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Total Synthesis Of An Analog Of Hydramycin And Derivatization Of Thiol-Terminated Carbohydrates And Development Of A Glycoconjugate Too Set For The Assembly And Presentation Of Carbohydrate Ligands On Surfaces, Medhanit Woldeghiorghis Bahta

Doctoral Dissertations

2-(1,2-Dihydroxy-1-(oxiran-2-yl)ethyl)-11-hydroxy-5-methyl-1Hnaphtho[ 2,3-h]chromene-4,7,12-trione (1), a pyranoanthraquinone isolated from Streptomyces violaceus P950-4, showed a potent antibacterial and cytotoxic activity. A model synthesis for analogs 2-(1,2-dihydroxy-1-(oxiran-2-yl)ethyl)-4H-chromen- 4-one (2) and2-(1-hydroxy-1-(oxiran-2-yl)ethyl)-1H-naphtho[2,3- h]chromene-4,7,12-trione (3) was developed by Dr. David White and Dr. Sarah Headrick. A new analog, 2-(1,2-dihydroxy-1-(oxiran-2-yl)ethyl)-1H-naphtho[2,3- h]chromene-4,7,12-trione (4), was designed to be structurally more similar to hydramycin with –CH2OH functionality on the pyranone ring and anthraquinone skeleton. Therefore, it is expected to have greater anticancer activity than either analogs 2 or 3. This dissertation will cover developments, challenges and solutions in …

Electroanalysis Of Metals In Biological And Environmental Samples At Bismuth Electrodes, Kristie Carter Armstrong

Doctoral Dissertations

An Advanced Oxidation Process (AOP) was designed for the decomposition of organic material in blood as a pretreatment for chromium analysis. Acidified porcine blood was treated with hydrogen peroxide and UV light for 60 min. The rate of decomposition was studied using UV/Vis spectroscopy. It was found that the order of the photolytic reaction with respect to hydrogen peroxide was 0.35. The pretreated blood was subsequently analyzed for chromium content by catalytic adsorptive stripping voltammetry at a bismuth film electrode. The concentration of chromium was determined to be 6.0 " 0.3 parts per billion (ppb). A bismuth bulk electrode was …

Alkoxide Routes To Inorganic Materials, George Harrison Thomas

Doctoral Dissertations

An all alkoxide solution chemistry utilizing metal 2-methoxyethoxide complexes in 2-methoxyethanol was used to deposit thin-films of metal oxides on single-crystal metal oxide substrates and on biaxially textured metal substrates. This same chemistry was used to synthesize complex metal oxide nanoparticles. Nuclear Magnetic Resonance spectroscopy was used to study precursor solutions of the alkaline niobates and tantalates. Film crystallization temperatures were determined from X-ray diffraction patterns of powders derived from the metal oxide precursor solutions. Film structure was determined via X-ray diffraction. Film morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM).

Epitaxial thin-films of strontium …

Boron And Metal Halides In Organic Synthesis, Scott T. Borella

Doctoral Dissertations

This dissertation summarizes the recent use of organoboron and metal halides to form new carbon-carbon bonds. Several novel reactions have been discovered. These include the halovinyl alkenylation of alkoxides with alkenylboron dihalides; alkynylation of alkoxides with alkynylboron dihalides; boron trichloride and ferric chloride-mediated allylation of alkoxides. The results of these studies strongly imply a cationic mechanism, and prompted a reinvestigation of the boron trihalide mediated alkyne-aldehyde coupling reaction. The olefin stereochemistry of the resultant 1,5-dihalo-1,4-pentadienes can be influenced by controlling the reaction temperature and the sequence of reagent addition. The reaction methodology of the research described herein can be characterized …

Synthesis And Reactivity Of Titanium Amido Complexes With Relevance To Olefin Polymerization, Michael A. Blanchard

Doctoral Dissertations

Ziegler-Natta catalysts are well known in the chemical industry. They are responsible for the production of more than half of the HDPE and HDPP worldwide annually. Ziegler-Natta catalysts exist in many forms, both in homogeneous and heterogeneous types as well as both with early and late transition metal basis. While Ziegler-Natta catalysts can exist in various forms, all polymerize via the same general mechanism. Dissecting the known mechanism(s) results in three items that must be in place for polymerization to occur. First, the active metal center must be highly Lewis acidic, enough to allow coordination of approaching olefins. Second, a …

Novel Approaches To Metal Ion Sensing, Nathan Allen Carrington

Doctoral Dissertations

The primary focus of this dissertation is the development of new chemical analyses for metal ions. Approaches combining electrochemical, spectroscopic, analytical, inorganic, and materials chemistry have been used to investigate novel methods for metal ion sensing. Topics discussed in this dissertation include pyridinium-functionalized sol-gel films for the enhanced electrochemical analysis of Cr(VI), pyridinium-functionalized sol-gel monoliths for the optical determination of Cr(VI), the use of the electrochemical quartz crystal microbalance for the determination of Pd(II), novel electrochemical and spectroscopic approaches to Fe(III) sensing, and the electrochemical quartz crystal microbalance investigation of the Cr(III)-DTPA complex.

Optimization Of Interfacial Interactions To Achieve The Nanoscale Dispersion Of Clay In Polymer/Clay Nanocomposites, Deepali Kumar

Doctoral Dissertations

Polymer clay nanocomposites are a promising class of multicomponent systems where incorporation of small amount of clay results in dramatic improvement of mechanical, thermal and barrier properties. However, accomplishment of these properties necessitates molecular level dispersion of the clay platelets in the polymer matrix. This thesis presents the guidelines for obtaining thermodynamically stable nanocomposites where strong specific interactions such as hydrogen bonding between the polymer and the clay can be utilized to achieve the desired goal of nanoscale dispersion of clay sheets.

In first part of the dissertation, optimization of intermolecular hydrogen bonding between the polymer and clay is carried …

Molecular Anion Spectroscopy And Stability, Jeffrey Daniel Steill

Doctoral Dissertations

A detailed and thorough computational investigation of the SF ₆ anion is undertaken, with additional calculations of other stable SF _n anions. The calculations are used to in- terpret recent infrared multi-photon dissociation (IRMPD) experiments of SF ₆ and SF ₅ anions done with the FELIX free electron tunable infrared laser in the spectral range of 450-850 cm^-1. The vibrational spectroscopy of negative molecular ions is crucial towards understanding the dynamics of electron transfer processes, as well as providing experimental validation for computational models of molecular bonding in anions. Many molecular negative ions have been shown to exhibit …

Synthesis Of Novel Boronated Amino Acids For Bnct An Alternate Cancer Therapy And Use Of Microwaves In Organic Synthesis, Abhijit Achyut Naravane

Doctoral Dissertations

Boron neutron capture therapy (BNCT) is a binary form of cancer treatment wherein ¹⁰B nuclei, when irradiated with thermal neutrons, produce high energy transfer particles. These particles, due to their size and energy, are confined to a radius of 9-10μm, which is comparable to the size of single cell. Potential BNCT agents reported in the literature include boron-containing amino acids, nucleic acids, nucleosides, antibodies, and other biomolecules.

In recent years, microwaves have gained importance in organic chemistry. Microwave induced reactions are energy efficient, often enhance reaction rates, and generally lead to enhanced product yields. Recent studies have …

Spectroscopic Investigations Of Complex Transition Metal Oxides, Jinbo Cao

Doctoral Dissertations

In this dissertation, I present spectroscopic studies of several model electronic and magnetic materials. Compounds of interest include VOx nanoscrolls, VOHPO4¢ 1 2H2O, and (La0:4Pr0:6)1:2Sr1:8Mn2O7. These materials are attractive systems for the investigation of optical gap tuning, lattice and charge dynamics, spin-lattice-charge coupling, and hydrogen bonding effects. I measured the optical properties of VOx nano- scrolls and the ion-exchanged derivatives to investigate the lattice and charge degrees of freedom. Selected V-O-V stretching modes sharpen and redshift with increasing amine size, which are microscopic manifestations of strain. We observed bound carrier localization in the metal exchanged nanoscrolls, indicating they are weakly …

Design And Synthesis Of Novel Sultams: A Family Of Non-Nucleoside Reverse Transcriptase Inhibitors And Modeling Studies Of A Rhodium Catalyst, Riyam Kafri

Doctoral Dissertations

3-Phenyl-2,3-dihydro-1,2-benzisothiazole 1,1 dioxide (NSC108406), identified as an HIV-1 reverse transcriptase inhibitor, is chosen for lead optimization. A series of analogues are docked using SYBYL FlexiDock into both wild-type (wt) reverse transcriptase (RT) and Tyr181 --> Cys181 (Y181C) RT, from the dataset of efavirenz (Sustiva®) bound to the enzyme. Minimizations using genetic algorithms are performed, and the lowest energy conformations are evaluated. Five structures emerge as good fits either in both enzymes or only in Y181C RT. 3-(m-Cyclopropylphenyl)- and 3-(isopropylfuranyl)-2-methyl-2,3- dihydro-1,2-benzisothiazole 1,1-dioxides do not exhibit improved binding in wt RT over efavirenz. In the Y181C pocket, the furanyl ring …

Preparation, Characterization And Reactivities Of Early Transition Metal Silyl Compounds, He Qiu

Doctoral Dissertations

This dissertation focuses on syntheses, characterization and reactivities of Groups 4 and 5 metal amide silyl complexes free of anionic π-ligands.

A summary of the research in this dissertation is provided in Chapter 1. Chapter 2 reports an unusual reaction between Ta(NMe₂)₄SiBu^tPh₂ (1) and O₂. Three products (Me₂N)₄Ta(OSiBu^tPh₂) (2), (Me₂N)₃Ta(ONMe₂)(OSiBu^tPh₂) (3) and (Me₂N)₂(Ph₂Bu^tSiO)₂(Me₂NCH₂NMe)₂Ta₂(μ …

Innovative Methods Of Biomedical Molecular Analysis: Capillary Electrophoretic Study Of Amyloid Beta Conformations And Magnetically Assisted Transport Evanescent Field Fluoro-Assays, Amber D. Wellman

Doctoral Dissertations

Though the study of the human proteome (proteomics) is far more complicated than that of the genome, it may prove to be the next step toward gaining insight into the operation of biological systems. Understanding the role proteins and peptides play in disease, whether that be by their structure, expression or function, could lead to the identification of disease biomarkers for diagnosis or engender possibilities for treatment. To this end, the work discussed herein delves into the capillary electrophoretic (CE) analysis of amyloid beta conformations involved in abnormal aggregation and the creation and optimization of a novel bioassay method. By …

Synthesis And Characterization Of Atomically Dispersed, Vanadosilicate Catalysts In Si8o20-Based Building Block Solids, Ming-Yung Lee

Doctoral Dissertations

Silica supported vanadium complexes have attracted interest as catalysts for a variety of catalytic reactions in the past two decades. Although many strategies have been developed for incorporating vanadyl species on silica surfaces, controlling dispersion and loading while simultaneously producing single site catalysts remains a challenging goal in this context and in catalysis as well.

A simple strategy for producing single-site and site-isolated vanadyl species has been explored which allows for control of both the connectivity to the support as well as the local surface structure around a V=O group. The main elements of this strategy involve construction of the …