TY - JOUR
T1 - Exploiting the interactions between the ruthenium Hoveyda–Grubbs catalyst and Al-modified mesoporous silica: the case of SBA15 vs. KCC-1
AU - Werghi, Baraa
AU - Pump, Eva
AU - Tretiakov, Mykyta
AU - Abou-Hamad, Edy
AU - Gurinov, Andrei
AU - Doggali, Pradeep
AU - Anjum, Dalaver H.
AU - Cavallo, Luigi
AU - Bendjeriou-Sedjerari, Anissa
AU - Basset, Jean-Marie
N1 - KAUST Repository Item: Exported on 2020-04-23
Acknowledgements: The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). The authors are grateful to the KAUST Supercomputing Laboratory (KSL) for the resources provided.
PY - 2018
Y1 - 2018
N2 - Immobilization of the 2 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-)Al-H]. The resulting supported Hoveyda-Grubbs catalysts have been fully characterized by advanced solid state characterization techniques (FT-IR, H and C 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 (d = 6 nm) or KCC-1 (d = 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.
AB - Immobilization of the 2 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-)Al-H]. The resulting supported Hoveyda-Grubbs catalysts have been fully characterized by advanced solid state characterization techniques (FT-IR, H and C 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 (d = 6 nm) or KCC-1 (d = 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.
UR - http://hdl.handle.net/10754/627503
UR - http://pubs.rsc.org/en/Content/ArticleLanding/2018/SC/C7SC05200F#!divAbstract
UR - http://www.scopus.com/inward/record.url?scp=85045061791&partnerID=8YFLogxK
U2 - 10.1039/c7sc05200f
DO - 10.1039/c7sc05200f
M3 - Article
C2 - 29780484
AN - SCOPUS:85045061791
VL - 9
SP - 3531
EP - 3537
JO - Chemical Science
JF - Chemical Science
SN - 2041-6520
IS - 14
ER -