ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Treffer pro Seite

Treffer 1 - 2 | 2 Treffer

Sortierung

Digitale Medien

Structural Studies and Catalytic Activity of MCM-41 and MCM-48 Modified With the Titanocenophane [SiMe2(η5-C5H4)2]TiCl2 (2000)

Ferreira, Paula ; Gonçalves, Isabel S. ; Kühn, Fritz E. ; [weitere]

Weinheim : Wiley-Blackwell

Berichte der deutschen chemischen Gesellschaft 2000 (2000), S. 551-557

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1434-1948

Schlagwort(e): Mesoporous materials ; MCM-41 ; MCM-48 ; Immobilisation ; Solid-state NMR ; Heterogeneous catalysis ; Titanium ; Titanocenes ; Chemistry ; General Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: Titanium(IV)-grafted mesoporous silicas have been prepared by diffusion of an excess of the ansa-bridged titanocene [SiMe2(η5-C5H4)2]TiCl2 into the channels of hexagonal MCM-41 and cubic MCM-48 in dichloromethane or tetrahydrofuran at room temperature. The choice of solvent determines the course of the reaction and hence the activity of the resulting materials as catalysts in the catalytic epoxidation of cyclooctene with tert-butylhydroperoxide. Magic-angle spinning (MAS) NMR (13C, 29Si) spectroscopy was used to characterise the local environment of the surface-bound titanium active sites. When dichloromethane is used, the dominant species anchored to the surface are isolated ansa-bridged titanocene fragments. When THF is used, the [SiMe2(η5-C5H4)2] unit is lost with the concomitant formation of surface-bound TiIV species coordinated by THF molecules. These materials showed the best catalytic performance per Ti atom for the conversion of cyclooctene. All materials were further characterised by means of elemental analysis, powder X-ray diffraction (XRD), N2 adsorption and FTIR spectroscopy.

Zusätzliches Material: 7 Ill.

Materialart: Digitale Medien

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Digitale Medien

Structural Studies of MCM-48 Derivatized with (1,1′-Ferrocenediyl)dimethylsilane (2000)

Ferreira, Paula ; Gonçalves, Isabel S. ; Mosselmans, Fred ; [weitere]

Weinheim : Wiley-Blackwell

Berichte der deutschen chemischen Gesellschaft 2000 (2000), S. 97-102

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1434-1948

Schlagwort(e): Mesoporous materials ; MCM-48 ; Immobilization ; (1,1′-Ferrocenediyl)dimethylsilane ; 13C and 29Si solid-state NMR ; Sandwich-complexes ; Chemistry ; General Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The walls of the cubic mesoporous silicate MCM-48 have been grafted with ferrocenyl end groups by a ring-opening reaction of the ansa-bridged ferrocene [Fe{(η-C5H4)2SiMe2}], carried out in a pentane solution at room temperature. The orange product has been characterized by elemental analysis, powder X-ray diffraction, 13C and 29Si solid-state NMR, N2 adsorption measurements, and Fe K-edge EXAFS. A high loading has been obtained (8.18 mass % Fe) and, as a result of the inclusion of the organometallic moiety, the N2 adsorption isotherm exhibits a lower uptake. Direct structural evidence for the surface attachment of both single ferrocenyl and short chain oligo(ferrocenyl) fragments has been obtained.

Zusätzliches Material: 6 Ill.

Materialart: Digitale Medien

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Treffer 1 - 2 | 2 Treffer