Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 13 of 13
Full-Text Articles in Entire DC Network
Part I N-Acylindole 2+2 Photocycloaddition Reactions Part Ii Enone 2+2 Photocycloaddition Reactions, David J. Hastings
Part I N-Acylindole 2+2 Photocycloaddition Reactions Part Ii Enone 2+2 Photocycloaddition Reactions, David J. Hastings
Digitized Theses
Part I. Ultra-violet irradiation of N-acylindoles in the presence of alkenes results in the formation of 2+2 photocycloadducts containing a cyclobutane ring derived from the bonding of the alkene termini to the 2 and 3-positions of the indole. The reaction proceeds via the triplet excited state of the N-acylindole with a quantum yield of product formation which is much less than that of the quantum yield for intersystem crossing. The reaction's inefficiency is explained by the existence of 1,4-biradical intermediates which can undergo cleavage to yield ground state starting materials in competition with ring closure to give the observed photocycloadducts. …
The Photophysics Of Polycyclic Aromatic Hydrocarbons Adsorbed On Silica Gel Surfaces: A Lifetime Distribution Analysis Approach, Yuan-Sheng Liu
The Photophysics Of Polycyclic Aromatic Hydrocarbons Adsorbed On Silica Gel Surfaces: A Lifetime Distribution Analysis Approach, Yuan-Sheng Liu
Digitized Theses
The relaxation process of excited molecules, in homogeneous systems, is routinely studied through the measurements of fluorescence lifetimes and fluorescence quantum yields. From these data, the radiative decay rate, and hence the non-radiative decay rate, can be easily derived. Effort has been made, in the present work, to conduct such a fundamental study with molecules adsorbed on silica gel surfaces.;The photophysics of six polycyclic aromatic hydrocarbons (PAH), comprising phenanthrene, chrysene, pyrene, perylene, benzoperylene and coronene, adsorbed on variously dehydroxylated silica gel surfaces, has been investigated in this work. It has been observed that the fluorescence lifetimes of these adsorbed PAHs …
Homo- And Hetero-Dinuclear Complexes Of Cobalt, David J. Elliot
Homo- And Hetero-Dinuclear Complexes Of Cobalt, David J. Elliot
Digitized Theses
The work presented in this thesis concerns the synthesis and characterization of a series of novel phosphine-carbonyl complexes of cobalt. Chapters 2 and 3 outline mononuclear and homodinuclear cobalt complexes, chapters 4 and 5 discuss heterobimetallic complexes (CoM(CO){dollar}\sb{lcub}\rm n{rcub}{dollar}({dollar}\mu{dollar}-dppm){dollar}\sb2{dollar}) (M = Rh,n = 3; M = Mn or Re, n = 5), and finally chapters 6 and 7 discuss complexes containing the {dollar}\mu{dollar}-PPh{dollar}\sb2{dollar} group and the complex ((CO){dollar}\sb2{dollar}({dollar}\eta\sp1{dollar}-dppm) Co({dollar}\mu{dollar}-dppm)BH{dollar}\sb2{dollar}), respectively.;Introduction of CO into Co(II)/phosphine/NaBH{dollar}\sb4{dollar} reaction systems, previously shown to produce a number of interesting complexes, has provided a novel approach to the synthesis of phosphine-carbonyl complexes of cobalt. A number …
Studies On The Compositional And Metabolic Heterogeneity Of Very Low-Density Lipoproteins In Hypertriglyceridemic Human Subjects, Andrew John Evans
Studies On The Compositional And Metabolic Heterogeneity Of Very Low-Density Lipoproteins In Hypertriglyceridemic Human Subjects, Andrew John Evans
Digitized Theses
Experiments were designed to characterize more fully specific aspects of the compositional and metabolic heterogeneity of Sf 60-400 very low density lipoproteins (VLDL) known to be associated with Type IV hypertriglyceridemia in humans. Apolipoprotein E (apo E) is thought to be an important mediator of VLDL catabolism. Heparin-Sepharose chromatography was shown to be a reproducible method for separating Type IV VLDL into apo E-poor and apo E-rich subfractions. The apo E-poor fraction was found to contain more intestinally-derived lipoproteins than the apo E-rich fraction. VLDL from subjects with Types I, III and V hyperlipoproteinemia could not be subfractionated in an …
Fundamental Studies Of Interactions Of Water With The Nickel(110) Surface, Brian William Callen
Fundamental Studies Of Interactions Of Water With The Nickel(110) Surface, Brian William Callen
Digitized Theses
The adsorption of water on Ni(110) has been studied by electron stimulated desorption ion angular distributions (ESDIAD), Fourier transform infrared-reflection absorption spectroscopy (FTIR-RAS), low energy electron diffraction (LEED), nuclear reaction analysis (NRA), and work function measurements ({dollar}\Delta\Phi{dollar}). The major findings in this study are: The saturation coverage of the first chemisorbed layer of water is 0.5 water molecules per surface Ni atom or 0.5 ML (1 ML = monolayer = 1.14 {dollar}\times{dollar} 10{dollar}\sp{lcub}15{rcub}{dollar} molecules cm{dollar}\sp{lcub}-2{rcub}{dollar}). The first chemisorbed layer exhibits c(2 x 2) symmetry, and is bonded to the surface monomerically (no evidence of intermolecular hydrogen bonding) with the plane …
Investigation Of Naphthacene Mobility On Silica, David Wayne Bjarneson
Investigation Of Naphthacene Mobility On Silica, David Wayne Bjarneson
Digitized Theses
Photophysical and photochemical examinations of polycyclic aromatic hydrocarbons adsorbed on metal oxide surfaces provide indirect evidence for the mobility of these species. We employ Fluorescence Photobleaching Recovery (FPR) to directly measure the mobility of naphthacene on various silica gel surfaces at low coverages. On normal phase silica, the rate of diffusion is found to be invariant of the surface treatment. The diffusion coefficient is constant at 2.5 {dollar}\times{dollar} 10{dollar}\sp{lcub}-10{rcub}{dollar} cm{dollar}\sp2{dollar} s{dollar}\sp{lcub}-1{rcub}{dollar}, but the mobile fraction shows a pronounced dependence on surface treatment. These results indicate that the mobility of the same population of naphthacene is being measured in each case, …
Part~I~Photoenolization Of Alpha,Beta-Unsaturated Ketones Part~Ii~Photochemical Studies Of Some N-Aroyl Substituted Indoles, David F. Wong
Part~I~Photoenolization Of Alpha,Beta-Unsaturated Ketones Part~Ii~Photochemical Studies Of Some N-Aroyl Substituted Indoles, David F. Wong
Digitized Theses
Part I. Ultra-violet light irradiation of {dollar}\alpha{dollar},{dollar}\beta{dollar}-unsaturated ketones possessing a {dollar}\gamma{dollar}-hydrogen as well as a {dollar}\gamma{dollar}-alkyl substituent results in isomerization to their {dollar}\beta{dollar},{dollar}\gamma{dollar}-unsaturated isomers. The process occurs by an intramolecular {dollar}\gamma{dollar}-hydrogen abstraction by the excited carbonyl to generate a dienol intermediate. The deconjugation reaction is not efficient for {dollar}\alpha{dollar},{dollar}\beta{dollar}-unsaturated ketones which do not possess a {dollar}\gamma{dollar}-alkyl substituent; this is because thermal 1,5-hydrogen transfer in the dienol intermediate gives back starting ketone efficiently. Part I of this thesis describes a procedure for trapping dienols generated photochemically from several {dollar}\gamma{dollar}-unsubstituted {dollar}\alpha{dollar},{dollar}\beta{dollar}-unsaturated ketones. The trap used is chlorotrimethylsilane in the presence of a …
The Structure, Biosynthesis And Function Of Corticosteroid Binding Globulin, Carolyn L. Smith
The Structure, Biosynthesis And Function Of Corticosteroid Binding Globulin, Carolyn L. Smith
Digitized Theses
Corticosteroid binding globulin (CBG) is the major plasma transport protein for glucocorticoids. Complementary DNAs for rat, mouse, rabbit and squirrel monkey CBG were isolated, sequenced and their deduced primary structures were aligned. Overall, they exhibit 40.9% identity, and their comparison revealed conserved N-glycosylation sites and the probable position of the cysteine located within the human CBG steroid binding domain. Rat CBG mRNA is produced primarily by the liver, and in adults, males have two-thirds the CBG mRNA levels of females. During the last third of pregnancy, maternal hepatic CBG mRNA levels are relatively constant while fetal levels are highest at …
Magnetic Resonance Spectroscopy Of Probe Labelled Glycolipids In Model Membranes, And Development Of Lipid Probes For Magnetic Resonance Imaging, Eugene Florio
Digitized Theses
Glycosphingolipids are the carbohydrate-bearing lipids of animal cells. These usually minor constituents of the plasma membrane have been proposed to have major roles in structure and recognition. Glycosphingolipids are distinctly different from phospholipids in that: (i) they possess donor H-bonding groups, (ii) they often have disproportionately long, single fatty acid chains and (iii) they can be {dollar}\alpha{dollar}-hydroxylated on the fatty acid chain.;As part of a research program to investigate the behaviour and interaction of glycosphingolipids in biological membranes we have developed spin labelled and deuterium labelled derivatives. These included novel 24-carbon (lignoceric acid) spin labelled at C-12 or C-16, and …
Solvent Dependence Of Photoinduced Intramolecular Electron Transfer, Jing-Yao Liu
Solvent Dependence Of Photoinduced Intramolecular Electron Transfer, Jing-Yao Liu
Digitized Theses
This work is a study of the solvent and temperature dependence of photoinduced intramolecular electron transfer (ET). The molecule containing a porphyrin and a quinone linked by a phenylalanine amino acid residue was synthesized. Excitation of this molecule (PPAQ) causes electrons to be transferred from the porphyrin to the quinone entity. The ET rate constants were measured by comparing the porphyrin fluorescence lifetime with or without the possibility of ET.;The ET rate constants of PPAQ were measured for several solvents and compared with data of other similar porphyrin-quinone linked molecules. A temperature dependence of ET rate constants study was also …
An In Vitro Examination Of Surface Tension Reduction By Pulmonary Surfactant In The Presence And Absence Of Inhibitory Agents, Amanda M. Cockshutt
An In Vitro Examination Of Surface Tension Reduction By Pulmonary Surfactant In The Presence And Absence Of Inhibitory Agents, Amanda M. Cockshutt
Digitized Theses
The surface activity of Lipid Extract Surfactant (LES), a clinical preparation used for the treatment of Neonatal Respiratory Distress Syndrome, and the effects of addition of surfactant-associated protein A (SP-A) and palmitic acid were assayed in vitro in the presence and absence of challenge by inhibitory agents. Measurements of surface activity were made with the pulsating bubble surfactometer and the captive bubble technique. The addition of SP-A to LES enhances the surface activity of the preparation, especially at low surfactant concentrations. SP-A accelerates the adsorption of surfactant lipids from the aqueous subphase to the air-liquid interface and causes enrichment of …
High-Resolution Core-Level Spectroscopies Of Molecular Silicon Compounds Using Monochromatized Synchrotron Radiation, John D. Bozek
High-Resolution Core-Level Spectroscopies Of Molecular Silicon Compounds Using Monochromatized Synchrotron Radiation, John D. Bozek
Digitized Theses
High-resolution core-level photoabsorption, photoelectron and photoionization mass spectra of numerous substituted silane molecules have been measured in the gas phase around the Si 2p ionization edges using monochromatized synchrotron radiation. Photoabsorption spectra were also measured around the Si 2s ionization edges and the Cl 2p ionization edges of the chlorine-containing molecules. Multiple-scattering X{dollar}\alpha{dollar} calculations were performed to aid in the assignment of the peaks observed in the photoabsorption spectra. The chemical series approach, where the effects of small systematic chemical changes in the composition of the molecule under study on the observed spectra provide useful aids for assignments, has been …
Laser-Molecule Interactions And The Effects Of Permanent Dipoles, Anne E. Kondo
Laser-Molecule Interactions And The Effects Of Permanent Dipoles, Anne E. Kondo
Digitized Theses
The spectral and dynamic effects associated with a non-zero difference, d, between the permanent dipole moments of two molecular states involved in a transition, are investigated for a variety of electromagnetic field-molecule interactions. Both analytical and exact numerical techniques are used to solve the time-dependent Schrodinger equation and to obtain the temporal populations of the molecular states and the associated absorption spectra, for molecular interactions with a Gaussian pulsed, or one or two continuous wave (CW), laser(s).;Analytical rotating wave approximation results are derived for a single CW laser interacting with a two-level d {dollar}\ne{dollar} 0 molecule with an excited state …