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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 Dynamics in the Liquid Phase by FT-NMR, FT-IR and Laser Raman Lineshape Analysis

Molecular Dynamics in the Liquid Phase by FT-NMR, FT-IR and Laser Raman Lineshape Analysis

Date: August 1988
Creator: Chen, Fu-Tseng Andy
Description: Nuclear magnetic resonance (NMR) provides a convenient probe for the study of molecular reorientation in liquids because nuclear spin-lattice relaxation times are dependent upon the details of molecular motion. The combined application of Raman and Infrared (IR) lineshape analysis can furnish more complete information to characterize the anisotropic rotation of molecules. Presented here are the studies of NMR relaxation times, together with Raman/IR Mneshape analysis of the solvent and temperature dependence of rotational diffusion in 1,3,5-tribromobenzene and 1,3,5-trifluorobenzene. In these experiments, it was found that the rotational diffusion constants calculated from Perrin's stick model were two to three times smaller than the measured values of D, and D,,. Similarly, rotational diffusion constants predicted by the Hu-Zwanzig slip model were too large by a factor of 2. Application of the newer Hynes-Kapral-Weinberg model furnished rotational diffusion constants that were in reasonable agreement with the experimental results. The vibrational peak frequencies and relaxation times of the isotropic Raman spectra of the υ1 modes of CD2Br2 and CHBr3 were studied in solution. The frequency shifts in non-interactive solvents were explained well on the basis of solution variations in the dispersion energy. In Lewis bases, the displacements were in some, but not all, cases ...
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.
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