Thesis (Ph. D.)--Catholic University of America, 1942. / Reproduced from type-written copy. "Literature cited": p. 41-43.

Thesis (M.S.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 113-118)

A new synthetic route to cyclophanenes 56, starting from an appropriate 2,6-dihalogen-substituted toluene via monothiacyclophanes as intermediate compounds, was developed. By this method, anti-5,8,13-16-tetramethyl [2,2] (1,3)cyclophan-1-ene, 56b, and anti-4,6,8,12,14,16-hexa-methyl [2,2] (1,3)cyclophan-1-ene, 56c, were first synthesized as well as three new monothiacyclophanes, anti-9,17-dimethyl-2-thia [3,2] (1,3) cyclophane, 72a, anti-6,9,14,17-tetramethyl-2-thia [3,2] (1,3) cyclophane, 72b, anti-5,7,9,13,15,17-hexamethyl-2-thia [3,2] (1,3) cyclophane, 72c. An X-ray structural determination of the monothiacyclophane 72a revealed an anti-stepped geometry of the molecule and that the aromatic rings were bent outward in a slightly distorted boat form. A reciprocal relationship between deviations of the inner carbons from their basal planes and distances between the inner carbons was found by comparison of X-ray data of four metacyclophanes. Several tricarbonylchromium(0) and η5-cyclopentadienyl-iron(I) complexes of cyclophanenes 56 were also prepared for the first time. The complexation effect and ring current reduction effects in these complexes were investigated through studies of their proton nmr spectra. An X-ray structure analysis of anti-8,16-dimethyl [2,2] (1,3) cyclophan-1-ene-cyclopentadienyliron(I), 105a, was determined and it was found that the bridge double bond (1.345A) has a cis geometry but with very large torsional angles: 24.7° for C-C=C-C and 41.6° for H-C=C-H. The bridge chemistry of cyclophanenes 56 and their metal complexes was investigated through some selected reactions. It was found that the cyclophanenes 56 were easily oxidized in attempted electrophilic additions to the bridge double bond. Bromination of the cyclophanene-iron complexes 105b and 105c did give the desired bromine adducts. However, it was found that the reactivity of the bridge double bond in cyclophanenes 56 is very low since most of the attempted reactions failed to give the desired products. The first synthesis of the (η6, η6-anti-4,6,8-trimethyl [2,2] (1,3) cyclophan-1,9-diene)-bis(tricarbonylchromium(0)), 133, was achieved through the dithiacyclophane route. An X-ray structure analysis of 133 was also determined and found that the two aromatic rings were inclined at 19.8° with respect to each other. / Graduate

No description available.

The behaviour of sands during loading has been studied in great detail. However, little work has been devoted to understanding the response of sands in unloading. Drained triaxial tests indicate that, contrary to the expected elastic behaviour, sand often exhibit contractive behaviour when unloaded. Undrained cyclic simple shear tests show that the increase in pore water pressure generated during the unloading cycle often exceeds that generated during loading. The tendency to contract upon unloading is important in engineering practice as an increase in pore water pressure during earthquake loading could result in liquefaction. This research contributes to filling the gap in our understanding of soil behaviour in unloading and subsequent reloading. The approach followed includes both theoretical investigation and numerical implementation of experimental observations of stress dilatancy in unload-reload loops. The theoretical investigation is done at the micromechanical level. The numerical approach is developed from observations from drained triaxial compression tests. The numerical implementation of yield in unloading uses NorSand — a hardening plasticity model based on the critical state theory, and extends upon previous understanding. The proposed model is calibrated to Erksak sand and then used to predict the load-unload-reload behaviour of Fraser River sand. The trends predicted from the theoretical and numerical approaches match the experimental observations closely. Shear strength is not highly affected by unload-reload loops. Conversely, volumetric changes as a result of unloading-reloading are dramatic. Volumetric strains in unloading depend on the last value of stress ratio (q/p’) in the previous loading. It appears that major changes in particles arrangement occur once peak stress ratio is exceeded. The developed unload-reload model requires three additional input parameters, which were correlated to the monotonic parameters, to represent hardening in unloading and reloading and the effect of induced fabric changes on stress dilatancy. The calibrated model gave accurate predictions for the results of triaxial tests with load-unload-reload cycles on Fraser River sand. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

This thesis describes the preparation of 5-chloro-2-trimethyl-stannyl-1-pentene (111) and its conversion into 5-chloro-2-lithio-1-pentene (112). The latter reagent, which reacts smoothly with cyclohex-anone at -78°C to give 5-chloro-2-(1-hydroxycyclohexyl)-1-pentene (132), was found to be thermally unstable at temperatures higher than -63°C. Reagent (112) was transformed into the Grignard reagent (144) and the organocopper-phosphine complex reagent (145). Conjugate addition of reagents (144) and/or (145) to cyclic enones under appropriate conditions followed by cyclization of the resultant products, effected useful methylenecyclohexane annulation sequences [(104) → (116)]. This methylenecyclohexane annulation method served as one of the two key steps in the syntheses of (±)-axamide-1 (174), (±)-axiso-nitrile-1 (173), and the corresponding C-10 epimers. Thus, copper(I)-catalyzed addition of the Grignard reagent (144) to 2-methyl-2-cyclo-penten-1-one (152), followed by cyclization of the resultant chloro ketone (159), gave the annulation product (170), which was converted into the enone (203). The other key step in the projected synthesis, which involved TiC1₄-catalyzed conjugate addition of the bis(trimethyl-silyl) ketene acetal (226) to the enone (203), provided a mixture of the keto acids (222) and (223). With appropriate functional group manipulations, (222) was converted into (±)-axamide-1 (174) and (±)-axisonitrile (173), while (223) was converted into (±)-10-epi-axamide-1 (224) and (±)-10-epi-axisonitrile-1 (225). [Formula Omitted] / Science, Faculty of / Chemistry, Department of / Graduate

<p> A theoretical solution for the progress of consolidation of a saturated soil layer subjected to cyclic loading is obtained. A comparison between the theoretical solution and the experimental results of Kaolin samples consolidating under cyclic loadings is presented. </p> / Thesis / Master of Engineering (MEngr)

Scope and Contents: This thesis is concerned with the properties of arcs of cyclic order three in the conformal plane. It establishes necessary and sufficient conditions for the union of two arcs of cyclic order three to be again an arc of cyclic order three, and for an arc of cyclic order three to be extensible to a larger arc of cyclic order three. / Thesis / Master of Science (MSc)

<p> The methylation of three isomeric hexasulphur diimides under basic conditions has been investigated. Both mono- and dimethylated products have been obtained from the 1, 5- and 1,4-hexasulphur diimides. The anion formed from the 1,3 isomer was found to undergo decomposition, the major products being polysulphides and N-methyl heptasulphur imide. The usefulness of proton NMR, mass spectra, and infrared spectra in conjunction with these compounds has been considered.</p> / Thesis / Master of Science (MSc)

No description available.