Thesis (Ph. D.)--University of Wisconsin--Madison, 1971. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

D.Sc. (Chemistry) / The aim of this study was to develop new methodology for the transformation of unsaturated carbohydrates utilising organometallic compounds. The first half of the study was directed toward developing a general synthesis of complex allyltins and in determining their application to carbon-carbon bond formation. It was decided to utilise carbohydrate substrates in this regard to develop a novel method of producing glycosides...

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Long-chain molecules are widely used in many commercial products, including waxes, oils, fats and soaps. This study focuses on the primary n-alkylammonium chlorides that have applications as surfactants, detergents and as models for bio-membranes. The specific topic of this investigation is the polymorphism of three series of n-alkylammonium halides. Polymorphism is the ability of a substance to exist in more than one crystal form. Due to the conformational flexibility of the long alkyl chain and the forces (hydrogen bonding and van der Waals interactions) dictating the packing in these compounds, more than one type of molecular packing is possible, resulting in the crystallization of various polymorphs for each compound. Various investigations of the polymorphism of n-alkylammonium halides have been published in the scientific literature. This includes mainly studies on the polymorphism and structures of n-alkylammonium chlorides. Only a few reports on investigations of the polymorphism of n-alkylammonium bromides were found in the literature, but no investigation of the polymorphism of n-alkylammonium iodides could be located. This study is limited to the medium chain length primary n-alkylammonium halides, CnH2n+1N+H3X- where n = 11 to 18 (except 17) and X = Cl, Br and I. It is expected that in this chain length range, both packing forces (hydrogen bonding and van der Waals interactions) will play a role in dictating the molecular packing. It was attempted to crystallize the maximum number of polymorphs of each compound by extensive variation of the crystallization conditions. The parameters varied include crystallization temperature, solvent and crystallization method. Information regarding the polymorphism of a compound crystallized under specific conditions were collected by the complementary techniques of X-ray diffraction and thermal analysis. X-ray diffraction is the ideal technique to study polymorphism because the result of such an investigation is the three-dimensional packing in the crystal structure. Due to the wide scope of the investigation, only the polymorphic forms stable at room temperature were investigated. The single crystal X-ray technique allows the determination of the crystal structure of a polymorph, but due to the tendency of the compounds to crystallize in thin plates, very few single crystals of good diffraction quality were obtained. Nine crystal structures were, however, determined. Most polymorphic forms were available as polycrystalline powders. The new techniques for crystal structure determination from powder data were employed to determine two crystal structures from powder diffraction data, although at lower precision, and further refined them by the Rietveld technique. Conventional X-ray powder diffraction is well suited to the identification of polycrystalline materials. The technique does not give direct information regarding the structural nature of the polymorph, but gives a unique fingerprint for each polymorphic form. All polymorphs that were obtained by the various crystallization techniques were characterised by X-ray powder diffraction, and the unique long Summary iispacing of each polymorphic form was determined from the position of the low angle diffraction peaks in the diffraction pattern. Linear correlations between the chain lengths and long spacings were used to search for the presence of isostructural series amongst the phases. More than one isostructural series could be identified for each homologous series of compounds. Thermal analysis techniques were employed to determine the phase transition temperatures and enthalpies of phase transitions occurring at temperatures above room temperature. In this investigation the thermal behaviour of polymorphs were investigated by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and hot stage microscopy (HSM). A stepwise melting behaviour that includes various solid-solid phase transitions was observed for all compounds studied. The sequence of phase transitions that occur with an increase in temperature were found to be unique to a specific polymorphic form. Thermogravimetric analysis provided information regarding the incorporation of solvent in the crystal lattice by monitoring the change of sample weight with increase in temperature. Hot stage microscopy allowed the visual observation of changes occurring in the morphology and texture of the sample with temperature. This investigation contributed a large amount of information to the pool of knowledge on the crystalline phases of the n-alkylammonium halides. Up to now, not much structural data on the crystal forms of these compounds were available in the literature. In this study, complex patterns of crystal packing and phase transitions were revealed. Six isostructural series of n-alkylammonium chlorides were identified, three of which have not been reported previously, and the crystal structure of one of the novel forms was determined. Four isostructural polymorphic forms of n-alkylammonium bromides were identified. Only two forms have been reported previously in the literature. Six crystal structures of compounds with a novel crystal form were determined. For the homologous series of n-alkylammonium iodides, four novel isostructural series were identified, and one structure was determined. Relationships between chain lengths and structural parameters like long spacings, unit cell parameters and phase transition temperatures were determined and expressed as mathematical functions. An analysis of all the known structures (structures reported in the literature and structures determined in this investigation) indicated that different molecular conformations and hydrogen bonds are responsible for differences in the packing, as expressed in the formation of polymorphs. A choice of anion for a specific compound (chloride, bromide or iodide) influenced not only the cell volume, as would be expected, but also dictated the preferential formation of pseudo-polymorphs and complex hydrogen bonding networks in the crystals themselves. Phase transition temperatures were found to be not simply a function of chain length, but to be significantly influenced by the anion and polymorphic form present. / Prof. G.J. Kruger

This study provides information about the kinetics of the hydrolytic ring cleavage of imidazolium compounds and the catalytic effect of micelles in this ring cleavage. 9-Methylcaffeine iodide was synthesized and its base catalyzed ring cleavage was studied. The ring cleavage, via alkaline hydrolysis of the imidazole moiety, showed pseudo-first order kinetics over the pH range of 7.28 to 10.81. Activation parameters were found to be: Ea = 29.4 Kcal mole-1, △H+ = 28.8 Kcal mole-1 , and △S+ = 27.4 cal mole-l deg -1 The kinetics were studied in the presence of micelles and no rate enhancement was observed. The mechanism for ring cleavage was also investigated. 9-Ethylcaffeine iodide was synthesized and its base catalyzed ring cleavage, at 30°C and a pH of 9.42, showed pseudo first order kinetics. 6 -3 -1 The kobs was found to be 1. 5 x 10-3 sec-1. The oxidation kinetics of 8 ,8-dihydro-9-methylcaffeine to 9-methylcaffeinE:· iodide were also examined.

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<p> Reaction of tetraphenylcyclobutadienepalladium halides, [(Ph4C4)PdX2]2, with [(C5H5)M(CO)3]2 (M=Mo or W) gave complexes of the type (Ph4C4)(C5H5)M(CO)X (M=Mo, X=Cl, Br or M=W, X=Br). Conversely, reaction of [(R4C4)PdBr2]2 (R=C6H5, p-CH3C6H4) with [(C5H5)Fe(CO)2]2 or (C5H5)Fe(Co)2Br led not to the expected transfer of the cyclobutadiene ring group onto iron, but to complexes of the type [(R4C4)M(C5H5)]+ FeBr4- (M=Pd or Ni). These were converted into the diamagnetic bromides. [(R4C4)M(C5H5)]+ Br- which, on treatment with sodium methoxide, gave the cyclobutenyl complexes (R4C4OMe)M(C5H5) of palladium and nickel.</p> <p> The complexes (R4C4)Co(Co)2X (R=C6H5, p-CH3C6H4, X=halogen) have been prepared by ligand-transfer reactions from [(R4C4)PdX2]2. The reactions of (R4C4)Co(CO)2X show considerable similarity to those of (C5H5)Fe(CO)2X, and evidence for a very strong metal-ring bond in the cobalt complex is presented. Reaction of (R4C4)Co(CO)2Br with C6F5Li gave the very stable (R4C4Co(CO)2C6F5. With aromatic hydrocarbons in the presence of AlCl3, (R4C4)Co(CO)2Br gave the stable [(R4C4)Co(π-Arene)]+; cycloheptatriene also reacted with (R4C4)Co(CO)2Br in the absence or a catalyst to give [(R4C4)Co(C7H8)]+. Nucleophilic attack occurred readily at the C7H8 ring in [(R4C4)Co(C7H8)]+ and less readily at the benzene ring in [(R4C4)Co(C6H6)]+ to give (R4C4)Co(cycloheptadienyl) and the (R4C4)Co(cyclohexadienyl) complexes, respectively.</p> <p> The order of susceptibility of π-complexed ligands in metal d^8 complexes towards nucleophilic attack, cycloheptatriene> benzene> (R4C4)> cyclopentadienyl, is proposed. A novel method for effecting hydride abstraction is reported. Aniline in [(Ph4C4)Co(π-Aniline)]+ is less basic than aniline itself by approximately 1.5 pK units.</p> / Thesis / Doctor of Philosophy (PhD)

<p> The amount of chloride ion incorporated into a copper electrodeposit prepared from an aqueous copper sulphate solution has been determined at low chloride concentrations by the use of radiotracers. It has been found that the electrodeposits have a surface layer which is enriched in chloride ion. Evidence has been obtained that incorporation of chloride is preceded by the formation of cuprous chloride. The incorporation of chloride has been found to be increased by the presence of organic additives in the solution. The polarization during the first 30 seconds of electolysis has been interpreted using the knowledge obtained from the radiotracer work.</p> / Thesis / Doctor of Philosophy (PhD)

<p> Measurements of the infrared absorption spectra of potassium and sodium halide crystals with substitutional H- ion impurities are presented and compared with calculations which use rigid ion and ordinary shell models for the defect along with phonon data obtained from inelastic neutron scattering measurements. It is shown that the shell model is necessary to give a satisfactory account of the observed anharmonic side band absorption in the sodium halide crystals and that it improves the rigid ion results for the potassium halide crystals. The same model also satisfactorily describes the impurity induced far-infrared absorption in these materials. Some Van Hove singularities observed in the far infrared measurements occur at frequencies predicted from phonon densities of states calculated from neutron scattering data while others occur at slightly different frequencies.</p> / Thesis / Doctor of Philosophy (PhD)