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The synthesis, structure and reactivity of organolanthanide complexes supported by a family of novel bis(phosphinimine)carbazole and bis(phosphinimine)pyrrole pincer ligands is presented. Through the systematic development of the ligand frameworks, rare earth metal species with unique structure and reactivity were encountered. A variety of complexes that exhibited unusual bonding modes were prepared and characterized by single-crystal X-ray diffraction and multinuclear NMR spectroscopy. Modulation of the ligand frameworks allowed for rational manipulation of the steric and electronic environment imparted to the metal. Incorporation of a variety of N-aryl rings (mesityl, phenyl, para-isopropylphenyl and 2-pyrimidine) and PR2 moieties (PPh2, PO2C2H4 and PMe2) into the ligand design led to rare earth complexes that revealed diverse reaction behaviour. In particular, C–H bond activation, sigmatropic alkyl migration and ring opening insertion reactivity were observed. Kinetic and deuterium labeling studies are discussed with respect to the unique reaction mechanisms encountered during the study of these highly reactive organometallic rare earth complexes. / xxvi, 247 leaves : ill. (some col.) ; 29 cm + 1 CD-ROM

The best type of information about the Earth's interior is seismic. Seismic wave velocity depends on the value of the bulk modulus of the rock. The geophysicist Sir Harold Jeffreys derived a relation between temperature and bulk modulus for solids. From this, and the well known variation of velocity with bulk modulus for solids, we derived the variation of velocity for solids with temperature. We compared this relation to general data on rocks in order to test Jeffreys' predictions in our applications. Next, using the above relation as well as the well known relation between temperature and radius for an adiabatic Earth, we found the variation of bulk modulus with radius. This relation was then compared to actual values of the bulk modulus of the Earth in each major region.The variation of bulk modulus with radius should have been a close fit to the derived equation. This closeness of the fit would then be a measure of how close a region was too adiabatic conditions.The results of this study seem to indicate that the inner core and the outer core of the Earth seem to be near adiabatic conditions. / Department of Physics and Astronomy

Thesis (Ph.D.)--Memorial University of Newfoundland. / Typescript. Bibliography: leaves 146-154. Also available online.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [137]-146).

Thesis (Ph. D.)--Université de Paris-Sud, 1987. / "Thèse présentée pour obtenir le titre de Docteur en Sciences ... soutenue le 22 octubre 1987." At head of title: Sujet. Includes bibliographical references.

Thesis (Ph. D.)--Kings College, Cambridge, 1966. / Includes bibliographical references.

Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1983. / Includes bibliographical references.

<p>Geochronological study of the Grenville Province has been an ongoing project at McMaster for the past 20 years. Over 1,500 orthogenesis samples have been collected from a 700,000 square kilometer region, and geochemically analyzed for Neodymium model ages. This vast area has been subjected to multiple accretion and ductile deformation episodes, creating great geological complexity.</p> <p>The two mam belts of the Grenville Province are the Allochthonous Belt, consisting of terranes which were laterally transported by the Grenville orogeny, and the underlying Parautochthonous Belt. The boundary separating these two major belts is termed the Allochthon Boundary Thrust (ABT) and represents the northwesterly limit of major crustal movement during the Grenville orogeny. Due to the high degree of exhumation of mid to lower crustal levels, identification of the ABT is difficult within Southwestern Ontario. As a result, lithological maps, such as the Geological Survey of Canada (GSC) map of the Grenville Province created by Davidson (1998), do not correctly identify sections of the ABT. In addition, impOliant geological features such as structural outliers (klippen) of the Allochthonous belt are not correctly identified. Along much of its length the ABT defines the boundary between Archean- Paleoproterozoic (> 1.8 Ga) and the Paleo- Mesoproterozoic «1.8 Ga) crust. Therefore, by measuring the isotopic composition of either side of the ABT the boundary can be clearly defined.</p> <p>Previously collected Nd isotope data were plotted on ESRI's Geographical Information System (GIS) and digitally represented. Interpolation based on sample age distribution was conducted to assess completeness of the data set. Interpolation techniques included triangulated irregular networks, inverse distance weighting, and kriging, which were used to obtain global and localized trends. This approach highlighted discrepancies between geological and geospatial interpretation, therefore highlighting areas which needed additional sampling.</p> <p>Nd-model analysis of olihogneiss from four areas collected within Northeastern Ontario and Southwestern Quebec have provided additional information to this interpolation process. Through the addition of these samples the boundaries of the ABT and klippen have become much more precise. Digital mapping of the terranes of the Grenville Province through integration of the aforementioned techniques has provided an improved understanding to the geological history of the Grenville Orogeny.</p> / Master of Science (MS)

<p>By studying signatures of life within extreme environments on Earth we better understand signatures of life that may be found within the geologic record on Earth as well as elsewhere in the universe. This thesis research utilized phospholipid fatty acid analysis (PLFA) in combination with carbon isotopic analysis (δ¹³C) to understand microbial carbon cycling and biosignatures within two Mars analogue environments.</p> <p>The Golden Deposit was an acid sulfate environment that was an analogue to the acid-sulfate conditions present on early Mars. Mixing of inflowing surface water and upwelling acidic groundwater on the deposit caused variations in water chemistry. Such variations resulted in differences in the microbial communities and carbon isotopic compositions within the Golden Deposit. The most acidic groundwater seep on the deposit had a distinct geochemistry, which selected for a unique microbial community and distinct carbon isotopic signatures. Variations detected within the small spatial area of the Golden Deposit indicated that biosignatures preserved on Mars might be highly variable making the unambiguous identification of past life on the planet more difficult.</p> <p>Three saline lakes of the Cariboo Plateau were used for this study and were analogues to environmental conditions present on early Earth as well as the alkaline, evaporitic conditions present on early Mars. All three lakes contained benthic microbial mat communities dominated by cyanobacteria. Photosynthetic influences by cyanobacteria resulted in an isotopic enrichment of the DIC pool. Enriched lake DIC values were preserved in precipitated carbonates (δ¹³C_carb) and the ∆¹³C_DIC-TOC(avg) was similarly preserved in ∆¹³C_carb-TOCvalues and were biosignatures of photosynthetic activity. The preservation of these biosignatures suggested that concentrations of CO₂ on early Earth did not necessarily exceed modern levels and that measuring the carbon isotopic compositions of carbon pools within saline, carbonate-rich deposits on Mars could lead to the identification of past life on the planet.</p> / Master of Science (MS)