Chemistry Commons^™

Exploring A Ring-Closing Metathesis Approach To The Archazolids, Brianne R. King

WWU Graduate School Collection

The archazolids are a complex family of natural products with distinct structural features. Inspired by these unique structural characteristics, our group sought to synthesize an analogue of this family, dihydroarchazolid B. We were encouraged to synthesize this analogue due to its high potential to be a potent cytotoxic agent against the vacuolar-type ATPases (V-ATPases) and because it is a simpler analogue than the parent natural products from a synthetic perspective. Within this work, a ring-closing metathesis (RCM) approach was explored in depth towards the completion of our target. From these efforts, a metathesis deactivating stereotriad was uncovered in a key …

Electron And Ion Spectroscopy Of Metal Hydrocarbon Complexes, Sudesh Kumari

Theses and Dissertations--Chemistry

Metal-hydrocarbon complexes were prepared in a laser-vaporization molecular beam source and studied by single-photon zero electron kinetic energy (ZEKE) and mass-analyzed threshold ionization (MATI) spectroscopy. The ionization energies and vibrational frequencies of the metal complexes were measured from the ZEKE and MATI spectra. Metal-ligand bonding and low-lying electronic states of the neutral and ionized complexes were analyzed by combining the spectroscopic measurements with quantum chemical calculations and spectral simulations.

In this dissertation, the metal complexes of mesitylene, aniline, cyclooctatetraene, benzene, ethene, and propene were studied. For each complex, different effects from metal coordination have been identified. Although metal-bis(mesitylene) sandwich complexes …

Structures And Electronic States Of Small Group 3 Metal Clusters, Lu Wu

Theses and Dissertations--Chemistry

Group 3 metal clusters are synthesized by laser vaporization in a pulsed cluster beam source and identified with laser ionization time-of-flight mass spectrometry. The adiabatic ionization energies and vibrational frequencies of these clusters are measured using mass-analyzed threshold ionization (MATI) spectroscopy. Their structures and electronic states are determined by combining the MATI spectra with quantum chemical calculations and spectral simulations. This dissertation focuses on the study of several small molecules, which include LaO₂, La₂, M₂O₂, M₃O₄, M₃C₂, and La₃C₂O, where …

Laser Spectroscopy Of Radicals Containing Group Iiia And Va Elements, Robert A. Grimminger

Theses and Dissertations--Chemistry

Radicals are interesting to study because of importance in so many processes such as semiconductor growth or stellar evolution. Laser induced fluorescence (LIF) and wavelength resolved emission spectra of jet cooled HPS, HAsO, AsD₂, H₂PS, and F₂BO have been measured using the pulsed discharge jet technique.

Several bands in the à ¹A′′ − X̃ ¹A′ transition of HPS were observed and assigned with the help of ab initio calculations. The ab initio geometries showed that HPS does not follow Walsh’s predictions for the angle change upon electronic excitation; Walsh predicts an increase …

Addressing Public Health Risks Of Persistent Pollutants Through Nutritional Modulation And Biomimetic Nanocomposite Remediation Platforms, Bradley J. Newsome

Theses and Dissertations--Chemistry

Due to their relative chemical stability and ubiquity in the environment, chlorinated organic contaminants such as polychlorinated biphenyls (PCBs) pose significant health risks and enduring remediation challenges. Engineered nanoparticles (NPs) provide a novel platform for sensing/remediation of these toxicants, in addition to the growing use of NPs in many industrial and biomedical applications, but there remains concern for their potential long-term health effects. Research highlighted herein also represents a transdisciplinary approach to address human health challenges associated with exposure to PCBs and NPs. The objectives of this dissertation research are two-fold, 1) to develop effective methods for capture/sensing and remediation …

Electrode And Electrolyte Additives For Lifetime Extension In Lithium-Ion Batteries, Kishore Anand Narayana

Theses and Dissertations--Chemistry

Lithium-ion batteries (LIBs) are the most commonly used type of rechargeable batteries with a global market estimated at $11 billion, which is predicted to grow to $60 billion by 2020. The global commercialization of Li-ion batteries is impeded by issues such as poor cycle life (5000 cycles achieved in some LIBs) in high energy and power density applications because of the rising internal resistance due to aging and safety concerns such as overcharge which ultimately leads to thermal runaway and explosions. A battery’s performance mainly depends on external factors such as electrode thickness and degree of compacting, and the type …

Cross Photoreaction Of Pyruvic And Glyoxylic Acids In Model Aqueous Aerosols, Shasha Xia

Theses and Dissertations--Chemistry

Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. Aerosols from natural and anthropogenic sources can be primary organic aerosols (POA), which are directly emitted to the atmosphere, or secondary organic aerosols (SOA) that are formed from chemical reactions of gas-phase precursors. At variance with the well investigated formation of SOA from gas phase precursors, the chemistry of aqueous SOAs that contribute to the total SOA budget remains unknown. Field measurements have revealed that carboxylic, dicarboxylic and oxocarboxylic acids are abundant species present in SOAs. This thesis …

A Study Of Lignin Depolymerization By Selective Cleavage Of The Cα-Cβ Linkages In Lignin Model Compounds Via Baeyer-Villiger Oxidation & An Investigation Of The Channeling Reaction In Nitrogen-Doped Multiwalled Carbon Nanotubes (N-Mwcnts), Nikhil Dilip Patil

Theses and Dissertations--Chemistry

A STUDY OF LIGNIN DEPOLYMERIZATION BY SELECTIVE CLEAVAGE OF THE Cα-Cβ LINKAGES IN LIGNIN MODEL COMPOUNDS VIA BAEYER-VILLIGER OXIDATION

Lignin is amorphous aromatic polymer derived from plants and is a potential source of fuels and bulk chemicals. Herein, we present a survey of reagents for selective stepwise oxidation of lignin model compounds. Specifically, we have targeted the oxidative cleavage of Cα-Cβ bonds as a means to depolymerize lignin and obtain useful aromatic compounds. In this work, we prepared several lignin model compounds that possess structures, characteristic reactivity, and linkages closely related to the parent lignin polymer. We observed that selective …

Synthesis And Analysis Of Copper Beta-Diketonate Complexes, Jonathan Stephen Casey

LSU Master's Theses

This research addresses the synthesis and characterization of Cu(II) complexes of silicon-based multidentate β-diketonate ligands. The possible products of the synthesis include (where L represents the coordinated ligand) cube Cu12L8, decahedron Cu24L16, and dodecahedron Cu30L20. This study aims to determine the structure of these discrete molecules, which may have applications in drug delivery, fuel storage, and chemical retention. Different techniques were involved in the characterization of Cu(II) complexes: Electrospray Ionization Time of Flight Mass Spectrometry (ESI-TOF MS), Atomic Force Microscopy (AFM) and Analytical Ultracentrifugation (AUC). In ESI-TOF MS, the exact mass of the molecules was attempted to be determined by …

Development Of Visible Light-Promoted Photocatalytic O-Glycosylation, C-H Activation Of Alkanes And Deoxygenation Of N-(Mesyloxy) Amides, Xiaoping Wang

LSU Master's Theses

This thesis is divided into four chapters reporting various aspects of the background of studies and the preliminary results I obtained in three projects. Chapter 1 gives a brief introduction to the concepts of photoredox catalysis, O-glycosylation, C-H functionalization and amidyl radicals. Chapter 2 describes the development of a visible light-promoted O-glycosylation catalyzed by Ru(bpy)3(PF6)2 or diphenyldiselenide under mild conditions. The glycosylation of primary and secondary alcohols with selenoglycosides was demonstrated with good yields, and disaccharides were constructed by coupling of the selenoglycosides in acetonitrile or dichloromethane with a glucosyl acceptor in moderate yields. The reactions catalyzed by Ru(bpy)3(PF6)2 were …

Doped Quantum Dot Luminescent Solar Concentrators, Christian S. (Christian Soren) Erickson

WWU Graduate School Collection

Optical concentration has the potential to lower the cost of solar energy conversion by reducing photovoltaic cell area and increasing photovoltaic efficiency. Luminescent solar concentrators (LSCs) offer an attractive approach to combined spectral and spatial concentration of both specular and diffuse light without expensive solar tracking, but they have been plagued by luminophore self-absorption losses which limit them from achieving their full potential. This thesis introduces doped semiconductor nanocrystals as a new class of phosphors for use in LSCs. In proof-of-concept experiments, visibly transparent, ultraviolet-selective luminescent solar concentrators have been prepared using colloidal Mn^2+-doped II-VI semiconductor nanocrystals that …

New Synthetic Strategies For Improved Gas Separation By Nanoporous Organic Polymers, Suha Altarawneh

Theses and Dissertations

Abstract NEW SYNTHETIC STRATEGIES FOR IMPROVED GAS SEPARATION BY NANOPOROUS ORGANIC POLYMERS Suha S. Altarawneh, Ph.D. The emission of carbon dioxide (CO2) from fossil fuel combustion is a major cause of climate change. Therefore, the efficient separation of CO2 from mixtures of gases such as flue gas and impure sources of CH4 (e.g. natural gas and landfill gas) is an essential step in meeting the ever increasing demands on natural gas and creating a cleaner environment. Carbon capture and storage technology (CCS) is one of the methods employed for gas separation using chemisorption and/or physisorption processes. Several materials such as …

Fabrication Of Nanoporous Gold And Biological Applications, Badharinadh Uppalapati

Theses and Dissertations

FABRICATION OF NANOPOROUS GOLD AND BIOLOGICAL APPLICATIONS By Badharinadh Uppalapati A Dissertation submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University. Virginia Commonwealth University, 2014 Major Director: Maryanne M. Collinson, Professor, Department of Chemistry Fabrication of nanoporous gold electrodes by dealloying Au:Ag alloys has attracted much attention in sensing applications. In the first part of this work, the electrochemical response of the redox active molecule, potassium ferricyanide, in a solution of bovine serum albumin in buffer, serum or blood was studied using nanoporous gold and comparisons made to planar gold. Nanoporous …

Affinity Enrichment And Mass Spectrometric Quantitation Of Protein Carbonyls, Suresh Narayanasamy

Theses and Dissertations

The importance of the role of oxidative stress in aging and numerous age-related diseases has become undeniable due to enormous weight of supporting evidence from the field of free radical biology. One of the most prominent oxidative modifications of proteins is the introduction of carbonyl groups. As with oxidative stress, protein carbonylation has been correlated with various disease states and natural aging. While protein carbonyls are relatively stable, reproducible detection and modification site localization are still challenging. This thesis details attempts to improve the analytical methodology used for the identification and quantitation of carbonylated proteins. We have studied the impact …

Quantitative Mass Spectrometric Investigations Of Protein Biomarkers: Serum Thymidine Kinase 1 And Human Osteopontin, Morse Faria

Theses and Dissertations

Mass spectrometry is being increasingly used in biomarker research mainly due to its ability to achieve high selectivity coupled with high sensitivity. This dissertation focuses on quantitative mass spectrometric investigations of two protein biomarkers i.e. serum thymidine kinase 1 (TK1) and human osteopontin (OPN).

First part of this research was focused on developing a liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method for measuring the activity of TK1 in serum by monitoring the conversion of a TK1 specific exogenous substrate, 3’-deoxy-3’-fluorothymidine (FLT), to its mono-phosphorylated form 3’-deoxy-3’-fluorothymidine monophosphate (FLT-MP). A method to quantify FLT-MP on LC-MS/MS was developed and …

Modified Seed Growth Of Iron Oxide Nanoparticles In Benzyl Alcohol: Magnetic Nanoparticles For Radio Frequency Hyperthermia Treatment Of Cancer, Stanley E. Gilliland Iii

Theses and Dissertations

Iron oxide nanoparticles have received sustained interest for biomedical applications as synthetic approaches are continually developed for precise control of nanoparticle properties. This thesis presents an investigation of parameters in the benzyl alcohol synthesis of iron oxide nanoparticles. A modified seed growth method was designed for obtaining optimal nanoparticle properties for magnetic fluid hyperthermia. With a one or two addition process, iron oxide nanoparticles were produced with crystallite sizes ranging from 5-20 nm using only benzyl alcohol and iron precursor. The effects of reaction environment, temperature, concentration, and modified seed growth parameters were investigated to obtain precise control over properties …

Fabrication And Characterization Of High Surface Area Gold Electrodes, Madhura S. Damle

Theses and Dissertations

High surface area gold electrodes are very good substrates for biosensors, catalysis and drug delivery. Their performance is characterized by good sensitivity, low detection limit and high signal. As a result, extensive research is being carried out in this field using different approaches of fabrication to generate high surface area porous electrodes of different morphology, pore size and structure. The morphology of the electrodes can be changed based on whether the approach involves a template or not, types of metal deposition, method and time of dealloying etc. The deposition of metal can be carried out using various approaches such as …

Catalytic Activity Of Heteropoly Tungstophosphoric Acid Supported On Partially Reduced Graphene Oxide Prepared By Laser And Microwave Irradiation, Mark Paul Jimena Dailo

Theses and Dissertations

The solid acid catalyst of the Keggin-type 12-tungstophosphoric acid (H₃PW₁₂O₄₀, HPW) is supported on partially reduced graphene oxide (PRGO) nanosheets for acid-catalyzed reactions. HPW is a new class of catalyst with a good thermal stability and high Bronsted acidity in order to replace common mineral acids. However, it has low specific surface area (1-5 m²/g). Therefore, the possibility of PRGO as a catalytic support for HPW is investigated due to its high surface area (2630 m²/g) and good thermal stability. The synthesis of HPW-GO catalyst is prepared using microwave and …

Structure Vs. Properties Using Chemical Graph Theory, Tabitha N. Williford

Electronic Theses and Dissertations

Chemical graph theory began as a way for mathematicians to bring together the areas of the Physical Sciences and Mathematics. Through its use, mathematicians are able to model chemical systems, predict their properties as well as structure-property relationships. In this dissertation, we consider two questions involving chemical graph theory and its applications. We first look at tree-like polyphenyl systems, which form an important family of compounds in Chemistry, particularly in Material Science. The importance can be seen in LEDs, transmitters, and electronics. In recent years, many extremal results regarding such systems under specific constraints have been reported. More specifically are …