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Part I 2+2 Photocycloaddition Reactions Of Cyclic Enones With Alkenes Part Ii Photochemical Reactions In Supercritical Fluids, David Andrew
Part I 2+2 Photocycloaddition Reactions Of Cyclic Enones With Alkenes Part Ii Photochemical Reactions In Supercritical Fluids, David Andrew
Digitized Theses
Part I. The irradiation of 2-cyclopentenone with ultraviolet light in the presence of alkenes results in the formation of 2+2 cycloadducts which contain cyclobutane rings. According to the Corey-de Mayo mechanism, the regiochemistry of the cyclobutane products is controlled by the relative orientation of the alkene and the cyclic enone in an exciplex intermediate which precedes the formation 1,4-biradicals along the reaction pathway.;The biradicals formed in the photocycloaddition reactions of 2-cyclopentenone, 2-methyl-2-cyclopentenone and 3-methyl-2-cyclopentenone with various alkenes were trapped as stable compounds by H{dollar}\sb2{dollar}Se. By determining the structures and relative yields of the trapped products, the structures and relative rates …
Glycosylation Of Peanut (Arachis Hypogaea L) Peroxidases, Lianglu Wan
Glycosylation Of Peanut (Arachis Hypogaea L) Peroxidases, Lianglu Wan
Digitized Theses
The cationic (C.PRX) and the anionic (A.PRX) peroxidase isozymes secreted into the medium of cell cultures are both 20% glycosylated proteins. They are stable and occur in high amounts (C.PRX, 5 mg and A.PRX 0.5 mg per litre of spent culture medium), and so provide an ideal system for the study of the effect of glycosylation on the structure and function of glycoproteins.;A novel method to detect glycoproteins and glycopeptides is proposed using periodic-acid Schiff's reagent dot-blotting assay on nitrocellulose membrane. At least 0.1 ug of glycan can be detected within 40 minutes.;The amino acid sequence of C.PRX is confirmed …
High Resolution Gas Phase Studies Of Inner-Shell Excitation And Decay, Zhifeng Liu
High Resolution Gas Phase Studies Of Inner-Shell Excitation And Decay, Zhifeng Liu
Digitized Theses
High resolution {dollar}L\sb{lcub}2,3{rcub}{dollar} x-ray absorption near-edge structure of P, S and Cl compounds are reported and analyzed with the aid of SW-X{dollar}\alpha{dollar} calculations. In the post-edge region, the outgoing channels are dominated by the d channels, and the post-edge features can be understood by the interactions between the d channels and the bonding environment, such as crystal-field splitting, and centrifugal potential. The pre-edge structures are found to be influenced by the d characters mixed into the unoccupied orbitals, which are again determined by the bonding environment.;High resolution photoelectron spectra are reported for the inner valence region of {dollar}N\sb2{dollar} and CO. …
Design And Implementation Of Expert Systems In Trace Metal Analysis, Sharbari Lahiri
Design And Implementation Of Expert Systems In Trace Metal Analysis, Sharbari Lahiri
Digitized Theses
Atomic Absorption Expert (AAexpert) is an expert system dealing with automated analysis for trace metals by atomic absorption spectrometry (AAS). This program consists of several stand-alone expert systems, each performing a specific task associated with the analysis.;In this thesis, the design and implementation of three important modules of AAexpert have been studied. These are (a) AAdiagnosis - detects problems associated with analytical data of poor quality and instrument malfunction, (b) AA-Quality Control (AA-QC) - provides a real-time assessment of the quality of measured absorbance values, and (c) AAmethods - selects a method of analysis from a method selection database and …
Rate And Equilibrium Constants Of Useful Reactions, Jinqiao Lu
Rate And Equilibrium Constants Of Useful Reactions, Jinqiao Lu
Digitized Theses
Part I. The halogenation of propiophenone has been reported to give rise to benzoic acid and acetic acid. It was discovered that under some conditions, the major product of the chlorination of propiophenone is 2-phenylglyceric acid, and that this appears to be a general reaction. 1-Phenyl-1,2-propanedione and 3-chloro-1-phenyl-1,2-propanedione have been proven to be the key intermediates on the chlorination path leading to 2-phenylglyceric acid. The migratory aptitudes of substituted methides ({dollar}\sp-{dollar}CH{dollar}\sb2{dollar}X) are also reported.;Part II. For the classical Michael reaction, the forward addition rate is second order overall, first order in the concentration of methyl cinnamate and first order in …
Aluminum, Silicon, Phosphorus And Sulfur K- And L-Edge X-Ray Absorption Spectroscopy Of Minerals And Glasses: Applications In Mineralogy And Geochemistry, Dien Li
Digitized Theses
Al, Si, P and S K- and L-edge X-ray absorption near-edge structure (XANES) spectra of a large selection of metal sulfide and silicate minerals and some glasses have been studied using monochromatized synchrotron radiation.;S K- and L-edge XANES spectra of metal sulfides are qualitatively interpreted based on MO/energy band models, reveal the DOS of unoccupied S s-, p- and d-like states, provide new insight into the electronic structure of the conduction band, and demonstrate the bonding interaction of metal d electrons with S 3s and 3p electrons. The S K- and L-edges shift to high energy with increase in oxidation …
Beta-Enolization In Bicyclic Ketones, David James Muir
Beta-Enolization In Bicyclic Ketones, David James Muir
Digitized Theses
A variety of bicyclic ketones was prepared and under strongly basic conditions (t-BuOK/t-BuOH/185{dollar}\sp\circ{dollar}C) their behaviour with respect to {dollar}\beta{dollar}-enolization was examined. Several new compounds were produced upon such treatment; these were identified on the basis of their {dollar}\rm\sp{lcub}13{rcub}Cmr{dollar} and {dollar}\rm\sp1Hmr{dollar} spectra.;3,3-Dimethylbicyclo (3.2.2) nonan-2-one slowly rearranged to 3,3-dimethylbicyclo (3.3.1) nonan-2-one, and the latter was stable. Similarly, 3,3-dimethylbicyclo (3.2.2) non-6-en-2-one rearranged to 3,3-dimethylbicyclo (3.3.1) non-6-en-2-one, which was not stable. Experiments with 3,3-dimethylbicyclo (3.3.1) non-6-en-2-one revealed that it was converted into five compounds. The major product, 2,2-dimethyl-4,5,6,7-tetra-hydrindan-1-one, arose from a {dollar}\beta{dollar}-enolate rearrangement. However, this enone underwent slow reduction to cis- and trans-8,8-dimethylbicyclo (4.3.0) …
Magnetic Circular Dichroism Spectroscopy Of Phthalocyanine Anions, John Douglas Mack
Magnetic Circular Dichroism Spectroscopy Of Phthalocyanine Anions, John Douglas Mack
Digitized Theses
An upgraded version of the program SIMPFIT is used to carry out deconvolution analyses on the uv-visible absorption and magnetic circular dichroism (MCD) spectra of zinc phthalocyanine, ZnPc({dollar}-{dollar}2), and the ring reduced anion radical of zinc phthalocyanine, (ZnPc({dollar}{lcub}-3{rcub})\rbrack\sp-.{dollar} A detailed study of the temperature dependence of the absorption and MCD spectra of ZnPc({dollar}-{dollar}2) shows that a significant fraction of the spectral intensity observed at room temperature can be assigned as 'hot' bands. This results in a significant discrepancy in the absorption and MCD band widths of the major transitions. Spectral band deconvolution was therefore carried out on data recorded at …
Transition Metal Rimmed Calixarenes And Their Supramolecular Chemistry, Wei Xu
Transition Metal Rimmed Calixarenes And Their Supramolecular Chemistry, Wei Xu
Digitized Theses
This thesis describes the design and the synthesis of novel anion and cation receptors in which sets of transition metal atoms are introduced on the rims of calixarene bowls.;A bowl-shaped calixresorcinarene 1 has been derivatized to incorporate either four phosphonite units to give a phosphonito-cavitand 2 or eight phosphinite units to give a phosphinito-calixresorcinarene 3. These derivatives have been used as multidentate ligands to incorporate transition metals on the upper-rim of the calixresorcinarene bowl. The chlorogold(I) complex of 4, 2(AuCl){dollar}\sb4{dollar} which was characterized by an X-ray structure determination, is shown to contain three AuCl units around the upper rim of …
The Photocatalytic Efficiency Of Titanium Dioxide Particles, Georg Riegel
The Photocatalytic Efficiency Of Titanium Dioxide Particles, Georg Riegel
Digitized Theses
Titanium dioxide particles in the anatase crystal form are more efficient in typical photocatalytic applications than are particles in the rutile crystal form. Furthermore, substantial variations in photocatalytic efficiency are generally found among different samples of anatase, as well as rutile particles. The aim of the present study was to identify the dominant cause of these variations. Since electrons at the conduction-band edge of anatase have a larger "driving force" in the reduction of dissolved {dollar}\rm O\sb2{dollar}, it was of particular interest to investigate if the dissimilar efficiencies found for particles of rutile and anatase are primarily due to differences …
The Behaviour Of Glycosphingolipids Under A Variety Of Structural And Environmental Influences, Dev Mitra Singh
The Behaviour Of Glycosphingolipids Under A Variety Of Structural And Environmental Influences, Dev Mitra Singh
Digitized Theses
The influence of naturally occurring glycosphingolipid (GSL) structural variations as modulators of glycolipid organization and dynamics was considered by wideline {dollar}\sp2{dollar}H-NMR in bilayer model membranes. Non-perturbing deuterium probes were placed at selected locations within polar and hydrophobic regions. A variety of environmental influences, which have been widely considered as major determinants of GSL function as recognition sites and structural elements, was examined.;GSL oligosaccharide orientation and motional order were monitored while systematically altering primary GSL structure changes and membrane environment. Each glycolipid, as a minor membrane component, demonstrated clear evidence of preferred average oligosaccharide orientation. Strikingly, the conformation and motional order …
Tetramesitylgermasilene: Synthesis And Reactivity Of A Germanium-Silicon Double Bond, Jeffrey A. Cooke
Tetramesitylgermasilene: Synthesis And Reactivity Of A Germanium-Silicon Double Bond, Jeffrey A. Cooke
Digitized Theses
This thesis describes the synthesis of tetramesitylgermasilene (Mesityl=2,4,6-trimethylphenyl), the first example of a compound containing a germanium-silicon double bond, from hexamesitylsiladigermirane, the first compound containing a three-membered ring composed of two germanium atoms and one silicon atom. The synthesis can be effected both thermochemically and photochemically; however, the germasilene can only be characterized in solution at {dollar}{lcub}-78{rcub}\sp\circ{dollar}C.;In addition, a remarkable 1,2-mesityl rearrangement of the germasilene to form a silylgermylene is reported, with discussion describing a similar rearrangement found in tetramesityldigermene, a compound containing a germanium-germanium double bond. Finally, the thesis details initial investigations into the reactivity of the germasilene with …
Oxidative Addition As A New Route To Organometallic Polymers And Dendrimers, Sudhir Achar
Oxidative Addition As A New Route To Organometallic Polymers And Dendrimers, Sudhir Achar
Digitized Theses
This thesis describes new routes to organometallic polymers and dendrimers employing an oxidative addition method. The new complexes {dollar}\lbrack\rm PtMe\sb2(NN)\rbrack{dollar} 1, (1b: (NN) = 4,4{dollar}\sp\prime{dollar}-di-tert-butyl-2,2{dollar}\sp\prime{dollar}-bipyridine; 1c: (NN) = 4,4{dollar}\sp\prime{dollar}-dimethyl-2,2{dollar}\sp\prime{dollar}-bipyridine; 1d: (NN) = 4-vinyl-4{dollar}\sp\prime{dollar}-methyl-2,2{dollar}\sp\prime{dollar}-bipyridine) were shown to be useful precursors to polymers. {dollar}\{lcub}{dollar}Note 1a: (NN)= 2,2{dollar}\sp\prime{dollar}-bipyridine{dollar}\{rcub}{dollar}.;The oxidative addition of organic halides (R-X) to 1 gave {dollar}\lbrack\rm PtXMe\sb2R(NN)\rbrack{dollar} {dollar}\rm\{lcub} (NN)\sb{lcub}1a{rcub}{dollar}: R-X = methyl 2-(bromomethyl)acrylate; 2-(bromomethyl)acrylic acid; 2-bromoethyl methacrylate; methyl bromoacetate; ethyl bromoacetate; bromoacetic acid; bromoacetonitrile and bromoacetamide. {dollar}\rm (NN)\sb{lcub}1b{rcub}{dollar}: (R-X) = 2-bromoethyl methacrylate and vinyl bromoacetate. {dollar}\rm (NN)\sb{lcub}1d{rcub}{dollar}: vinyl bromoacetate; 2-bromoethyl methacrylate; acryloyl chloride and vinylbenzyl chloride{dollar}\{rcub}{dollar}.;The free radical polymerization of the …
Charge Redistribution And Electronic Behaviour Of Gold-Coper Alloys: Bulk And Surface Studies, Markus Kuhn
Charge Redistribution And Electronic Behaviour Of Gold-Coper Alloys: Bulk And Surface Studies, Markus Kuhn
Digitized Theses
The electronic and physical properties of noble metals and their alloys have been the focus of research for many years. They are considered prototypes for the investigation of full d-band interactions and Friedel charge screening.;We have studied a series of bulk Au-Cu alloys, with varying compositions and ordering, in order to determine the nature and amount of charge transfer between the two components. We also examine the validity of two models; charge compensation and d-d repulsion. To probe the electronic behaviour upon alloying, we employ two techniques, namely photoemission and X-ray absorption. From photoemission, we find unique behaviour in the …
Repair Of Uv-Irradiated Plasmids In Escherichia Coli And Chinese Hamster Cells, Masood-Ur-Rehman Baig
Repair Of Uv-Irradiated Plasmids In Escherichia Coli And Chinese Hamster Cells, Masood-Ur-Rehman Baig
Digitized Theses
Nucleotide excision repair of DNA, demonstrated by the removal of cyclobutane pyrimidine dimers (CPDs), proceeds much more rapidly in genes undergoing transcription than in inactive genes and this rapid repair is confined to the strand being transcribed. The phenomenon is referred to as transcription-repair coupling and it has been demonstrated to occur in the chromosomes of mammalian cells, yeast cells and Escherichia coli. It was of interest to examine the repair characteristics of plasmids both in E. coli and Chinese hamster (CHO) cells.;Some of the findings obtained with the E. coli system were the following: The Rec A function is …
Ionic Conductivity Of Rubidium Chloride, Marcia Lee Vernon
Ionic Conductivity Of Rubidium Chloride, Marcia Lee Vernon
Digitized Theses
This investigation describes a theoretical and experimental examination of the defect properties of rubidium chloride. A theoretical study of the defect properties of RbBr and RbI is also presented.;Defect energy calculations were carried out on RbCl, RbBr and RbI using the HADES code and electron-gas potentials that were fitted to the crystal properties. Damping of the long-range dispersion energy was introduced during fitting of the potential and in the calculation of perfect lattice and defect properties.;In addition, defect energy calculations were done on Rb{dollar}\sb2{dollar}S using potentials developed for the RbCl:S{dollar}\sp{lcub}2-{rcub}{dollar} system. These calculations represent the first theoretical study of the …
Evidence For A Continuum Model Of Diffusion In Lipid Bilayer Membranes: Synthesis And Studies Of Macrocyclic Polyamides In Monolayer And Lipid Bilayer Systems, Patricia Alison Paprica
Evidence For A Continuum Model Of Diffusion In Lipid Bilayer Membranes: Synthesis And Studies Of Macrocyclic Polyamides In Monolayer And Lipid Bilayer Systems, Patricia Alison Paprica
Digitized Theses
This research project is directed towards establishing the relationship between the surface areas of intermediately sized molecules (50-300A{dollar}\sp2{dollar}) and their lateral diffusion coefficients in lipid bilayer membranes. Synthetic methods were developed to allow for the preparation of two series of macrocyclic polyamide amphiphiles, with and without fluorescent nitrobenzoxadiazole (NBD) labels, using macrocyclic polyamine aza-crown ethers as starting materials.;The geometry of the macrocyclic polyamides were determined using variable temperature NMR, which has indicated that both the C(O)-N bond and NBD-N bond in the smallest, labelled macrocyclic polyamide exhibit partial double bond character. As a consequence of this restricted bond rotation, both …
Role Of Colligin In Collagen Biosynthesis, Neeraj Jain
Role Of Colligin In Collagen Biosynthesis, Neeraj Jain
Digitized Theses
Colligin, a glycoprotein of molecular mass 46 kDa, is localized in the endoplasmic reticulum of diverse kinds of cells which produce collagen I. It binds collagen type I and type IV. As a step towards defining the role of colligin in the cell, the binding characteristics were studied in detail. Two different binding assays were developed. These studies showed that three moles of colligin bind per mole of procollagen with a K{dollar}\sb{lcub}\rm d{rcub}{dollar} of about 25 nM. In vivo cross-linking experiments revealed that colligin also binds to procollagen in the ER along with two other ER resident proteins, PDI and …
Adamantane-Like Clusters Of The Zinc-Group Elements, Yuyang Wu
Adamantane-Like Clusters Of The Zinc-Group Elements, Yuyang Wu
Digitized Theses
Three new types of chalcogenate-bridged adamantane-like clusters of the zinc-group elements have been studied in detail: those with alkylthiolates as bridging ligands, formulated as (({dollar}\mu{dollar}-{dollar}\rm SAlk)\sb6(MX)\sb4\rbrack\sp{lcub}2-{rcub}{dollar} (Alk = Me, Et, 1-Pr, 2-Pr, 1-Bu, 2-Bu, c-{dollar}\rm C\sb6H\sb{lcub}11{rcub}{dollar}(Cy), or CH{dollar}\sb2{dollar}Ph (Bz); M = Zn, Cd, or Hg; X = Cl, Br, or I); those with phosphines as terminal ligands, formulated as (({dollar}\mu{dollar}-ER){dollar}\sb6{dollar}(CdPPh{dollar}\sb3)\sb{lcub}4-n{rcub}{dollar}(Cd){dollar}\sb{lcub}n{rcub}\rbrack \sp{lcub}2+{rcub}{dollar} (E = S or Se; R = 1-Pr, 2-Pr, 1-{dollar}\rm C\sb5H\sb{lcub}11{rcub}{dollar} (1-Pe), Cy, or Ph; n = 0, 1, or 2); and those with halides as bridging ligands, formulated as (({dollar}\mu{dollar}-ER){dollar}\sb{lcub}6-m{rcub}(\mu{dollar}-X){dollar}\sb{lcub}m{rcub}{dollar}(MX){dollar}\sb4\rbrack\sp{lcub}2-{rcub}{dollar} (E = S or Se; R = Et, …
Mechanistic And Synthetic Investigations In Sulfonyl Chemistry And Acyl Transfer, Zhen Rong Guo
Mechanistic And Synthetic Investigations In Sulfonyl Chemistry And Acyl Transfer, Zhen Rong Guo
Digitized Theses
This thesis contains three chapters dealing with the organic chemistry of sulfonyl and carbonyl compounds. The first chapter describes the synthesis and rate studies of a series of {dollar}\beta{dollar}-methoxy sulfones and their unsubstituted parent compounds designed to test some basic ideas of the nature of the electronic effects of substituents in saturated systems. The substrates were designed to illustrate the effect of the change of the H{dollar}\sb\alpha{dollar}-C{dollar}\sb\alpha{dollar}-C{dollar}\sb\beta{dollar}-O dihedral angle on the rate of base-promoted H-D exchange reaction. The presence of a {dollar}\beta{dollar}-methoxy group affected the H-D exchange rates by factors varying from a few hundred to greater than ten thousands. …
Quantum Yields And Mechanism In Titanium Dioxide Mediated Photocatalysis, Lizhong Sun
Quantum Yields And Mechanism In Titanium Dioxide Mediated Photocatalysis, Lizhong Sun
Digitized Theses
The photocatalytic pathway in TiO{dollar}\sb2{dollar} suspensions was examined using a spin trap/EPR technique within a competition kinetic scheme. Experimental results from competition reactions indicate that there is a marked difference in kinetic behaviours between the systems with (heterogeneous) and without (homogeneous) a TiO{dollar}\sb2{dollar} suspension, which confirms that the reaction pathway of {dollar}\cdot{dollar}OH radicals in the TiO{dollar}\sb2{dollar} suspension is at least partly heterogeneous. A photocatalytic mechanism is proposed.;A method of determining the trapping efficiency of {dollar}\cdot{dollar}OH radicals was developed with the help of a spin trap/EPR method, using the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO), for the measurement of growth rates of …