Thesis (Ph. D.)--University of Wisconsin--Madison, 1931. / Typescript. With this are bound: The dielectric constants of binary mixtures : IX. The electric moments of certain substituted phenols and their relation to the stereochemistry of the oxygen atom / By John Warren Williams and John M. Fogelberg. Reprinted from Journal of the American Chemical Society, vol. 52 (1930), p. 1356-1363 -- Die Anwendung der Debyeschen Dipoltheorie auf binäre Flüssigkeitsgemische : III. Derivative des Ammoniaks / Von John M. Fogelberg und John Warren Williams. "Sonderdruck aus 'Physikalische Zeitschrift', 32. Jahrg., 1931, Heft I, S. 27-31." Includes bibliographical references (leaves 43-44).

Thesis--Wisconsin. / Vita. Includes bibliographical references.

Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies.

A photoelectron (PE) spectrometer has been modified to study unstable molecules. Reconstruction of the ionization chamber has made the ionization region more easily accessible, and a quadrupole mass spectrometer has been added in order to provide mass spectral identification data under the same conditions as the PE experiment. The system is controlled by a LSI 11/03 microcomputer with suitable interfacing hardware. A real-time operating system program has been developed for data handling. Light sources such as the HLc (Hydrogen Lyman a line, l0.2eV) and HL[sub=αβƴ] (a mixture of Hydrogen Lyman α, β and ƴ lines) radiations were used to reduce ion-fragmentation. Pure S₄N₄, S₄N₂, S₃N₃ and S₂N₂ were synthesized and studied with this system. The interrelationship between the gas phase reactivities of these compounds has been established. The study of CH₃NO, its trans and cis dimers, and its isomer, CH₂NOH, has clarified some mistakes in species identification in previous PE spectroscopic work on CH₃NO and its dimers. These two studies illustrate our ability to identify unstable species even in a very complex mixture with this system. A cryopump was constructed and may be positioned close to the ionization region opposite to the sample inlet, which may be a fine nozzle. This fast pumping nozzle system has been used to produce nearly pure N₂0, and a charge-transfer complex (CH₃)₂0-BF₃, and excellent PE spectra of these species were obtained. A library of computer programs has been established which provides a wide variety of quantum mechanical computations applicable to PE band assignments. These programs, such as CNDO/2, MINDO/3, MNDO, HAM/3, GAUSSIAN 70 and 76, and RSPT (for perturbation corrections to Koopmans' theorem), were used throughout this work and their accuracy and efficiency assessed. Koopmans' theorem has been shown to break down if applied to the ionization of CH₃NO and N₂O₄. Moreover, shake-up processes in the Hel region have been studied for these two molecules and S₄N₂. Several of the molecules, such as S₄N₂, S₃N₃ and (CH₃)₂0-BF₃, have not been investigated by PE spectroscopy before. / Science, Faculty of / Chemistry, Department of / Graduate

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Because of the need for data on the geometry of nitrogen in arylamines, the determination of the crystal and molecular structures of tri-(p-fluorophenyl)-amine (TFPA) and tri-(p-iodophenyl)-amine (TIPA) was undertaken as the subject of this dissertation.

by Chi-Keung Lam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 100-103). / Abstract also in Chinese. / Acknowledgments --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Table of contents --- p.iv / Index of compounds --- p.v / List of tables --- p.vi / List of figures --- p.vii / Chapter Chapter 1. --- Introduction / Chapter 1.1 --- Some aspects of urea/thiourea inclusion chemistry --- p.1 / Chapter 1.2 --- General chemistry of monocyclic oxocarbons --- p.5 / Chapter 1.2.1 --- Synthesis of monocyclic oxocarbons --- p.5 / Chapter 1.2.2 --- Aromaticity of monocyclic oxocarbon anions --- p.20 / Chapter 1.2.3 --- Reactions of monocyclic oxocarbons --- p.25 / Chapter 1.3 --- Aim of the present research --- p.31 / Chapter Chapter 2. --- Description of crystal structures / Chapter 2.1 --- Urea-anion inclusion compounds --- p.32 / Chapter 2.1.1 --- Bis(tetra-n-propylammonium) squarate-urea-water (1/ 6/2) --- p.32 / Chapter 2.1.2 --- Tetra-n-butylammonium hydrogen squarate-urea-water (1/1/1) --- p.38 / Chapter 2.1.3 --- Bis(tetraethylammonium) squarate-tetraethylammonium hydrogen carbonate- urea-water (1/2/4/6) --- p.42 / Chapter 2.1.4 --- Bis(tetra-n-propylammonium) croconate-urea-water (1/5/2) --- p.47 / Chapter 2.2 --- Thiourea-anion inclusion compounds --- p.53 / Chapter 2.2.1 --- Bis(tetraethylammonium) squarate-thiourea-water (1/4/ 2) --- p.53 / Chapter 2.2.2 --- Bis(tetraethylammonium) squarate-thiourea (1/6) --- p.59 / Chapter 2.2.3 --- Bis(tetra-n-propylammonium) squarate-thiourea-water (1/ 4/2) --- p.66 / Chapter Chapter 3. --- Summary and discussion / Chapter 3.1 --- Urea/thiourea monocyclic oxocarbon anions inclusion compounds --- p.71 / Chapter 3.2 --- Structural features and topological correlations of the host lattices --- p.72 / Chapter 3.3 --- Hydrogen bonding and linkage modes of urea and thiourea molecules --- p.87 / Chapter Chapter 4. --- Experimental / Chapter 4.1 --- Preparation of crystals --- p.91 / Chapter 4.2 --- X-ray Crystallography --- p.93 / References --- p.100 / Appendix Atomic coordinates and thermal parameters of the new inclusion compounds --- p.104

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. December 2015. / It is well-established that there is electronic communication between the equatorial and axial ligands in the cobalt corrins. It can therefore be anticipated that the electronic structure of the corrin ligand will affect the chemistry of the axial coordination sites of Co(III) in these complexes. To probe this cis-influence the electronic structure of the corrin was perturbed by substituting the H atom at C10 by Br (which is π electron-donating towards the corrin) in aquacobalamin ([H2OCbl]+), and by NO2 (which is strongly electron-withdrawing) and NH2 (which is strongly electron-donating) in aquacyanocobester ([ACCbs]+). The first part of this study was dedicated to aqua-10-bromocobalamin ([H2O-(10-Br)Cbl]+) and the second part to aquacyano-10-nitrocobester ([AC-(10-NO2)Cbs]+) and aquacyano-10-aminocobester ([AC-(10-NH2)Cbs]+). The successful synthesis of [H2O-(10-Br)Cbl]+, was verified by ESI-MS, 1H and 13C NMR, uv-vis spectroscopy and XRD. The stability constants for the substitution of coordinated H2O by a series of anionic (N3 –, NO2 –, SCN–, SO3 2–) and neutral N-donor ligands (imidazole, DMAP) were obtained for [H2OCbl]+, [H2O-(10-Br)Cbl]+ and [H2O-(10-Cl)Cbl]+ under the same conditions. Substitution of the C10 H by Cl or Br favours the coordination of anionic ligands, but discriminates against the binding of neutral N-donor ligands. The anionic ligands bind more strongly to [H2O-(10-Br)Cbl]+ than to [H2OCbl]+ with log K values between 0.05 and 0.62 (average 0.33) larger. Conversely, neutral ligands bind less strongly to [H2O-(10-Br)Cbl]+ than to [H2OCbl]+ with log K values between 0.29 and 0.36 (average 0.33) smaller. DFT (BP83/TZVP) calculations were used to rationalise these observations. When H is changed to Cl or Br, the metal ion becomes less positive. When the β ligand changes from a neutral to an anionic ligand, the partial charge on the C10 substituent becomes more negative. Replacing C10 H by Cl or Br discriminates against a neutral ligand because of the greater electron richness of the metal. If the ligand is an anion, however, the charge donation can be accepted by delocalisation onto the C10 substituent. The reaction kinetics of the substitution of H2O in [H2O-(10-Br)Cbl]+ were determined for the ligands N3 – and imidazole and were compared with values available for [H2OCbl]+ and [H2O-(10- Cl)Cbl]+. The results showed that both N3 – and imidazole react more slowly with [H2O-(10- Br)Cbl]+ than with [H2OCbl]+, consonant with the previous observations for [H2O-(10-Cl)Cbl]+. Although ΔH‡ values are smaller, they do not compensate for significantly more negative values of ΔS‡, indicative of a transition state that occurs earlier along the reaction coordinate in [H2O- (10-Br)Cbl]+ and [H2O-(10-Cl)Cbl]+ whereas the transition state occurs later along the reaction coordinate with [H2OCbl]+. It is argued that this is a consequence of the lower charge density on the metal, making it a better electrophile both towards the incoming and the departing ligand. Dicyano-10-nitrocobester ([DC-(10-NO2)Cbs]) and dicyano-10-aminocobester ([DC-(10- NH2)Cbs]) were synthesised from dicyanocobester [DCCbs] by established methods and converted to the aquacyano form so that the thermodynamics and kinetics of the substitution of coordinated H2O by a variety of ligands could be investigated. The stability constants for the substitution of coordinated H2O by a number of neutral (imidazole, DMAP, methylamine) and anionic (N3 –, NO2 –, SCN–, SO3 2–, CN–) ligands were determined for [ACCbs]+, [AC-(10-NO2)Cbs]+ and [AC-(10-NH2)Cbs]+ in 50% isopropanol. The soft anions (SO3 2– and CN–) bind better to the softer Co(III) metal centre in [AC-(10-NH2)Cbs]+ and [ACCbs]+ than in [AC-(10-NO2)Cbs]+ and the converse is true for the hard anions (N3 –, NO2 – and SCN–). The case is less clear for the N-donor ligands; DMAP clearly has a higher affinity for [AC-(10- NH2)Cbs]+ and [ACCbs]+ than for [AC-(10-NO2)Cbs]+, but there is little discrimination in the case of imidazole and methylamine. This implies that the affinity of the metal for an exogenous ligand depends on the electron density at the metal centre. DFT calculations showed that as the C10 substituent is changed from NH2 to H to NO2, the charge density on the metal centre decreases and the metal becomes harder. The kinetics of the substitution of H2O by CN– in [ACCbs]+, [AC-(10-NO2)Cbs]+ and[AC-(10- NH2)Cbs]+ in 50% isopropanol were determined. The results showed that the substitution of coordinated H2O proceeded with biphasic kinetics and through a dissociative interchange (Id) mechanism where there is nucleophilic participation of the entering ligand in the transition state. The slower phase corresponds to the substitution of coordinated H2O trans to OH– in the aqua hydroxo species, which, together with the dicyano species, is inevitably present in solutions of [ACCbs]+, and the faster phase corresponds to the substitution of the coordinated H2O trans to CN– in the aquacyano species. The difference in rate of the reaction of the [AC-(10-Z)Cbs] (Z = H, NH2 and NO2) was not very large, the ratio between the largest (for Z = H) and the smallest (for Z = NO2) is just over 40, and does not follow the electron donor properties of Z. This is misleading, however, because of a compensation effect between ΔH‡ and ΔS‡. As values of ΔH‡ become smaller, which causes an increase in the reaction rate, ΔS‡ becomes less positive (or more negative), which causes a decrease in the reaction rate. Hence, comparing rate constants at any particular temperature is not very informative and the compensation effect masks the very significant differences in the reactivity of the metal ion towards the entering CN– ligand. The compensation effect is attributed to the position of the transition state along the reaction coordinate, which depends on the charge density on the metal ion. Indeed, if all three reactions had the same value of ΔS‡ then the values of the rate constant would be in the approximate ratio 109:106:1 for Z = NH2, H and NO2, respectively. This study shows that how profoundly the perturbation of the electronic structure of the corrin affects the thermodynamic and kinetic properties of the Co(III) ion, and provides further evidence that the unusual chemistry of Co(III) in the cobalt corrins is a consequence of the cis-influence of the equatorial macrocyclic ligand. / LG2017