Thesis (doctoral) - Universität, Zürich, 2006. / Includes bibliographical references and indexes.

Thesis (doctoral)-Universität, Marburg, 2005. / Includes bibliographical references (p. 308-352).

Thèse (M.A.) -- Université Laval, 2004. / Bibliogr.: f. [160]-170. Publié aussi en version électronique.

Thesis (M.L.A.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 54-57) Also available in print.

Frankfurt (Main), Univ., Diss. S. Maftei-Kick, T. Kick, 2000.

Universiẗat, Diss., 2003--Kassel. / Lizenzpflichtig.

Univ., Diss., 2006--Marburg

An investigation into the chemistry of solutions of titanium dioxide in fused alkali metal borates has been made, with the emphasis on the ability of the alkali borate melts to dissolve TiO2 and subsequently crystallize TiO2 and/or complex alkali metal titanates. The preparation and properties of potassium titanates with K2O/TiO2 mol ratio ≤1 has been studied. In addition the thermal decomposition of potassium hexafluorotitanate monohydrate (reported to yield potassium tetratitanate) has been investigated. The decomposition product has been identified as an oxyfluorotitanate. The compounds crystallized on slow cooling of alkali borate + TiO2 melts have been identified. The titanium containing product(s) have been correlated with the concentration of borate groups containing non-bridging oxygens, which depends on the alkali metal cation. Phase diagrams for the M2O.B2O3 + TiO2 (M = Na, K) systems have been obtained. Mass transport in M2O.2B2O3 + TiO2 (M = Li, Na, K) systems has been studied, via measurements of electrical conductivity, as a function of temperature and TiO2 concentration. Additional information on the alkali borate melts has been obtained from measurements of the optical basicity of M2O + B2O3 (M = Li, Na, K, Rb, Cs) glasses, using Pb(II) as probe ion. The results of these measurements have confirmed that the nature of the alkali metal cation significantly affects the basicity of fused alkali borate solvents. Extraction of TiO2 from ilmenite and titaniferous slag, using selected low-basicity alkali borate solvents has been attempted. The results indicate that TiO2 may be separated from ilmenite in essentially a one-step process.

Zugl.: Gießen, Univ., Diss., 1988 u.d.T.: Brake, Ludwig: Die Anfänge des Eisenbahnbaus in Frankfurt, Hessen-Darmstadt, Kurhessen und Nassau 1830- 1866.

The coordination chemistry of compounds featuring P-P and P—Sb bonds has been investigated to define the fundamental features of bonding in these systems. New reaction methodologies to form P—P bonds have been evolved based on careful consideration of bond strengths in the gas and condensed phase. Insights revealed from systematic studies of molecular structures have been used to augment and expand the scope of existing models for structural prediction (e.g. VSEPR theory). Unique classes of catena-antimony compounds have been discovered, illustrating a remarkable structural and electronic diversity for this heavy p-block metal. Detailed mechanistic examinations have revealed a previously unrecognized mode of ligand activation for phosphine complexes of very electrophilic acceptors. Stable sources of the hitherto unisolated and highly reactive tris-triflate reagents, E(OTf)3 (E = P, As, Sb, Bi), have been prepared and their coordination chemistry as Lewis acids and oxidizing agents has been mapped. Collectively, the findings described here span a range of coordination chemistry paradigms for p-block elements that may be broadly applicable across the periodic table. A robust plan has been proposed for applying these insights towards the preparation of fundamentally interesting molecular frameworks and towards new strategies for small molecule activation. / Graduate / 0488 / 0485