Chemistry Commons^™

Kinetic And Thermodynamic Acidities Of Selected Weakly Acidic Hydrocarbons, Darrell R. Strait

Doctoral Dissertations

"The kinetic and thermodynamic acidities in methanol for bromoform and phenylacetylene have been determined at various temperatures. The thermodynamic acidities of phenylacetylene were obtained through a quench method which involved tritium tagging of the phenylacetylene anions present at equilibrium. With the use of this method, a pK_a of 18.34 for phenylacetylene at 0ºC was obtained. Through the use of these acidities, it was shown that the kinetics for these proton exchange processes are not diffusion controlled.

Isotope effects ( k_H/ k_D) were obtained for chloroform, bromoform and phenylacetylene at three temperatures (0ºC, -10ºC and -20ºC). …

The Chemical And Electrochemical Oxidative Decarboxylation Of Methyliminodiacetic Acid In Acid Media, Rita Kathleen Hessley

Doctoral Dissertations

"Methyliminodiacetic acid (MIDA) is oxidized with cerium. (IV) in both perchloric and sulfuric acids to give sarcosine, formaldehyde, and carbon dioxide"--Abstract, page 2.

A Study Of The Kinetic And Thermodynamic Properties Of Carbon Acids In Methanol, Dennis L. Filger

Doctoral Dissertations

The thermodynamic acidity (pK_a) of iodoform in methanol was determined at 25°C and 35°C; the values are 18.74 and 18.05, respectively . These acidity constants were determined by a modification of the equilibrium quenching technique which involves the conversion of the conjugate base of iodoform, present at equilibrium, to the radioactively labelled acid.

The rate constants for the methoxide-catalyzed hydrogentritium exchange of chloroform, iodoform, 9-phenylfluorene and indene were determined in methanol at various temperatures. The second-order rate constants obtained from these studies were shown to be the rate constants for removal of a triton. The activation parameters (ΔH …

Metal Salt Catalyzed Carbenoids Ii, Robert Stephen Mcdaniel Jr.

Doctoral Dissertations

"The interaction of diazomalonic esters with olefins in the presence of homogeneous Cu(II) catalyst species has been examined relating to olefin structure effects and catalyst structure effects using partial rate data as a method of determining the mechanistic aspects of the various reactions.

It has been possible to examine the mechanistic details of cyclopropanation, C-H insertion, and both "dimer" forming reactions.

Cyclopropanation proceeds via a transition state including olefin, copper (II), ligands, and carbene C-H insertion results from hydrogen abstraction prior to collapse of the transition state. "Dimer" is formed by the attack of diazo compound on the carbenoid carbon, …

Base-Induced Reactions Of P-Nitrobenzyl Compounds, Paul Henry Ruehle

Doctoral Dissertations

"The base-induced reactions of several p-nitrobenzyl compounds were studied. The products varied with changes in the leaving groups. With relatively poor leaving groups (Cl, S⁺(Me)₂), p,p'- dinitrostilbene was produced in good yield. The products of the reaction of p-nitrobenzyl chloride and hydroxide ion in 50% aqueous dioxane were 52.0% p,p'-dinitrostilbene, 43.9% cis- and trans-p,p'-dinitrostilbene oxides, 3.2% p-nitrobenzyl alcohol, and traces of other compounds. With dissolved oxygen, no stilbene was produced; the main product was 88% cis- and trans-p,p'-dinitrostilbene oxides. The addition of small amounts of di-t-butyl nitroxide caused a decrease in both the rate of the reaction and the amount …

The Internal Chemical Shift. A Key To Bonding In Aromatic Molecules. I. Internal Shift Correlations, Donald W. Beistel, Holger E. Chen, P. J. Fryatt

Chemistry Faculty Research & Creative Works

The study of proton shift behavior in nine families of disubstituted benzenes has provided quantitative correlations of internal and meta shifts among all families. The equations of correlation are useful in the prediction of shifts to an error of 0.015 ppm. The studies demonstrate shift additivity for the 4-substituted halobenzenes and suggest a chain rule relationship for substituent effects in those compounds. For that reason, previous theories of substituent interactions involving inductive and resonance contributors appear incorrect when applied to proton shift data. In decreasing order of up field shift at the ortho protons the substituents studied include N(CH3)2, NH2, …

Radiative And Predissociative Lifetimes Of The A ²Σ+ State Of Oh, Richard Orlin Sutherland, Richard A. Anderson

Chemistry Faculty Research & Creative Works

Lifetime measurements have been made on the A 2Σ+ state of OH by the delayed coincidence technique in conjunction with an interrupted rf discharge through water vapor. Lifetimes are reported for rotational states up to K=29 and K=20 in the ν=0 and ν=1 vibrational levels, respectively, and on the unresolved levels of ν=2. A predissociation, previously predicted from relative intensity measurements, resulting from a curve crossing by the repulsive 4Σ− state, was observed for the rotational states above K=23 of ν=0, for those above K=14 of ν=1, and for all those of ν=2. These lifetime data are discussed qualitatively in …

A Study Of The Ability Of Surface Active Materials To Increase The Evaporation Rates Of Small, Freely Falling Water Drops, David Alan Sierawski

Masters Theses

"The evaporation rate at 30°C of water droplets partially covered by surface active materials (SAM) were determined. While two of the SAM were studied at a single dew point depression (ΔT_DP), seven others were examined over a range of ΔT_DP values. It was found, by comparison with pure water drops under identical conditions, that SAM increases the evaporation rate as compared to the rate of an uncontaminated drop. The lack of effect of the hydrophobic chain length and the possible effect of the hydrophilic group on this phenomenon are discussed. The explanation proposed is that at 30°C …

A Computer-Oriented Course In Chemical Spectroscopy, D. (Donald) W. Beistel

Chemistry Faculty Research & Creative Works

No abstract provided.

Adsorption Of Water On Gold, Jean-Marc Louis Deschanel

Masters Theses

"Water adsorption isotherms on gold films were measured with a quartz crystal microbalance. Two gold films were studied: a "dirty" gold film contaminated by approximately one monolayer of carbon, and a "clean" gold film prepared by evaporating gold from a heated tungsten wire under high vacuum.

Water was found to chemisorb on both films according to a Freundlich type adsorption isotherm. Isosteric heats of adsorption were computed from the isotherm data. On the "clean" gold surface the isosteric heat showed a logarithmic decrease with increasing water coverage. The highest measured value for the heat of adsorption was 35 kcal mole …

Desorption Of Phosphorus From Si (111) Surfaces, Cesar Michel Magnin

Masters Theses

"Auger electron spectroscopy and mass analysis are used as complementary methods in evaluating desorption kinetics. For phosphorus on silicon, the order of desorption and activation energies of desorption are determined from continuously monitored phosphorus Auger electron signals during heating. These measurements indicate that diatomic phosphorus dissociates when adsorbed onto clean silicon. Mass spectrometer flash desorption spectra show that at least four distinct surface bonds are associated with the desorption of phosphorus. The dominant desorbed species is diatomic phosphorus at high coverage (> 0. 1 monolayer) and atomic phosphorus at low coverage (< 0.07 monolayer)"--Abstract, page ii.

Pmr Spectra Of The 4-Alkylnitrobenzenes, Donald W. Beistel, Hsin-Liang Chen

Chemistry Faculty Research & Creative Works

Evidence of first-order alkyl-ring proton coupling is reported for the 4-alkylnitrobenzenes. Typical coupling constants of 0.7 Hz and 0.3 Hz were found for α-alkyl coupling with the ortho and meta ring protons, respectively, when the alkyl function was methyl, ethyl, and isopropyl. No β-alkyl coupling with ring protons was observed for the ethyl, isopropyl, or t -butyl groups, suggesting that the magnitude of the coupling constant is vanishingly small.

The Synthesis And Spectroscopic Properties Of Vanadium(Iii) Squarate Trihydrate, S. M. Condren, Hector O. Mcdonald

Chemistry Faculty Research & Creative Works

Vanadium(III) squarate trihydrate has been prepared; and the infrared, X-ray diffraction, and electronic spectra of the complex indicate that the central metal atom is in a slightly distorted octahedral field. A thermogravimetric study has shown that the complex loses three water molecules upon heating. A hydroxy-bridged, dimeric structure has been proposed from these data. © 1973, American Chemical Society. All rights reserved.

Scavenging Of Atmospheric Particles By Water Drops, Ming-Shian Wu

Doctoral Dissertations

"In the first paper, the mechanisms of particle capture and coalescence of aerosols by a moving water drop in the atmosphere are studied using the boundary-layer flow approximation. The particle trajectory is computed by solving the equations of motion of the particle both outside and inside the boundary layer using the Adams-Moulton method. The grazing trajectory is found by a trial-and-error technique. The collision and collection efficiencies of scavenging due to particle inertia and to the velocity gradient of the flow field are then computed for water drops ranging from 0.1 to 1.0 mm in radius and for particle of …

The Atomic Absorption Determination Of Ultra-Trace Tellurium In Rocks Utilizing High Sensitivity Sampling Systems, Richard D. Beaty

Doctoral Dissertations

"The sampling boat and the graphite furnace have been shown to possess the required sensitivity to detect tellurium at ultra-trace levels, in a variety of sample types, by atomic absorption. In the sampling boat approach, tellurium in sample solutions is chemically separated and concentrated by extraction into methyl isobutyl ketone before measurement. For samples exhibiting extraction interferences or excessively high background absorption, a preliminary separation of tellurium by coprecipitation with selenium is described. Using this technique, tellurium can be quantitatively detected down to 5 nanograms and linear response is observed to 100 nanograms. Relative standard deviations of better than 7% …

Anionic Polymerization Of A Series Of 5-Membered Cyclocarbosiloxanes, Balaraman Suryanarayanan

Doctoral Dissertations

"A study has been made on the anionic polymerization of a series of 5-membered cyclocarbosiloxanes with methyl and/or phenyl substituents. The polymerization was initiated by lithium n-butyldiphenylsilanolate in the presence of tetrahydrofuran. Six 5-membered cyclocarbosiloxanes (2,2,5,5-tetramethyl-1-oxa-2,5-disilacyclopentane; 2,2,5- trimethyl-5-phenyl-1-oxa-2,5-disilacyclopentane; 2,5-dimethyl-2,5-diphenyl- 1-oxa-2,5-disilacyclopentane; 2,2-dimethyl-5 ·,5-diphenyl-1-oxa- 2,5-disilacyclopentane; 2-methyl-2,5,5-triphenyl-1-oxa-2,5-disilacyclopentane; 2,2,5,5-tetraphenyl-1-oxa-2,5-disilacyclopentane) were synthesized. Since the chemical shifts of the protons of the cyclic monomers and the polymers formed were different, the rate of polymerization of the cyclic monomers was measured utilizing an NMR spectrometer. The effects of tetrahydrofuran concentration, initiator concentration and water concentration on the rate of polymer formation and on the molecular weight of …

Approaches To The Synthesis Of Azabullvalene, Thomas Rudolph Steinheimer

Doctoral Dissertations

"Three approaches to the synthesis of the heretofore unknown azabullvalene, the pi electron equivalent heterocyclic congener of bullvalene itself, are described. Two of the schemes are based upon the assumption that the most convenient method for the introduction of the nitrogen atom is via thermal rearrangement of the appropriate azide.

The first involved the generation of the homobarrelene carbon skeleton and sub sequent decomposition of its azide. This compound arises formally as the product of the Diels-Alder addition of acetylene to the bicyclic valence isomer of tropyl azide (cyclohepta-1, 3, 5- trienyl-7-azide). In order to achieve this goal, Diels-Alder additions …

A Study Of The Pulse-Height Response Of Silicon Surface-Barrier Detectors To High-Energy Heavy Ions, Gregory Dan Smith

Doctoral Dissertations

"The pulse-height defect (PHD) of high-energy heavy ions in silicon surface-barrier detectors can be divided into three components: (1) energy loss in the gold-surface layer, (2) a nuclear-stopping defect, and (3) a defect due to recombination of electron-hole pairs in the plasma created by the heavy ion. The plasma recombination portion of the PHD was the subject of this study using the variation of the PHD with (1) the angle of incidence of incoming heavy ions, and (2) changes in the detector bias. The Tandem Van de Graaff accelerator at Argonne National Laboratory was used to produce scattered beam ions …

Distribution Of Mass And Charge In The Spontaneous Fission Of ²⁴⁴Cm, K. F. Flynn, B. Srinivasan, Oliver Manuel, Lawrence Elgin Glendenin

Chemistry Faculty Research & Creative Works

The distribution of mass and charge in the spontaneous fission of ²⁴⁴Cm has been investigated by radiochemical and mass spectrometric determination of the fission yields for 40 mass chains and 2 shielded nuclides (independent yields). The mass distribution is highly asymmetric with a relative probability of asymmetric-to-symmetric fission (peak-to-valley ratio) of greater than 5700. The average masses of the light and heavy groups are 103.1 and 138.7, respectively. The characteristics of the mass distribution, as well as the division of nuclear charge indicated by the independent yields of the two shielded nuclides, are consistent with the systematics established from …

A Study Of Some Complexometric Titrations In Nonaqueous Solvents, Ngo The Hung

Masters Theses

"Complexometric titrations of calcium, zinc and lead with polyaminocarboxylic acids: ethylenediaminetetraacetic acid (EDTA), 1,2-diaminocyclohexanetetraacetic acid (DCTA), ethyleneglycol-bis(2-aminoethylether)tetraacetic acid (EGTA) and tetraethylenepentamine (tetren) have been investigated and compared in the following organic solvents: methanol, dimethyl formamide, dimethyl sulfoxide and methyl ethyl ketone. Various end point detection methods have been used: direct visual titration with metallochromic indicators and instrumental detection by photometry, potentiometry (mercury electrode and lead ion selective electrode) and amperometry. Calcium, zinc and lead can be determined up to trace levels (ppm) under specific conditions. A concrete application of this thesis is the determination of zinc or calcium in a …

Studies On The Mechanism Of Action Of Nerve Growth Factor., D. (Daniel) B. Hier, B. G. Arnason, M. Young

Chemistry Faculty Research & Creative Works

No abstract provided.

An Aircraft, Aerosol Sampling Program: Some Preliminary Results, J. F. Stampfer

Chemistry Faculty Research & Creative Works

An aircraft sampling program to determine the vertical and size distributions of that part of the atmospheric aerosol with radius greater than 0.25 μ is described. The feasibility of using a single engine aircraft and a light scattering particle analyzer, for this work, is shown. Examples of the data are given and preliminary conclusions are drawn about the normal size distribution, effect of lapse rate on the vertical aerosol concentration gradient, effect of relative humidity on the size distribution, and the possibility of producing high concentrations of giant particles aloft. © 1972.

Structural And Magnetic Properties Of [(Ch₃)₃Nh] Cucl₃2h₂O, D. B. Losee, J. N. Mcelearney, A. Siegel, Richard Lewis Carlin, A. A. Khan, J. P. Roux, William Joseph James

Chemistry Faculty Research & Creative Works

The crystal structure at room temperature and the low-temperature heat capacity and magnetic susceptibilities of single crystals of [(CH3)3 NH]CuCl3 2H2O are reported. The monoclinic crystals belong to the space group P21c with a=7.479(10), b=7.864(11), c=16.730(23), =91.98(3)°, and Z=4. The structure consists of chains of edge-sharing [CuCl4(OH2)2] octahedra running along the a axis. Each copper atom is coordinated in a square plane by two water molecules and two chlorine atoms, with two more chlorine atoms at a longer distance. The susceptibility data can be fitted adequately between 1.5 and 20°K by a CurieWeiss law [ga=2.080.01, gb=2.020.01; gc=2.110.01; a=(0.380.03)°K, b=(0.360.03)°K, c=(0.410.03)°K], …

Adsorption Of Dichromate At The Air-Solution Interface, Josephine Juch Wang

Masters Theses

"The adsorption of dichromate ion with the surfactants, tetradecylpyridinium bromide and tetradecyltrimethylammonium bromide at the air-solution interface was studied by surface tension and turbidity measurements in order to better understand the process of ion flotation. Surface tension measurements were used to study the effect of dichromate ion concentration on precipitation in dilute surfactant solutions. At higher concentration, near and above the cmc, light scattering was used to detect precipitation. The concentration of dichromate required to cause precipitation decreases with increasing surfactant concentration until the erne is approached, after which increasing concentrations of dichromate are required with increasing concentration of surfactant. …

Studies Of Neutron Capture Produced Rare Gas Isotopes In Rocks And Minerals Containing Chlorine, Selenium And Tellurium, David E. Sinclair

Masters Theses

"Noble gas mass spectrometry was used to study rare nuclear processes in terrestrial rocks and minerals. An excess of ³⁶Ar was detected in a chlorine-rich rock. The excess ³⁶Ar has been produced in rocks near the earth's surface due to capture of cosmic-ray-produced neutrons on ³⁵Cl. Measurement of ³⁶Ar formed by the ³⁵Cl(n, γ)³⁶Cl(β^-)³⁶Ar process makes possible a new method for determining the surface residence time of chlorine-rich minerals

Excess ⁸²Kr and excess ⁸³Kr were detected in selenium-rich ores. The excess ⁸²Kr results from double beta …

Selected First Row Transition Metal Coordination Compounds Of 2-(N-Aminomethyl)-3-Quinuclidinone Chelates, Richard Cecil Dickinson

Doctoral Dissertations

"As part of a project directed towards elucidating the characteristics of ligands which coordinate to give complexes having tetrahedral structures, a study of chelates containing the bulky quinuclidine group has been made. With 2-(N-morpholinylmethyl)-3-quinuclidinone (MQN), complexes having the general formula M(MQN)X₂ were prepared where the metal ion was Co(II), Ni(II), Fe(II), Cu(II), and Mn(II). The ligands 2-(N-piperidinylmethyl)-3-quinuclidinone (PQN) and 2-(N-dimethylaminomethyl)-3-quinuclidinone (DQN) were prepared along with the analogous cobalt(II) chloride complexes. The series of complexes Co(MQN)X₂ where X = Cl, Br, or I were prepared, and magnetic susceptibilities and spectral data obtained. They have room temperature magnetic moments in the range …

The Utilization Of High Sensitivity Noble Gas Mass Spectrometry In The Detection Of Iodine-129 And Plutonium-244, Mervet S. Boulos

Doctoral Dissertations

"Mass spectrometric analysis of the xenon isotopes in natural gas wells demonstrates that radioactive isotopes of element number 53 (I) and element number 94 (Pu) were present at the time of the Earth's formation. Evidence for the now extinct nuclide¹²⁹I (t_1/2 = 17 x 10⁶ years) was found in CO₂ -rich gas while evidence for the now extinct ²⁴⁴Pu (t_1/2 = 82 x 10⁶ years) was discovered in other natural gas wells. The amounts of ¹²⁹I in thyroids was measured by combining neutron activation analysis with noble gas mass spectrometry. The current …

Substituent Effects On The Magnetic Resonance Spectra Of 1, 4-Disubstituted Benzenes, Holger Er-Chah Chen

Doctoral Dissertations

"The Nuclear Magnetic Resonance spectra of five complete series of para-substituted benzenes have been investigated: the benzoic acids, benzonitriles, benzoyl chlorides, methyl benzoates and nitrobenzenes. Precise values of aromatic proton chemical shifts and coupling constants were obtained from LAOCOON3 computer analyses of the spectra. Using the relative internal chemical shift technique of Beachell and Beistel, excellent linear correlations among all five series were found. All substituents gave proton shifts which lay on the least-squares line, so it is concluded that all substituents are well behaved. Using the correlation plots the chemical shifts of the aromatic ring protons can be predicted …

Condensation And Sublimation Of Carbon Dioxide And Water Molecules At Cryogenic Temperatures, Victor Cazcarra

Doctoral Dissertations

"Measurements of the condensation coefficient of CO₂ and H₂O have been made using a molecular beam and quartz crystal microbalances. The dependence of the condensation coefficient on variables such as population density on the substrate, temperature of the substrate, molecular beam intensity and temperature of the molecular beam, was investigated. The results are explained using heterogeneous nucleation theory for low density population, and a new approach for high density population is presented. The rate of sublimation of these two gases was measured directly. The results are reported in terms of vapor pressure in the range 10⁻⁹ to 10⁻⁴ Torr. The …

Mössbauer-Effect Studies Of The Phase Transitions In Antiferroelectric Pbzro₃ And Ferroelectric Pbti₀.₀₂Zr₀.₈O₃, James P. Canner, C. M. Yagnik, Robert Gerson, William Joseph James

Physics Faculty Research & Creative Works

The Mössbauer spectra were studied for the antiferroelectric compound PbZrO₃ and for the closely related ferroelectric PbTi_0.2Zr_0.8O₃. In both cases, a substitution of 5-mol% BiFeO₃ was made to permit the Mössbauer measurements. Little difference was found in the isomer shift in these compounds, whether they were in the ferroelectric, antiferroelectric, or cubic state, indicating that the bonding character is not affected by the transitions among the states. There was a pronounced and approximately equivalent dip in the recoil-free fraction at the Curie points of both the antiferroelectric and ferroelectric materials, associated with …