WMe6 tamed by silica: Si-O-WMe5 as an efficient, well-defined species for alkane metathesis, leading to the observation of a supported W-methyl/methylidyne species

Abstract
The synthesis and full characterization of a well-defined silica-supported ≡Si-O-W(Me)5 species is reported. Under an inert atmosphere, it is a stable material at moderate temperature, whereas the homoleptic parent complex decomposes above -20 °C, demonstrating the stabilizing effect of immobilization of the molecular complex. Above 70 °C the grafted complex converts into the two methylidyne surface complexes [(≡SiO-)W(≡CH) Me2] and [(≡SiO-)2W(≡CH)Me]. All of these silica-supported complexes are active precursors for propane metathesis reactions. © 2013 American Chemical Society.

Citation
Samantaray, M. K., Callens, E., Abou-Hamad, E., Rossini, A. J., Widdifield, C. M., Dey, R., … Basset, J.-M. (2014). WMe6 Tamed by Silica: ≡Si–O–WMe5 as an Efficient, Well-Defined Species for Alkane Metathesis, Leading to the Observation of a Supported W–Methyl/Methylidyne Species. Journal of the American Chemical Society, 136(3), 1054–1061. doi:10.1021/ja410747g

Acknowledgements
The authors acknowledge the KAUST Nuclear Magnetic Resonance Core Lab and technical assistance of Dr. Kazuo Yamauchi. The authors also thank Dr. Nassima Riache for her fruitful discussions. Mr. Benoit Vincenti is thanked for inert-atmosphere sample preparation prior to solid-state NMR experiments upon 2. A.J.R. acknowledges support from an EU Marie-Curie IIF fellowship (PIIF-GA-2010-274574). C.M.W. acknowledges the Natural Sciences and Engineering Council of Canada (NSERC) for a postdoctoral fellowship. Computational resources for DFT calculations were provided by the Pole Scientifique de Modelisation Numerique (PSMN). This work was supported by funds from King Abdullah University of Science and Technology.

Publisher
American Chemical Society (ACS)

Journal
Journal of the American Chemical Society

DOI
10.1021/ja410747g

PubMed ID
24369727

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