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This investigation is concerned with a study of the properties of scandium-germanium systems, and a study of the properties of selenium and zinc doped gallium arsenide„ In part one the physical properties of scandium and germanium are used to empirically estimate the relative solubility of scandium in germanium. It was shown that scandium and germanium are miscible in the liquid phase and that scandium has a very low solid solubility in germanium. Crystals of scandium-doped germanium were grown and analyzed using Hall constant and resistivity measurements from liquid nitrogen temperature to room temperature. The results show that the crystals grown are p-type, but that this behaviour cannot be completely attributed to scandium. However, it was shown that if scandium does not form compounds on crystal growth, it has a maximum solubility in germanium of less than one part per million. Methods for analysing the results of experimental measurements, to determine the concentration of acceptors, donors and free carriers, and the ionization energies are given. In part two the properties of selenium and zinc doped gallium arsenide were studied, again using resistivity and Hall measurements. Selenium and zinc were determined to be shallow donors and acceptors respectively. The concentration of the impurities present were determined and the properties of the material were discussed. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

<p> New uranium(VI) complexes of a-hydroxyquinoline ligands of formulae U02(R-Q)2 R-QH have been prepared. In these compounds, the additional liquid is likely bonded as a zwitterion. Appropriate substitution in the 2- and 7-positions lead to interesting steric effects. Some uranium(VI) complexes reported in the literature have been re-examined and found to be incorrectly formulated. </p> <p> The scandium(III) complex of a-hydroxyquinoline obtained from aqueous solution was. found to be Sc(C9H6N0) 3 •H20 and not Sc(CgH&N0) 3 •C 9H7NO as previously reported. In the absence of water, Sc (CgH&NO) 3 •C 9H7NO 'Was obtained. New scandium(III) complexes of formulae Sc(R-Q) 3 •R-QH and Sc(R-Q) 3 •H20 have been prepared. </p> / Thesis / Doctor of Philosophy (PhD)

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Thesis (Ph.D.)--Northwestern University, 2003. / Includes bibliographical references (leaves 150-161).

Thesis advisor: Jason S. Kingsbury / The research of diazoalkanes dates back more than 100 years, yet a disproportionally small number of methods have been developed to utilize their unique reactivity patterns. This review seeks to analyze the history of methods used to synthesize diazoalkanes and to highlight the parallel growth in methods for their use in carbonyl expansion reactions. The development of Sc(III)-catalyzed ring expansion of cyclic ketones with non-stabilized diazoalkanes is presented. A brief overview of previous contributions to ring expansion methodology is presented in order to provide appropriate context to newly discovered methods. Our strategy for method development centered on several issues of practicality with regard to efficient synthesis of diazo nucleophiles as well as their safe handling. The results of this initial discovery laid the groundwork for the development of the first catalytic enantioselective ring expansion of cyclic ketones with diazoalkanes. As well as an improved methylene insertion reaction of silyl-substituted diazomethanes. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Our effort to provide an efficient route to serine glycosides with utility in glycopeptide synthesis has led to the identification of two particularly effective promoters of O-glycosylation. Indium(III) bromide and scandium(III) triflate were shown to be superior promoters of microwave accelerated O-glycosylation utilizing peracetyl carbohydrate donors. 247, 249 These Lewis acids afforded several advantages over previously described promoters including, increased yields, tolerance to moisture, decreased environmental toxicity, ease of work up, and increased reproducibility. Both affected the microwave accelerated glycosylation of Fmoc-ser-OH with sugar peracetates providing superior yields to previously reported methods. For larger scale work the two step route involving the glycosylation of Fmoc-Ser-OBn followed by removal of the benzyl protecting group via hydrogenolysis was preferred. Of the two Lewis acids, the minimally active indium (III) bromide was preferred, as it afforded slightly higher yields and was effective in catalytic quantities. Three groups of helical DAMGO glycopeptide analogs were synthesized in order to provide a better understanding of the structure activity relationships of these opioid peptides. Although the introduction of the amphipathic helix significantly affected binding of the DAMGO message, there was no correlation between binding affinity at the individual opioid receptors and the degree of helicity. In general, addition of the helical address imparted increased affinity for the kappa receptor. The nature of the linker connecting the N-terminal DAMGO sequence and the C-terminal helical address effected binding affinity only slightly. Successive addition of positive charges to the address increased binding at all three opioid receptors until a maximum was reached at a positive two address charge. Although, the amphipathic helix was shown to moderate receptor selectivity, the native mu preference of the DAMGO message was retained Two groups of fluorescent analogs of the mixed δ / μ opioid agonist MD100 were prepared. Within the first series, the fluorescent label was attached to the interior of the address sequence employing the pNZ moiety as a secondary protecting group. The second series of analogs was based on NovaTag™ resin, and allowed for attachment of the fluorophore at the carboxy terminus. The influence on helicity imparted by fluorophore conjugation depended on the nature and point of attachment of the label. The disruption of secondary structure associated with attachment of the fluorescent correlated with decreased binding affinity at the individual opioid receptors. Preliminary in vivo results were encouraging. The least parent like of the MD100 fluorescent analogs was shown to be taken up into endothelial cells. This suggests that the labeled glycopeptides are likely to cross the blood-brain barrier.