TU Darmstadt / ULB / TUbiblio

Solid-State NMR Characterization of Wilkinson's Catalyst Immobilized in Mesoporous SBA-3 Silica

Grünberg, A. and Xu, Y. P. and Breitzke, H. and Buntkowsky, G. :
Solid-State NMR Characterization of Wilkinson's Catalyst Immobilized in Mesoporous SBA-3 Silica.
[Online-Edition: <Go to ISI>://WOS:000279856100032]
In: Chemistry-a European Journal, 16 (23) pp. 6993-6998.
[Article] , (2010)

Official URL: <Go to ISI>://WOS:000279856100032

Abstract

The Wilkinson's catalyst RhCl(PPh3)(3) has been immobilized inside the pores of amine functionalized mesoporous silica material SBA-3 and The structure of the modified silica surface and the immobilized rhodium complex was determined by a combination of different solid-state NMR methods. The successful modification of the silica surface was confirmed by Si-29 CP-MAS NMR experiments. The presence of the T-n peaks confirms the successful functionalization of the support and shows the way of binding the organic groups to the surface of the mesopores. P-31-P-31 J-resolved 2D MAS NMR experiments were conducted in order to characterize the binding of the immobilized catalyst to the amine groups of the linkers attached to the silica surface. The pure catalyst exhibits a considerable P-31-P-31 J-coupling, well resolvable in 2D MAS NMR experiments. This I-coupling was utilized to determine the binding mode of the catalyst to the linkers on the silica surface and the number of triphenylphosphine ligands that are replaced by coordination bonds to the amine groups. From the absence of any resolvable P-31-P-31 J-coupling in off-magic-angle-spinning experiments. as well as slow-spinning MAS experiments, it is concluded, that two triphenylphosphine ligands are replaced and that the catalyst is bonded to the silica surface through two linker molecules.

Item Type: Article
Erschienen: 2010
Creators: Grünberg, A. and Xu, Y. P. and Breitzke, H. and Buntkowsky, G.
Title: Solid-State NMR Characterization of Wilkinson's Catalyst Immobilized in Mesoporous SBA-3 Silica
Language: German
Abstract:

The Wilkinson's catalyst RhCl(PPh3)(3) has been immobilized inside the pores of amine functionalized mesoporous silica material SBA-3 and The structure of the modified silica surface and the immobilized rhodium complex was determined by a combination of different solid-state NMR methods. The successful modification of the silica surface was confirmed by Si-29 CP-MAS NMR experiments. The presence of the T-n peaks confirms the successful functionalization of the support and shows the way of binding the organic groups to the surface of the mesopores. P-31-P-31 J-resolved 2D MAS NMR experiments were conducted in order to characterize the binding of the immobilized catalyst to the amine groups of the linkers attached to the silica surface. The pure catalyst exhibits a considerable P-31-P-31 J-coupling, well resolvable in 2D MAS NMR experiments. This I-coupling was utilized to determine the binding mode of the catalyst to the linkers on the silica surface and the number of triphenylphosphine ligands that are replaced by coordination bonds to the amine groups. From the absence of any resolvable P-31-P-31 J-coupling in off-magic-angle-spinning experiments. as well as slow-spinning MAS experiments, it is concluded, that two triphenylphosphine ligands are replaced and that the catalyst is bonded to the silica surface through two linker molecules.

Journal or Publication Title: Chemistry-a European Journal
Volume: 16
Number: 23
Uncontrolled Keywords: heterogeneous catalysis nmr spectroscopy phosphorus wilkinson's catalyst rhodium hydrogenation catalysts transition-metal complexes inorganic hybrid materials ruthenium(ii) complex selective oxidation controlled-release nanoparticles olefins alkenes surface
Divisions: 07 Fachbereich Chemie > Physical Chemistry
07 Fachbereich Chemie
Date Deposited: 27 Oct 2014 20:40
Official URL: <Go to ISI>://WOS:000279856100032
Additional Information:

624XS Times Cited:9 Cited References Count:69

Export:

Optionen (nur für Redakteure)

View Item View Item