled …

Synthesis And Electrochemical Studies In Microstructured Media, Jamie Norton

All Dissertations

In-situ electrochemical methods involving both oxidative and reductive mediators were employed to modify the oxidation state (doping level) of PEDOT polymers in colloidal PEDOT-coated silica core-shell particles that were prepared as a dispersion encapsulated in a hydrogel matrix. The modifications of the redox states of the PEDOT coating induced a change in the absorbance characteristics. A mediated electron transfer system was employed to ferry charge from the electrodes of the cell to the isolated particles. The mediator diffuses between the electrode surface and the PEDOT-coated particles to accomplish (de)doping. The developed system was a fully self-contained and electrically driven device. …

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 …

Formation Of Bicyclic Pyrroles From The Catalytic Coupling Reaction Of 2,5-Disubstituted Pyrroles With Terminal Alkynes, Involving The Activation Of Multiple C-H Bonds, Chase S. Yi, Jie Zhang

Chemistry Faculty Research and Publications

Substituted bicyclic pyrroles are produced directly from the coupling reaction of 2,5-disubstituted pyrroles with terminal alkynes, involving the activation of multiple C–H bonds and regioselective cyclisation.

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.

Micellar Templates And Spectroscopic Rulers For Synthesis And Characterization Of Site‐Isolated Inorganic Catalysts, Brittni Scruggs

Chemistry Student Honors Theses

The controlled preparation of active sites on heterogeneous catalysts could improve several catalyst systems by optimizing catalyst efficiency and increasing reaction selectivity. Cetyltrimethylammonium bromide (CTAB) micelles were used as templating structures to encapsulate and deposit aminopropyltriethoxysilane (APS) onto silica. Methods of determining the number of available surface amines were explored; in particular, cobalt(II) titrations and ninhydrin tests were developed. Further characterization of the surface amines after micelle removal and surface alkylation with tetramethyldisilazane (TMDS) was performed by using fluorescence resonance energy transfer (FRET). Indole‐3‐propionic acid, a fluorescence donor, and a variety of fluorescence acceptor molecules have been reacted with the …

Method Of Preparing A Chiral Substrate Surface By Electrodeposition, Jay A. Switzer, Hiten M. Kothari, Shuji Nakanishi, Eric W. Bohannan

Chemistry Faculty Research & Creative Works

A solid substrate comprising a surface comprising an achiral array of atoms having thereupon a chiral metal oxide surface. The chiral metal oxide surface is prepared by electrodeposition of a chiral metal oxide array from a solution of a chiral salt of the metal. In one embodiment, chiral CuO is grown on achiral Au(001) by epitaxial electrodeposition. The handedness of the film is determined by the specific enantiomer of tartrate ion in the deposition solution. (R,R)- tartrate produces an S—CuO(l 1 T) film, while (S,S)-tartrate produces an R—CuO(Tl 1) film. These chiral CuO films are enantiospecific for the electrochemical oxidation …

Real-Time Plasma Controlled Chemistry In A Two-Frequency, Confined Plasma Etcher, Vladimir Milosavljevic, Albert R. Ellingboe, Cezar Gaman, John V. Ringwood

Articles

The physics issues of developing model-based control of plasma etching are presented. A novel methodology for incorporating real-time model-based control of plasma processing systems is developed. The methodology is developed for control of two dependent variables (ion flux and chemical densities) by two independent controls (27 MHz power and O2flow). A phenomenological physics model of the nonlinear coupling between the independent controls and the dependent variables of the plasma is presented. By using a design of experiment, the functional dependencies of the response surface are determined. In conjunction with the physical model, the dependencies are used to deconvolve the sensor …