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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Untersuchungen zur Wirkstoffproduktion extremophiler Mikroorganismen sowie Biosynthese und Derivatisierung ausgewählter mikrobieller Naturstoffe / Investigations on the Production of Bioactive Metabolites by Extremophilic Microorganisms as well as Biosynthesis and Derivatization of Selected Microbial Natural Products

Kubicek-Pejic, Adrijana 31 October 2007 (has links)
No description available.
32

Totalsynthese der Mansouramycine A-E aus Streptomyces sp. und Rhodium-katalysierte 1,2-Additionen an cyclische Enone / Total synthesis of Mansouramycine A-E from streptomyces sp. and rhodium catalized 1,2-additions to cyclic enones

Beerlink, Johannes 14 October 2008 (has links)
No description available.
33

Palladium-katalysierte Kreuzkupplungen zu 1,2-Dialkenylcycloalkenen: Ausgangsstoffe zur Synthese vielfältiger cyclischer Kohlenstoffgerüste / Formation of 1,2-Dialkenylcycloalkenes via Palladium-Catalyzed Cross-Coupling Reactions: Starting Materials for the Synthesis of Various Cyclic Carbon-Skeletons

Zezschwitz, Eckart Paultheo von 04 November 1999 (has links)
No description available.
34

Methanophenazin: Strukturaufklärung und Totalsynthese eines neuartigen Cofaktors aus methanogenen Archaea / Methanophenazine: Structure and Total Synthesis of a New Co-factor from Methanogenic Archaea

Tietze, Mario 02 November 2000 (has links)
No description available.
35

Development of Viable Synthetic Approaches to Highly Functionalized Small Ring Systems - Synthesis of Novel Cyclopropylacrylates as Monomers for Low-Shrinkage Polymer-Composites / Development of Viable Synthetic Approaches to Highly Functionalized Small Ring Systems - Synthesis of Novel Cyclopropylacrylates as Monomers for Low-Shrinkage Polymer-Composites

Bahutski, Viktar 21 January 2004 (has links)
No description available.
36

Synthesis of New Spirocyclopropanated beta-Lactams and Their Application as Building Blocks for beta-Amino Acid Peptides / Synthesis of New Spirocyclopropanated beta-Lactams and Their Application as Building Blocks for beta-Amino Acid Peptides

Zanobini, Alessandra 02 November 2005 (has links)
No description available.
37

Unprecedented Synthetic and Reactivity Studies of Compounds with Low Valent Group 14 Elements

Jana, Anukul 22 October 2009 (has links)
No description available.
38

Bildungsbedingungen und rationale Synthesestrategien: MOF-5 und seine Homologen

Hausdorf, Steffen 30 September 2011 (has links)
MOF-5 ist der Archetyp einer neuartigen Klasse hochporöser Materialien, den Metal Organic Frameworks, die unter anderem zur Anwendung als effektive Gasspeicher geeignet sind. Im Rahmen dieser Arbeit werden die seiner Bildung zugrunde liegenden Reaktionen untersucht. Aus den Erkenntnissen dieser Untersuchungen wurden zwei neue Syntheseverfahren entwickelt. Eines der Verfahren beruht auf der Phasenumwandlung von Zinkterephthalaten und ermöglichte die Laborsynthese von MOF-5 in 100 g-Mengen. Ein zweites Verfahren bedient sich des Strukturaufbaus mit Hilfe vorgefertigter anorganischer Cluster, wodurch erstmals die Synthese von MOF-5-Homologen anderer Metalle als Zink gelang.
39

Electronic properties of metal-organic and organic-organic interfaces studied by photoemission and photoabsorption spectroscopy

Molodtsova, Olga 18 July 2007 (has links)
In this work systematic studies of the organic semiconductor CuPc have been presented. In general the investigation can be devided in three parts. In the first one we have studied the electronic structure of clean CuPc thin film. The next two parts are devoted to organic-organic and metal–organic interface formation, where one of the interface components is CuPc thin film. The main results of this thesis are: - The electronic structure of the pristine organic semiconductor CuPc (valence band and empty states) has been obtained by a combination of conventional and resonant photoemission, near-edge X-ray absorption, as well as by theoretical ab initio quantum-chemical calculations. A qualitative assignment of different VB structures has been given, or in other words the contributions of different atomic species as well as sites of the CuPc molecule to the electronic DOS has been established. In particular, it was shown, that the HOMO is mainly comprised of the spectral weights from the orbitals of carbon pyrolle atoms. Additional contributions to the HOMO stems from the benzene atoms. A combined experimental and theoretical study of the unoccupied electronic density of states of CuPc was presented. Our study allows identifying the contributions from different parts of the molecule to the unoccupied DOS and the measured spectra, which lays grounds for future studies of the evolution of the CuPc electronic states upon e.g. functionalization or doping. Application of similar studies to other organic semiconductors will also provide significant insight into their unoccupied electronic states. - The electronic properties of the organic heterointerfaces between fullerite and pristine copper phthalocyanine were studied. Both interfaces, CuPc/C60 and C60/CuPc, were found to be non-reactive with pronounced shifts of the vacuum level pointing to the formation of an interfacial dipole mainly at the CuPc side of the heterojunctions. The dipole values are close to the difference of the work functions of the two materials. Important interface parameters and hole-injection barriers were obtained. The sequence of deposition does not influence the electronic properties of the interfaces. - CuPc doped with potassium was studied by means of photoemission and photoabsorption spectroscopy. A detailed analysis of the core-level PE spectra allows one to propose possible lattice sites, which harbor the potassium ions. Contrasting to a few results reported in the literature, the films prepared in this thesis showed no finite electronic density of states at the Fermi level. - Two stages of the In/CuPc interface formation have been distinguished. The low-coverage stage is characterized by a strong diffusion of the In atoms into the organic film. Metal ions occupy sites close to the pyrolle nitrogen and strongly interact with molecules transferring negative charge to CuPc. Indium diffusion into the organic films saturates at a stoichiometry of In2CuPc. Subsequently, in the second stage the formation of a metallic indium film occurs on the top of the In2CuPc film. - Upon deposition on CuPc film Sn and Ag atoms do not diffuse into the organic film forming metallic clusters and/or thin metallic overlayer. Sharp metal-organic film interface is formed, in contrast to indium and potassium deposition. Presented experimental results also give evidence for absence of noticeable chemical reaction of Sn and Ag with CuPc thin film. - The systematic investigation of interface formation between CuPc thin film and various metals gives us the possibility to summarize all results with demonstrating similarities and differences for all systems studied.
40

Untersuchungen zur Synthese von Yohimban- und Campthoteca-Alkaloiden durch Domino-Knoevenagel-Hetero-Diels-Alder-Reaktion / Efforts toward the total synthesis of yohimban and campthoteca alkaloids via domino Knoevenagel-hetero-Diels-Alder reaction

Klapa, Katharina Anna 17 January 2007 (has links)
No description available.

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