Physical Sciences and Mathematics Commons^™

The Effects Of Hydrogen Bonding On The Spectral Properties Of 2'-Acetonaphthone, Kristine A. Loparo

Honors Theses

The effects of hydrogen bonding on the luminescent properties of 2'-acetonaphthone (2-AN) have been studied. Solvents of varying hydrogen bond donor abilities such as perfluorohexane(PFH), cyclohexane, ethanol, methanol, water, trifluoroethanol(TFE), and hexafluoroisopropanol(HFIP) have been used. An attempt is made to find a relationship between solvent hydrogen bond donor ability, the energy and efficiency of fluorescence emission and changes in 2-AN electronic absorption in these solvents. The 2-AN spectral properties have also been studied in mixed solvent systems where the molecule is dissolved in a nonpolar solvent, either PFH of cyclohexane, and one of the fluorinated alcohols (TFE or HFIP) is …

The Construction And Testing Of A System For Flash Photochemical Studies Of Organotransition Metal Compounds, Robin Lynn Miller

Honors Theses

The main objective of my research efforts was to construct a flash photolysis system which would enable one to carry out time-resolved studies of photoinitiated reactions of organometallic hydrides. Such a development involved two major tasks. First, it required establishing a functioning vacuum line. Organometallic complexes are extremely sensitive to oxygen and water. Therefore these contaminants must be removed if one is to have any success in studying their reactions. A vacuum line is the most efficient means for degassing both solvent and solute Second, it involved modifying our flash photolysis apparatus. Changes in the flash rig included upgrading the …

C13- And H-Nmr Studies Of The Bisulfite Addition Products Of Simple Carbonyl Compounds, Diane A. Piasecki

Honors Theses

No abstract provided.

Conformational Energy Calculations Of Tyrocidine, Leslie Beth Shapiro

Honors Theses

The minimum energy conformation of the cyclic decapeptide tyrocidine was calculated using the Empirical Conformational Energy Program for Peptides (ECEPP). Half of the amino acid sequence of tyrocidine is identical to the amino acid sequence found in the cyclic decapeptide gramicidin-S. Hence this study focuses on the conformation of the decapeptide that is not contained in gramicidin-S. This study calculates the conformation of a tripeptide ASN-GLN-TYR without the consideration of the presence of a beta bend formation because there is a low probability that a beta bend exists in this location. Two of the lowest energy conformations found in this …

A Mechanistic Study Of The Saponification Of Pivaloate Esters, Beni Brian Wolf

Honors Theses

The reactions of the esters of trimethyl acetic acid (pivalic acid) have been followed kinetically (Walrath 1977 and Watkins 1986) in the presence of alkali in a 3:1 ethyl cellosolve: water solvent at 64°C. Through the use of both optically active pivaloates and O18 as a tracer, the positions of bond fission during saponification for several pivolates have been determined. With the secondary butyl ester bimolecular attack on both the acyl- and the alkyl- carbon atom is observed in the presence of alkali. Partial racemization of the product secondary butyl alcohols suggests that for a saponification of secondary butyl pivaloates …

The Synthesis And Characterization Of Two All-Aliphatic Sterically Hindered Diesters Of Alpha, Alpha, Alpha', Alpha'-Tetramethyladipic Acid, Ronald L. Willson

Honors Theses

The bis-t-butyl- and bis-neopentyl glycol- diesters of α, α, α', α'-tetramethyladipic acid were synthesized via their diacid chlorides. α, α, α', α'-Tetramethyladipic acid was first prepared by a free radical coupling reaction of pivalic acid because it is not commercially available. The products of all syntheses were characterized by NMR and infrared spectra.

Paleogeography And Paleoenvironments Of The Lower Unit, Fossil Butte Member, Eocene Green River Formation, Southwestern Wyoming, Roberto Enrique Biaggi

Loma Linda University Electronic Theses, Dissertations & Projects

During Eocene time sediment accumulated in Fossil Lake, in what developed to be a small linear and structurally controlled basin. Fossil Lake was one of several lakes into which the Green River Formation was deposited in Wyoming, Utah and Colorado.

Detailed stratigraphic analysis of the Lower Unit of the Fossil Butte Member revealed a well developed lacustrine sequence south of Fossil Butte, and indicates four major depositional facies: (1) open lacustrine, (2) marginal lacustrine, (3) carbonate mudflat, and (4) marginal fluvio-deltaic. The open lacustrine facies is characterized by kerogen rich to kerogen poor finely laminated micrites , that consist mainly …

Substituent Effects On Strained Rings. Part A ; The Kinetics Of Hydrolysis Of A Quinuclidone Using Ftir. Part B, Yeu-Yi Chiu

Theses

PART A: The energies of a series of monosubstitued propane, cyclopropane and cyclopropene compounds were calculated using ab initio molecular orbital calculations optimized at the 3-21G level using Gaussian 82 and Gaussian 86 programs. The effects of substituents on stabilization energies and geometries are rationalized with respect to the parent molecules. The result is presented which indicated that for substituted cyclopropyl and cyclopropenyl compounds, most of the substituents induce stabilization except the —NC substituent group is destabilizing in cyclopropyl and cyclopropenyl systems. Indications of relative electrostatic and resonance effects are also analyzed. A linear free energy relationship has been exam-ined …

Determination Of Benzo(A)Pyrene Metabolites In The Bile Of Winter Flounder From The New York Bight, Xingmin Liu

Theses

A method for detecting the concentration of BaP Metabolites in fish tissues has been developed. The analytical procedure includes extraction of PAH and BaP Metabolites from fish bile, liver extract and muscle extract; reduction of metabolites to BaP using hydriodic acid; and subsequent analysis of the BaP by thin layer chromatography with fluorescence detection. The method is applied to tissues from fish collected from polluted as well as clean reference waters and experimental tanks with dilutions of treated industrial wastewater. Experimental results on one kind of bottom-dwelling fish, winter flounder, which comes from the Hudson-Raritan Estuary, NY, where the water …

Synthesis Of Highly-Strained Gem-Difluoro Compounds By Reaction Of Difluoromethylene With Cycloalkenes, Deyi Yang

Theses

Trans-Cyclooctene is thought to be more reactive than cis-cyclooctene due to its trans-structure. When cis or trans-clooctene reacts with difluormethylene (:CF₂), trans-9,9-difluorobicyclo[ 6,1,0] nonane was generated in much higher yield than cis-9,9-difluorobicyclo[6,1,0]nonane. [PhCF₃P⁺CF₂Br]Br^- was chosen to be the difluoromethylene precursor in this study. The reason was that the reaction condition for trans-cyclooctene and :CF₂ should be at low temperature. Only [PhCF₃P⁺CF₂Br]Br^- could generate CF₂ at lower temperature (e.g. room temperature). We succeeded in the synthesis of trans-9,9-difluorobicyclo[6,1,0]nonane and its cis isomer and …

Synthesis Of Site Specific 1, N^2-Ethenodeoxyguanosine In A Small Oligonucleotide, Kathryn A. Carolin

Wayne State University Theses

Malondiadehyde (MDA) is a known carcinogen and mutagen produced by lipid peroxidation and prostaglandin synthesis in vivo. MDA is unique from structurally related compounds, methyl glyoxal and acrolein, because it produces frameshift mutations whereas the latter compounds induce base-pair substitutions. MDA forms several adducts with deoxyguanosine but it is not certain which one causes the frameshift mutations. Ideally, a single adduct on a replicating genome could simulate the in vivo process by which MDA mutagenesis would occur. This technique is known as site-specific mutagenesis. The approach of choice for site-specific mutagenesis experiment is the gapped heteroduplex method which requires the …

Origins Of The Quantum Efficiency Duality In The Primary Photochemical Event Of Bacteriorhodopsin, Robert R. Birge, Leonore A. Findsen, Albert F. Lawrence, Mark Masthay, Chian-Fan Zhang

Chemistry Faculty Publications

Experimental and theoretical evidence is presented which suggests that two distinct forms of light-adapted bacteriorhodopsin may exist. We propose that these two forms have characteristic photocycles with significantly different primary quantum yields. INDO-PSDCI molecular orbital procedures and semiempirical molecular dynamics simulations predict that one ground state geometry of bR undergoes photochemistry with a primary quantum yield, Φ1, of ~ 0.27, and that a second ground state geometry, with a slightly displaced counterion, yields Φ1 ~ 0.74. This theoretical model is supported by the observation that literature measurements of Φ1 tend to fall into one of two categories- those that observe …

Molecular And Electronic Structure Of Siladiimide And Other Allenic X=Y=X Compounds, Mark S. Gordon, Michael W. Schmidt, S. Koseki

Mark S. Gordon

The preferred geometric structures of the allene analogues CH2=Si=CH2 (1), NH=Si=NH (2), PH=Si=PH (3), NH= C=NH (4), and NH=Si=CH2 (5) are examined at the RHF /6-31 G(d) level of theory, and that of 2 is further examined at the MP2/6-31G(d) computational level. The prediction that at the SCF level compounds 1, 3, 4, and 5 prefer orthogonal geometries like allene, while 2 prefers a planar structure, is examined with the aid of localized molecular orbitals, correlated energies, and, in the case of 2, a detailed analysis of the potential energy surface. The latter is very flat, and at the highest …

Assignment Of The Raman Active Lattice Vibrations In Various Phases Of 1,2,4,5 Tetrabromobenzene And 1,2,4,5-Tetrachlorobenzene Crystals, K.M. White, Craig J. Eckhardt

Craig J. Eckhardt Publications

Results of polarized Raman spectroscopy are reported and used to obtain complete assignment of the optical lattice modes of 1,2,4,5-tetrabromobenzene crystals for both the beta and gamma phases. Similar information is provided for the beta phase of 1,2,4,5-tetrachlorobenzene crystal. The results are compared with lattice-dynamics calculations. Discrepancies with previously reported measurements and calculations are discussed and rationalized. The Journal of Chemical Physics is copyrighted by The American Institute of Physics.

Total Maximum Daily Loads And Waste Load Allocations For Las Vegas Bay: Rationale And Calulations, State Of Nevada: Division Of Environmental Protection

Publications (WR)

In September 1987 the Nevada Division of Environmental Protection revised Water Quality Standards for Las Vegas Wash (LVW) and Lake Mead. Standards were set for chlorophyll-a and unionized ammonia in Las Vegas Bay (LVB) (NDEP 1987). The 1986 and 1987 LVB data showed non-achievement of both the chlorophyll-a and unionized ammonia standard which triggered an analysis of total phosphorus and total ammonia Total Maximum Daily Loads and Waste Load Allocations which are presented in this report.

This report is separated into three sections:

1. 1987 Las Vegas Bay Water Quality Conditions and Seasonal Periodicity.

2. Concentration Estimates at Northshore Road …

A Study Of Denitrosation Of N-Nitroso Compounds By Irradiation With Long-Wavelength Uv Light, Zhenyu J. Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

N-Nitrosamines and N-nitrosamides have been reported to be mutagenic. N-Nitrosamides are direct mutagens that need no activation to be mutagenic, whereas N-nitrosamines need to be enzymatically activated to exert their mutagenicity. Oxidative demethylation of nitrosamines is a commonly accepted activation mechanism. Another pathway of nitroso compounds, denitrosation, has recently been proposed. The mechanism of denitrosation, however, is still unknown.

The purpose of this study was to use a photo -reaction model to explore the possible denitrosation mechanism of N-nitroso compounds. An N-nitrosamine, N-nitrosomorpholi ne (NMOR), and an N-nitrosamide, N-methyl-N'-nitrosoguanidine (MMNG), were irradiated with long-wavelength UV light in the presence of …

The Electrochemical And Sniftirs Behavior Of Copper(I)Tetrakisbenzonitrile, Mark Anderson, Daniel Blackwood, Thomas Richmond, Stanley Pons

Mark R. Anderson

No abstract is currently available.

Us Patent: Probe Sampler For Atomic Spectroscopy, John Marshall, D Littlejohn

Professor John Marshall

UK Patent Application No. 8305745, filed 2nd March 1983 and United States Patent 4824241 granted 25th April 1989

Theoretical Studies Of Three-Membered Ring Compounds Y2h4x (Y = C, Si; X = Ch2, Nh, O, Sih2, Ph, S), Jerry A. Boatz, Mark S. Gordon

Mark S. Gordon

The heats of formation of the three-membered ring compounds Y 2H4X (Y = C, Si; X = CH2, NH, 0, SiH2, PH, S) and the thermodynamics of the insertion reactions X+ YH2=YH2 -- c-Y2H4X are predicted by using MP2/6-31G(d) energies at the 6-31G(d) geometries. Bent bond lengths are calculated by tracing the path of maximum electron density connecting two nuclei, with the 6-31G(2d) basis set at the 6-31G(d) structures. The short Si-Si internuclear distances in Si2H4X (X = CH2, NH, 0, PH, S) apparently are the result of severe bond bending rather than significant 1r character in the Si-Si bonds.

Theoretical Studies Of Bond Stretch Isomerism In Silabicyclobutanes, Jerry A. Boatz, Mark S. Gordon

Mark S. Gordon

The structures and relative energies of the bond stretch isomers of tetrasilabicyclo[l.l.O]butane (1), 1,2,3-trisilabicyclo[ l:l.O]butane (2), and 1,3-disilabicyclo[l.l.O]butane (3) are predicted at the GVB/3-21G* level, with the u and u* bridge bond molecular orbitals correlated in the GVB wave function. The transition-state structure and intrinsic reaction coordinate connecting each pair of bond stretch isomers are calculated. Two transition states joining the bond stretch isomers of 3 are located. The more stable isomer in all three molecules is the one with the longer bridge bond.

On The Kelvin Electrostatic Generator, S. Desmet, F. Orban, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The Kelvin generator is an amazing electrostatic device which poses many questions. The authors report the results of their investigations of this device under various controlled conditions with both nonpolar and polar liquids and a sodium chloride aqueous solution. They have found that the generator works well even if the two liquid streams originate from different electrically insulated reservoirs. In addition they propose a model in which the electric charge results from the separation of the hydrogen and hydroxyl ions as the water droplets form.

The Spectroscopy And A State Dynamics Of The Neibr Van Der Waals Complex, William Robert Simpson , '88, Thomas Alex Stephenson

Chemistry & Biochemistry Faculty Works

The A  3Π1←X  1Σ+ laser‐induced fluorescence excitation spectrum of the NeIBr van der Waals complex is reported and analyzed to extract information regarding the structure and vibrational predissociation dynamics of the complex. While no definitive geometric information regarding NeIBr is obtained, our data indicate that a linear geometry is at least plausible. The vibrational predissociation lifetimes are a strong function of A state vibrational level and range from 2.6 to 23 ps. The variation in lifetime with vibrational level is consistent with the results of previous measurements on rare gas–halogen complexes, particularly NeBr2.

Decomposition Of Normal-Coordinate Vibrational Frequencies, Jerry A. Boatz, Mark S. Gordon

Mark S. Gordon

A decomposition scheme for the partitioning of normal-coordinate vibrational frequencies into individual internal-coordinate "intrinsic~ frequencies is presented. This scheme assigns to each internal coordinate a frequency that is representative of a vibration described solely by motion of that particular coordinate. This facilitates the interpretation of harmonic vibrational frequencies and their associated normal-coordinate displacements, especially in those cases where the normal coordinates are best described by the coupling of several internal coordinates. The utility of the method is demonstrated via application to several simple hydrides and cycloalkanes, using ab initio SCF molecular structures and Cartesian force constant matrices.

Theoretical Studtes Of The Insertion Reactions Of Atomic Carbon And Silicon Into Methane And Silane, Shogo Sakai, John Deisz, Mark S. Gordon

Mark S. Gordon

The mechanisms for the insertions of atomic (ID and 3P) carbon and silicon into the C-Hand Si-H bonds of methane and silane are investigated by ab initio SCF methods, many body perturbation theory, and a localized molecular orbital (LMO) analysis. The LMO analysis shows that the insertion of 1D atoms into CH4 and SiH4 may be classified into two types: cationic hydrogen transfer and anionic hydrogen transfer. For the triplet atoms the LMO analysis suggests two different insertion reaction mechanisms: the near abstraction and the pull-push mechanisms.

Condensation Coefficient Measurement For Water In The Umr Cloud Simulation Chamber, Donald E. Hagen, John L. Schmitt, Max B. Trueblood, John C. Carstens, Daniel R. White, Darryl J. Alofs

Physics Faculty Research & Creative Works

A systematic series of condensation coefficient measurements of water have been made using the University of Missouri-Rolla cooled-wall expansion chamber which simulates the thermodynamics of cloud. This coefficient is seen to decrease from a value near unity, at the outset of simulation, to a value in the neighborhood of 0.01 toward the end of a simulation. Final values of this coefficient are sufficiently low as to contribute significantly to the broadening of the drop-size distribution in cloud.

A Complete Set Of Elastic Constants Of Crystalline Anthracene By Brillouin Scattering, R.C. Dye, Craig J. Eckhardt

Craig J. Eckhardt Publications

All 13 elastic constants of a vapor grown, uncut, anthracene single crystal were determined from acoustic phonon velocities obtained by the Brillouin scattering method. The phonon velocities are plotted for three crystallographic planes containing the crystal axis. The relationships between phonon velocities and lattice dynamics are discussed. A minimizing procedure is introduced for converting phonon velocities of low symmetry systems into elasticity coefficients. This is shown to have several advantages over previous methods used. The results are compared with those obtained by previous studies of anthracene elastic constants.

Mechanistic Studies Of The Far-Uv Photochemical Ring-Opening And Cleavage Reactions Of 1, 1-Dimethyl-1-Silacyclobut-2-Ene, Mark G. Steinmetz, B. S. Udayakumar, Mark S. Gordon

Mark S. Gordon

Direct photolyses of 1,1-dimethyl-1-silacyclobut-2-ene (1) at 214 nm in tert-butyl alcohol gave 29% tert-butoxydimethyl(2-propenyl)silane (2), 4.3% (Z)-tert-butoxydimethyl(1-propenyl)silane [(Z)-3], 6.9% (E)-tert-butoxydimethyl(1-propenyl)silane [(E)-3], and 5.9% tert-butoxytrimethylsilane (4) at 49% conversion. Products 2-4 were primary, and the total quantum yield of formation was 0.11. Use of tert-butyl alcohol-0-d led to >98% monodeuteration: 2-dl had 93.5% of the label at cl and 6.5% at c3 of the 2-propenyl group, (E)- and (Z)-3-d1 [(E),(Z)-3-dd were labeled >95% at C3 of the 1-propenyl group, and 4-d1 was deuterated at a silyl methyl. Cleavage of a silacyclopropylmethylene intermediate to 1,1-dimethyl-1-silaethene accounts for the labeling of 4-d1 and …

Heats Of Formation Of Alkylsilanes, Mark S. Gordon, Jerry A. Boatz, Robin Walsh

Mark S. Gordon

Theoretical heats of formation at 298 K for several alkylsilanes, predicted at the MP2/6-31G(d) level of theory, are compared with recently obtained experimental and additivity values. Excellent agreement is obtained between the ab initio and additivity values and with the more reliable experimental values for acyclic alkylsilanes. The ab initio heats of formation for the silacycloalkanes permit the evaluation of strain energy increments for the additivity scheme. Comparison is made with limited experimental data.

Particle-Particle Coincidence Measurements For 1,2,3h And 4he In The Reaction 480 Mev 56fe + Natag, Graham F. Peaslee, N. N. Ajitanand, John M. Alexander, Roy Lacey, L. C. Vaz, Morton Kaplan, M. Kildir, D. J. Moses, D. Logan, M. S. Zisman

Faculty Publications

Particle-particle coincidence measurements have been made between light charged particles (1,2,3H and He4) produced in the reaction (8.5 MeV/nucleon) 56Fe+natAg. This coincidence requirement emphasizes central collisions leading to evaporation residues. Average multiplicities are found to be approximately three alphas and approximately four protons per evaporation residue; these values imply that approximately (1/2 the initial excitation energy of about 211 MeV is evacuated from the evaporation residues by these particles. This fractional energy evacuation by charged particles is considerably larger than that found for the similar reaction (8.5 MeV/nucleon) Ag40. In both reactions the effective emission barriers for H1 and He4 …

Measured Spectra Of The Hygroscopic Fraction Of Atmospheric Aerosol Particles, Darryl J. Alofs, Donald E. Hagen, Max B. Trueblood

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The relation between dry diameter (X₀) and critical supersaturation (S_c) for atmospheric submicron aerosol particles is investigated using a long term air sampling program at Rolla, Missouri. The particles are passed through an electrostatic aerosol size classifier, and then through an isothermal haze chamber. Results are reported in terms of an apparent volume fraction of soluble material, ε_v defined such that for particles composed only of ammonium sulfate and water insoluble compounds, ε_v is the actual volume fraction of soluble material. The probability distribution of ε_v is found to be approximately Gaussian in …