Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants produced mainly from the incomplete combustion and pyrolysis of organic matter. PAHs are among the major contaminants at over 800 Superfund sites, nationwide. Thermal remediation is used as a method to remediate soils contaminated with PAHs through the use of heat to mobilize...
A synthetic approach toward the two major fragments of cathedulin K-19,
euonyminol (4) and dimethyl cathate (69), was investigated. Synthesis of
dimethyl cathate was accomplished in 3 steps starting from 73. Efforts directed
towards the synthesis of euonyminol, a highly oxygenated dihydroagarofuran
sesquiterpene, was advanced to a stage in which...
Polyoxometalates (POMs) are anions consisting of three or more early transition metals ™ (Gr V and VI) oxoanions (in their highest oxidation state) linked together by a shared oxygen bond to form a 3D framework. Polyoxometalates (POMs) are a rapidly growing class of metal oxo clusters with a wide range...
The core-electron ionization potentials for mono- and
di(trifluoromethyl)benzene, for chlorofluoromethanes and for
chlorine have been measured in order to give information on
the electron distribution in these molecules and to investigate
differences between the inductive effect of fluorine
and that of CF3. For trifluoromethylbenzene the measured
ionization potentials in eV...
Contaminant transport in ground water is an important environmental process that
affects a host of natural systems. Transport of contaminants is affected by many
processes, including aqueous complexation, adsorption, and redox reactions. One of the
most important components of an aquifer that controls transport is iron-oxide. In this
study, the...
The Diels-Alder reaction represents a promising tool for use in
asymmetric synthesis. The reaction involves a rigid transition state
that facilitates the formation of one diastereomeric transition state
and is reversible. This satisfies two necessary criteria for
asymmetric synthesis.
The Diels-Alder reactions of 1,l-dialkylspiro[2.4]-4,6- heptadienes
with maleic anhydride and p-benzoquinone...
The photoelectron spectra of a series of halogenated
molecules have been investigated in the gas phase. Both
core-ionization energies and Auger kinetic energies were
measured to probe the nature of the interaction that holds
a core electron to the molecule.
It was found that satellite structure (shake) could be
used...
Trichloroethene (TCE) is the most frequently detected organic contaminant in groundwater, is classified as a probable human carcinogen, and exhibits toxicological effects on the human endocrine, immune, developmental, and reproductive systems. While significant research efforts have been devoted to the development of strategies for remediating TCE-contaminated groundwater, their advancement is...
Refractory inclusions from Kaba (CV3) chondrite were studied by
instrumental neutron activation analysis (INAA) and electron probe
microanalysis (EPMA). The inclusions observed cover a wide range of
chemical patterns, mineral assemblages and textures, indicating the
complexity of early solar nebular conditions. The elemental
abundances normalized by Cl chondritic abundances vary...
Optimization of the galvanovoltammetric determination of dissolved
chlorine in a flowing stream was achieved through the use of
an analog computational device and improvements in the design of the
galvanovoltammetric cell and accompanying electronic circuitry. An
analysis system, applicable to industrial use over a range of flow
rates and dissolved...
Lycopodium alkaloids have generated enormous amounts of interest from the scientific community, both as synthetic targets and for their medicinal properties. Herein is described work towards a unifying approach to large segments of the Lycopodium family. An organocatalyzed intramolecular heteroatom Michael reaction method, for the construction of piperidine and piperizine...
The emphasis of this work has been in two areas of optical materials - the
crystal-chemical development of new optical frequency converters and the synthesis
and study of new hosts for Cr³⁺ luminescence and lasing.
A simple method has been developed to identify promising frequency-doubling
materials containing triangular oxoanions by...
Three aspects of glow discharges have been studied: glow discharge oscillations,
sputtering, and coupling between cathode and anode regions the two most important
regions in a glow discharge. Cathode and anode processes are tightly coupled by electron
and ion coupling effects. Both electron and ion coupling effects were observed by...
The first asymmetric synthesis of (-)-7-epicylindrospermopsin via intramolecular nitrone cycloaddition is described. The synthesis utilized a convergent approach to prepare the cycloaddition precursor 176, which was assembled by condensation of hydroxylamine 175 with aldehyde 145. Hydroxylamine 175 was synthesized from ethylene glycol (166) in seven steps. Aldehyde 145 was completed...
PART I. Asymmetric syntheses of both natural (+)- and nonnatural (-)-byssochlamic acid via a [2+2] photoaddition-cycloreversion strategy are described. X-ray crystallographic analysis of the cyclohexylamine salt 99 showed that the structure of the monomethyl ester 100 from esterase hydrolysis of 44 was originally misassigned as 56. The enantiomeric relationship of...
Linear alkylbenzenesulfonate (LAS) is the most widely used anionic surfactant in
commercial detergent formulations. The environmental fate of LAS is of interest because
of its disposal to wastewater treatment facilities and subsequent occurrence as a
micropollutant in surface waters and groundwater. While LAS fate in wastewater
treatment systems and surface...
More than 30 members of the diverse amphidinolide family of biologically active macrolides have been isolated over last three decades. From this family, amphidinolides C and F stand among the most complex and densely functionalized affiliates. Recently, we have accomplished the first total synthesis of amphidinolide F. The all-carbon framework...
The rate of removal of benzene, toluene, ethylbenzene and the xylene isomers (BTEX) from contaminated groundwater is needed to design remediation processes. Benzylsuccinic acid (BSA) and methyl-benzylsuccinic acid (methyl BSA) are unambiguous metabolites of anaerobic BTEX biodegradation. An analytical method for quantitative determination of BSA in groundwater samples was developed....
Naturally occurring assemblies, such as DNA and proteins, utilize intermolecular forces (i.e H-bonding and van der Waals) to assemble. Utilizing these electrostatic interactions has only just started in the past five decades to be a tool used in synthetic chemistry in what is known as supramolecular chemistry. Supramolecular chemistry has...
Several new solid-state inorganic borates have been prepared and
characterized. Single crystals of the simple orthoborate ScB0₃ were
grown and its structure was determined by single-crystal X-ray
methods. The new borates Li₃Sc(B0₃)₂, LaSc₃(B0₃)₄, NdSc₃(B0₃)₄,
SrNaB0₃, and Li4Ln4MB90₂₃ (Ln = Y, Er, and Gd; M = Al and Ga) were
identified...
Oxylipins are a class of bioactive lipid metabolites derived from polyunsaturated fatty acids (PUFAs) via enzymatic and non-enzymatic pathways. In order to elucidate their overall biological effects, the knowledge of the entire oxylipin profile is needed as oxylipins can have similar or opposing effects in regard to inflammatory events. Their...
A large-scale preparative method for potassium di-n-butylborate
in triethylamine solvent has been developed. The reaction of
potassium di-n-butylborate I with trifluoromethyl iodide has been
shown to yield trifluoromethyl di-n-butylborane and other products.
Reaction of this substance with boron trifluoride gave trifluoromethyl
boron difluoride. Reactions of diboron tetrafluoride, boron tribromide,
and...
Copper in blood and liver can be divided into several fractions.
Copper in blood is about evenly divided between erythrocytes and
plasma. Normal concentrations for most species range between one and
two parts per million. Plasma copper is mainly a copper protein,
ceruloplasmin and a loosely bound form, reacting directly...
The (±) 8,9:13,14-diseco-norestradiol, a large ring hormone
analog, and its related derivatives, were prepared by a ring expansion
approach. The key step of this approach is the establishment of the
benzocyclododecenone system via the Caubere reaction. This step
not only provides a favorable ring size, it also sets the necessary...
Four strategies which involve synthetic elaboration of
the shikimate nucleus are discussed. Methyl shikimate was
differentially protected as the 3,4-0-cyclopentylidene ketal
and as the 5- 0- tert- butyldiphenylsilyl ether. The methyl
ester was then reduced with diisobutylaluminum hydride and
the resulting allylic alcohol was oxidized to aldehyde 47
with pyridinium...
A study of the effects of structural modification at
the alpha position of ethyl 2-bromocarboxylates on their
rates of addition to two alkene pairs was undertaken. In
the competition between 3-propoxypropene and 1-octene at
70°, a 37% increase in selectivity was observed in going
from carboxylates generating primary radicals to...
A new approach towards a total synthesis of paeoniflorigenin is discussed. The approach involves the application of regio- and stereoselective [2+2] photocycloaddition for the preparation of a key intermediate, cyclobutanone 86, and model studies on diiodosamarium (Sm12) mediated pinacol coupling of a diketone. Intermolecular [2+2] photocycloaddition of a,13unsaturated lactam 33...
A sensitive, selective, rapid analytical method based on large-volume injection (LVI)
liquid chromatography/ tandem mass spectrometry was developed using
commercially-available hardware that eliminates the need for either off-line or on-line
solid phase extraction. Centrifugation followed by the direct injection of 1,800 µL
was used for the quantification of illicit drugs,...
The work presented in this thesis deals with the mechanisms by which a vibrationally excited diatomic molecule gives up its energy to a host monatomic lattice at low temperature. The vibrational lifetimes (v"=1) of the metal oxides Ba0 and A10 in their ground electronic states are studied using pulsed dual...
Two studies were conducted involving rare earth elements. In the
first study, the use of rare earth diethylenetriaminepentaacetic acid
(DTPA) complexes as stable actiable tracers, a method of stable-isotope
tracing with post-sampling neutron activation analysis, was explored.
The persistence of rare earth DTPA complexes in estuarine waters was
measured in...
Novel donor-typed ternary graphite intercalation compounds (GICs) are synthesized and characterized containing (1) pyrrolidinium cations with DMSO co-intercalates; (2) alkali metal cations with crown ether co-intercalates; and (3) alkali metal cations with polyethylene glycol co-intercalates. Structural and compositional data are obtained for the stable products. A new ether-amine co-intercalate exchange...
In recent decades, there has been increased attention on human exposure to, and subsequently toxicity of, Polycyclic Aromatic Hydrocarbons (PAHs). PAHs are widespread organic pollutants and some have been shown to be toxic, carcinogenic and mutagenic. This research was focused on understanding the link between global PAH emissions and lung...
Lycopodium alkaloids have shown widespread and noteworthy biological activity, consisting of over 250 known natural products. Moreover, their structural complexity and diversity have attracted considerable attention from numerous laboratories including our own. Recently, we have developed a unified approach that would provides access to numerous, previously unprepared C₁₀-functionalized lycopodium alkaloids....
Since their discovery in the 1990s, the great potential of carbon nanotubes (CNTs) has made them a focus of many research endeavors, including their application as components of biosensors. The inherent chemical "inertness" of CNTs makes their application to biosensing a challenge. It is necessary to "decorate" their surfaces to...
Novel graphite intercalation compounds (GICs) and associated chemistry have been explored, specifically: (1) containing alkyl- substituted imidazolium cations; (2) a series containing alkaline earth metal (Mg, Ca, Sr, Ba) cations with ethylenediamine (en) co-intercalates; (3) showing reversible intragallery M-M bonding and (4) via electrochemical intercalation of Mg cations with potential...
An automated instrument based on a single-board microcomputer
was developed for use in voltammetric analyses. Operator input of
numerous experiment parameters allows any type of voltammetric
analysis to be implemented and multiple scans to be run unattended.
A three operational amplifier potentiostat is used to control
the cell voltage and...
In this dissertation, the structure and electronic properties of multiple metal oxide thin films are characterized and presented. Prompt inorganic condensation (PIC) of metal-oxo and –hydroxo clusters was evaluated as a technique for making metal oxide clusters in two separate studies. The first focuses on the synthesis of lithium niobate...
The relative rates of hydrogen abstraction from 1-phenylalkanes and a,w-diphenylalkanes using N-bromosuccinimide and bromotrichloromethane were determined at 70°C. In both cases the reactions were photoinitiated. Only benzylic bromination was observed. The 1-phenylalkanes reacted with both reagents to give rates largely independent of substrate. Similarly, the rate of the reaction between...
The design, construction and operation of a fluorometric reaction
rate instrument is described. The instrument is designed for simple
operation with maximum versatility. Advantages and modes of
operation of the system are discussed in detail. The instrument is
used for the kinetics-based determination of trace levels of Ag and Al....
Carboxylic acids have played an important role in the field of actinide (An) and lanthanide (Ln) separations and the reprocessing of irradiated nuclear fuel. Recent bench-scale experiments have demonstrated that 3-carboxy-3-hydroxypentanedioic acid (citric acid) is a promising aqueous complexant that can effectively aid in the separation of transition metals from...
Solid-state amorphous materials show amazing promise in thin-film electronics. The interface-to-bulk ratio of thin films makes interfacial chemistries of these systems of utmost importance. Thin films of amorphous metals, dielectrics and semiconductors have novel chemistries that are not only based upon their elemental constituent makeup, but also based upon the...
One post-transcriptional mechanism that regulates the progression of cancer and other diseases involves small 22-23 nucleotide sequences called microRNA (miR). Early detection of small changes in concentration of these biomarkers holds potential to diagnose diseases at their earliest stages. Use of current nucleic-acid based biosensors, like molecular beacons, for in...
The enantioselective total synthesis of quinolizidine-containing natural product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These natural products are members of the lycopodium alkaloids, which have attracted significant attention due to their exciting biological activities and the diverse structural scaffolds. Key steps in...
Traditional approaches for the direct preparation of alkenes are unable to fully control either the stereochemical configuration of the carbon-carbon double bond or else the regiochemistry of the substituents surrounding it. The recently introduced concept of carbenoid eliminative cross-coupling (CEXC) offers a remedy to these deficiencies by providing for a...
An important aspect in device technology is the
processing of GaAs to produce highly-resolved etch
patterns on the substrate. This is done typically on the
GaAs(100) surface. Recently, a number of methods, all
using chlorinated vapor reactants, have been applied to
fabrication of GaAs devices. In spite of these
technological...
The oxide/electrolyte solution interface has been studied experimentally by two methods, and a mathematical model for the interface has been developed. The change in interfacial potential with solution composition was determined through the capacitance of electrolyte/oxide/semiconductor (EOS) structures and the charge through potentiometric titrations of colloidal oxide suspensions. The differential...
An expedient approach to the synthesis of a wide range of highly programmable biaryl templates has been accomplished. Utilizing the Diels-Alder [4+2] cycloaddition, a wide range of tri- and tetra-ortho-substituted biaryls have been synthesized in only three to four steps from commercially available materials. We have successfully synthesized entire classes...
Metal-oxo clusters can be described as soluble pieces of metal-oxide frameworks. Currently, metal-oxo clusters are being considered as solution-based precursors for extreme ultraviolet (EUV, 13.5 nm) photoresist materials, which are a crucial component in the fabrication of microelectronic devices. Two different photoresist precursor systems have been investigated – alkyltin clusters...
Studies of the use of NADH as the monitored fluorophore for enzymatic fluorescence kinetic methods are discussed. Interference studies
for the detection of NADH and the adaptation and optimization of fluorescence kinetic measurements to four serum assays are also described.
A microcomputer-controlled flow injection analysis (FIA) system was
designed and...
Ultrafast spectroscopy has recently gained momentum as a powerful, noninvasive characterization toolset capable of studying a diverse array of samples with applications in chemistry, physics, biology, engineering, and more. Two popular ultrafast spectroscopic techniques include femtosecond transient absorption (fs-TA) and femtosecond stimulated Raman spectroscopy (FSRS). The latter of these techniques...
Complex organic transformations, such as the addition of pyrrole to ketene using planar chiral organocatalyst (*PPY), the four-component anhydride- Manniach reactions, and the site-selective desymmetrization of meso-1,2-diol, are remarkable synthetic reactions that provide high yield and high selectivity. However, the exact mechanism and origins of stereocontrol for theses synthetic organic...