Die Reaktivität von Diboranen(4) (1,2-Dihalogendiboranen(4)) gegenüber von metallischen und nicht-metallischen Lewis-Basen wurde untersucht. Die Ergebnisse zeigen, dass die oxidative Addition einer Bor-Halogen-Bindung an ein Platin(0)-Komplex selektiv verläuft und in trans-Diboran(4)yl-Bisphosphan-Platin-Komplexen resultiert. Bei Verwendung von 1,2-Dihalogen-1,2-diaryldiboranen(4) findet sich in den korrespondierenden trans-Diboran(4)yl-Platin-Komplexen eine dative Bindung des Platin-Zentralatoms zum entfernten zweiten Bor-Atom, welche sowohl in Lösung als auch im Festkörper beobachtet wird. Die erhaltenen trans-Diboran(4)yl-Komplexe wurden auf ihre Reaktivität untersucht, hierbei konnte erstmals durch Reduktion ein Diboren-Platin-Komplex synthetisiert werden. Die Untersuchung der Reaktivität von nicht-metallischen Lewis-Basen ergab eine Reihe von sp2-sp3-Diboranen an die entweder PEt3 oder PMeCy2 koordiniert ist. In Abhängigkeit des sterischen Anspruches finden sich zwei Isomere mit 1,2- und 1,1'-Anordnung der Halogene. Die 1,2-Isomere zeigen hierbei im Festkörper eine Bor-Halogen-Bor-Brücke mit einer dativen Halogen-Bor-Bindung zwischen dem Halogen und dem sp2-Borzentrum. / The reactivity of diboranes(4) (1,2-dihalodiboranes(4)) towards metal and non-metal Lewis-Bases was examined. The results have shown that the oxidative addition of the boron-halide bond to a platinum center results exclusively in the corresponding trans-diboran(4)yl-bisphosphane-platinum complexes. Using 1,2-dihalo-1,2-diaryldiboranes(4) for the oxidative addition to platinum(0) reveals the corresponding trans-diboran(4)yl platinum complexes with a dative platinum boron bond to the remoted boron atom of the diboran(4)yl ligand. This structural motive can be found in solution as well as in the solid state. The reactivity of the obtained trans-diboran(4)yl-platinum complexes were investigated. Here a diborene-platinum complex was synthesized for the first time by reduction chemistry. The investigation of the reactivity of diboranes(4) toward non-metal Lewis-Bases, such as PEt3 or PMeCy2, lead to sequence of sp2–sp3 phosphine adducts of diboranes. Depending on the steric demand of the used phosphanes two isomers were identified and characterized. The isomers distinguish between the 1,2- and 1,1’-substitutions pattern of the halides, which are formed by a 1,2-rearrengment, which is favoured for the bulky PMeCy2. In the solid state the 1,2-isomers are showing a boron-halide-boron bridge and a rare dative boron-halide bonding interaction to the sp2 boron center.

Diese Dissertation befasst sich mit der Darstellung und Reaktivität von Lewisbasenstabilisierten Bor-Bor-Mehrfachbindungssystemen. Besonderes Augenmerk lag hierbei auf der Aktivierung von Element-Wasserstoff-Bindungen von Boranen, Aminen, Silanen und Phosphanen durch NHC-stabilisierte Diborine. Des Weiteren wurde die Aktivierung von Bor-Bor-, sowie Phosphor-Phosphor-Einfachbindungen untersucht. Zusätzlich wurde die Reaktivität gegenüber Carbenen und aromatischen Stickstoffbasen näher beleuchtet. / This dissertation deals with the representation and reactivity of Lewis base-stabilized boron-boron multiple bond systems. Special attention was paid to the activation of element-hydrogen bonds of boranes, amines, silanes and phosphanes by NHC-stabilized diborins. Furthermore, the activation of boron-boron and phosphorus-phosphorus single bonds was investigated. In addition, the reactivity towards carbenes and aromatic nitrogen bases was investigated.

Recent scholarship has taken an interest in C. S. Lewis's political views and how they are manifested in his fiction. However, few have thoroughly analyzed the specific political implications of his children's series, The Chronicles of Narnia. Part of this may be because Lewis himself insisted his fiction was nonpartisan. The heavily religious allegories in the series can also overshadow the political commentary. This thesis contributes to the growing discourse on political commentary in Lewis's fiction by identifying four concerns he had with progressive education and then demonstrating how he criticizes them in Prince Caspian, The Voyage of the Dawn Treader, and The Silver Chair. It then proposes that Lewis presents Narnia as a remedy to progressive education by providing a moral, classical, and literary education to its fictional visitors and real-life readers.

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In der vorliegenden Arbeit wurden Diorganobismut-Spezies hinsichtlich ihrer Eigenschaften als Liganden in Übergangsmetallkomplexen, ihrer Lewis-Azidität, ihrer Eignung als Katalysatoren und die Generierung niedervalenter Spezies untersucht. / In this work, neutral and cationic diorganobismuth species have been studied, focusing on the rationalization of their Lewis acidity, their use as ligands in complexes of main group and transition metals and the identification of active catalysts.

<p>This dissertation is a critical examination of the fictional works of G.S. Lewis, focussing upon the concepts of reality, truth and perspective as they are expressed in the fiction. The discussion follows the narrative of each work in turn, thus orienting the reader by means of the works themselves, rather than by means of rubrics concerning their subjects or themes. The intent is to follow Lewis's precept, that the good reader should attend to any work of literature as something made as well as something said. The introduction surveys the development of Lewis's thought on the nature of reality and truth, and of the role of the imagination and the reason in apprehending these things. Evidence from Lewis's letters (including unpublished letters), essays, apologetics, addresses and autobiography is considered. A survey of the major criticism of Lewis's fiction is included in the introduction. A chapter of analytical discussion is then devoted to each of the books of the Ransom trilogy, to the Chronicles of Narnia as a series, and to Till We Rave Faces. </p> <p> Lewis came to believe in the existence of an ultimate, central Reality in the person of God, ln whom all lesser realities focus, and from whom they depend. He believed also in man's ability to perceive truth -- valid asssrtions concerning these realities -through the exercise of the reason, and adherence to the moral law. Mythopoeic and symbolic literature had, in Lewis's estimation, the unique ability to convey reality whole into the mind of the receptive reader. The concentration of this kind of literature upon unusual and unexpected subjects, he believed, could serve to correct the reader's perspective upon reality, by furnishing the imagination with those materials which the implicit materialism and naturalism of much of modern "realistic" literature might have kept from the reader's consideration. Lewis's own fantasies -- a science-fiction trilogy, seven fairy-tales, and a novel based on the old myth of Cupid and Psyche -- are unified by their preoccupation with the importance of an undistorted perspective upon reality, the possibility of perceiving truth, and of distinguishing truth from error, of the dependence of all reality upon an ultimate, central Reality, and of the possibility of knowing that Reality by entering into a personal relationship with God. </p> / Thesis / Doctor of Philosophy (PhD)