• Treffer 7 von 12
Zurück zur Trefferliste

Immobilization of Functionalized Triphenylphosphine Ligands and their Complexes for Application in Catalysis

  • The present PhD thesis is mainly focused on synthesis, characterization and catalytic application of functionalized triphenylphosphine (TPP) ligands and their complexes. We developed a simple and effective strategy to immobilize TPP: A methylester group attached to one of the phenyl rings of TPP allowes the derivatization of the ligand with 3-trimethoxysilylpropylamine, a typical silane coupling agent used for the covalent immobilization of organic compounds on silica surfaces. The resulting functionalized TPP was further coordinated to Pd, Rh and Ru precursors to achieve homogeneous complexes which can be tethered on silica by the post synthetic grafting method and co-condensation method. The obtained heterogeneous catalysts exhibited excellent activity, selectivity and reusability in Suzuki, hydrogenation and transfer hydrogenation reactions. In order to investigate the stability of the catalysts, different types of characterizations such as TEM, solid state NMR of the used catalysts as well as AAS of filtrate and leaching tests were carried out. The results prove the practicability and efficiency of our method. This strategy was further modified to generate an anionic side chain linked to the TPP core by simply replacing the trimethoxysilylpropylamine group by sodium(3-amino- 1-propanesulfonate), which allowes the immobilization on imidazolium modified SBA-15 through electrostatic interaction. The obtained material was further reacted with PdCl2(CNPh)2 and the resulting hybrid material was used for the hydrogenation of olefins allowing mild reaction conditions. The catalyst shows excellent activity, selectivity and stability and it can furthermore be reused for at least ten times without any loss of activity. TEM images of the used catalyst clearly show the absence of palladium nanoparticles, proving the high stability of the palladium compound. By AAS no palladium could be detected in the products and further leaching tests very- fied the reaction to be truly heterogeneous. This concept of non-covalent immobili- zation guarantees a tight bonding of the catalytically active species to the surface in combination with a high mobility, which should be favorable for other catalyses.
  • Immobilisierung von funktionalisierten Triphenylphosphanliganden und deren Komplexe für den Einsatz in der Katalyse

Volltext Dateien herunterladen

Metadaten exportieren

Weitere Dienste

Teilen auf Twitter Suche bei Google Scholar
Verfasserangaben:Lei Wang
URN (Permalink):urn:nbn:de:hbz:386-kluedo-26107
Betreuer:Werner Thiel
Sprache der Veröffentlichung:Englisch
Jahr der Fertigstellung:2011
Jahr der Veröffentlichung:2011
Veröffentlichende Institution:Technische Universität Kaiserslautern
Titel verleihende Institution:Technische Universität Kaiserslautern
Datum der Annahme der Abschlussarbeit:17.02.2011
Datum der Publikation (Server):07.03.2011
Freies Schlagwort / Tag:catalysis; heterogenous catalysis; hydrogenation; immobilization; silica; suzuki coupling
GND-Schlagwort:Heterogene Katalyse; Immobilisierung; Katalyse; Katalytische Hydrierung; Siliciumdioxid
Fachbereiche / Organisatorische Einheiten:Fachbereich Chemie
DDC-Sachgruppen:5 Naturwissenschaften und Mathematik / 540 Chemie
Lizenz (Deutsch):Standard gemäß KLUEDO-Leitlinien vor dem 27.05.2011