Exploiting the interactions between the ruthenium Hoveyda–Grubbs catalyst and Al-modified mesoporous silica: the case of SBA15vs.KCC-1
| Autor: | Eva Pump, Baraa Werghi, Andrei Gurinov, Pradeep Doggali, Mykyta Tretiakov, Edy Abou-Hamad, Jean-Marie Basset, Dalaver H. Anjum, Luigi Cavallo, Anissa Bendjeriou-Sedjerari |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
010405 organic chemistry chemistry.chemical_element General Chemistry Mesoporous silica 010402 general chemistry Metathesis 01 natural sciences 0104 chemical sciences Catalysis Ruthenium Propene Grubbs' catalyst chemistry.chemical_compound chemistry Polymer chemistry Mesoporous material Organometallic chemistry |
| Zdroj: | Chemical Science. 9:3531-3537 |
| ISSN: | 2041-6539 2041-6520 |
| DOI: | 10.1039/c7sc05200f |
| Popis: | Immobilization of the 2nd generation Hoveyda–Grubbs catalyst HG-II onto well-ordered 2D hexagonal (SBA15) and 3D fibrous (KCC-1) mesostructured silica, which contained tetra-coordinated Al, has been investigated through the Surface Organometallic Chemistry (SOMC) methodology. The main interest of this study lies in the peculiarity of the silica supports, which display a well-defined tetrahedral aluminum hydride site displaying a strong Lewis acid character, [(Si–O–Si)(Si–O–)2Al–H]. The resulting supported Hoveyda–Grubbs catalysts have been fully characterized by advanced solid state characterization techniques (FT-IR, 1H and 13C solid state NMR, DNP-SENS, EF-TEM…). Together with DFT calculations, the immobilization of HG-II does not occur through the formation of a covalent bond between the complex and the Al-modified mesoporous silica as expected, but through an Al⋯Cl–[Ru]-coordination. It is not surprising that in functionalized olefin metathesis of diethyldiallyl malonate, DEDAM (liquid phase), leaching of the catalyst is observed which is not the case in non-functionalized olefin metathesis of propene (gas phase). Besides, the results obtained in propene metathesis with HG-II immobilized either on SBA15 (dpore = 6 nm) or KCC-1 (dpore = 4 or 8 nm) highlight the importance of the accessibility of the catalytic site. Therefore, we demonstrate that KCC-1 is a promising and suitable 3D mesoporous support to overcome the diffusion of reactants into the porous network of heterogeneous catalysts. |
| Databáze: | OpenAIRE |
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