Digital Commons Network^™

Electrochemical Cleavage Of Phenylsulfones, Joseph E. Lohr

Master's Theses

No abstract provided.

Modeling The Reaction Mechanism Of Poly(Vinyl Chloride) During Pyrolytic Decomposition, Brian Scott Glaser

Dissertations and Theses @ UNI

With the advent of new polymer technology, many different types of plastics and plastic additives are being produced. These new types of additives and plastics make the recycling of polymers increasingly difficult. In 1994 approximately 75 billion pounds of plastics were produced and over 40 million pounds were vinyl type plastics (thermoplastic). Although, thermoplastic can be reground and remolded into like products, of the 40 million pounds of thermoplastic, only 5 million pounds were recycled. In contrast, thermoset plastic is another type of plastic that not easily recycled through traditional methods. Thermoset plastic consists of varying plastic resins that are …

Selective Production Of Limonene During Pyrolytic Decomposition Of Polyisoprene, James Edward Haworth

Dissertations and Theses @ UNI

Recycling of scrap tires has become an increasingly important environmental issue. In the United States alone, scrap tires generated has reached an amount of 2 million tons per year. Although these tires contain many useful and valuable products, approximately 70 % are disposed of in landfill sites, open dumps, or are stockpiled. Pyrolysis permits a method of separating the hydrocarbon oils, activated carbon, and high grade steel. Although current methods of pyrolysis permit the production of hydrocarbons such as limonene, the low yield of valuable compounds limits the economics of the process. Modeling the chemistry of pyrolysis using Fourier transform …

Photophysics And Photochemistry Of Carbocations, Maria R. Valentino

Dissertations

No abstract provided.

Characterization Of Ground And Excited Electronic State Deprotonation Energies Of Systems Containing Double Bonds Using Natural Bond Orbital Analysis, J. K. Badenhoop, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Natural bond orbital analysis is applied to the ground and excited states of a set of neutral, cationic, and anionic doubly bonded species H_nC=XH_n (X=C, N, O) isoelectronic with ethylene. The character of the excitation is correlated with calculated charge shifts and geometry changes upon relaxation. For these planar molecules, depopulation of the π bond or population of the π∗ antibond causes an out‐of‐plane twist or pyramidalization upon relaxation correlated to the amount of charge shift. These nonplanar distortions generally lower the energy more than changes in bond lengths and angles. Population of a σ_XH^{∗ …}

Electrodeposition Of Copper Indium Sulfide Films From Organic Solutions, Arif Raza, Robert Engelken, Brandon Kemp, Imran Khan, Wasim Aleem, Chris Barber

Journal of the Arkansas Academy of Science

We report on organic solutions ofCuCl 2 ,InClg, and elemental sulfur for electrodepositing CuIn x Sv films. CuInS 2 and CuInSe 2 are promising solar cellmaterials; our work on CuInSg prefaces planned work on plating CuInSe 2 from nonaqueous solvents. Two promising solvent systems are (1) mixed propylcne carbonate and water and (2) mixed ethylene glycol, propionic acid, and water (Engelken et al., 1988). Gray-brown films ofCuInx Sy (nominally GuInS2 ) have been plated from both baths. Major problems include (1) reduction ofCu+2 to Cu and Cu x S by the solvent at high temperatures (T>l()0°C), hence depleting Cu+2,(2) …

1,1′-Diketone And 1,1′-Dinitrile Derivatives Of 2,2′-Biimidazole, Paula M. Secondo, William M. Barnett, Harvest L. Collier, Russell G. Baughman

Chemistry Faculty Research & Creative Works

The crystal structures of 2,2′-biimidazole-1,1′-diacetone, C₁₂H₁₄N₄O₂, and 2,2′-biimidazole-1,1′-diacetonitrile, C₁₀H₈N₆, have been determined. Both molecules crystallize with coplanar rings having substituents in a trans disposition with a center of inversion located midway between the bridging C atoms.

Rotating Disk Ion Selective Electrodes, John Cassidy, David Mullen, Karen Casey, Patrick Cullen

Articles

A simulation was undertaken to predict the transient potential response following a concentration step at a rotating disk electrode comprised of an ion selective layer. A basis for this simulation was that the potential response would be independent of rotation rate since the diffusion layer is larger than the double layer at the electrode. In practice it was found that the potential response does vary with rotation rate. The response was such that the apparent concentration of the analyte in solution decreased with increased rotation rate. The reason for this behavior is due to the disruption of the double layer …

The Effect Of Atomic Hydrogen On The Growth Of Gallium Nitride By Molecular Beam Epitaxy, Zhonghai Yu, S. L. Buczkowski, N. C. Giles, T. H. Myers, Michelle Richards-Babb

Faculty & Staff Scholarship

GaN was grown by molecular beam epitaxy using an rf plasma source. Growth under gallium‐rich conditions at 730 °C was required to produce high quality layers as indicated by photoluminescence, Hall effect, atomic force microscopy, and x‐ray diffraction measurements. Atomic hydrogen has a significant effect for Ga‐rich growth, increasing growth rates by as much as a factor of 2.

Valence-Band Electronic Structure Of Mos2 And Cs/Mos2(0002) Studied By Angle-Resolved X-Ray Photoemission Spectroscopy, Michelle Richards-Babb

Faculty & Staff Scholarship

The angle dependence of the valence-band photoemission from the trigonal prismatic layered MoS2shows both the forward-scattering features normally observed in core-level photoelectron diffraction and, in addition, the initial-state orbital character associated with partially occupied, nonbonding MoIV(4dz2+4dx2−y2 +4dxy) orbitals near the top of the valence band. The difference in forward scattering between the Mo and S emitters is also used to assess relative contributions from the Mo and S atomic orbitals at specific binding energies within the valence band. Deposition of cesium (0.23 ML Cs with 1 ML equal to the Cs saturation coverage) onto the basal plane of MoS2 …

Acidic Marine Biotoxins Implicated In Diarrhetic Shellfish Poisoning, Eoin P. Carmody

Theses

An okadaic acid (OA) etiology has been demonstrated for most outbreaks of diarrhetic shellfish poisoning (DSP) in Europe, An isomer of OA, dinophysistoxin-2 (DTX-2), has recently been found in Irish waters and, in 1991 and 1994, was the major toxin during prolonged infestations in cultivated mussels (Mytilus edulis) along the south-west coast of Ireland.

The OA class of DSP toxins have been analysed by HPLC using modified versions of three established fluorescent derivatisation methods. A ‘dual tag’ method for the confirmation of specific toxins has also been developed.

Survey work has been carried out over the past four years on …

Structures, Thermochemistry, And Electron Affinities Of The Pfn And Pfn- Series, N=1-6, Gregory S. Tschumper, Justin T. Fermann, Henry F. Schaefer

Chemistry Faculty Research & Creative Works

A quantum mechanical study of the phosphorus fluorides and their singly charged anions was carried out. A range of density functional methods was used. Optimized geometries, adiabatic electron affinities, vertical electron affinities, vertical detachment energies, and stabilities toward the loss of a single fluorine atom or fluorine ion are reported. These properties were evaluated exhaustively using four exchange-correlation functionals: Becke's 1988 exchange functional with the correlation functional of Lee, Yang, and Parr, Becke's 1988 exchange functional with the 1986 correlation functional of Perdew, Becke's three parameter Hartree-Fock/density functional hybrid exchange functional with the correlation functional of Lee, Yang, and Parr …

1,1′-Diacetyl-2,2′-Biimidazole, Paula M. Secondo, Colin A. Hester, Harvest L. Collier, Russell G. Baughman, A. W. Cordes

Chemistry Faculty Research & Creative Works

A crystallographic twofold rotation axis passes through the C-C bond joining the imidazole rings of the title compound, C₁₀H₁₀N₄O₂. the molecule crystallizes in a cis disposition. the planar acetyl group is twisted by 5.0 (3)° with respect to the imidazole ring and the two imidazole rings are tilted by 60.53 (5)° in relation to one another.

Nucleation And Growth Of Gan On Sapphire By Mbe, Steven Buczkowski

Graduate Theses, Dissertations, and Problem Reports (ETD)

GaN was grown by molecular beam epitaxy in an effort to determine nucleation and growth conditions which lead to high quality, single-crystal films. Atomic force microscopy (AFM) was used to show that growth under Ga-rich conditions promotes the nucleation of films with large nucleation domains leading to a lower density of intrinsic defects related to domain boundaries. These conditions are also shown to promote a 2-D growth mode resulting in films with a high degree of nucleation domain coalescence and surface roughnesses below 2 nm. Addition of atomic hydrogen, using a thermally-cracked source, is shown to increase the growth rate …

Highly Reactive Zerovalent Metals From Metal Cyanides, Reuben D. Rieke

Department of Chemistry: Faculty Publications

Novel zerovalent metal species and organometallic reagents are disclosed. The zerovalent metal species are directly produced by reaction of a reducing agent on a metal cyanide salt. Preferably, the zerovalent metal species are directly produced by reaction of an alkali metal reducing agent with a metal cyanide salt. The organometallic reagent results from the reaction of the zerovalent metal species and an organic compound having one or more stable anionic leaving groups.

Interactions Among The Stationary Phase, The Mobile Phase, And The Solute In Liquid Chromatographic Systems, Zengbiao Li

Theses and Dissertations

Interactions among the stationary phase, the mobile phase, and the solute in liquid chromatography' have been studied. A strong dependence of the stationary phase properties on the mobile phase composition may arise from their interactions.

The solvatochromic comparison method, which can give estimates for the dipolarity-polarizability, the hydrogen-bonding acidity, and the hydrogen-bonding basicity of a solvent, represented by the solvatochromic parameters π⁺, α and β, respectively, was used to study the surface properties of silica in the presence of n-hexane-chloroform or n-hexane-ethyl ether mixtures. A high dipolarity- polarizability, a high hydrogen-bonding acidity, and a low hydrogen-bonding basicity …

Galvanostatic Pulse And Pulse Reverse Plating Of Zinc-Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko N Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, K-M. Yin

Faculty Publications

Galvanostatic pulse and pulse reverse techniques have been used to study the plating of zinc–nickel alloys in the presence of nonyl phenyl polyethylene oxide. The effects of average current density, rotation speed of disc electrode and the presence of nonyl phenyl polyethylene oxide in the electrolyte on deposition of zinc–nickel alloys were evaluated. Zinc–nickel plating bath solution chemistry was studied by determining the equilibrium concentrations at various pH levels. It was found that the alloy composition was determined by solution equilibria, mass transfer of the electroactive species within the diffusion layer and by the surface coverage of nonyl phenyl polyethylene …

Alternatives To Nitroprusside As Hypotensive Agents, Timothy Casey Mccullough

Honors Theses

The drug sodium pentacyanonitrosylferrate(2-)dihydrate, more commonly known as nitroprusside or nipride (Fig. 1), is a common vasodilating agent given clinically to patients with hypertension.12.22 Nitroprusside is effective in emergency rooms as it quickly reduces high blood pressure, but dosages are limited because of fear that cyanide could be released also. Nitroprusside is effective because the vasodilating agent nitric oxide, NO, is released. Nitric oxide is also recognized as an important biochemical messenger molecule.22 Our research involves a search for different species that could introduce nitric oxide into the body without cyanide. Transition metal complexes involving ruthenium, iron, and cobalt that …

Synthesis And Characterization Of Bifunctional Silica Gel Surfaces, Alufelwi Maxwell Tshavhungwe

Masters Theses

Bifunctional silica surfaces consisting of various combinations of the following organofunctional silanes were synthesized and characterized using diffuse reflectance infrared spectroscopy: hexamethyldisilazane, octyldimethylmethoxysilane, phenyldimethylethoxysilane, (3-aminopropyl) -dimethylmethoxysilane, ( 2 - cyanoethyl)triethoxysilane, and trimethylmethoxysilane.

The relative amounts of organosilanes loaded on a silica surface were obtained from band area ratios of IR bands. Ratios of organosilanes bonded to the same silica surface were calculated from normalized band areas of the isolated silanol peak. In reactions in which surface coverage was incomplete, the relative amount of inaccessible silanols was determined from the band area ratio of the silanol peak. Comparisons of organosilane loading …

Mechanistic Studies On Malate Dehydrogenase From Escherichia Coli, S. Kirk Wright

Masters Theses

Kinetic studies and chemical modification studies were performed on malate dehydrogenase from Escherichia coli (eMDH). Chemical modification studies using diethylpyrocarbonate and iodoacetic acid, along with log V/K profiles indicate that one ionizing group with a pK_a between 7.9 and 8.5 acts as a general acid/base in the catalytic mechanism. Log V profiles suggest that malate binds to the correctly protonated form of the enzyme. These results imply that a histidine residue is required for catalysis.

A primary deuterium kinetic isotope effect of 1.43 (±0.14) was observed on V/K using malate-2-d, while no isotope effect was measured on V_{max …}

Characterization Of The Structural And Electronic Properties Of Spin-Coupled Dinuclear Copper(Ii) Centers By Proton Nmr Spectroscopy, Julie M. Brink, Rachel A. Rose, Richard C. Holz

Chemistry Faculty Research and Publications

The ¹H NMR spectra of a series of well-characterized μ-phenoxo and μ-alkoxo spin-coupled dicopper(II) complexes have been investigated. The complexes studied were [Cu₂(BPMP)(OH)]²⁺ (1) (BPMP = 2,6-bis[[bis(2-pyridylmethyl)amino]methyl]-4-methylphenol), [Cu₂(CH₃HXTA)(OH)]^2- (2) (CH₃HXTA = N,N ‘-(2-hydroxy-5-methyl-1,3-xylylene)bis(N-carboxymethylglycine), [Cu₂(m-XYL)(OH)]²⁺ (3) (m-XYL = 2,6-bis[[bis(2-pyridylethyl)amino]methyl]phenol), and [Cu₂(TBHP)(OAc)]²⁺ (4) (TBHP = N,N,N ‘,N  ‘-tetrakis[(2-benzimidazolyl)methyl]-2-hydroxy-1,3-diaminopropane). The magnetic interactions of these complexes range from strongly antiferromagnetically to weakly ferromagnetically coupled. Both …

The Development, Molecular Characterization And Application Of A Model Stratum Corneum Lipid System, Rita M. Hatfield

Dissertations

No abstract provided.

Molecular Studies Of Human Erythrocyte Spectrin: Head To-Head Interactions, Nasser Qtaishat

Dissertations

No abstract provided.

Development Of A Unique Photothermal Interferometer, Michael Henry

Dissertations

No abstract provided.

Na+-H+ Exchange And Na+-Li+ Exchange In Human Erythrocytes: An Nmr Investigation, Yuling Chi

Dissertations

No abstract provided.

Bromobis(Diethyldithiocarbamato)(4-Methoxyphenyl)Tellurium(Iv), Steinar Husebye, Thoralf Engebretsen, Martin D. Rudd, Sergey V. Lindeman

Chemistry Faculty Research and Publications

The crystals of the Te^IV complex p-CH₃OC₆H₄Te(Et₂NCS₂)₂Br are isomorphous with those of the the iodine and mixed iodine/bromine analogues previously investigated. The structure is pentagonal bipyramidal at the Te atom with four S atoms [Te-S 2.618-2.721 (1) Å] and the Br atom [Te-Br 2.943 (1) Å] in equatorial positions. The p-methoxyphenyl group is axial [Te-C 2.147 (3) Å]. The second axial position is approached by a Br atom of a centrosymmetrically related complex [TeBr 3.423 (1) Å, C-TeBr 173.1 (1)°] so that the molecules are …

Bromobis(Dimethyldithiocarbamato)(4-Methoxyphenyl)Tellurium(Iv) Dichloromethane Hemisolvate, P-Meoc6H4Te(Me2Ncs2)2Br.0.5ch2Cl2, Steinar Husebye, Steffen Kudis, Sergey V. Lindeman

Chemistry Faculty Research and Publications

The structure of the title Te^IV complex, C₁₃H₁₉BrN₂OS₄Te.045(CH₂Cl₂), is pentagonal bipyramidal with four S atoms [Te-S 2.623 (1)-2.717 (1) Å] and the Br atom [Te-Br 2.890 (1) Å] in equatorial positions. The p-methoxyphenyl group is axial [Te-C 2.145 (3) Å] and the second axial position seems to be occupied by a dithiocarbamate group of a neighbouring molecule acting as a -ligand [TeC 3.751 (3) Å, C-TeC 170.2 (1)°], so that molecules are joined into centrosymmetric associations by this secondary coordination.

A New Prodelphinine Type Alkaloid From, Ali H. Meri̇çli̇, Filiz Meri̇çli̇, Hans Becker, Ayhan Ulubelen

Turkish Journal of Chemistry

In a previous study we have isolated five known and a new diterpenoid alkaloids from the aerial parts of {\it Aconitum nasutum}. In the present paper the structure of a new and rather rare diterpenoid alkaloid aconasutine was determined by using 1D and 2D NMR techniques.

Transmission Electron Microscopy (Tem) Study Of Polycrystalline Ru:Ag/Alumina Supported Catalyst System., S. Tajammul Hussain

Turkish Journal of Chemistry

Transmission Electron Microscopy (TEM) was used to characterize bimetallic Ru/Ag Catalyst samples dispersed on a high surface area Alumina support. The addition of Ag increases the metal dispersion but no consistent trend is observed. Ag forms crystallites of various shape and sizes, some of them are present in the close vicinity of Ru but not forming Ru:Ag bimetallics. A part of Ag crystallites cover the Ru surface hence blocking Ru emission. These irregular shaped crystallites are possibly responsible for the increase in metal dispersion. Particles below 2.5 nm were Ag particles, between 2.5 to 5.0 nm were Ru:Ag mixed crystallites …

A Comparison Of Normal(-Cn) And Reversed (C-18) Phase Chromatographic Behaviour Of Polycyclic Aromatic Hydrocarbons, S. Fatma Aygün, Mustafa Özci̇mder

Turkish Journal of Chemistry

Because of the well-known carcinogenic and mutagenic character of polycyclic aromatic hydrocarbons (PAHs), still new methods have been tried for their qualitative and quantitative determinations in various smaples. Liquid chromatography is one of the most widely applied techniques. In this study we used liquid chromatography in normal and reversed phase modes for the determinations of PAHs and tried to find a relation between the retention times and various parameters, such as molecular shape, water solubility and number of carbon atoms.