Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 88-95). Also available on the World Wide Web.

A general broad line nuclear magnetic resonance study was made of the ¹⁹F spectra of WF₆ and the adducts IF₇ • AsF₅ and SF₄ • AsF₅ to determine the temperature dependence of the spectra, interpret the line shapes with respect to isotropic and anisotropic chemical shifts and identify non-equivalent fluorine sites in the compounds. The temperature dependence of the second moment at 30 MHz indicated that rigid lattice conditions probably existed at 77°K for WF₆ and IF₇ • AsF₅ but not for SF₄ • AsF₅. The dependence indicated an nmr transition in the vicinity of 200°K for the first two compounds and one commencing below 77°K for the third. From the second moments in the vicinity of the transitions, activation energies mere determined for the average motions involved. The field dependence of the second moments of the compounds was examined, where possible, at 2, 16, 30, 40, 56.4, and 94.1 MHz at 77° and 295°K. The compounds' spectra were resolved, with varying degrees of success, into components. For WF₆ an approximate resolution could be made into two components corresponding to the four equatorial and two axial fluorines in the distorted octahedron at 77°K. The two adducts could both be resolved, especially at 295°K or above, into components which supported the ionic formulations IF⁺₆ AsF⁻₆ and SF⁺₃ AsF⁻₆. Non-equivalent fluorine sites within individual ions could not be detected. From the observed and estimated second moments of the resolved components above and below the transitions, the probable reorientations occuring above the transitions were suggested. The rigid lattice theoretical second moment calculations enabled suggestions to be made for the crystal structures of WF₅ and SF⁺₃AsF⁻₆ and for the bond lengths in IF⁺₆AsF⁻₆ . For the first there had been confusion, at least here, about the space group, while the second has not yet been the subject of reported X-ray studies. Axial symmetry of the chemical shift tensors was assumed. Then, taking account of the relative shifts between the resolved components, averaqe values of the chemical shift anisotropies for each of WF₆ and IF⁺₆ AsF⁻₆ were determined from expressions relating the field squared dependence of the second moment to those quantities. The mean isotropic shifts of the total F spectra for each compound were measured where possible at each field at 77° and 295° K with respect to CF₃. COOH. From those the shifts of the resolved components were calculated relative to HF. Then from the isotropic shifts and the anisotropies, the principal values of the axially symmetric shift tensors were determined. The principal values enabled estimates to be made of I (ionic) and ℓ(double bond) characters, neglecting hybridization, in the M-F bonds of the hexafluoride groups. From these values a prediction was made for I and ℓ in the axial and equatorial bonds in PuF₆ . / Science, Faculty of / Chemistry, Department of / Graduate

The work reported here is: 1) a detailed study of the ¹⁹F nuclear magnetic resonance (n.m.r.) spectra of KPO₂F₂. The temperature dependence of the second moment and line width is interpreted in terms of reorientation of the PO₂F₂⁻ anion in the crystal lattice. A detailed analysis of the line shape at low temperatures is used to yield the interatomic spacings of the PF₂ fragment in the PO₂F₂⁻ anion. 2) an investigation of the n.m.r. adiabatic rapid passage technique as a quick and simple method for determining nuclear Zeeman spin-lattice relaxation times, T₁. The limitations of the experiment are examined and correction formulae are presented. The temperature dependence of T₁ is observed for the globular molecules, exo- and endo-pentadienyl maleic anhydride, for the fatty acid soap, lithium stearate, and for the inorganic salt, KPO₂F₂. The data are interpreted to yield some of the kinetics of molecular motion in these solids. 3) a ¹⁹F nuclear magnetic resonance investigation of polycrystalline K₂NbF₇ and K₂TaF₇, yielding some of the kinetics of molecular motion. The crystal structures, as seen by n.m.r., are found to be essentially identical. 4) an investigation of the ¹⁹F n.m.r. spectra of paramagnetic RhF₅. and IrF₅. This study has been reasonably successful in elucidating the molecular configuration of these substances, a problem uniquely suitable to the n.m.r. technique and insoluble to most other methods of structural analysis. The very large resonance shifts are interpreted in terms of unpaired electron density at the fluorine atoms. 5) a brief examination of the electron spin resonance spectra of X-irradiated polycrystalline KPO₂F₂ and Na₂PO₃F. Two anion radicals, PO₃⁼ and PO₂F⁻ , are identified and, within certain approximations, the nearly isotropic hyperfine coupling constants are evaluated and interpreted in terms of unpaired electron spin densities at the magnetic nuclei. Presentation of Data The organization of this dissertation differs from the form usually found. The justification offered in its behalf is that the topics covered can more easily be listed in a horizontal rather than a vertical array. Therefore, the presentation, theoretical comparison and discussion of the data have been grouped together for each topic. The order in which topics are considered depends on their priority in common discussion and their interdependences. The first to be considered is the n.m.r. line shape of the fluorine resonance in KPO₂F₂. Then, using experimental results as a guide, a determination of the interatomic distances is attempted. The temperature dependences of the n.m.r. line shape is presented and a model describing the type of molecular motion is sought. An explanation of the adiabatic rapid passage technique is then considered because it is used to obtain the spin-lattice relaxation time data. The spin-lattice relaxation time data of ¹⁹F in CaF₂ and KPO₂F₂ and of the ¹H in lithium stearate and endo- and exo-pentadienyl maleic anhydride are then considered. The limits of applicability of the adiabatic rapid passage technique are considered. The n.m.r. line shape of the fluorine resonance in K₂NbF₇ and K₂TaF₇ and its variation with temperature are interpreted in terms of molecular motion. A modified line width-correlation frequency equation first derived by Bloembergen, Purcell and Pound is used to derive an activation energy describing the hindered reorientation of the NbF₇⁼ and TaF₇⁼ anions in the low temperature solids. The n.m.r. line shape of the fluorine resonance in IrF₅- and RhF₅ is used to elucidate the molecular structure, a problem uniquely suitable to n.m.r. The large resonance shifts of the fluorine resonances may be used to obtain the unpaired electron density at the fluorine nuclei. The e.s.r. line shape observed for X-irradiated polycrystalline KPO₂F₂ and Na₂PO₃F is interpreted in terms of the •PO₂F⁻ and the •PO₃⁼ radicals, respectively. The hyperfine coupling constants are obtained and the electron density at the phosphorous and fluorine atoms are estimated. / Science, Faculty of / Chemistry, Department of / Graduate

Call number: LD2668 .T4 1978 K86 / Master of Science

Sulfonyl fluoride systems and their derivatives, RS02F, where R represents hydrocarbon/fluorocarbon moieties continue to be of considerable interest. The incorporation of the sulfonyl fluoride group (S02F) into molecular systems can lead to compounds that are useful as ion-exchange resins, surface active agents, fuel cell electrolytes, and strong sulfonic acids/salts. Interest in preparing SF5 containing sulfonyl fluorides led to the synthesis of the ᵝ-sultone, SF5CHCF20S02, and its rearranged product. Hydrolysis of the sultone gave SF5CH2S02F which led to the sulfonic acid and salt, SF5CH2S03H•H20 and (SF5CH2S03)2Ca. Esters of the sultone were prepared by reaction of the sultone with fluorinated alcohols in the presence of NaF to give SF5CH(S02F)C(O)OR where R = CH2CF3 and CH(CF3)2. Polymeric SF5/S02F containing esters were prepared by reaction of allyl esters, RCX(S02F)C(O)OCH2CH=CH2, in ultraviolet light where R = CF3 or SF5 and X= H or F. Fluorinated silver carboxylate salts have been useful in preparing fluoroesters from alkyl iodides. Therefore, a new silver salt, FS02CF2C(0)0Ag was prepared and characterized; its reaction with (CH3)3SiI, HOCH2CH2I and alkyl bromides and iodides are reported. In addition, new SF5 containing fluoropolymers were synthesized via reaction of fluorinated olefins with SF5Br. Reactions of SF5 containing olefins with CF30Cl, C1F and Cl2 provide reagents that may be of potential use as precursors to sulfonyl fluoride containing systems. All new compounds were characterized by their respective infrared, nmr and mass spectra.

Thesis (M.S.)--University of North Texas, May, 2008. / Title from title page display. Includes bibliographical references.

Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Steven K. Dentel, Dept. of Civil & Environmental Engineering. Includes bibliographical references.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (p. 145-154).

The ¹H and ¹⁹F nuclear magnetic resonance (n.m.r.) spectra of a series of hexopyranosyl and pentopyranosyl fluorides were examined in some detail. The ¹H n.m.r. analyses (first order) enabled the gross molecular conformations to be determined and at the same time provided an opportunity to check the anomeric assignments previously made through application of other techniques. The¹⁹F n.m.r. parameters were then considered and several steric dependencies were observed. The ¹⁹F chemical shifts are controlled, in part, by the spatial orientation of the fluorine, but also, by the orientation of remote acetate groups or other substituents. Rules were subsequently developed for predicting the ¹⁹F chemical shifts for axial fluorines attached to C₁ of a pyranose carbohydrate. These rules were used to predict the ¹⁹F chemical shifts of the remaining "rare" giycopyranosyl fluorides. It was also noted that the ¹⁹F-¹H couplings resemble the ¹H-¹H couplings in that J(trans) > J(gauche). Moreover these ¹⁹F-¹H couplings are several times larger than the corresponding ¹H-¹H couplings and are also more sensitive to their precise steric environment. This study led to the observation that the β-D-anomers of the pentopyranosyl fluorides exist in the alternate chair form (¹C₄), which allows the fluorine atom to adopt an axial orientation. Subsequent to these initial n.m.r. investigations, a new reaction sequence was developed for the addition of "XF" to alkenes, Whereas this reaction sequence (AgF and X₂) results only in trans addition to cyclohexene (courtesy of D.L. Jones); it results in both cis and trans additions to cyclic vinyl ethers, although the trans adduct(s) always predominate: a possible reaction mechanism is discussed. This reaction sequence (X = I, Br,CI) was first applied successfully to D-glucal triacetate and then extended to other α,β-unsaturated cyclic ethers. The reaction products to D-glucal triacetate were for the most part crystalline. These 2-deoxy-2-halo-D-hexo-pyranosyl fluorides proved to be excellent models for extending previously observed electronegative dependencies. Moreover, when related to the 2-deoxy-D-glycopyranosyl fluorides, these compounds revealed that the orientation of remote substituents must play an important role in - determining ¹⁹F chemical shifts. Finally, a brief introduction is given to the utilization of both the "selective irradiation" and the "spin-tickling" methods for determining the relative signs of proton-proton coupling constants of carbohydrate derivatives. For most saturated carbohydrates the vicinal ¹H-¹H couplings have been found to be positive and the geminal couplings are negative in sign. For unsaturated derivatives both vicinal and geminal couplings are positive. The signs of the couplings of an episulphide derivative are the same as those of the saturated carbohydrates, whereas, the signs for an epoxide resemble those of unsaturated carbohydrates. These findings arc in accord with previous experimental and theoretical results. It has been demonstrated that the signs of long-range ( ⁴J) couplings of saturated derivatives exhibit a regular stereospecificity: those between two equatorially oriented protons (⁴ J, ₑ,ₑ) being positive and those between an axial and an equatorial proton (⁴Jₑ,ₐ ) being negative in sign. These findings are contrasted with the previous theoretical predictions and their potential as an adjunct to stereochemical studies is discussed. For unsaturated carbohydrate derivatives the long-range couplings are all negative in sign. The "selective irradiation" and "spin-tickling" homonuclear magnetic double resonance (n.m.d.r.) techniques have been used to determine the relative signs of the vicinal and geminal ¹⁹F- ¹H couplings of a series of glycopyranosyl fluorides. In all cases these two couplings have the same relative signs. Heteronuclear decoupling experiments on 2-bromo-2-deoxy-α-D-mannopyranosyl fluoride triacetate showed that for this derivative the vicinal coupling between H₁ and H₂ and the geminal coupling between H₁ and F₁ have the same relative signs. On this basis an absolute positive sign was assigned to both vicinal and geminal ¹⁹F- ¹H couplings. / Science, Faculty of / Chemistry, Department of / Graduate

The attempt to prepare SF₅NOsO₃ by the reaction of OsO₄ and SF₅NH₂ in diethyl ether was not successful. The product obtained was a pale yellow crystalline substance which was identified as OsO₄ by infrared spectra and mass spectrometric data. No indication of SF₅NOsO₃ was observed. Several attempts to prepare Hg(NSF₂)₂ by the treatment of Hg(NCO)₂ with SF₄ in a solvent, such as THF, DMSO, (CH₃)PO₄ or CHCl₃, have failed, apparently due to interfering side reaction and decomposition. In THF and (CH₃)₃P0₄ systems, COF₂ was produced, but no Hg(NSF₂)₂ was produced in the solid product as shown by the infrared spectrum that there was no absorption band at 1313 cm⁻¹ as reported by Glemser for νS=N. No reaction was observed in CHC1₃ at room temperature or 100ºC. The reaction between Mo(CO)₆ and hot ethanol produced a green solution and a dark brown precipitate, for which the C and H analyses were not in agreement with the formula postulated by Buslaev as Mo(OC₂H₅)(OH)₃. The product of the reaction of the green solution and CsF was a light brown precipitate which showed no carbonyl group absorption in the. region at 2000 cm⁻¹. This should be observed for the compound to be postulated as Cs₃Mo₂(CO)₄F₄(OH)₃ by Buslaev. / Master of Science