UNT Libraries - 39 Matching Results

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Vibrational Spectra and Potential Function of Tetrachlorocyclopropene

Description: The laser Raman spectra of tetrachlorocyclopropene in the liquid and solid phases have been recorded and vibrational assignments are presented. These results along with root mean squared vibrational amplitudes from electron diffraction data have been employed in a normal coordinate analysis in which a 19 parameter potential function is refined. This potential function, originally expressed in terms of compliance constants, is then used to derive the corresponding conventional and relaxed force … more
Date: August 1981
Creator: Adame, I. Ernesto (Ignacio Ernesto)
Item Type: Refine your search to only Thesis or Dissertation
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(4+2)-Cycloaddition Reactions of Ketenes; Pyranones

Description: This study deals with the (4+2)-cycloaddition reactions of 4-π electron compounds with ketenes. Chloroketenes were generated in situ from the corresponding chlorinated acid chlorides in the presence of the ketenophiles. Chloro-, dichloro- and diphenylketenes reacted with 1-methoxy-3-trimethylsiloxy-l,3-butadiene, and 2,4-bis(trimethylsiloxy)-1,3-pentadiene to yield the corresponding dihydropyrans. The dihydropyrans yielded substituted 4-pyranones on hydrolysis.
Date: August 1983
Creator: Agho, Michael O. (Michael Osarenogowu)
Item Type: Refine your search to only Thesis or Dissertation
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Purification of HMG-CoA Reductase and Regulation by Protein-Lipid Interactions

Description: The enzyme 3-Hydroxy-3- Methylglutaryl Coenzyme A Reductase catalyzes the rate limiting step of hepatic cholesterol biosynthesis and is unique among the enzymes in the early part of the pathway in that it is membrane bound. This gives rise to potential regulation of the enzyme through interactions with the endoplasmic reticulum membrane. A purification procedure has been developed which consistently produces enzyme of high specific activity. In order to fully characterize the interactions betwe… more
Date: December 1982
Creator: Brent, Lynn G. (Lynn Gran)
Item Type: Refine your search to only Thesis or Dissertation
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The Influence of Selected Non-Bonded Interactions on Vicinal Carbon-Carbon Coupling Constants

Description: The body of information concerning carbon-carbon spin-spin coupling constants now includes a large number of coupling constants, the establishment of a dihedral angular dependence on 3JCC, and the application of 3JCC to conformational analysis. This study adds another dimension to the growing wealth of information associated with 13 C-NMR: the influence of some non-bonded interactions on 3JCC Four types of non-bonded interactions that could influence vicinal carbon-carbon NMR coupling constants… more
Date: May 1982
Creator: Canada, Edward D. (Edward Dee)
Item Type: Refine your search to only Thesis or Dissertation
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Molecular Dynamics and Interactions in Liquids

Description: Various modern spectroscopies have been utilized with considerable success in recent years to probe the dynamics of vibrational and reorientational relaxation of molecules in condensed phases. We have studied the temperature dependence of the polarized and depolarized Raman spectra of various modes in the following dihalomethanes: dibromomethane, dichloromethane, dichloromethane-d2, and bromochloromethane. Among other observed trends, we have found the following: Vibrational dephasing times cal… more
Date: May 1985
Creator: Chen, Jen Hui
Item Type: Refine your search to only Thesis or Dissertation
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The Study of Low Temperature Silene Generation

Description: The reactions of tert-butyl-, sec-butyl-, and n-butyllithium with dimethylfluorovinylsilane include addition to the double bond to give both silene and silenoid intermediates, fluorine substitution, and a novel vinyl substitution. For the tert-butyllithium reaction, product stereochemistry and trapping experiments using both cyclopentadiene and methoxytrimethylsilane show that silenes are not formed in THF. In hexane about 67% of the 1,3-disilacyclobutanes obtained arise from silene dimerizatio… more
Date: August 1985
Creator: Cheng, Albert Home-Been
Item Type: Refine your search to only Thesis or Dissertation
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Raman Studies of Molecular Dynamics and Interactions in Liquids

Description: In order to explore the N-H stretching region of aliphatic amines, we performed a study of the Raman spectrum of n-propylamine at various concentrations in cyclohexane. Statistical analysis provided evidence of a second symmetric stretching vibration, which we were able to assign to nonhydrogen bonded NH2 groups. To obtain additional evidence on the existence of monomers in n-propylamine and to further study hydrogen bonding and Fermi resonance in aliphatic amines, we extended the investigation… more
Date: May 1984
Creator: Friedman, Barry R. (Barry Richard)
Item Type: Refine your search to only Thesis or Dissertation
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Computational studies of the potential energy surface for O(³P) + H₂S: Characterization of transition states and the enthalpy of formation of HSO and HOS

Description: Article on computational studies of the potential energy surface for O(³P) + H₂S and the characterization of transition states and the enthalpy of formation of HSO and HOS.
Date: January 1, 1995
Creator: Goumri, Abdellatif; Laakso, Dianna; Rocha, John-David Ray; Smith, C. E. & Marshall, Paul
Item Type: Refine your search to only Article
open access

A New Chromophoric Organic Molecule Toward Improved Molecular Optoelectronic Devices

Description: The characterization of 2,3,6,7,10,11-hexabromotriphenylene, Br6TP, is presented toward its potential use as an n-type organic semiconductor and metal-free room temperature phosphor. The crystal structure shows both anisotropic two-dimensional BrBr interactions and inter-layer ?-stacking interactions. Photophysical characteristics were evaluated using solid-state photoluminescence and diffuse reflectance spectroscopies, revealing significantly red-shifted excitations in the visible region for… more
Date: December 2012
Creator: Halbert, Jason Paul
Item Type: Refine your search to only Thesis or Dissertation
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Targeted and Metal-loaded Polymeric Nanoparticles As Potential Cancer Therapeutics

Description: Polymeric nanoparticles were designed, synthesized, and loaded with metal ions to explore the therapeutic potential for transition metals other than platinum found in cisplatin. Nanoparticles were synthesized to show the potential for polymer based vectors. Metal loading and release were characterized via Inductively Coupled Plasma Mass Spectrometry (ICP MS), Energy Dispersive X-Ray Spectroscopy (EDX), X-Ray Photoelectron Spectroscopy (XPS), and Elemental Analysis. Targeting was attempted wi… more
Date: May 2014
Creator: Harris, Alesha N.
Item Type: Refine your search to only Thesis or Dissertation
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GC/MS Analysis of Chlorinated Organic Compounds in Municipal Wastewater After Chlorination

Description: A study has been conducted for the qualitative and Quantitative analysis of chlorinated organic compounds in water. The study included the adaptation of Amberlite XAD macroreticular resin techniques for the concentration of municipal wastewater samples, followed by GC/MS analysis. A new analytical method was developed for the determination of volatile halogenated organics using liquid-liquid extraction and electron capture gas chromatography. And, a computer program was written which searches r… more
Date: August 1982
Creator: Henderson, James E. (James Edward)
Item Type: Refine your search to only Thesis or Dissertation
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Synthesis and Characterization of Two and Three Coordinate Gold (I) Conjugated and Rigid Metallodendrimers

Description: This dissertation is a study of two major topics that involve synthetic strategies for new classes of phosphorescent gold(I)-based metallodendrimers. The phosphorescence of organic and inorganic luminophores originates from spin-orbit coupling owing to internal or external heavy atom effects as well as metal-centered emissions. Previous work in the Omary group entailed systematically designed small molecules, metallopolymers, and unconjugated metallodendrimers that contain d10 and d8 metals, w… more
Date: August 2012
Creator: Kaipa, Ushasree
Item Type: Refine your search to only Thesis or Dissertation
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Synthesis of Ketene Thioacetals and Their Monosulfoxide Derivatives and the Thermal Rearrangements of Diallylic Ketene Thioacetals

Description: Ketene dimethyl thioacetal monosulfoxide was prepared in 68% overall yield in two steps starting from methylmagnesium chloride. The yield of dithioacetic acid was improved significantly by employing tetrahydrofuran as solvent and using elevated temperatures. A one-pot synthesis of ketene thioacetals from alkyl halides was developed and several ketene thioacetals were prepared by this method. Direct oxidation of ketene thioacetals using m-chloroperoxybenzoic acid provided a general route to kete… more
Date: August 1982
Creator: Kaya, Riza
Item Type: Refine your search to only Thesis or Dissertation
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Silene Stereochemistry

Description: The reaction of tert-butyllithium with chloromethylphenylvinylsilane at low temperatures in hexane gave a 48% yield of a mixture of the five isomers of 1,3-dimethyl-1,3-diphenyl-2,4-dineopentyl-1,3-disilacyclobutane, formed by the head-to-tail dimerization of both E- and Z-1-methyl-1-phenyl-2-neopentylsilenes, along with an acyclic dimer. These were separated and their stereochemistry was established by ('1)H- and ('13)C-NMR spectroscopy. The E- and Z-silenes were also trapped as their {4 + 2} … more
Date: August 1984
Creator: Lee, Myong Euy
Item Type: Refine your search to only Thesis or Dissertation
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Synthetic and Structural Chemistry of Ligand-substituted Triosmium Clusters and a Rhenium(i) Complex

Description: The reaction of 2-[(diphenylphosphino)methyl]-6-methylpyridine (PN) with Os3(CO)12-n(MeCN)n [where n = 0 (1), 1 (2), 2 (3)] has been investigated. Os3(CO)12 reacts with PN in the presence of Me3NO to afford the clusters Os3(CO)11(1-PN) (4) and 1,2-Os3(CO)10(1-PN)2 (5). X-ray diffraction analyses confirm the equatorial coordination of the phosphine(s) in 4 and 5, with the two phosphines in the latter cluster exhibiting a 1,2-trans orientation about the Os-Os vector that contains the two ligand… more
Date: August 2013
Creator: Lin, Chen-Hao
Item Type: Refine your search to only Thesis or Dissertation
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