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  Partner: UNT Libraries
 Degree Discipline: Chemistry
 Collection: UNT Theses and Dissertations
Mixed Alkyllithim/Lithium Alkoxide Aggregates with Less Sterically Crowded Alkyl Groups

Mixed Alkyllithim/Lithium Alkoxide Aggregates with Less Sterically Crowded Alkyl Groups

Date: December 1997
Creator: Thornton, Terry L. (Terry Lee), 1962-
Description: Mixed alkyllithium / lithium alkoxide aggregates in the form (RLi)n(ROLi)m were formed by addition of corresponding alcohol compounds at different Li/O ratios. Variable temperature 13C and 6Li NMR spectroscopy were used to verify the formation of the mixed aggregates and to study their behavior in hydrocarbon solution. Spectra for the lithium n-propoxide / n-propyllithium and iso-butyllithium / lithium iso-butoxide systems each indicated at least one mixed aggregate.
Contributing Partner: UNT Libraries
Mobile Order Theory as Applied to Polycyclic Aromatic Heterocycles

Mobile Order Theory as Applied to Polycyclic Aromatic Heterocycles

Date: August 1997
Creator: Fletcher, Kristin A.
Description: Experimental mole fraction solubilities of benzil, thianthrene, trans-stilbene, thioxanthen-9-one, diphenyl sulfone and dibenzothiophene sulfone are determined in pure noncomplexing and complexing solvents. Predicted solubility values are calculated for benzil, thianthrene, trans-stilbene and thioxanthen-9-one using expressions derived from Mobile Order theory. Large deviations between experimental and predicted solubilities in alcohol solvents exist, therefore optimized solute - solvent association constants are determined. Previously measured thianthrene solubilities in five binary alkane + cyclohexane solvent mixtures are compared with values predicted from Mobile Order theory using the measured solubility in each of the pure solvents as input parameters. The experimental mole fraction solubility of benzil in eight binary alcohol + 1-octanol solvent mixtures are also measured and compared with predicted values.
Contributing Partner: UNT Libraries
Molecular Modeling Study of Oxidative Degradation of Polyperfluoroethers Catalyzed by Iron Fluoride Surfaces : An Extended Hückel Theory Approach

Molecular Modeling Study of Oxidative Degradation of Polyperfluoroethers Catalyzed by Iron Fluoride Surfaces : An Extended Hückel Theory Approach

Date: May 1995
Creator: Wang, Yanbin
Description: Extended Hückel methods are known to be a useful tool in understanding surface phenomena. Important quantities about atoms and chemical bonds can be obtained from this computationally simple method, although caution must be exercised in interpreting the results. Application of Extended Hückel calculations to large metal clusters reveals the role of d orbitals in solids. Basic ideas of constructing model compounds have been developed. Several model systems for surface chemisorption processes are constructed in order to understand the surface catalyzed oxidative degradation of polyperfluoroethers. The activation of oxygen molecules can be explained. The Lewis acid character of the iron fluoride surface can be predicted. Based on these results, mechanisms of the degradation processes are discussed.
Contributing Partner: UNT Libraries
Naphth [2,3-d] Imidazoline-2,4,9-Triones

Naphth [2,3-d] Imidazoline-2,4,9-Triones

Date: August 1966
Creator: Witkowski, Joseph T.
Description: The study of some acylurea derivatives of 2-amino-3-alkylamino- and -3-arylamino-1,4-naphthoquinones was undertaken to determine the course of reaction under conditions similar to those used by J. R. Hoover and A. R. Day to prepare 2-alkyl-1H-naphth[2,3-d] imidazole-4.9-diones from 2-acylamino-3-amino-1,4-naphthoquinones.
Contributing Partner: UNT Libraries
Naphthoquinone Studies

Naphthoquinone Studies

Date: 1955
Creator: Padgett, William A.
Description: This thesis describes a series of naphthoquinone reactions employing pyridine carboxylic acid derivatives (nicotinic acid derivatives). The products of these reactions will be tested by Parke, Davis and Company for their activity against the tubercle bacillus and other pathogenic microorganisms.
Contributing Partner: UNT Libraries
Nitration of Thiophene Analogs of DDT

Nitration of Thiophene Analogs of DDT

Date: February 1953
Creator: Buttram, Jack Rhea
Description: Since thiophene very often yields compounds that are analogous to benzene derivatives in general physiological properties, it was decided to attempt to prepare the nitro and amino derivatives of 1,1,1-trichloro-2,2-bis-(2-thienyl)-ethane (V) as well as the nitro and amino derivatives of 2,2,3-trichloro-1,1-bis-(2-thienyl)-butane (VI).
Contributing Partner: UNT Libraries
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 by this worker.
Contributing Partner: UNT Libraries
Nitrogen Derivatives of Naphthoquinone

Nitrogen Derivatives of Naphthoquinone

Date: August 1952
Creator: Hall, Robert L.
Description: This thesis investigates nitrogen derivatives of naphthoquinone.
Contributing Partner: UNT Libraries
Nitrogen Derivatives of Naphthoquinone

Nitrogen Derivatives of Naphthoquinone

Date: June 1953
Creator: Wood, Frank M.
Description: A series of nitrogen derivatives of 1,4-naphthoquinone, which are structurally similar to the compounds of Hall, has been prepared by this worker. In general, the amido groups are those of the long-chain, fatty acids, and it is believed they will have increased physiological activity. These compounds are to be tested for medicinal activity by Parke-Davis and Company.
Contributing Partner: UNT Libraries
An NMR study of 2-ethyl-1-butyllithium and of 2-ethyl-1-butyllithium/lithium 2-ethyl-1-butoxide mixed aggregates

An NMR study of 2-ethyl-1-butyllithium and of 2-ethyl-1-butyllithium/lithium 2-ethyl-1-butoxide mixed aggregates

Date: May 2001
Creator: Ferreira, Aluisio V. C.
Description: A 1H, 13C, and 6Li NMR study of 2-ethyl-1-butyllithium indicated that 2-ethyl-1-butyllithium exists only as a hexameric aggregate over the entire temperature range of 25 to - 92.1 ° C in cyclopentane. Reacting 2-ethyl-1-butyllithium with 2-ethyl-1-butanol resulted in alkyllithium/lithium alkoxide mixed aggregates, apparently of the form Ra(RO)bLia+b. A multinuclear, variable temperature NMR study of samples with O:Li ratios of 0.2 and 0.4 showed, in addition to the alkyllithium, the formation of four mixed aggregates, one of them probably an octamer. Higher O:Li ratio samples showed the formation of several other mixed aggregates. Mixing 2-ethyl-1-butyllithium with independently prepared lithium 2-ethyl-1-butoxide formed the same mixed aggregates formed by in situ synthesis of lithium alkoxide. Lithium 2-ethyl-1-butoxide also exists as aggregates in cyclopentane.
Contributing Partner: UNT Libraries