Homo ludens: Überlegungen zur historischen Anthropologie des Spiels

Homo ludens is one of the most important figures in modern anthropology. At the same time, (post-)modern theories have invoked the game to formulate a firm antithesis to anthropological concepts. This essay outlines 20th and early 21st century controversies about the game and homo ludens in order to develop a third position: one that, following Leibniz and Walter Benjamin, has the human being vanish in substance for the sake of subsequent historical recurrenc

Intermediates in Iron Group Metal-Catalyzed Hydrogenation Reactions

The present thesis reports on the development of iron group metal-catalyzed hydrogenation reactions. Specifically, mechanistic investigations have been focused to develop better catalysts in future. Chapter 1 advocates kinetic poisoning experiments for the distinction between homogeneous and heterogeneous catalysis with standard laboratory equipment. Chapter 2 reviews dibenzo[a,e]cyclooctatetraene, a typical homogeneous catalyst poison. Simple cobalt catalysts for C=C, C=O, and C=N hydrogenations have been developed in Chapter 3: Olefinic substrates stabilize the reduction of cobalt salts to obtain cobalt nanoparticles. Chapter 4 describes homogeneous hydrogenation catalysts for alkene and imine hydrogenation based on highly-reduced cobaltates. The redoxactive ligand bis(imino)acenaphthene (BIAN) allowed the isolation and detailed mechanistic analyses of olefin cobaltate and hydride intermediates. Related cobaltate catalysts have been developed for amine-borane (de)hydrogenations and transfer hydrogenations to imines, chinolines and alkenes in Chapter 5. Chapter 6 reports on the synthesis, characterization and catalysis of a dimeric iron ate complex with four bridging hydrides. In Chapter 7, olefin-stabilized nickel nanoparticle catalysts have been developed for alkene hydrogenation based on a nickel metalate. These catalysts exhibit a remarkable functional group tolerance. Chapter 8 highlights recent studies by the groups of Bedford and Neidig for ironcatalyzed cross-coupling reactions by triorganoferrates as active species. Chapter 9 summarizes the results of this thesis

Vulväre intraepitheliale Neoplasie - Entwurf eines Gesamtbildes

Entwurf eines Gesamtbildes der VIN mit Diagnostik, Therapie, DD`s und neueste Forschungen zur besseren Differenzierung. Schwerpunkt auch auf HPV-Infektionen

Cobalt-Catalyzed Hydrogenations via Olefin Cobaltate and Hydride Intermediates

Redox noninnocent ligands are a promising tool to moderate electron transfer processes within base-metal catalysts. This report introduces bis(imino)acenaphthene (BIAN) cobaltate complexes as hydrogenation catalysts. Sterically hindered trisubstituted alkenes, imines, and quinolines underwent clean hydrogenation under mild conditions (2-10 bar, 20-80 degrees C) by use of the stable catalyst precursor [((Dipp)BIAN)CoBr2] and the cocatalyst LiEt3BH. Mechanistic studies support a homogeneous catalysis pathway involving alkene and hydrido cobaltates as active catalyst species. Furthermore, considerable reaction acceleration by alkali cations and Lewis acids was observed. The dinuclear hydridocobaltate anion with bridging hydride ligands was isolated and fully characterized