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Siegel der Universität
Department für Chemie - Arbeitsgruppe Prof. Strey

Mikroemulsionen als Reaktionsmedien für Suzuki-Kupplungen

Banu Yesilyurt, 2013


Due to their environmental safety and immensely large interface, microemulsions are suitable as a medium for organic synthesis reactions for the ecological and efficient synthesis of fine chemicals. By setting up a threephase system, it is possible to isolate products, catalysts and byproducts through phase separation from each other. However, due to the different extraction tendencies of the various homologs of a technical surfactant, multiple applications of the catalyst containing microemulsion phase drives, with each reaction cycle, a continuous shift of the phase boundaries to higher temperatures. Therefore, the influence of the extraction on the phase behavior of the technical system H2O – nheptane  Marlipal® 24/50 was examined in this work. The consequent phase shift to higher temperatures resulting from extraction was counteracted by two approaches. On the one hand, the phase shift was compensated for by addition of more hydrophobic technical co-surfactants. On the other hand, this effect can be avoided through the use of homologous pure short-chain surfactants. For this purpose, the phase behaviors of the system H2O – ndecane – C4E1 and the system H2 nheptane  Marlipal® 24/50 were characterized. Subsequently, the speed of the phase separation in the threephase region of the systems H2 ndecane – C4E1 and H2 nheptane  Marlipal® 24/50 was investigated at their mean temperature by eye and using an apparatus to visualize phase separations.