Thesis (Ph. D.)--University of Wisconsin--Madison, 1948. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 53-54).

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1939. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed April 26, 2010) Includes bibliographical references (p. 43-45) and index (p. 46-47)..

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 210-214).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 73-75).

The object of this work was to produce and identify reaction intermediates in systems containing group I and group II halides treated with fluorine. The systems which are studied in detail are the NaCl and KCl/F₂ and SrCl₂/F₂ systems. In accordance with predictions from kinetic studies, ESR has shown that treatment of vacuum-sublimed NaCl with F₂ at room temperature produces a defect containing an unpaired electron, and that the decay of this defect is retarded by Cl₂. The ESR spectrum indicates an anisotropic g-factor and unresolved hyperfine structure. In KCl, a spectrum is obtained which is closely similar except that the hyperfine structure is partly resolved. The spectra appear consistent with interactions of the unpaired electron with Cl atoms, rather than with F or such impurities as 0 or Br, and can be accounted for adequately by a model of the defect as linear Cl[formula omitted], i.e., an H center or something very similar. For NaCl, the spectra indicate that the vacuum-sublimed material is sometimes partly oriented. It is suggested that centers with one-electron deficiency are observable at such high temperatures in vacuum-sublimed material because this consists of essentially perfect crystals devoid of sites which could accept a second electron from the centers. The reaction of SrCL₂ powder or single crystal with fluorine at room temperature produces a defect, stable after removal of fluorine but located close to the reaction interface only, which has an electron spin resonance absorption. The ESR spectrum is consistent with a model of the defect as a chlorine atom displaced from an anion site towards a neighbouring anion vacancy. The principal directions of the hyperfine tensor and g-tensor are two two-fold axes and a four-fold axis of the SrCl₂ lattice. The tensor components indicate that the unpaired electron is localized on the Cl atom, and suggests that the atom is subject to a strong crystal field determind chiefly by two nearest-neighbour cations which define a two-fold axis of the crystal. The unpaired electron is in an orbital mainly of p-character and aligned along a two-fold axis which is probably the one perpendicular to the line of the cations. The single-crystal spectrum, although haying orientation-dependent line positions, has line shapes and intensities resembling those of a powder spectrum. This suggests a range of relative displacement of Cl atoms and neighbouring cations along a "reaction co-ordinate" which is probably a four-fold axis of the crystal. / Science, Faculty of / Chemistry, Department of / Graduate

No description available.

Thesis (Ph. D.)--Lehigh University, 1997. / Includes vita. Bibliography: leaves 78-79.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Organic-inorganic hybrid materials of divalent transition metal halides and simple organic molecules are known to exhibit interesting properties, with both the organic and the inorganic metal halide components contributing to the overall properties of the material (Aakeroy, Champness and Janaik, 2010) (Alexandre et al., 2007) (Aruta et al., 2004) (Criado et al., 1999) (Chondroudis and Mitzi, 1999) (Mitzi, Chondroudis and Kagan, 2001) (Robin and Fromm, 2006). The benzamide molecule was chosen as the primary organic component in this study, due to its potential to form aromatic interactions, and the fact that it possesses two potential sites for hydrogen bonding or protonation or coordination, via the amide group. In addition, the 4-aminobenzamide molecule was investigated due to its similarity to the benzamide molecule, except for an additional functional group on the opposite side of the amide group. A range of inorganic, divalent transition metal chlorides and bromides were selected as inorganic components, including CuX2, CdX2, CoX2, MnX2, HgX2 and ZnX2, where X = Cl or Br. Both ionic and neutral coordination type materials can be formed through the combination of the organic components and inorganic components described above, and the outcome of the reaction is controlled by the presence or absence of acid in the reaction medium. In acidic medium protonation of the organic component results in the formation of an ionic material, and in the absence of an acid a neutral coordination material results from the coordination of the organic component to the metal atom of the metal halide component. The stoichiometry and concentration of the acid will also have an influence on the structure as some of the organic ligand may remain unprotonated. In this study seven novel neutral coordination type structures and one ionic material were characterised by single crystal X-ray diffraction. Four isostructural, neutral, one-dimensional coordination polymer structures were observed for the combination of benzamide with CuCl2, CuBr2, CdCl2 and CdBr2 respectively. In this isostructural series the metal ions adopt an octahedral geometry in the case of the Cd analogues, and a tetragonal geometry, due to Jahn-Teller distorsion, for the Cu members of the series. The combination of ZnCl2 with benzamide yielded an isolated, zero-dimensional, neutral coordination compound in which the zinc(II) ion displays a tetrahedral geometry. An octahedral, paddle wheel-type, isolated, zero-dimensional coordination molecule formed from the combination of MnBr2 and benzamide. In all the coordination compounds of benzamide, coordination was found to occur through the oxygen atom of the amide group, while the NH2 group participates in intra- and intermolecular hydrogen bonding interactions. Due to the poor basicity of benzamide, only one ionic compound of this organic component was characterised structurally. In this compound, formed in combination with HgBr2, half of the benzamide molecules are protonated, and a unique, novel, one-dimensional perhalometallate anion was observed in this structure. The combination of 4-aminobenzamide with CoBr2 yielded an isolated, zero-dimensional, neutral coordination structure, in which the cobalt(II) ion adopts an octahedral geometry. The neutral, coordination compound formed between 4-aminobenzamide and CuBr2 has a trigonal bipyramidal geometry, and in addition to the organic and halogeno ligands, aqua ligands are also coordinated to the metal ion in both of the 4-aminobenzamide-containing molecules. Hydrogen bonding and aromatic interactions occur in all of the structures, and these interaction geometries were analysed in detail. It was found that these interactions play an important role in the cohesion of the units in the structure, with exception of the ionic compound of benzamide, which displays strong hydrogen bonding interactions but long aromatic centroid-to-centroid distances. Diffuse reflectance spectroscopy (DRS) was employed to measure the band gaps of the series of isostructural, one-dimensional coordination polymers. These measurements indicated that the Cd analogues in this series have band gaps that place them in the category of electronic insulators. The Cu members of this series were found to be two-band gap materials, with the lower of the two band gaps falling within the conductor range, while the higher band gap falls in the semi-conductor range for the structure containing CuBr2 and benzamide and the structure containing CuCl2 and benzamide. The suitability of Density Functional Theory (DFT) calculations to theoretically calculate the electronic structures and band gap values of the isostructural series of one-dimensional coordination polymers was tested in this study. The plane-wave cut off energy and k-point grid were optimised for the structures, and a range of functionals were tested. The best performing functional was used to calculate the band gap energies, the band structures and the density of states for the four isostructural materials. DFT calculations are known to underestimate band gap energies, and even though the calculated band gaps differ from the experimentally measured band gaps, this difference is smaller than expected. In addition, the DFT calculations were successful in predicting and providing insight into the electronic characteristics of the materials. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Chemistry / unrestricted

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy