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 Degree Discipline: Chemistry
 Collection: UNT Theses and Dissertations
Derivatives of 1,4-Naphthoquinone and 1,4-Anthraquinone

Derivatives of 1,4-Naphthoquinone and 1,4-Anthraquinone

Date: August 1959
Creator: Aboytes, Peter
Description: The purpose of this investigation was the synthesis of some 1,4-naphthoquinones and 1,4-anthraquinones. It will be shown that some of these substituted quinones exhibit physiological properties.
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Base Effects on the Thermal Decomposition of Sec-butyllithium Solutions

Base Effects on the Thermal Decomposition of Sec-butyllithium Solutions

Date: June 1966
Creator: Adams, George Michael
Description: The pyrolysis of sec-butyllithium in solution was studied in an attempt to understand the loss of stereo-specificity and the atypical kinetics that have been reported. Additionally, the effect of added lithium alkoxides was studied to determine their effects on the highly reactive sec-butyllithium substrate.
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Baeyer-Villiger Oxidation of 1,7- & 1,9-dibromopentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione

Baeyer-Villiger Oxidation of 1,7- & 1,9-dibromopentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione

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Date: May 2004
Creator: Akinola, Adeniyi O.
Description: Baeyer-Villiger oxidation of 1,9-dibromopentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione (1,9-dibromo-PCU-8,11-dione) was performed by using an excess amount of m-chloroperbenzoic acid (3 equivalents) and resulted in the formation of the corresponding monolactone. The reaction would not proceed to the dilactone stage. The structure of the reaction product was established unequivocally via single crystal X-ray diffraction. Baeyer-Villiger oxidation of 1,9-dibromo-PCU-8,11-dione using ceric ammonium nitrate (CAN) was also performed and afforded a mixture of lactones. Only one of these lactones, which also contained an alkene functionality, could be isolated and characterized. 1,7-dibromo-PCU-8,11-dione was also reacted with CAN, yielding the mono-lactone, which has also been characterized.
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The Synthesis and Reactivity of Bis(silyl)acetylenes

The Synthesis and Reactivity of Bis(silyl)acetylenes

Date: May 1987
Creator: Albanesi, Todd E. (Todd Edward)
Description: Six bis(silyl)acetylenes with the following varied silicon substituents were prepared: I (Me, Me); II (H, H); III (Cl, H); IV (Cl, Cl); V (OMe, H); VI (OMe, OMe). While I and II may be prepared by the reaction of dilithio- or bis(bromomagnesium)-acetylide with appropriate chlorosilane, similar reactions designed to give III - VI give oligomers, YMe_2Si(C≡C-SiMe_2)_nY, VII, Y = Cl, OMe, as the major products indicating that the acetylenic functionality on silicon activates the chlorosilane toward nucleophilic substitution. Compounds III and IV were prepared by free radical chlorination of II. Methanolysis of III and IV gave quantitative yields of V and VI, respectively. In the presence of mineral acid, VI readily cyclized to give high yields of the cyclic siloxane octamethyl-4,9-dioxa-3,5,8,10-tetrasila-cyclodeca-1,6-diyne, VIII, and the analogous triyne, IX. It was determined that V and VI could be prepared directly from II in high yield by methanolysis with palladium catalyst. Vaska's complex also accomplished the conversion. I attempted to prepare bis(ethoxydimethylsilyl)acetylene by using of Wilkinson 's catalyst for hydrosilylation with acetaldehyde. The principal product of this reaction was 1-(dimethylsilyl)-3,5,5-trimethyl-4-oxa-3-silacyclopent-1-ene, XI.
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Kinetic studies and computational modeling of atomic chlorine reactions in the gas phase.

Kinetic studies and computational modeling of atomic chlorine reactions in the gas phase.

Date: August 2009
Creator: Alecu, Ionut M.
Description: The gas phase reactions of atomic chlorine with hydrogen sulfide, ammonia, benzene, and ethylene are investigated using the laser flash photolysis / resonance fluorescence experimental technique. In addition, the kinetics of the reverse processes for the latter two elementary reactions are also studied experimentally. The absolute rate constants for these processes are measured over a wide range of conditions, and the results offer new accurate information about the reactivity and thermochemistry of these systems. The temperature dependences of these reactions are interpreted via the Arrhenius equation, which yields significantly negative activation energies for the reaction of the chlorine atom and hydrogen sulfide as well as for that between the phenyl radical and hydrogen chloride. Positive activation energies which are smaller than the overall endothermicity are measured for the reactions between atomic chlorine with ammonia and ethylene, which suggests that the reverse processes for these reactions also possess negative activation energies. The enthalpies of formation of the phenyl and β-chlorovinyl are assessed via the third-law method. The stability and reactivity of each reaction system is further rationalized based on potential energy surfaces, computed with high-level ab initio quantum mechanical methods and refined through the inclusion of effects which arise from the ...
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Nitrogen Derivatives of I-phenylazimidoquinone

Nitrogen Derivatives of I-phenylazimidoquinone

Date: 1956
Creator: Armistead, John Wilson
Description: A series of analogous reactions employing as a nucleus I-phenylazimidoquinone has been investigated.
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Mercury-Sensitized Photochemical Reactions of Isopropyl Alcohol

Mercury-Sensitized Photochemical Reactions of Isopropyl Alcohol

Date: May 1959
Creator: Armstrong, Andrew Thurman
Description: This thesis describes the reactions of mercury-sensitized isopropyl alcohol when bombarded with 2537 Angstrom radiation.
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The Reactions and Emission Spectra of Propylene in Electrodeless Discharge

The Reactions and Emission Spectra of Propylene in Electrodeless Discharge

Date: May 1959
Creator: Armstrong, Andrew Thurman
Description: This thesis describes the reactions and emission spectra of propylene under radio frequency energy radiation.
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A Study of the Reduction Products of N-(4-Nitrophenacyl)-4-(1-Hexyl)pyridinium Bromide

A Study of the Reduction Products of N-(4-Nitrophenacyl)-4-(1-Hexyl)pyridinium Bromide

Date: 1950
Creator: Arnwine, Bennie C.
Description: Because of the structural analogies between these compounds and several other physiologically active compounds, such as chloroamphenicol, 4,4'-diaminodiphenyl sulfone, and 2,2-bis-(p-aminophenyl)-1,1,1-trichloroethane, a more complete study of the reduction products and the sequence of catalytic reduction of N-(4-nitrophenacyl)-4-(1-hexyl)pyridinium bromide was made in this investigation.
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Sensitization of Lanthanides and Organic-Based Phosphorescence via Energy Transfer and Heavy-Atom Effects

Sensitization of Lanthanides and Organic-Based Phosphorescence via Energy Transfer and Heavy-Atom Effects

Date: May 2010
Creator: Arvapally, Ravi K.
Description: The major topics discussed are the phosphorescence sensitization in the lanthanides via energy transfer and in the organics by heavy atom effects. The f-f transitions in lanthanides are parity forbidden and have weak molar extinction coefficients. Upon complexation with the ligand, ttrpy (4'-p-Tolyl-[2,2':6',2"]-terpyridine) the absorption takes place through the ligand and the excitation is transferred to the lanthanides, which in turn emit. This process is known as "sensitized luminescence." Bright red emission from europium and bright green emission from terbium complexes were observed. There is ongoing work on the making of OLEDs with neutral complexes of lanthanide hexafluoroacetyl acetonate/ttrpy, studied in this dissertation. Attempts to observe analogous energy transfer from the inorganic donor complexes of Au(I) thiocyanates were unsuccessful due to poor overlap of the emissions of these systems with the absorptions of Eu(III) and Tb(III). Photophysics of silver-aromatic complexes deals with the enhancement of phosphorescence in the aromatics. The heavy atom effect of the silver is responsible for this enhancement in phosphorescence. Aromatics such as naphthalene, perylene, anthracene and pyrene were involved in this study. Stern Volmer plots were studied by performing the quenching studies. The quenchers employed were both heavy metals such as silver and thallium and lighter ...
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The Synthesis and Testing of Differential Herbicides

The Synthesis and Testing of Differential Herbicides

Date: 1948
Creator: Ashmore, James
Description: This investigation was limited to the preparation of substituted phenoxyacetic acids and related compounds. The types of substances prepared for testing can, in general, be placed in three groups. These are: aryloxyacetic acids, arylmercaptoacetic acids, and those acids containing the thiophene nucleus.
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Manufacturer [Sic] of Densified-Refuse Derived Fuel (d-RDF) Pellets and Methods for the Determination of d-RDF Pellet Densities

Manufacturer [Sic] of Densified-Refuse Derived Fuel (d-RDF) Pellets and Methods for the Determination of d-RDF Pellet Densities

Date: December 1986
Creator: Attili, Bassam Saleem
Description: There are 150 million tons of Municipal Solid Waste (MSW) annually produced in the United States, which is approximately equivalent to 150 million barrels of oil. MSW production is inexhaustible, and is increasing on an annual per capita basis of approximately three per cent. After controlling the moisture and adding a binder, the combustible portion of MSW was converted to pellets. The objects of this project were to 1) evaluate the binder, 2) prepare the pellets, and 3) evaluate the pellets with regard to density. The manufacture of pellets was conducted at the Naval Air Station, Jacksonville, Florida. The evaluation of the binders and the pellets was done at North Texas State University (NTSU). There were three procedures for measuring the density. The first, using water displacement, was from the American Society for Testing and Material (ASTM). The second, using wax coating, was also from ASTM. The third, using sharply-cut cylindrical pellets, was developed at NTSU.
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Thermal and Flash Photolysis Studies of Ligand-Exchange Reactions of Substituted Metal Carbonyl Complexes of Cr and Mo

Thermal and Flash Photolysis Studies of Ligand-Exchange Reactions of Substituted Metal Carbonyl Complexes of Cr and Mo

Date: May 1989
Creator: Awad, Hani H. (Hani Hanna)
Description: Thermal and flash photolysis studies of ligand-substitution reactions of cis-(pip)(L)M(CO)_4 by L' (pip = piperidine; L, L' = CO, phosphines, phosphites; M = Cr, Mo) implicate square-pyramidal [(L)M(CO)_4], in which L occupies a coordination site in the equatorial plane, as the reactive species. In chlorobenzene (= CB) solvent, the predominant species formed after flash photolysis and a steady-state intermediate for the thermal reaction is cis—[(CB)(L)M(CO)_4], for which rates of CB-dissociation increase with increasing steric demands of coordinated L. Rates of CB-dissociation from trans-[(CB)(L)M(CO)_4] intermediates, formed after photolysis but not thermally, exhibit no observable dependence on the steric properties of the coordinated L.
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Hydantoin Derivatives as Anticonvulsants. I. 5-Cyclohexylalkyl-5-(2-Thienyl)Hydantoins

Hydantoin Derivatives as Anticonvulsants. I. 5-Cyclohexylalkyl-5-(2-Thienyl)Hydantoins

Date: 1949
Creator: Baker, Andy Albert
Description: The study herein described represents a continuation of the work on 5-(2-thienyl)-5-substituted hydantoins which has been in progress in the laboratories of the North Texas State College for the past several years. It has for its purpose the study of the effect of lengthening the carbon chain connecting a cyclohexyl radical to 5-(2-thienyl)hydantoin in the 5- position.
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Studies in the Hydantoin Series. II. 5-(3-Pyridyl)hydantoin and Its Derivatives

Studies in the Hydantoin Series. II. 5-(3-Pyridyl)hydantoin and Its Derivatives

Date: 1957
Creator: Banta, Marion Calvin
Description: It is the purpose of this investigation to study the chemistry of 5-(3-pyridyl)hydantoin and to compare its properties with those of 5-phenylhydantoin.
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Computational Studies of Selected Ruthenium Catalysis Reactions.

Computational Studies of Selected Ruthenium Catalysis Reactions.

Date: December 2007
Creator: Barakat, Khaldoon A.
Description: Computational techniques were employed to investigate pathways that would improve the properties and characteristics of transition metal (i.e., ruthenium) catalysts, and to explore their mechanisms. The studied catalytic pathways are particularly relevant to catalytic hydroarylation of olefins. These processes involved the +2 to +3 oxidation of ruthenium and its effect on ruthenium-carbon bond strengths, carbon-hydrogen bond activation by 1,2-addition/reductive elimination pathways appropriate to catalytic hydrogen/deuterium exchange, and the possible intermediacy of highly coordinatively unsaturated (e.g., 14-electron) ruthenium complexes in catalysis. The calculations indicate a significant decrease in the Ru-CH3 homolytic bond dissociation enthalpy for the oxidation of TpRu(CO)(NCMe)(Me) to its RuIII cation through both reactant destabilization and product stabilization. This oxidation can thus lead to the olefin polymerization observed by Gunnoe and coworkers, since weak RuIII-C bonds would afford quick access to alkyl radical species. Calculations support the experimental proposal of a mechanism for catalytic hydrogen/deuterium exchange by a RuII-OH catalyst. Furthermore, calculational investigations reveal a probable pathway for the activation of C-H bonds that involves phosphine loss, 1,2-addition to the Ru-OH bond and then reversal of these steps with deuterium to incorporate it into the substrate. The presented results offer the indication for the net addition of aromatic C-H ...
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Quantitative Chemical Analysis of the Soils of Erath County, Texas

Quantitative Chemical Analysis of the Soils of Erath County, Texas

Date: June 1938
Creator: Barnes, Benjamin F.
Description: A chemical analysis of representative samples of Windthorst sand, Denton sand, and Denton clay has been made, and this analysis shows that their composition has a strict correlation with respect to their geological origins. The analyses of the different soils have shown the Windthorst sand to be highly deficient in all of the essential elements, whereas the Denton sand is deficient in only one; namely, phosphorus. The analysis of the Denton clay showed it to be highly fertile. From the consideration of the pH and the lime content, it has been determined to some extent what crops will grow in each of the soils.
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Infrared Studies of Anions of Barbituric Acids

Infrared Studies of Anions of Barbituric Acids

Date: August 1960
Creator: Barnhart, Richard Lee
Description: As long ago as 1881, it was realized that a functional group of atoms in a molecule would cause an absorption band to appear at a particular frequency in the infrared spectrum of the molecule. In more recent years, the concept of characteristic group frequencies has become firmly established and has resulted in the present widespread use of infrared spectroscopy. There appear to have been relatively few studies of infrared absorption of organic acids as compared with their salts.
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The Stereochemistry of Silenes and Alpha-Lithio Silanes

The Stereochemistry of Silenes and Alpha-Lithio Silanes

Date: May 1987
Creator: Bates, Tim Frank
Description: When E- or Z-l-methyl-l-phenyl-2-neopentylsilene was generated by the retro-Diels-Alder vacuum-sealed tube thermolysis of its corresponding anthracene adduct, in the presence of various alkoxysilanes, only one diastereomeric adduct was formed in each case, showing that the reactions are stereospecific. An x-ray crystal structure of the methoxytriphenylsilane adduct of the E-silene confirmed its relative configuration as (R,S) or (S,R). This demonstrated that the addition of alkoxysilanes to silenes is stereospecific and syn. The relative configurations of similar alkoxysilane and alkoxystannane adducts to E- and Z-l-methyl-l-phenyl-2-neopentylsilene were assigned based on a combination of xray structures and *3C NMR data. A strong, nonbonded oxygen-metal interaction is apparent in all of those compounds studied. Treatment of the alkoxystannane adducts with alkyl lithium reagents results in tin-lithium exchange in some cases. The results indicate that the resulting <x-lithio alkoxysilanes are not configurationally stable in either THF or hydrocarbon solvents. The reaction of tert butyl lithium with a-trimethylsilylvinylmethylphenylchlorosilane in hydrocarbon solvents yields E- and Z-l-methyl-l-phenyl-2-neopentyl-2-trimethylsilylsilene. In the absence of any traps these silenes undergo a novel tert butyl lithium catalyzed rearrangement to 2-phenyl-3-trimethylsilyl-5,5-dimethyl-2-silahex-3-ene. These silenes were also trapped as their [4+2] cycloadducts with anthracene. The Z-isomer of the anthracene adduct was separated and its stereochemistry confirmed by ...
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Stereoisomerism of Dimethyl Muconate

Stereoisomerism of Dimethyl Muconate

Date: 1950
Creator: Bearden, Robert Gene
Description: The acid which is analogous to the next member of the diphenylpolyenes, 1,4-diphenylbutadiene, is muconic acid. This acid has been chosen to be investigated in an effort to isolate all the stereoisomers of a set containing more than two isomers.
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Comparison of Homework Systems (Four Web-Based) used in First-Semester General Chemistry

Comparison of Homework Systems (Four Web-Based) used in First-Semester General Chemistry

Date: May 2009
Creator: Belland, Joshua
Description: Web-based homework systems are becoming more common in general chemistry as instructors face ever-increasing enrollment. Yet providing meaningful feedback on assignments remains of the utmost importance. Chemistry instructors consider completion of homework integral to students' success in chemistry, yet only a few studies have compared the use of Web-based systems to the traditional paper-and-pencil homework within general chemistry. This study compares the traditional homework system to four different Web-based systems. Data from eight, semester classes consisting of a diagnostic pre-test, final semester grades, and the number of successful and unsuccessful students are analyzed. Statistically significant results suggest a chemistry instructor should carefully consider options when selecting a homework system.
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A Fractionation Column for the Separation of Products of the Alkylation of Isobutane and Isobutene

A Fractionation Column for the Separation of Products of the Alkylation of Isobutane and Isobutene

Date: 1941
Creator: Berry, Quinton
Description: This thesis describes a fractionation column method of separating isobutane and isobutene to isolate isooctane.
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A Qualitative Analysis of the Products of the Reaction Between Chlorosulfonic Acid and 2, 2, 4-Trimethylpentane

A Qualitative Analysis of the Products of the Reaction Between Chlorosulfonic Acid and 2, 2, 4-Trimethylpentane

Date: 1941
Creator: Black, Harry
Description: This study was made in an attempt to analyze qualitatively the reaction products formed when chlorosulfonic acid reacts with 2, 2, 4-trimethylpentane.
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Photochemical Silene Syntheses

Photochemical Silene Syntheses

Date: August 1987
Creator: Bobbitt, Kevin L. (Kevin Lee)
Description: We report the attempted syntheses of two photochemical dimethylsilene precursors, both of which are derived from polyphenyl silanorbornadiene skeletons. Possible synthetic schemes and our results are reported herein. Photolysis of 1,2-divinyl-1,1,2,2-tetramethyl-1,2-disilane at room temperature in a cyclohexane solution of 1,3-butadiene produces 1,1-dimethyl-2-(vinyldimethylsilylmethyl) silene which is trapped in high yields to afford the E- and Z-1,1-dimethyl-2-(vinyldimethylsilylmethyl)-3-vinyl-1-silacyclobutanes in 42 and 29% yields, respectively, along with minor amounts of 1,1-dimethyl-2-(vinyldimethylsilylmethyl)-1-silacyclohex-3-ene, 9%. Low Pressure Flow Pyrolysis at 450º C of either the E- or Z-isomer provides a relatively mild thermal source of the silene in the gas phase. Two products, 1,1,3,3-tetramethyldisilacyclohex-3-ene and 2,2,5,5-tetramethyl-2,5-disilabicyclo[2.2.1]hexane, are formed from an intramolecular rearrangement of the silene. Other reactions of the 3-vinylsilacyclobutanes include geometric isomerization, ring expansion to the silacyclohex-3-ene, and a homodienyl-1,5-hydrogen shift to 3,3,6,6-tetramethyl-3,6-disiladeca-1,4,8-triene. Synthetic schemes, successful and unsuccessful, for hydrido silene, acylpolysilene, and fluorine substituted silene precursors are discussed in the final chapter.
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