Physical Sciences and Mathematics Commons^™

An Nmr Analysis Of The Hydrolysis Of Alpha-Bromopropionic Acid, Barbara A. Jensen

Honors Theses

The kinetics of hydrolysis of ∝-bromopropionic acid were investigated at 80° and a constant pH of 3.3. An average first order rate constant of 4.74x10-3 min-1 was determined. This hydrolysis reaction has been studied by several workers. It is unique in that the reaction proceeds through inversion reactions, the first involving the carboxylate ion. This paper covers the first study where the pH of the system was maintained constant. The design if an inexpensive pH-stat for this purpose is given. The experiment and/ or data lend themselves useful for treatment in physical chemistry where the students must gather data in …

Saponification Of Several Esters Of Pilvalic Acid, Kevin Thomas Watkins

Honors Theses

The base promoted hydrolysis, saponification, of several esters of pivalic acid (trimethyl acetic acid – C (CH3)3COOH) has been studied. Kinetic studies were performed and a possible mechanism for the reactions is proposed. The saponification of esters has been well studied. Ingold1 proposes three possible mechanisms for the reaction; Bac2, Bal1, and Bal2. The B stands for base promoted, the ac and al for acyl oxygen cleavage or alkyl oxygen cleavage, respectively, and the 1 or 2 for first or second order kinetics.

Luminescence Probes For The Measurement Of Oxygen, Mary Katherine Carroll

Honors Theses

The goal of this project was to design an optical sensor for oxygen. One type of system suitable for oxygen detection in aqueous solutions is based on two distinct emission bands: one band oxygen-sensitive, the other insensitive to oxygen quenching. By taking the ratio of these bands, a quantitative measurement of the oxygen present could be obtained. This could be accomplished in a system where a fluorescing compound, through triplet state energy transfer, causes a lanthanide ion to luminesce. By choosing a compound which has a triplet energy near the excitation wavelength of terbium (III) or europium (III) and which …

The Triplet State Photophysics Of Phenanthrene, Roberta Susnow

Honors Theses

The first excited triplet state (TI state) of aromatic hydrocarbons such as phenanthrene acts as an intermediate in many chemical and photochemical reactions. The TI state is a metastable state and its lifetime can be measured in terms of its decay to the ground state. The duration of this decay is on the order of microseconds. Therefore, techniques for measuring the kinetics of fast reactions must be employed in the determination of the rate of the TI state decay, one such technique that is utilized in this research is flash photolysis. The rate of the Tl state decay is greatly …

Data Collection And Presentation Procedures For The U.S. Army's Chemical Hazard Assessment Warning System (Chaws), Michael H. Merry

All U.S. Government Documents (Utah Regional Depository)

This report describes the basic procedures and references more detailed documents for the operation of meteorological and air quality sensing instrumentation, data depiction and analysis systems for an incinerator pilot plant located at the Tooele Army Depot site near Salt Lake City, Utah. It discusses the site topography and climatology, sensor configuration, calibration, quality assurance and data reporting procedures for the monitoring system and demonstrates their compliance with applicable environmental regulations of United States Federal Government and the State of Utah.

Crystal Structure And Charge Transfer Energies Of Complexes Of The Donor Biphenylene With The Acceptors Tcnb And Pmda, John J. Stezowski, Rolf-Dietrich Stigler, Norbert Karl

John J. Stezowski Publications

Biphenylene:tetracyanobenzene (BPN:TCNB), C₁₂H₈:C₁₀H₂N₄, crystallizes in a monoclinic lattice, space group P2₁/a, Z = 2, with a = 15.215(2) Å, b = 7.260(1) Å, c = 7.573(1) Å, β = 90.05(1)° at 296 K. The BPN donor and TCNB acceptor molecules form two symmetry-related mixed linear [001] stacks with the donor and acceptor molecular planes tilted to each other (within the individual stacks) at an angle of Φ = 7.6°. Biphenylene:pyromellitic-dianhydride (BPN:PMDA), C₁₂H₈:C₁₀H₂O₆, crystallizes in two …

Identification Of N Epsilon-Carboxymethyllysine As A Degradation Product Of Fructoselysine In Glycated Protein, Mahtab U. Ahmed, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

The chemistry of Maillard or browning reactionosf glycated proteins was studied using the model compound, Nu-formyl-W-fructoselysine(f FL), an analog of glycated lysine residues in protein. Incubation of fFL (15 mM) at physiological pH and temperature in 0.2 M phosphate buffer resulted in formation of lVcarboxymethyllysine (CML) in about 40% yield after 15 days. CML was formed by oxidative cleavage of fFL between C-2 and C-3 of the carbohydrate chain and erythronic acid (EA) was identified a s , the split product formed in the reaction. Neither CML nor EA was formed from fFL under a nitrogen atmosphere. The rate of …

Potential Primary Pyrolysis Processes For Disilane, Mark S. Gordon, Thanh N. Truong, Elizabeth K. Bonderson

Mark S. Gordon

Four competing unimolecular decomposition pathways for disilane are considered with use of MP4 energies obtained with an extended basis set and geometries obtained at the MP2/6-31G** computational level. The 1,1- and 1,2-eliminations of H2 and the elimination of silylene to form silane all have similar endothermicities, but the very high activation energy for the I ,2-elimination eliminates this process as a significant contributor at low energies. If disilene is formed in the thermal decomposition of disilane, the more likely source is its higher energy isomer silylsilylene via a relatively low energy I ,2-hydrogen shift.

Thermal Decomposition Of Silane, Mark S. Gordon, David R. Gano, J. Stephen Binkley, Michael J. Frisch

Mark S. Gordon

The essential features of the potential energy surface for the thermal decomposition of silane have been calculated with extended basis sets, augmented by correlation corrections. It is predicted that the transition state for the molecular elimination lies 56.9 kcaljmol above silane. For the reverse reaction, the transition state is less than 2 kcal/mol above the separated fragments, silylene and molecular hydrogen, but 4.8 kcal/mol above a long-range potential well. In the latter, the silylene-H2 separation is 1.78 A, and the bond in H2 has stretched by more than 0.05 A. This indicates a significant electronic interaction between the fragments even …

Theoretical Studies Of Reactions Of Silanimine (H2sinh) And Its Isomer Aminosilylene (Hsinh2), Thanh N. Truong, Mark S. Gordon

Mark S. Gordon

The structure and reactivity of unsaturated singlet silicon-nitrogen compounds is theoretically investigated. Ab initio calculations demonstrate that the planar silylene HSiNH2 is the global minimum on the SiNH3 surface, with the planar doubly bound species H2SiNH 18 kcaljmol higher in energy. The internal rotational barriers are computed to be 26.9 kcaljmol for HSiNH2 and 37.9 kcaljmol for H2SiNH. However, the barrier for the inversion of H2SiNH is only 5.6 kcaljmol, so that inversion is favored over rotation for this species. The isomerization connecting H2SiNH to HSiNH2 has a barrier of 60 kcaljmol. The transition-state structures, as well as the exothermicities …

Simultaneous Knudsen- And Torsion-Effusion Measurements Of The Vapor Pressures Of Triphenyl Aluminum And Triphenyl Boron, Steven Wayne Govorchin

Masters Theses

The sublimation pressures of triphenyl aluminum and triphenyl boron have been determined from simultaneous measurements of the rate of mass effusion and torsional recoil. For triphenyl aluminum the measured vapor presures are expressed by the equations:

logio (P_k/P°) = (12.76 ± 1.25) - (8214 ± 572) (K/T)

logio (P_t/p °) = (12.83 ± 1.34) - (8206 ± 615) (K/T)

where P_k and P_t are the pressures measured by the Knudsen-effusion and torsional-recoil techniques, respectively, and p° = 101.325 kP_a. For triphenyl boron the measured vapor pressures are expressed by the equations:

log …

Laser Pump And Probe Excited State Absorption Measurements, Shawpin Jong

Electrical & Computer Engineering Theses & Dissertations

A pump and probe technique was used to investigate triplet-triplet excited state absorption in solutions of the scintillators 2,5 diphenyloxazole (PPO) and 2,1 naphthyl,5 phenylzole (a-NPO) in several solvents.

KrF excimer radiation (248 nm) was used to pump the samples under investigation as well as a tunable dye laser which was used as the probe. Time-resolution was obtained by changing the optical path difference between the pump and probe beams.

Transient excited state absorption was measured in a wide spectral region between 330 nm and 600 nm, showing a peak at 400 nm for PPO solutions, and two …

Improvement Of Trace Aluminum Determination By Electrothermal Atomic Absorption Spectrophotometry Using Phosphoric Acid, Chris Craney, Kurt Swartout, F. Smith, C. West

Chris L. Craney

No abstract provided.

Analysis Of Slit-Distorted Small-Angle X-Ray Scattering Intensities Without Desmearing, Jerry Goodisman, F. Delaglio, H. Brumberger

Chemistry - All Scholarship

Experimental small-angle X-ray scattering intensities, generated from a primary beam of known intensity profile, are often 'desmeared' to obtain point-collimated intensities. A much simpler way is shown of using the known beam intensity profile to derive, from the experimental scattering intensity, the quantities required for calculation of surface areas.

Small-Angle X-Ray Scattering Analysis Of Catalysts: Comparison And Evaluation Of Models, H. Brumberger, F. Delaglio, Jerry Goodisman, M. Whitfield

Chemistry - All Scholarship

Small-angle X-ray scattering (SAXS) can be used to obtain interphase surface areas of a system, such as a supported-metal catalyst, composed of internally homogeneous phases with sharp interphase boundaries. Measurements of SAXS for samples of porous silica, alumina, platinum on silica, and platinum on alumina are reported. A variety of models and forms for the correlation function, the Fourier transform of which gives the X-ray scattering, are considered, and theoretical and measured intensities are compared. A criterion of fit for comparing models with different numbers of parameters is proposed. It is shown that values for the single interphase surface area …

Ganes: A Computer Program For The Simulation Of Laboratory Spectra Of Evaporative Light Particles In Heavy Ion Reactions, N. N. Ajitanand, R. Lacey, Graham F. Peaslee, E. Duek, John M. Alexander

Faculty Publications

A computer program called GANES has been written to simulate the evaporation of light particles in heavy ion reactions. The program uses the very efficient “weighted Monte Carlo” method. GANES has been designed to treat two-body breakup reactions such as fusion fission and three-body breakup reactions such as sequential fission (of a heavy product) after a primary inelastic collision. GANES calculates energy spectra for light particles evaporated from a composite nucleus before scission, and also from fully accelerated fragments after scission. Mass, energy and angular distributions of the heavy fragments are taken into account. Energy spectra (inclusive and exclusive) of …

Electrochemical Reduction Of Alkyl Halides At Vitreous Carbon Cathodes In Dimethylformamide, James Cleary, Mohammed Mubarak, Kenneth Viera, Mark Anderson, Dennis Peters

Mark R. Anderson

At vitreous carbon electrodes in dimethylformamide which contains tetramethylammonium perchlorate, cyclic voltammograms for 1-iododecane, 1-bromodecane, and 2-bromooctane consist of one irreversible reduction wave signaling formation of the alkyl carbanion, whereas voltammograms for 2-iodooctane, t-butyl bromide, and t-butyl iodide reveal stepwise generation of the alkyl radical and carbanion. Large-scale electrolysis of 1-iododecane at reticulated vitreous carbon yields decane, eicosane, 1-decene, and 1-decanol; the first two compounds arise, respectively, from reaction of decyl carbanions with a proton donor and with unreduced alkyl iodide, whereas the last two species are produced via chemical attack of hydroxide ion on 1-iododecane. Reduction of 1-bromodecane results …

Electrochemistry Of 1,1,4,4-Tetraphenyl-1,3-Butadiene, 1,1,4,4-Tetraphenyl-1,2-Butadiene, And 1,1,4,4-Tetraphenyl-1-Butene In Dimethylformamide, Tsu-Yu Chen, Mark Anderson, Dennis Peters

Mark R. Anderson

In dimethylformamide containing tetra-n-butylammonium perchlorate, 1,1,4,4-tetraphenyl-1-butene exhibits a single polarographic wave; preparative-scale reduction of the starting material produces 1,1,4,4-tetraphenylbutane.A polarogram for 1,1,4,4-tetraphenyl-1,3-butadiene consists of three waves. Large-scale electrolysis of 1,1,4,4-tetraphenyl-1,3-butadiene at potentials corresponding to either the first or second wave yields 1,1,4,4-tetraphenyl-1-butene in the absence of a proton donor and a mixture of 1,1,4,4-tetraphenyl-2-butene and 1,1,4,4-tetraphenyl-1-butene in the presence of excess glacial acetic acid. If 1,1,4,4-tetraphenyl-1,3-butadiene is electrolyzed at a potential on the third polarographic wave, one obtains 1,1,4,4-tetraphenylbutane in the absence of a proton donor but a mixture of 1,1,4,4-tetraphenyl-2-butene and 1,1,4,4-tetraphenylbutane in the presence of glacial acetic acid. …

Π-Bond Strengths In Hp=Ph, H2p=P, Hp=Nh, And Hn=Nh, Michael W. Schmidt, Mark S. Gordon

Mark S. Gordon

The chemistry of the HP=PH 1r bond found in the recently isolated diphosphene compounds is considered in several ways. The P=P 1r-bond strength is found by computing the rotation barrier (36 kcalfmol) and is compared to that found for HN=NH (63.5 kcalfmol) and HP=NH (47 kcalfmol). The structure of the HPPH anion is presented. Various electronic states of the H2PP isomer are considered and compared to those of HPPH. Dipole moments and PP stretching frequencies are reported. The concerted hydrogenation of diphosphene is also examined.

Biomarker Geochemistry Of The Miocene Monterey Formation, West San Joaquin Basin, California: Implications For Petroleum Generation, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Much of the Miocene Monterey Formation of California is rich in biogenic sediment, especially organic matter and silica. Because of the geologic structure, the Monterey in the subsurface near Lost Hills in the San Joaquin Basin forms a natural laboratory for the study of the diagenetic responses of these materials. Rocks of similar age and lithology are buried to depths ranging between 500 and 3500 m, and are thus exposed to a temperature range of 45–130°C. The diagenetic progression of silica from opal-A to opal-CT to microquartz is well-documented in Monterey burial history studies. However, diagenetic indicators need to be …

A Study Of Dislocations In Crystals Using The Technique Of Chemical Etching, Ramona R. Dennis

Honors Theses

The beauty of many of the crystalline solids has attracted man's attention from the earliest times. Eventually the science of crystallography developed from studies of their shapes. The word crystal sterns from the Greek word "krystallos" meaning "clear ice." The word was first applied to describe the clear quartz crystals found in the Swiss Alps. The crystals were thought to be formed from water under conditions of extreme cold.

The earliest recorded crystallographic observation was in 1597 by Andreas Libarius. He noticed that crystals of different substances often have characteristic shapes. He suggested that the salts in mineral water could …

The Use Of Scheffe-Equivalent Equations To Predict Physical Properties Of Neoprene, Cheng Y. Loh

Retrospective Theses and Dissertations

The goal of this study is to find a more organized and directed approach to build models for mixture systems. An attempt is made to generate and then compare Scheffe (mixture) models with those generated by McGee using the ‘conventional’ method for neoprene data. The models are judged on their ability to predict physical properties of neoprene by comparing the following: predicted and actual values by inspection; the calculated % error of prediction; the squared multiple correlation coefficients; adjusted squared multiple correlation coefficients; the Fisher statistic and significance probability. Scheffe models do not have an intercept term and test statistics …

Ion Selective Electrodes Based On Aza- Substituted Crown Ethers, Lisa Ann Wellington

Retrospective Theses and Dissertations

A cation-responsive electrode system has been developed which incorporates aza-substituted crown ethers as ligands. In a novel application, uncomplexed crown ethers were used in the pelletized form for ionic transport. Electrodes have been produced which can be conditioned for a particular ion and following their use, be reconditioned and reused for other ions. Preparation method and lifetime studies are included.

The responses of two crown ethers with plasticizers were evaluated for thirteen representative cations. The concentration range covered in each evaluation was 1 x 10^-1 to 1 x 10^-7 M. For those ions exhibiting Nernstian or near-Nernstian response, …

Chemical Applications Of Scanning Tunneling Microscopy, Paul West, John Kramer, David V. Baxter, Robert J. Cave, John D. Baldeschwieler

All HMC Faculty Publications and Research

The development of a scanning tunneling microscope at the California Institute of Technology is well under way. Electron tunneling has been demonstrated, and preliminary surface images of gold films have been obtained. Additional instrumental development is required to achieve the atomic resolution which is required for the study of chemical processes on surfaces. A theoretical model is also being developed for the study of tunneling of electrons from the probe to surfaces with molecular species absorbed, and with atomic and molecular species intervening between the probe and the surface. These experimental tools and theoretical models, which are being developed concurrently, …

Mutual Orientation Effects On Electron-Transfer Reactions Between Porphyrins, Robert J. Cave, Paul Siders, R.A. Marcus

All HMC Faculty Publications and Research

Mutual orientation effects on the rate of nonadiabatic electron transfer between several diporphyrin pairs of experimental interest are examined. The electronic matrix element for electron transfer is calculated within a one-electron spheroidal model for a variety of states and orientations which are relevant to both biological and synthetic electron-transfer systems. Both the mutual orientation of the pairs and the nodal structure of the donor and acceptor orbitals can have large effects on calculated rates.

Electrochemistry Of Dihalogenated Nicotonic Acids In Aqueous And Aprotic Media, Ali U. Shaikh, Tappi A. Dixon, Lourie A. Battles, Frank L. Setliff

Journal of the Arkansas Academy of Science

The electrochemical reduction of several 2,5- and 5,6- dihalonicotinic acids have been studied in dimethyl sulfoxide as well as in aqueous buffers of different pH. The polarographic half-wave potentials for the reduction of these compounds in both media are reported here. The compounds appear to reduce at the carboxyl group. The presence of halogen atoms on the pyridine ring facilitates reduction.

Electrochemical Investigation Of The Effects Of Temperature, Ph, And Electrolyte On The Electron Transfer Reactions Of Cytochrome C, Kent Brian Koller

Theses and Dissertations

Spectroelectrochemical and electrochemical methods have been used to investigate the characteristics of heterogeneous electron transfer between cytochrome c and indium oxide electrodes. Direct electron transfer between cytochrome c and solid electrodes is of interest due to the interfacial character of electron transfer between the protein and its membrane-bound physiological redox partners. The conformation of ferricytochrome c is affected more by changes in temperature or pH than is its reduced form, ferrocytochrome c. This difference in conformational stability is attributed to the +1 charge of the heme in ferricytochrome c that is largely embedded in the hydrophobic interior of the enzyme. …

The Association Of Nadph With The Guanine Nucleotide Exchange Factor From Rabbit Reticulocytes: A Role Of Pyridine Dinucleotides In Eukaryotic Polypeptide Chain Initiation, Jaydev N. Dholakia, Timothy C. Muesser, Charles L. Woodley, Lawrence J. Parkhurst, Albert J. Wahba

Chemistry Department: Faculty Publications

The guanine nucleotide exchange factor (GEF) was purified to apparent homogeneity from postribosomal supernatants of rabbit reticulocytes by chromatography on DEAE-celiulose and phosphocellulose, fractionation by glycerol gradients, and chromatography on Mono S and Mono Q (Pharmacia). At the Mono S step GEF is isolated as a complex with the eukaryotic polypeptide chain initiation factor 2 (eIF-2) and is separated from this factor by column chromatography on Mono Q. An emission spectrum characteristic of a reduced pyridine dinucleotide was observed when GEF was subjected to fluorescence analysis. By both coupled enzymatic analysis and chromatography on reverse-phase or Mono Q columns, the …

A Preliminary Study On The Separation Of Bovine Plasma Albumin-Copper Ion Dimer And Trimer Reaction Products By Ion-Exchange Chromatography, James T. Miller

Honors Theses

When bovine plasma albumin is in the presence of copper metal ions at pH values below the isoelectric point, a dimerization reaction takes place between the protein molecules. The kinetics of this reaction have been previously studied by using light scattering techniques. These techniques involve monitoring the amount of light scattered as the dimerization reaction proceeds. As the amount of dimer present increases, more light is scattered due to increased molecular size in the solution. Accurate calculations of the rate of this reaction depend upon knowing the ratio of dimer to monomer concentrations at any given time. Unfortunately, evidence has …

Plasma‐Substrate Interaction: Effect Of Volatile Oligomers In Silicone Rubber On Plasma Polymerization Of Fluorine‐Containing Monomers, Y. ‐S Yeh, H. Yasuda

Chemistry Faculty Research & Creative Works

The cause of the conspicuous Si content consistently observed on plasma polymers deposited on silicone rubber was investigated in this study. Plasma polymers of tetrafluoroethylene and of hexafluoroethane were deposited on the inside surface of Silastic tubings with and without oligomers by using a semicontinuous plasma polymerization reactor. This tube coating reactor is unique in the sense that the only surface which interacts with the plasma is the substrate surface (i.e., inside wall of tubing) and that plasma polymerization occurs in a very small volume of 3.3‐mm‐I.D. and 2‐cm‐long section of tubing at any given time. These two factors render …