Physical Sciences and Mathematics Commons^™

Nickel Catalyzed Cyclizations Of Alkynyl-Etones And Their Application To The Formal Synthesis Of Pentalenic Acid, Kevin Schlosser

Honors Theses

Pentalenic acid is a very important molecule because it is a biosynthetic intermediate of pentalenolactone, which has antibiotic effects on Grampositive/ negative bacteria and pathogenic fungi. These effects are due to its ability to inhibit glyceraldehyde 3-phosphate dehydrogenase.1 However, the total synthesis of pentalenic acid is very lengthy.2 This project will begin the process of finding a more convenient route to pentalenic acid. Previously in this laboratory there have been experiments conducted in the cyclization of enones with nickel (0)3 It is hypothesized that this method can be used to shorten the preparation of pentalenic acid. As illustrated by the …

New Enantioselective Lewis Acid Catalysts, Mustafa Guzel

All Theses

Recently, many organic chemists have been ultimately interested in research in the synthesis of enantiomerically pure organics which are useful to synthesis of biologically active agents and prodrug substances. In the past decades, the new concepts in catalyst design unexpectedly explored the direction of natural product synthesis. In many cases, using enantioselective catalysts are the most suitable and efficient method into enantiopure systems.

The Effect Of Chromium Compounds On The Mutagenic Rate Of Benzo[A]Pyrenediolepoxide In Human Fibroblasts, Yordanos Tesfai

Masters Theses

Cancer researchers are interested in identifying the environmental causes and synergistic influences of different chemical carcinogens in order to decrease the risk of cancer. There are numerous studies which have investigated the effect of individual carcinogens but relatively few in which a well defined mixture of chemicals have been used. The present study was performed to examine the effect of chromium compounds on benzo[a]pyrene diolepoxide (BPDE) induced cytotoxicity and mutagenicity in human fibroblasts. Cytotoxicity was measured by the ability to fonn colonies while selection of 6-thioguanine resistant mutants were used to study mutagenesis in human fibroblasts.

Our results indicate that …

Rapid Method For Determination Of Iodine Numbers Of Vegetable Oils, Ondrej Hendl

Masters Theses

There is a great deal of interest by the public about the total unsaturation of fats and oils used in commercial products as an indication of nutritional value. Dealers in fats and oils are extremely interested in characterizing these products. The unsaturation is a guide to the expected stability of food additives, such as edible oils and foods in which they are used. Unsaturation is typically evaluated as an iodine number (IN), calculated for these additives based on their consumption of iodine through addition across the carbon-carbon double bonds. The classical titration method can typically take 45 minutes.

The investigation …

Side Chain Effect On Micellarly Catalyzed Hydrolysis Of Hydroxamic Acids In Perfluorooctanoic Acid Environment, A.C. Menik Fernando

Masters Theses

The side chain effect on micellar catalysis of hydroxamic acids with perfluorooctanoic acid as the reactive counterion surfactant in aqueous acetonitrile solution has been demonstrated in this thesis.

The rate constant-surfactant concentration profiles were used to estimate the critical micelle concentration and the second order rate constant for hydrolysis in the aqueous bulk phase.

The pseudo-phase ion exchange model satisfactorily explains the surfactant effect. The second order rate constants in the aqueous bulk phase show a direct relationship with steric substituent constants. The major influence of the change in micellar catalysis is the location in the micelle where the substrate …

Mass Transport Of Volatile Organic Compounds Between The Saturated And Vadose Zones, Monte S. Harner

Theses and Dissertations

Volatile organic compounds (VOCs) dissolved in the saturated zone are transported into the vadose zone primarily by gaseous phase diffusion. If the saturated zone is remediated, VOCs present in the vadose zone may become a secondary source of contamination for the groundwater. The amount of VOCs that remain in the vadose zone is dependent on site hydrology, soil properties, and the chemical properties of the contaminants. The purpose of this study was to determine what conditions caused VOC concentrations in the vadose zone to significantly recontaminate the saturated zone. A one-dimensional numerical model was developed to investigate the transport of …

The Biodegradation Characteristics Of Proposed Fuel Systems Icing Inhibitors (Fsii), Charles E. Meshako

Theses and Dissertations

The biodegradation characteristics of three fuel system icing ihhibitors (FSII) were evaluated. FSII are jet fuel additives that partition into water readily and are present in the water drained from storage tank bottoms in concentrations approaching 40%. These concentrations raise concerns as to the disposal and handling of these wastes. The current FSII, DiEGME was evaluated along with two new candidates, dipropylene glycol and glycerol formal. DiEGME appeared to be moderately but not completely biodegradable. It is likely that much of it would be removed in a wastewater treatment plant. Dipropylene glycol only showed signs of degradation after more than …

Modeling Marine Exposure To Polychlorinated Biphenyls From Sunken Ships, Charles N. Wendt

Theses and Dissertations

In the past, the U.S. Navy has routinely conducted SINKing EXercises (SINKEX) for training, weapon effectiveness tests, and economic disposal of aging assets. Recent concern over polychlorinated biphenyl (PCB) chemicals aboard such target vessels has resulted in a suspension of SINKEX. The U.S. Navy has approximately 200 vessels currently requiring such disposal. Environmental legislation and health concerns preclude selling such vessels to foreign governments or scrapping. This work attempted to model the fate and transport of these PCBs by examining their transport to coastal water and their accumulation in the marine food chain. The model includes biodegradation, upwelling, partitioning of …

Synthesis And Characterization Of Novel Sf5 Containing Fluoroalkyl Iodides And Derivatives, Julia Anne Renn

Dissertations and Theses

Preparation of four SF5-containing fluoroalkyl iodides and derivatives thereof was accomplished beginning with a simplified synthesis of ICF2CF2I. Characterization of the products followed using a variety of spectroscopic and physical methods. The simplified method for preparing ICF2CF2I from iodine and tetrafluoroethylene (TFE) involved a reaction temperature of approximately 54°C and pressures of less than two atmospheres for the TFE. The synthesized ICF2CF2I was reacted with S2F1o and tetrafluoroethylene to give SF5CF2CF2I. The subsequent synthesis of the SFs containing fluoroalkyl iodides and derivatives were carried out using SFsCF2CF2I as the starting material in a Carius tube reaction vessel. The synthesized SFs …

The Effect Of Deposition Of H2s On The Catalyst Activity Of 1.5 % Pt On [Gamma]-Al2o3, Ping Zhu

Theses

The impact of hydrogen sulfide (H₂S) pretreatment on the oxidation activity of powdered 1.5% Pt/γ-AL₂O₃ catalyst was investigated in this study. Fresh 1.5% Pt/γ-Al₂O₃ catalyst was aged with different concentrations of H₂S in air at 400 °C for 24 hours. Then, the aged and fresh catalysts were tested to determine the oxidation activity with diagnostic gases which contained either 1% propane or 1% carbon monoxide in dry air. The test results indicated that the catalysts were deactivated for carbon monoxide oxidation and promoted for propane oxidation as a function of …

A Hplc Method To Assay Mycotoxins - Fumonisin, Ochratoxin And Zearalenone, Nalini Sadagopan

Masters Theses

A HPLC method to quantitate the mycotoxins Fumonisin B1 (FB1), Ochratoxin A(OA), and Zearalenone (ZON) was developed and validated. Mycotoxins are secondary metabolites of fungi like Fusarium, Asperigillus and Penicillium that contaminate crops. They have a wide array of chemical structures which facilitate their analytical detection.

The analytical method consists of reverse phase chromatography and fluorescence detection. Sample cleanup was performed using SAX and C18 cartridges prior to analysis on the HPLC.

The method developed for FB1 is unique in that it is more sensitive, accurate, and reproducible than the existing methods. Automation is one of the salient features that …

Reactions Of Chlorine And Some Of Its Oxygen Derivatives With Phenol, Lizhuo Zhang

Masters Theses

Chlorine is widely used in industry. It is also the most commonly used disinfectant in water treatment plants. Since the amount of chlorine used is increasing each year, environmental and health concerns arise due to its reactivity with various of organic compounds. Many chlorinated organic compounds are toxic and as a result other non-chlorinating compounds, such as chlorine dioxide, might be potential substitutes in the future, especially in water treatment plants.

Previous studies have indicated that chlorinated organic compounds are not formed when chlorine dioxide is used as a disinfectant. Furthermore no reaction occurs between chlorite and phenol in the …

Comparison Of Positive Screening And Confimatory Results From Federally Mandated Drug Testing Of Urine, Mary M. Stuck

Community & Environmental Health Theses & Dissertations

The purpose of this study was to analyze the accuracy of FDA approved immunoassays for the detection of drug positive urine samples.

Federal civilian employees are tested under the strict protocol of the Department of Health and Human Services mandatory guidelines for federal workplace drug testing programs. The guidelines provide for a two instrument testing protocol for the analysis of urine samples. The first is an FDA approved immunoassay. Samples which test positive on this screening immunoassay are then submitted for confirmatory testing with the "gold standard" gas chromatography/mass spectrometry.

Agency monthly drug testing summaries, required under the DHHS guidelines …

Reactions Of Aqueous Chlorine With Alanylphenylalanine In Model Solutions And In A Wastewater, Thomas C. Fox

Chemistry & Biochemistry Theses & Dissertations

Model solutions of the dipeptide alanylphenylalanine were chlorinated to four different chlorine-to-amino nitrogen (Cl₂/Ala-Phe) mole ratios and analyzed by high performance liquid chromatography. At mole ratios ≤ 1, N-chloroalanylphenylalanine was the only major product. As the Cl₂/Ala-Phe mole ratio was increased to ≥ 2, N,N-dichloroalanylphenylalanine was the only major product. In model solutions (pH 7.0) the dichlorinated dipeptide decomposed (t_1/2= 4.1 hr) to form a stable N-chloroketimine, which has a half-life of 125 hours. This N-chloroketimine then decomposed to form phenylalanine.

To follow these reactions in a wastewater, alanyl-p-[ …

Concentrations, Complexation And Speciation Of Total Dissolved Zinc In The Chesapeake Bay, Charles William Henry Iii

Chemistry & Biochemistry Theses & Dissertations

This is the first research to examine the horizontal, vertical, and temporal variability of total dissolved zinc, organic complexation of zinc, and zinc speciation in the Chesapeake Bay. Filtered (0.45μm) surface and bottom water samples were taken along the salinity gradient of the Chesapeake Bay in October 1993, March 1995, July 1995, and October 1995. Analysis by Differential Pulse Anodic Stripping Voltammetry (DP ASV) indicated that total dissolved zinc concentrations in the Bay ranged from 2.9 ± 0.7nM to 38.8 ± 2nM. Total zinc was highest at the northern end of the Bay (low salinity), approximately 10 times lower at …

Flash Photochemical Kinetics Of Chromium Carbonyls, Jason David Katz

Honors Theses

Chromium hexacarbonyl, Cr(C0)6, has been shown to be a very effective photochemical catalyst for many reactions, such as the 1,4- hydrogenation and 1,4-hydrosilatlon of conjugated 1,3-dienes resulting in the formation of a cis alkene product in greater than a 99% percent yield. The catalytic power of Cr(CO)6 has merited its study by many investigators, mostly with regard to the structure of the catalytic intermediates, rather than the actual kinetics of individual steps in the mechanism. The goal of this study is to construct a database of both rate and mechanistic information on the reactions of Cr(CO)6 with various alkenes and …

Determination Of Conditions For Oye In Which There Is No Ion Present In The Active Site, Melissa J. Morris

Honors Theses

Old Yellow Enzyme (OYE) has been the subject of extensive research since the early 1930's. However, the structure of OYE was not determined until 1994, and its physiological function still remains a mystery. Investigations into the function of OYE involve uncovering the details of protein-substrate interactions through the use of x-ray crystallography. OYE is known to oxidize NADPH, but attempts to crystallize the OYE-NADPH bound complex have been hampered by the presence of chloride in the active site of OYE. This competition prevents an accurate assessment of the structure of OYE bound to NADPH. This study will examine the possibility …

A Graph Theoretic Study Of The Similarity Of Discrete Structures, Heather D. Gavlas

Dissertations

A basic problem in drug design consists of finding a compound that satisfies a spectrum of biological and chemical properties. Although drug design problems are central to pharmaceutical research, statisticians have yet to become involved in this area as these problems are viewed statistically as optimization problems. Before statistical optimization procedures can be defined on these spaces whose points are structures and not vectors, very basic mathematical notions of distance must be defined. Graphs have been used as mathematical models to represent the bonding arrangements of molecules for quite some time. In fact, if some of the methodology used by …

An Investigation On Nonenzymatic Autoxidation Of Phenolic Compounds In Natural Waters, Lei Jiang

Masters Theses

The nonenzymatic autoxidation of the phenolic compounds chlorogenic acid in aqueous solution was studied. The study demonstrated that the oxidation rate of chlorogenic acid was strongly dependent on pH. The higher the pH, the faster the rate of oxidation. The involvement of phenolate ions and radicals in oxidation reactions are two possible reasons for the pH dependency. The presence of a trace amounts of reducible transition metal ions, such as copper(II), dramatically increases the oxidation rate of chlorogenic acid. Light also increases the oxidation rate of chlorogenic acid. However, the photochemical reaction was a much slower process.

The TLC and …

Inclusion Processes Of Cyclodextrins And Their Polymers: A Molecular Modeling Study, Stacey L. Fellows

Honors Theses

Cyclodextrins (COs) and cyclodextrin polymers (CDPs) are molecules capable ot creating host/guest complexes, where a host molecule allows another molecule, a guest, to bind to it without either molecule losing its molecular identity. CDs are hydrophilic t,, 11, contain a unique hydrophobic cavity that can attract organic guest molecules. CDP is a derivative of CD and consist of two or more CD units connected by chains of glyceryl linkages (-CHrCHOH-CH2-O-). CDPs are typically more hydrophilic- than the CD monomers making them more useful for applications. However, behavior of the CDP is not as well-cinderstood as that of the monomer. Computer …

Introduction Of The Gas Chromatograph Into The Introductory Chemistry Laboratory, Jonathan Calvert Wedvik

Honors Theses

No abstract provided.

Synthesis And Characterization Of Β-Cyclodextrin Polymers, Jodie L. Iannacone

Honors Theses

Cyclodextrin polymers (CDPs) are water Joluble polymers composed of either a, fl, or y cyclodextrin (CDl monomers. TI,ese commercially available polymers are synthesized ming epichlorohydrin and consist of CD monomers joined by repeating glycer;l linkers (-(CH2-CHOH-CH2-ln) with an average n value of 12-15. GPC analysis of these polymers indicate two major component peaks that have molecular weights (MW) of 2,000 (one CD/ polymer chain) and 9-10,000 (4-5 CDs/polymer chain). These polymers have been used to study the binding interactions of various fluorescence probes. It has been shown that the pyrene fluorescence lifetime increases and its emission I/III ratio decreases in …

Design And Application Of A Compact, Multipurpose, Laser-Based Spectrometer, Andrew M. Leach

Honors Theses

A compact laser-based spectrometer has been designed and characterized. This design of this instrument gives it the ability to collect absorbance, fluorescence, and scattering signals simultaneously. A diode laser is used as the excitation for this instrument. Several optical arrangements have been tested in order to allow for the best possible signal collection. Electronics have been designed and constructed in order to facilitate the simultaneous collection of signals. This instrument has been characterized using several dyes and scattering agents. Fluorescence limits of detection for Methylene Blue and Nile Blue A have been calculated at 2 ppb. The spectrometer has been …

Flow Injection Analysis With A Laser-Based Detector For On-Line Determination Of Sulfide, Glucose, And Ethanol, Manisha Tinani

Honors Theses

In this research a flow injection (FI) apparatus with a laser-based detector is characterized using three chemical systems and the results are compared to those obtained by other researchers using conventional instrumentation. Each chemical system involves Methylene Blue (MR), a common redox indicator. A 670-nm diode laser is used as the excitation source, and the resulting fluorescence is measured. In the first system, MB is formed as a product of the reaction of N,N-dimethylphenylenediamine (DMPD), iron (lll) and sulfide in the presence of acid. A three-line FI manifold is employed. The amount of sulfide in water samples, including a complicated …

The Crystallization Of Estrogen-Binding Protein, Jeffrey R. Weinstein

Honors Theses

Candida albicans is a yeast that is known to target humans with weakened immune systems. The growth rate and invasiveness of C. albicans is stimulated in the presence of estrogens. Experimental evidence suggests that the estrogen-binding protein (EBP) from C. albicans may be involved in the estrogen-induced increase in growth rate. In order to investigate the possible involvement of EBP in this process, work is underway to determine the atomic structures of EBP alone and bound to estrogen. Protein crystals of EBP have been grown at 4°C in the presence and absence of estrogen using vapor diffusion techniques from a …

Speciation And Determination Of Trace Lead : Methodology Development And Analysis Of Natural Waters Using Chelex-100 And Gfaas, Xidan Ma

Theses

The development of a method for speciation, preconcentration, and determination of lead was successfully conducted using Chelex-100 and graphite furnace atomic absorption spectroscopy (GFAAS). Sorption under static conditions and direct measurements in the bead slurry or after fast elution of lead from beads with HNO3 solution was used. The effects of buffers, sorption kinetics, filtration criteria, sample concentration, resin particle size and temperature program for the GFAAS were carefully studied. In this study, synthetic aqueous samples containing lead were preconcentrated under static conditions using the ion exchange resin, Chelex-100, and the resin was directly analyzed using GFAAS. The batch preconcentration …

The Reactions Of Nox With Diesel Soot Over Cu-Zsm-5 Catalyst, Shu Sun

Theses

Air pollution from the exhaust of Diesel engines consisting of relatively high concentrations of NO_x and particulates is a difficult problem to overcome because no fully effective technology to control these emission is available. The existing methods to reduce NO_x and soot can not satisfy the provisions of the 1990 CAAA (Clean Air Act Amendment). Cu-ZSM-5, a catalyst in which Cu has been ion-exchanged with H+, can catalyze the decomposition of NO to N₂ and O₂ and reduction to N₂ and O₂ with light hydrocarbons such as propene or Diesel soot in the presence …

Fluorinated Polymer Films - Synthesis And Characterization, Anja Ulrike Schnurer

Dissertations and Theses

Three polyfluoroalkyl epoxides, (I OCH2CHCH20CF2CF2S02F, II OCH2CHCH2(CF2)gF and III OCH2CHCH20(CF2)CF(CF3)S02F) were photopolymerized with a cycloaliphatic diepoxide (Cyracure UVR-6110) to form highly crosslinked glassy films. Depth-dependent surface analysis with XPS show that these films are highly enriched with sulfonyl fluoride groups in the outer molecular surface. Film compositions of 17 % wt and more of the fluorinated I and III show surface characteristics of a film composed of 100 % wt of the polymerized sulfonyl fluoride epoxide monomer (at depths for 50 A for each sample). Even films that are prepared with only 1 % wt or less (compound III) of …

Methods And Methodologies For Organic Synthesis, Frank Favaloro

Honors Theses

Methods and methodologies for organic synthesis

Optimization Of Porous-Membranes Utilized In Chlor-Alkali Technology Via The Use Of Porosity And Electrochemical Impedance Spectroscopy, Jo Ann Jackson

Electronic Dissertations and Theses

A fundamental understanding of porous diaphragm membrane utilized by Dow Chemical Company in the production of chlorine gas and caustic soda, is integral to optimizing its performance. Several factors have been identified as integral components in this effort to optimize the chlorine cell diaphragm. Among these components are the diaphragm's porosity, pore size, thickness and tortuosity. Several methods have been utilized in an effort to determine not only the desired values of each of these variables but also to develop ways of achieving these desired values. Because not all of these variables can be measured directly, other methods of collecting …