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  Partner: UNT Libraries
 Department: Department of Chemistry
 Language: English
 Degree Level: Master's
 Collection: UNT Theses and Dissertations
1-(4, 4'-Dinitrodiphenylmethyl)-Piperidines; 1-(4-Nitrobenzyl)-and 1-(4-Nitrobenzoyl)-Piperdines

1-(4, 4'-Dinitrodiphenylmethyl)-Piperidines; 1-(4-Nitrobenzyl)-and 1-(4-Nitrobenzoyl)-Piperdines

Date: 1953
Creator: Sammons, George D.
Description: This study experiments with the methods of 1-(4, 4'-Dinitrodiphenylmethyl)-Piperidines; 1-(4-Nitrobenzyl)-and 1-(4-Nitrobenzoyl)-Piperdines.
Contributing Partner: UNT Libraries
Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

Access: Use of this item is restricted to the UNT Community.
Date: August 2013
Creator: Fogueri, Uma
Description: In this work we address two problems in computational chemistry relevant to biomolecular modeling. In the first project, we consider the conformer space of melatonin as a a representative example of “real-life” flexible biomolecules. Geometries for all 52 unique conformers are optimized using spin-component scaled MP2, and then relative energies are obtained at the CCSD (T) level near the complete basis set limit. These are then used to validate a variety of DFT methods with and without empirical dispersion corrections, as well as some lower-level ab initio methods. Basis set convergence is found to be relatively slow due to internal C-H…O and C-H…N contacts. Absent dispersion corrections, many DFT functionals will transpose the two lowest conformers. Dispersion corrections resolve the problem for most functionals. Double hybrids yield particularly good performance, as does MP2.5. In the second project, we propose a simple DFT-based diagnostic for nondynamical correlation effects. Aλ= (1-TAE [ΧλC]/TAE[XC])/λ where TAE is the total atomization energy, XC the “pure” DFT exchange-correlation functional, and ΧλC the corresponding hybrid with 100λ% HF-type exchange. The diagnostic is a good predictor for sensitivity of energetics to the level of theory, unlike most of the wavefunction-based diagnostics. For GGA functionals, Aλ values approaching unity ...
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Acetophenone Derivatives; N-Diphenylmethyl and N-Fluorenyl Piperidines

Acetophenone Derivatives; N-Diphenylmethyl and N-Fluorenyl Piperidines

Date: 1949
Creator: Middleton, William J.
Description: This thesis is a study of α-(4-aminophenylsulfonyl)-acetophenone derivatives; n-diphenylmethyl and n-fluorenyl piperidines.
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Addition Reactions of Some Aromatic Aldazines

Addition Reactions of Some Aromatic Aldazines

Date: August 1954
Creator: O'Dell, Stewart
Description: The paper explores the conclusion that the addition compound was bicyclic, and that the addition of each of the two moles of cyanic acid was dependent upon the other.
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The Adsorption of Radioactive Isotopes on Precipitates

The Adsorption of Radioactive Isotopes on Precipitates

Date: January 1954
Creator: Bulloch, Newman Payne
Description: This thesis concerns the investigation of radioisotopes as indicators for precipitation reactions. As a precipitate forms in the presence of a radioisotope, adsorption may take place on its surface. If this adsorption changes markedly at the stoichiometric point it will be possible to use this variation as an indicator for the reaction.
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The Adsorption of Radioactive Isotopes on Specific Precipitates

The Adsorption of Radioactive Isotopes on Specific Precipitates

Date: August 1954
Creator: Yarbrough, Kenneth N.
Description: The purpose of this investigation is to reveal the effects of certain factors affecting adsorption on some specific precipitates. It is hoped that the choice of precipitate types will enable extension of the information gained here to other precipitates similar to those investigated.
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Amine Derivatives of 3-chloro-5(8?)-nitro-1,4-naphthoquinone

Amine Derivatives of 3-chloro-5(8?)-nitro-1,4-naphthoquinone

Date: August 1952
Creator: Whitaker, Leroy, 1929-
Description: This work deals with the preparation of amine derivatives of 3-chloro-5(8?)-nitro-1,4-naphthoquinone which are to be tested for anti-tubercular activity by Parke, Davis and Company.
Contributing Partner: UNT Libraries
Amino Acid Complexes of Rhodium(III)

Amino Acid Complexes of Rhodium(III)

Date: August 1965
Creator: Waller, James F.
Description: This thesis will explore and study rhodium, a group VIII element that has rarely been studied.
Contributing Partner: UNT Libraries
a-Amino Alcohol Derivatives of Methyl P-Nitrophenyl Acetate

a-Amino Alcohol Derivatives of Methyl P-Nitrophenyl Acetate

Date: 1947
Creator: Prindle, Hershel B.
Description: This thesis describes the synthesis of a series of dialkylaminoalkoxy derivatives of methyl p-nitrophenylacetate for testing as anti-histamine or hay fever drugs.
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An Analysis of Elementary Science Material Included in Certain Courses of Study and Text Books

An Analysis of Elementary Science Material Included in Certain Courses of Study and Text Books

Date: August 1937
Creator: Maurice, Katherine
Description: The purpose of this study is to assess the contribution of elementary science to the curriculum. The finding of the investigation summarized in table form.
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An Analysis of the Effectiveness of Computer Assisted Instruction in General Chemistry at an Urban University.

An Analysis of the Effectiveness of Computer Assisted Instruction in General Chemistry at an Urban University.

Date: May 2002
Creator: McGuffey, Angela
Description: The science-major General Chemistry sequence offered at the University of Houston has been investigated with respect to the effectiveness of recent incorporation of various levels of computer technology. As part of this investigation, questionnaire responses, student evaluations and grade averages and distributions from up to the last ten years have been analyzed and compared. Increased use of web-based material is both popular and effective, particularly with respect to providing extra information and supplemental questions. Instructor contact via e-mail is also well-received. Both uses of technology should be encouraged. In contrast, electronic classroom presentation is less popular. While initial use may lead to improved grades and retention, these levels decrease quickly, possibly due to a reduction in instructor spontaneity.
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An Analysis of the Naphtha Cut of Cooke county, Texas, Crude Oil

An Analysis of the Naphtha Cut of Cooke county, Texas, Crude Oil

Date: August 1938
Creator: Jones, Homer
Description: This study attempted to determine hydrocarbons in the crude oil by comparing the results obtained using the two methods of analysis: chemical analysis and Kurtz-Headington analysis. The Kurtz-Headington analysis was found to be adequate to determine hydrocarbons in the crude oil.
Contributing Partner: UNT Libraries
ANTI Preference of the Pyramidalized Radical Center to the Two Fluorines in Difluoro Cyclic Compounds.

ANTI Preference of the Pyramidalized Radical Center to the Two Fluorines in Difluoro Cyclic Compounds.

Date: May 2008
Creator: Tanna, Jigisha
Description: An extensive study of disubstituted cycloalkanes like CnH2n where n=3,4,5 and 6 using DFT((U)B3LYP/6-31G(d) and 6-311+G(2df,2p)) calculations is presented focusing on the effect of pyramidalization of the radical center. A potential energy surface (PES) analysis shows that the radical prefers to pyramidalize anti to the two cis fluorines in the disubstituted cycloalkanes. The degree of pyramidalization for 1,2-difluorocyclopropyl radical is 43.9o away from the cis fluorines whereas for 1,3-difluorocyclobutyl radical, 1,3-difluorocyclopentyl radical and 1,3-difluorocyclohexyl radical is 3.8o, 5.4o and 14.5o respectively away from the cis fluorines. The importance of this pyramidality effect in these compounds is discussed in context with the carbon-hydrogen bond dissociation energies (BDE's) because the preference of the radical centers to pyramidalize anti to the fluorines affects the bond dissociation energy. Importance of steric effect and unfavorable electronic interactions have been extensively explored in planar permethylated cyclobutadiene (Me4CBD) and cyclooctatetraene (Me8COT) using ((U)B3LYP/6-31G(d) and 6-311+G(2df,2p)) calculations. It is thought that steric interactions dominate electronic interactions in Me8COT, while this works opposite in case of Me4CBT. Instead, in Me4CBD the number of unfavorable electronic interactions between π bonds and out-of-plane hydrogens plays the dominant role in determining the relative energies. Interactions between the π bonds of CBD and ...
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Application of Concentration, Adsorption and pH in the Precipitation of the Metal Ions of Groups II and III

Application of Concentration, Adsorption and pH in the Precipitation of the Metal Ions of Groups II and III

Date: June 1937
Creator: Cockerell, Leone Doris
Description: In this thesis, the process involved in the precipitations and separations of the metal of Group II and Group III studied. Suggestions have also been offered whereby students can make an analysis without loosing metals in the initial precepitation.
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An Application of the Reformatsky Reaction to the Thiophene Series of Compounds

An Application of the Reformatsky Reaction to the Thiophene Series of Compounds

Date: 1949
Creator: Hicks, Howard A.
Description: In view of the increasing importance of thiophene derivatives as chemotherapeutic agents, it was considered of interest to apply the Reformatsky reaction to the synthesis of compounds containing the thiophene nucleus with the thought that these might serve as intermediates for further syntheses.
Contributing Partner: UNT Libraries
Applications of Nanomanipulation Coupled to Nanospray Mass Spectrometry in Trace Fiber Analysis and Cellular Lipid Analysis.

Applications of Nanomanipulation Coupled to Nanospray Mass Spectrometry in Trace Fiber Analysis and Cellular Lipid Analysis.

Date: December 2008
Creator: Ledbetter, Nicole
Description: The novel instrumentation of nanomanipulation coupled to nanospray mass spectrometry and its applications are presented. The nanomanipulator has the resolution of 10nm step sizes allowing for specific fine movement used to probe and characterize objects of interest. Nanospray mass spectrometry only needs a minimum sample volume of 300nl and a minimum sample size of 300attograms to analyze an analyte making it the ideal instrument to couple to nanomanipulation. The nanomanipulator is mounted to an inverted microscope and consists of 4 nano-positioners; these nano-positioners hold end-effectors and other tools used for manipulation. This original coupling has been used to enhance the current abilities of cellular probing and trace fiber analysis. Experiments have been performed to demonstrate the functionality of this instrument and its capabilities. Histidine and caffeine have been sampled directly from single fibers and analyzed. Lipid bodies from cotton seeds have been sampled indirectly and analyzed. The few applications demonstrated are only the beginning of nanomanipulation coupled to nanospray mass spectrometry and the possible applications are numerous especially with the ability to design and fabricate new end-effectors with unique abilities. Future study will be done to further the applications in direct cellular probing including toxicology studies and organelle analysis of ...
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Applications of Single Reference Methods to Multi-Reference Problems

Applications of Single Reference Methods to Multi-Reference Problems

Date: May 2015
Creator: Jeffrey, Chris C.
Description: Density functional theory is an efficient and useful method of solving single-reference computational chemistry problems, however it struggles with multi-reference systems. Modifications have been developed in order to improve the capabilities of density functional theory. In this work, density functional theory has been successfully applied to solve multi-reference systems with large amounts of non-dynamical correlation by use of modifications. It has also been successfully applied for geometry optimizations for lanthanide trifluorides.
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An Approach Towards the Total Synthesis of Clonostachydiol

An Approach Towards the Total Synthesis of Clonostachydiol

Date: August 1995
Creator: Maiti, Tushar B. (Tushar Baran)
Description: The syntheses of the unsymmetrical 14-membered bismacrolides have been reviewed. A total synthesis of clonostachydiol, the latest to join this family, has been attempted using trimethylsilyl acetylene as the builiding block and palladium catalyzed reactions for the formation of key bonds. The alkyne groups were introduced by Stille coupling of trimethylstannylethynyltrimethylsilane with an acid chloride for one fragment and by addition of lithiotrimethylsilyl acetylene to an aldehyde for the other. Lactic acid derivatives were chosen as starting materials for both fragments, thus introducing two of the chiral centers. The remaining stereocenters were introduced using stereoselective reductions of ketones.
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The Ascorbic Acid Metabolism of Fifty College Women in the North Texas State Teachers College

The Ascorbic Acid Metabolism of Fifty College Women in the North Texas State Teachers College

Date: 1943
Creator: Harshbarger, Marjorie
Description: A study of the ascorbic acid metabolism of a group of fifty college women in the North Texas State Teachers College between the months of April and July, 1943.
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Attempted Synthesis of 5-Allyl-5-(2-Thienyl)-Barbituric Acid

Attempted Synthesis of 5-Allyl-5-(2-Thienyl)-Barbituric Acid

Date: 1947
Creator: Skinner, Charles Gordon
Description: This thesis describes attempts to synthesize 5-allyl-5-(2-thienyl)-barbituric acid as an improved anticonvulsant.
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Attempted Synthesis of Dibarbituric Acid

Attempted Synthesis of Dibarbituric Acid

Date: 1944
Creator: Pickard, Porter Louis
Description: This study is an attempted synthesis of dithienyl barbituric acid.
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The Attempted Synthesis of some Heterocyclic Sulfones

The Attempted Synthesis of some Heterocyclic Sulfones

Date: 1949
Creator: Compton, William David
Description: This thesis describes two experiments: one related to antihistamines, and the other related to antitubercular compounds.
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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

Access: Use of this item is restricted to the UNT Community.
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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Barbituric Acids as Anticonvulsants.  IV.  5-Substituted-Mercapto Derivatives of 5-Phenylbarbituric Acids.

Barbituric Acids as Anticonvulsants. IV. 5-Substituted-Mercapto Derivatives of 5-Phenylbarbituric Acids.

Date: 1951
Creator: Shahan, Howard Wayne
Description: This study involves compounds of the barbituric acid series are well known for their use as anesthetics and sedatives.
Contributing Partner: UNT Libraries
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