The primary focus of this work is on examining structure-property relationships of interest for high-power nonlinear optical and laser crystals. An intuitive and simply illustrated method for assessing the nonlinear optical potential of structurally characterized noncentrosymmetric materials is introduced. This method is applied to materials including common quartz and tourmaline...
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...
The use of an adjacency matrix to determine distant (not maximal or
minimal) subgroup and supergroup relationships between crystallographic spacegroup
types is described. Full lists of space-group types that are supergroups and
subgroups for every space-group type were compiled. A list of the space-group
types connected to each space-group type...
A series of compounds, 7-8 and 20-25, were tested as competitive inhibitors of 2,5-dihydroxyacetanilide epoxidase I (DHAE I) and DHAE II. A Hammett plot was constructed for each enzyme to determine the effect of electron density on inhibition. DHAE I gave a linear, highly correlated plot (r²=0.91) that signifies the...
The transport and deposition of airborne contaminants, including semivolatile
organic compounds (SOCs), to high elevation ecosystems is
recognized as a potential threat to these ecosystems. The objectives of
this research were to develop an analytical method to measure a wide
range of SOCs in high elevation lake sediment and to...
Many pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers
(PBDEs), and polycyclic aromatic hydrocarbons are persistent, bio-accumulative, and
toxic. These semi-volatile organic compounds (SOCs) can undergo atmospheric
transport and deposition in cold, remote ecosystems. A better understanding of their
accumulation in the fish of these ecosystems is important to better predict...
Two nonlinear optical experiments are presented in which the third-order electronic susceptibility of molecules is used to generate Raman signals. The first one uses a single 532 nm beam from a Nd:YAG laser to produce Stimulated Raman Scattering in benzene and deuterated benzene. With a simple experimental set-up, stimulated emission...
The variegated aqueous chemistries of metal cations are applied to the design and synthesis of non-toxic solution precursors suitable for additive printing of large-area oxide electronics. Polycondensation behaviors of aqueous Al+3 and PO4 +3 are manipulated in the deposition of atomically smooth amorphous aluminum oxide phosphate (AlPO) dielectric films. AlPO...
The rearrangement of a homoallyl cation to a cyclopropylcarbinyl cation is thought to play a role in the biogenesis of a variety of cyclopropane-containing natural products,¹ a hypothesis which has previously led to the design of successful biomimetic syntheses of several natural products.² The strategy underlying this approach to cyclopropane...
Ambient high-volume (hi-vol) air samples were collected between March 15th and May 30th 2002, at Cheeka Peak Observatory (CPO), located on the tip of the Olympic Peninsula, Washington State. This sampling campaign was in conjunction with the 2002 Inter-Continental Transport and Chemical Transformation (ITCT 2K2) Campaign and the Photochemical Ozone...
7,7'-Dihydroxy-8,8'-biquinolyl (azaBINOL) was prepared from 7-hydroxyquinoline via N,N-dimethyl O-quinol-7-yl carbamate by directed ortho-metallation followed by FeCl₃-mediated oxidative coupling of the 8-lithioquinoline intermediate. Saponification of the resulting dicarbamate provided crystalline (±)-azaBINOL in 56% overall yield. 6,6'-Bis(dimethylaminocarbonyl)-7,7'-dihydroxy-8,8´-biquinolyl was prepared from the same dicarbamate by a double anionic-Fries rearrangement in 43% yield. 7,7'-Bis(diethylamino-carbonyloxy)-6,6'-diiodo-8,8´-biquinolyl...
An intramolecular variant of the modified-Julia olefination was demonstrated by the synthesis of α,β-unsaturated lactones in a mild and (Z)-selective fashion. The lynchpin reagent (benzothiazol-2-sulfonyl) acetic acid was synthesized in a straightforward fashion in 86% overall yield from commercially available 2-mercaptobenzothiazole via conversion to ethyl (benzothiazol-2-ylthio)acetate by base mediated alkylation...
Many D2d-symmetric 2,2',6,6'-tetrasubstituted biphenyls are
readily prepared via net oxidative dimerization of appropriate
1,3-disubstituted benzenes. Conversion of such proprochiral
compounds to useful C2-symmetric chiral biphenyls requires
formal replacement of two substituents on opposing aryl ring
units with alternate groups. This under exploited
desymmetrization tactic has been demonstrated for the
generation...
The purpose of this research was to compare four different media that were used to monitor SOC atmospheric concentrations in remote ecosystems. The accumulation of semi-volatile organic compounds, including pesticides, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), was investigated in lichen, 2-year old conifer needles, resin-based passive air sampling...
New analytical methods and instrumentation were developed for the determination of dissolved oxygen (DO) at low concentrations in water. The methods were based on monitoring the absorbance increase due to the oxidation of reduced indigo carmine (IC) by oxygen in the sample in different types of spectrometer cells. Spectrophotometer cells...
A microfluidic nanofiltration module has been designed, fabricated and applied to the continuous-flow, pressure-driven, post-synthetic purification of macromolecules and nanoparticles via diafiltration using a commercially available organic solvent resistant nanofiltration membrane, STARMEM 122. This module will readily interface with other microscale components within a
"nanofactory" for the rapid synthesis, purification...
The epoxide deoxygenation reaction is formally the reverse of theepoxidation reaction. Compared to epoxidation, which has reached its fullmaturity, epoxide deoxygenation has not been as intensively developed.Among the few deoxygenation reagents, a handful are catalytic in a metalcomplex, show high stereospecificity and operate under mild conditions. Acommon feature of all...
This research was undertaken to develop a sensitive, selective, and rapid analytical method to measure ethyl glucuronide (EtG) and ethyl sulfate (EtS) in urine as urinary biomarkers of alcohol exposure. Large-volume injection (LVI) coupled with liquid chromatography / electrospray tandem mass spectrometry was used to eliminate the need for either...
Fluorinated alkyl substances, which can be persistent, toxic, and
bioaccumulative, have been quantitated in many densely populated and
remote regions, including in air, surface waters, groundwater, and biota;
however, little is known about their transport or behavior in the environment.
Wastewater effluent is one of the principal routes for introducing...
While fluorochemicals have been detected all over the world and in wastewater
treatment plants, the effect of wastewater effluent on the receiving waters has not been
evaluated. In the first study, the mass flow of fluorochemicals emanating from
wastewater treatment plants along the Glatt River in Switzerland was evaluated. The...
An analytical technique has been developed for the determination of methylmercury compounds in environmental samples. The technique is based on a two-stage procedure. In the first stage, methylmercury compounds are isolated from the sample matrix as methylmercury chloride (MeRgCl) by distillation. The distillation procedure is based on a series of...
A novel, portable, filter fluorometer was developed for the determination of chloroform and TCE at environmentally-relevant levels when coupled with improved sampling techniques and reagents. Reagents selective for the TCE or chloroform convert these toxic species into fluorescent species that can be monitored. The fluorometer is based on LED excitation...
In this dissertation, I present the work of developing more efficient and economical techniques for fragmenting large bio-molecules, and ultimately making mass spectrometry a more powerful tool in proteomics, DNA sequencing, and other areas of biomolecular analysis.
Aiming at lowering the installation and operating cost, and delivering electron capture dissociation...
Over the last decade, the use of highly branched macromolecules, called dendrimers, is emerging. Polyamidoamine (PAMAM) dendrimers, in particular, have attracted high interest due to their unique properties, such as well-defined size, shape, and solubility in water. Our group, as part of an interdisciplinary team, is currently working on developing...
Effective methods for the enantiopure formation of substituted piperidine rings are significantly important due to their presence in alkaloid products. A valuable method to form these ring systems would be via an intramolecular heteroatom Michael addition from the corresponding enone or enal. Described herein is a methodolgy that has been...
The thermodynamic properties of 39 PBDEs have been calculated using Gaussian 03
on the B3LYP/6-31G(d)//B3LYP/6-31G(d) level. The PBDE congeners' enthalpies of
formation increase with increasing number of bromines and show a strong dependence on
the bromine substitution pattern. The effects of bromine substitution pattern have been
quantitatively studied by GAM...
The recent quest for improved functional materials like high permittivity dielectrics and/or
multiferroics has triggered an intense wave of research. Many materials have been checked for their
dielectric permittivity or their polarization state. In this report, we call for caution when samples are
simultaneously displaying an insulating behavior and a...
The rhenium (V) complex Tp'ReO₂ (Tp' = hydrido-tris-(3,5-
dimethylpyrazolyl)borate), generated in situ from PPh₃ reduction of
Tp'Re0₃, reacts with small ring heterocycles such as epoxides and
episulf ides. The strained trans-cyclooctene ring provides an unusual
thermodynamic bias against direct atom transfer, but trans-cyclooctene
oxide still produces substantial amounts of trans-cyclooctene....
Patterning of metal oxides typically involves a multi step process, involving
depositing a resist, patterning that resist with some form of lithography, etching the
oxide through the resist, and finally removing. This process can be simplified if the
resist is removed and replaced with a metal oxide that can be...
Epitaxial LaRh₁/₂Mn₁/₂O₃ thin films have been grown on (001)-oriented LaAlO₃ and SrTiO₃ substrates using pulsed laser deposition. The optimized thin film samples are semiconducting and ferromagnetic with a Curie temperature close to 100 K, a coercive field of 1200 Oe, and a saturation magnetization of 1.7μB per formula unit. The...
In this dissertation, I present electronic spectroscopy of a few biologically relevant species and their complexes with solvent molecules in the gas phase using a variety of techniques, including resonantly enhanced multiphoton ionization (REMPI), laser induced fluorescence (LIF), and zero kinetic energy (ZEKE) photoelectron spectroscopy. My work on several methylated...
Capillary electrophoresis as a technique has many applications in a broad range of fields including forensics, environmental analysis, and biological analysis and as a separation method for samples such as oligonucleotides, peptides, proteins, and pharmaceuticals. The research conducted herein is for the antibiotic pharmaceutical ciprofloxacin HCl and three impurities. Sample...
A direct purge technique was developed for the determination of chloroform or trichloroethylene (TCE) in water samples. These volatile organic solvents are transferred from the water sample to a reagent where they are trapped and react to form products (Fujiwara chemistry) that are monitored fluorometrically. Chloroform in a water sample...
A Diels-Alder approach to biaryls (DAB) has been applied towards the synthesis
of highly substituted, programmable biaryl templates. Tri- and tetra-ortho-substituted
biaryls can be produced in just three to four steps from commercially available materials
utilizing the Diels-Alder [4+2] cycloaddition. The methods described herein will
illustrate the ability of mono...
The concept of reducing laboratory operations in scale such that they fit on a microfluidic chip has been met with great enthusiasm. Lab-on-a-chip devices promise to be cost effective to operate due to reduced reagent consumption, have the potential to offer shorter analysis times due to their short path lengths,...
Chlorinated aliphatic hydrocarbons (CAHs) such as vinyl chloride (VC) and 1,-2 dichioroethane (DCA), are wide-spread groundwater pollutants found at many contaminated field sites around the world. Quantitative tools are needed to determine the in situ rates of VC and DCA transformation to ethene in contaminated groundwater. The objective of this...
Dielectrophoresis (DEP) is a separation method in which a non-uniform electric
field is used to induce a dipole moment in a suspended particle. If the polarization
of the particle is greater than that of the suspending medium, the particle will move
towards the region of higher field strength (positive DEP);...
Detection technique that proposed utilizing electrochemically controlled, reversible ion extraction into polymeric membrane in an alternating galvanostatic/ potentiostatic mode was introduced. This method is studied in detail to comprehend the advantages of the novel sensor (pulstrode) compared to the potentiometric ion selective electrode (ISE), studies included possible applications and limitations....
The fragmentation characteristics of protonated peptides have been investigated using
tandem mass spectrometry (MS/MS) under various fragmentation regimes and detailed
density functional theory (DFT) reaction pathway calculations. The DFT calculations
predict novel salt-bridge stabilized transition structures as well as consecutive reactions
occurring in proton-bound dimers for some of the ions...
New chemical synthesis strategies have been investigated for the preparation of acceptor-type graphite intercalation compounds (GIC's) with fluoroanions in order to obtain new materials and to develop a better understanding of the synthetic approaches and properties of the products. New GIC's containing borate chelate anion such as bis(oxalato)borate, CxB[OC(O)C(O)O]₂•δF, are...
The preparation and characterization of thin film oxides and chalcogenides by pulsed laser deposition (PLD) is presented. An overview of fundamental PLD concepts are presented and are followed by a description implementation and development of the PLD systems at OSU. We present the results of thin film growth of high...
The Gd3+ ion has been used to induce quantum splitting in luminescent
materials by using cross-relaxation energy transfer (CRET). In Nd:LiGdF4, quantum
splitting results from a two-step CRET between Gd3+ and Nd3+, first involving a
transition 6G→6I on Gd3+ and an excitation within the 4f3 configuration of Nd3+
followed by...
The two sulfur isotopomers of sulfur trioxide, ³²S¹⁶O₃ and ³⁴S¹⁶O₃, have been studied via high resolution infrared and Coherent anti-Stokes Raman (CARS) spectroscopy. The v₁ symmetric SO stretching Q-branches observed by the latter are quite different, being especially complex for ³²S¹⁶O₃ Understanding this band structure required analysis of infrared-active hot...
High resolution spectroscopy was used to study the properties of two simple polyatomic molecules, sulfur trioxide, SO₃, and carbon suboxide, C₃O₂. The fundamental modes and several hot bands of the ¹⁸O isotopic fonns of SO₃ (³²S¹⁸O₃ and ³⁴S¹⁸O₃) have been investigated using both infrared spectroscopy and coherent anti-Stokes Raman scattering...
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....
Atmospheric measurements of semivolatile organic compounds (SOCs) were made at Mt. Bachelor Observatory (MBO), located in Oregon’s Cascade Range, to understand the trans-Pacific and regional transport of SOCs from urban areas. High volume air sampling (~644 m³ for 24 hour periods) of both the gas and particulate phases was conducted...