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Reactions Of Group 14-Halide Bonds With Dimethylplatinum(Ii) Complexes, Christopher James Levy
Reactions Of Group 14-Halide Bonds With Dimethylplatinum(Ii) Complexes, Christopher James Levy
Digitized Theses
The oxidative addition of E-X bonds (E = Si, Ge, Sn; X = halide) to {dollar}\lbrack\rm PtMe\sb2(diimine)\rbrack{dollar} yields a number of new Pt(IV) complexes containing Pt-E linkages. The complexes {dollar}\lbrack\rm PtXMe\sb2(Me\sb3Si)(diimine)\rbrack{dollar} (X = Br, I) are the first well-characterized examples of Pt(IV)-silyl species. The X-ray structure of {dollar}\lbrack\rm PtIMe\sb2(Me\sb3Si)(bipy)\rbrack{dollar} shows the longest single Pt-I bond reported, and demonstrates the very strong trans influence of the {dollar}\rm Me\sb3Si{dollar} ligand. The X-ray structure of {dollar}\lbrack\rm PtIMe\sb2(Me\sb3Sn)(bipy{dollar}-{dollar}\sp{lcub}t{rcub}\rm bu\sb2)\rbrack{lcub}\cdot{rcub}0.5Me\sb3SnI{lcub}\cdot{rcub}CH\sb2Cl\sb2{dollar} reveals a five coordinate {dollar}\rm Me\sb3SnI{dollar} unit with a novel {dollar}\rm I\cdot\cdot\cdot Sn{dollar}-I interaction.;Many of the Pt-Sn systems studied involve the rapid reversible oxidative addition …
Electronic Structure Of Gold-Silver Bimetallics, Arthur Bzowski
Electronic Structure Of Gold-Silver Bimetallics, Arthur Bzowski
Digitized Theses
The main thrust of this thesis concerns studies of the electronic structure of Au-Ag bimetallic materials, both in bulk alloys and in metallic overlayers on Ru(001). First, a series of bulk Au-Ag alloys: Au{dollar}\rm\sb{lcub}0.75{rcub}Ag\sb{lcub}0.25{rcub},\ Au\sb{lcub}0.67{rcub}Ag\sb{lcub}0.33{rcub},\ Au\sb{lcub}0.50{rcub}Ag\sb{lcub}0.50{rcub},\ Au\sb{lcub}0.25{rcub}Ag\sb{lcub}0.95{rcub},\ and\ Au\sb{lcub}0.05{rcub}Ag\sb{lcub}0.95{rcub}{dollar} has been studied using X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and X-ray absorption near-edge structure (XANES). It is found that in alloys with {dollar}>{dollar}50% atomic Au, the alloy d-band width narrows little relative to that of pure Au; however at 50% (and less) atomic Au concentration, the widths of the Au-Ag alloy d-band are much smaller than that …
Homo- And Hetero-Nuclear Clusters Of Platinum And Rhenium, Leijun Hao
Homo- And Hetero-Nuclear Clusters Of Platinum And Rhenium, Leijun Hao
Digitized Theses
ABSTRACT HAS BEEN ARCHIVED 07/22/97;
Intramolecular Aldol Condensation Reactions And Transacetalization Equilibria, Junan Guo
Intramolecular Aldol Condensation Reactions And Transacetalization Equilibria, Junan Guo
Digitized Theses
Part I. Intramolecular aldol condensation reactions. The detailed kinetics and equilibrium for the intramolecular aldol condensation reaction of 2,5-hexanedione, 2, 6-heptanedione, 1-phenyl-1, 5-hexanedione and 5-oxohexanal were studied and correlated in terms of Marcus theory. All the reactions, with the readily explained exception of the intramolecular aldol addition of 5-oxohexanal, gave us approximately constant intrinsic barriers: 14.49 {dollar}\pm{dollar} 0.82 kcal/mol for the intramolecular aldol addition step and 13.99 {dollar}\pm{dollar} 0.74 kcal/mol for the subsequent dehydration step, which are also in excellent agreement with the intrinsic barriers found for intermolecular aldol condensation reactions.{dollar}\sp{lcub}16{rcub}{dollar} This means that Marcus theory is applicable to intramolecular …
The Growth And Magnetic Properties Of Metal Overlayer Systems: Palladium/Copper(100), Iron/Aluminum(100) And Iron/Sulfur/Gallium Arsenide(100), Geoffrey William Anderson
The Growth And Magnetic Properties Of Metal Overlayer Systems: Palladium/Copper(100), Iron/Aluminum(100) And Iron/Sulfur/Gallium Arsenide(100), Geoffrey William Anderson
Digitized Theses
Epitaxial growth of a metal overlayer on an appropriate substrate can be utilized to create systems which exhibit unique chemical and magnetic properties. This thesis will outline the investigation of three metal overlayer systems: Pd/Cu(100), Fe/Al(100) and Fe/S/GaAs(100). In the Pd/Cu(100) system the growth and evolution of defects were examined using re-emitted positron spectroscopy. Two changes in growth mode were observed: at 0.5 monolayer (representing the completion of the first alloy layer) and 1 monolayer Pd coverages (representing the start of bulk Pd growth). The bulk Pd film was observed to contain 1% vacancy-type defects. In the Fe/Al(100) system the …
Marcus Theory Applied To Acetal Cleavage And Aldol Reactions, Jonathan Arthur Barker
Marcus Theory Applied To Acetal Cleavage And Aldol Reactions, Jonathan Arthur Barker
Digitized Theses
The acid catalyzed and uncatalyzed hydrolysis of the acetal 2,2-dimethoxypropane (DMOP) and the ortho ester trimethylorthoacetate (TMOA) have been studied in aqueous solution at 25{dollar}\sp\circ{dollar}C. Theoretical and experimental evidence have been found for a base catalyzed E2 mechanism of DMOP hydrolysis proceeding through an enol ether. This mechanism is neither predicted nor observed for TMOA hydrolysis. The specific acid catalyzed and uncatalyzed rate constants for hydrolysis are for DMOP k{dollar}\rm\sb{lcub}H+{rcub}=(2.5\pm0.3)\times10\sp3\ M\sp{lcub}-1{rcub}s\sp{lcub}-1{rcub},\ k\sb w=(3.6\pm0.2)\times10\sp{lcub}-8{rcub}\ s\sp{lcub}-1{rcub},\ k\sb{lcub}OH-,E2{rcub}=(2.8\pm0.4)\times10\sp{lcub}-8{rcub}\ M\sp{lcub}-1{rcub}s\sp{lcub}-1{rcub},\ and\ for\ TMOA\ k\sb{lcub}H+{rcub}=(2.05\pm0.12)\times10\sp4\ M\sp{lcub}-1{rcub}s\sp{lcub}-1{rcub},\ k\sb w=(3.7\pm0.3)\times10\sp{lcub}-6{rcub}\ s\sp{lcub}-1{rcub}.{dollar} General acid catalysis was observed for TMOA with four general acids. From the Bronsted plot, {dollar}\alpha=0.76\pm0.05.{dollar} …
New Porphyrins As Semiconductor Photosensitizers: Molecular Engineering For Solar Energy Conversion, Biswajit Choudhury
New Porphyrins As Semiconductor Photosensitizers: Molecular Engineering For Solar Energy Conversion, Biswajit Choudhury
Digitized Theses
The organizing properties of surface-active porphyrins can be employed to obtain large area, ordered arrays of electroactive organic molecules. The design, synthesis, and characterization of two families of surface active porphyrins, possessing variety of side chains, is described. These materials are solid at room temperature and exhibit well-behaved monomolecular films at an air-water interface.;In compressed monolayers, the porphyrin ring appears to be oriented so that the plane of the ring is perpendicular to the surface. The surface pressure-molecular area isotherms change with the length and nature of the side chains in a manner which suggests that a long side chain …
Intermolecular Forces And Statistical Mechanics Of Liquids, Maria Koulis
Intermolecular Forces And Statistical Mechanics Of Liquids, Maria Koulis
Digitized Theses
This research is involved with the construction of potential energy models for the interaction of closed shell atoms and/or molecules and with the study of the thermodynamic properties of pure liquids and liquid mixtures, through the use of statistical mechanical perturbation theory.;The previously developed Exchange-Coulomb potential energy model for the interaction of closed shell atoms is modified to correct its unphysical behaviour for small interspecies distances and so that it is applicable for interactions involving molecules. The new potential energy model is based on using the Heitler-London energy to represent the repulsive part, and a damped and overall corrected dispersion …
On The Palmitoylation Of Surfactant-Associated Protein C, Riad Qanbar
On The Palmitoylation Of Surfactant-Associated Protein C, Riad Qanbar
Digitized Theses
Surfactant-associated protein C (SP-C) contributes to the surface active properties of pulmonary surfactant. Processed from a 21 kDa precursor, the mature form of SP-C is 34-35 amino acids in length. Both the precursor and the mature protein are modified by palmitoylation. Due to its small size and extreme hydrophobicity, SP-C has been difficult to isolate, detect and study. Using molecular exclusion chromatography, SP-C was isolated from calf lung surfactant extract, characterized by partial sequencing, amino acid analysis, tricine polyacrylamide gel electrophoresis, and absence of immune-reactivity with antibodies raised against surfactant-associated protein B (SP-B). A method was developed to label, detect …
Circular Dichroism And Luminescence Studies Of Copper Binding To Metallothionein, Paul Anthony Presta
Circular Dichroism And Luminescence Studies Of Copper Binding To Metallothionein, Paul Anthony Presta
Digitized Theses
The metallothioneins (MT) are a class of low molecular weight, cysteine rich proteins found in almost all living things. The high sulfhydryl content imparts to these proteins the unique ability to bind a wide range of metals. The metallothioneins have been implicated in the storage and transport of essential metals, such as zinc and copper, and in the detoxification of toxic metals, such as cadmium. However, the exact physiological functions of these proteins remain a matter of speculation. In particular, little is known about the interactions of copper with MT. In this thesis, the structural and mechanistic properties of copper …
A New Photocatalytic Reactor For The Photodegradation Of Organic Contaminants In Water, Julio E. Valladares
A New Photocatalytic Reactor For The Photodegradation Of Organic Contaminants In Water, Julio E. Valladares
Digitized Theses
The {dollar}\rm TiO\sb2{dollar} photocatalytic degradation and mineralization of organic pollutants in water has been broadly demonstrated at the laboratory level for a wide number of organic pollutants. However, there are still some problems that need to be addressed in order to make this technology more practical. The design of heterogeneous photocatalytic reactor systems, still in the infancy of their development, is facing different problems such as light scattering, oxygen starving, particle separation and mass transfer. Additionally, there have also been a lack of a general method to evaluate the performance of the different reactor systems.;The present work addresses these problems …
Part I 2+2 Photocycloaddition Reactions Of N-Acylindoles With Alkenes Part Ii Photochemical Reactions In Supercritical Carbon Dioxide, Islet Brian Des
Part I 2+2 Photocycloaddition Reactions Of N-Acylindoles With Alkenes Part Ii Photochemical Reactions In Supercritical Carbon Dioxide, Islet Brian Des
Digitized Theses
Part I. Irradiation of 2-methyl, 3-methyl and 2,3-dimethyl substituted N-acylindoles in the presence of alkenes results in the formation of {dollar}\lbrack{dollar}2+2{dollar}\rbrack{dollar} cycloadducts which contain cyclobutane rings. The regiochemistry of the major product in all cases examined was found to be the result of initial bond formation from the 2-position of the N-acylindole to the less substituted terminus of the alkene. The quantum yield of cycloadduct formation was determined for the photocycloaddition reaction of the N-benzoyl derivatives with methyl acrylate and for the N-carboethoxy derivatives with 2-methylpropene. The reaction efficiency was found to be dependent on two factors. The first of …
Spectroscopic Properties Of Copper Binding To The Protein Metallothionein, Anna Rae Green
Spectroscopic Properties Of Copper Binding To The Protein Metallothionein, Anna Rae Green
Digitized Theses
Metallothionein (MT) is a low molecular weight protein found in the kidneys and livers of all mammals. Twenty of its 61 or 62 amino acid residues are cysteinyl residues, allowing the protein to act as an impressive chelating agent. Although it has been well established that mammalian MT binds seven M(II) (M = Cd(II), Zn(II), Hg(II)) ions tetrahedrally in two metal-thiolate clusters of the form M{dollar}\sb4{dollar}(S{dollar}\rm\sb{lcub}cys{rcub})\sb{lcub}11{rcub},{dollar} (the {dollar}\alpha{dollar} domain) and {dollar}\rm M\sb3(S\sb{lcub}cys{rcub})\sb9,{dollar} (the {dollar}\beta{dollar} domain), little is known about the structure of copper-containing metallothioneins. In this thesis, absorption, circular dichroism (CD) and emission spectroscopies and excited state lifetime data are …
Structural Studies On Silver(I) Metallothionein, Ziqi Gui
Structural Studies On Silver(I) Metallothionein, Ziqi Gui
Digitized Theses
Metallothioneins (MT) are a class of low molecular weight, cysteine rich proteins in almost all living things. These proteins have been found to bind a wide range of metals both in vivo and in vitro due to the unusually high cysteinyl sulfur content. The metallothioneins are believed to possess the ability to store and transport essential metals, such as Zn(II) and Cu(I), and also to detoxify toxic metals, such as Cd(II) and Hg(II). However, the precise physiological functions of these proteins still remain unclear to date. As silver(I)-metallothioneins have shown different stoichiometric ratios of Ag:MT from Zn(II)- and Cd(II)-metallothioneins in …
High Resolution And Wideline Nmr Studies Of Membrane Associated Molecules Involved In Signal Transduction, Alan Cavell Rigy
High Resolution And Wideline Nmr Studies Of Membrane Associated Molecules Involved In Signal Transduction, Alan Cavell Rigy
Digitized Theses
The primary focus of our investigations were centered around understanding the biochemical basis of the early events involved in signal transduction. Our work has involved two novel systems: (1) sphingolipid metabolites and (2) a synthetic peptide representing the transmembrane region of the human epidermal growth factor receptor (hEGFR).;Sphingolipid metabolites have emerged as physical modulators of many signalling pathways, including cell growth regulation, and signal transduction. N,N-({dollar}\sp2{dollar}H{dollar}\sb6{dollar}) -dimethylsphingosine and ({dollar}\sp2{dollar}H{dollar}\sb4{dollar}) -lysogalactosyl ceramide were produced by partial synthesis and studied via wideline {dollar}\sp2{dollar}H NMR, as a function of pH. Spectra of ({dollar}\sp2{dollar}H{dollar}\sb6{dollar}) -dimethylsphingosine identified that the molecule's orientation and behaviour are largely …
Variable Energy Photoelectron Spectra Of Organometallic Compounds Of The Late Transition Metals, Xiaorong Li
Variable Energy Photoelectron Spectra Of Organometallic Compounds Of The Late Transition Metals, Xiaorong Li
Digitized Theses
This thesis describes photoelectron spectroscopy (PES) studies with variable photon energy for organometallic molecules of late transition metals, including cobalt, rhodium, iridium, nickel, palladium, platinum, copper, and silver. Synchrotron radiation (in the range of 30 to 170 eV photon energy) and traditional helium I (21.22 eV) and helium II (40.81 eV) light sources were used in this study, with the aid of theoretical ground state and cross section calculations by using X{dollar}\alpha{dollar}-SW and Gelius model methods. With these techniques the variation of band intensities as a function of photon energy were investigated. The very different intensity features between metal d …