4.6 Article

Substantiating the Influence of Pore Surface Functionalities on the Stability of Grubbs Catalyst in Mesoporous SBA-15 Silica

Journal

CHEMISTRY-A EUROPEAN JOURNAL
Volume 17, Issue 15, Pages 4254-4265

Publisher

WILEY-V C H VERLAG GMBH
DOI: 10.1002/chem.201002740

Keywords

Grubbs catalyst; heterogeneous catalysis; mesoporous materials; olefin metathesis; phosphines; surface chemistry

Funding

  1. National Science and Engineering Research Council (Canada)
  2. Canadian Foundation for Innovation
  3. Fonds quebecois de la recherche sur la nature et les technologies (Province of Quebec)

Ask authors/readers for more resources

The influence of pore surface functionalities in mesoporous SBA-15 silica on the stability of a model olefin metathesis catalyst, namely Grubbs I, is substantiated. In particular, it is demonstrated that the nature of the interaction between the ruthenium complex and the surface is strongly depending on the presence of surface silanols. For this study, differently functionalized mesoporous SBA-15 silica materials were synthesized according to standard procedures and, subsequently, the Grubbs I catalyst was incorporated into these different host materials. All of the materials were thoroughly characterized by elemental analyses, nitrogen physisorption at -196 degrees C, thermogravimetric analyses, solid-state NMR spectroscopy, and infrared spectroscopy (ATR-IR). By such in-depth characterization of the materials, it became possible to achieve models for the surface/catalyst interactions as a function of surface functionalities in SBA-15; for example, in the case of purely siliceous silanol-rich SBA-15, octenyl-silane modified SBA-15, and silylated equivalents. It was evidenced that large portions of the chemisorbed species that are detected spectroscopically arise from interactions between the tricyclohexylphosphine and the surface silanols. A catalytic study using diethyldiallylmalonate in presence of the various functionalized silicas shows that the presence of surface silanols significantly decreases the longevity of the ring-closing metathesis catalyst, whereas the passivation of the surface by trimethylsilyl groups slows down the catalysis rate, but does not affect significantly the lifetime of the catalyst. This contribution thus provides new insights into the functionalization of SBA-15 materials and the role of surface interactions for the grafting of organometallic complexes.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available