17 O MAS NMR studies of oxo-based olefin metathesis catalysts: a critical assessment of signal enhancement methods

D. Grekov (1) , Y. Bouhoute (2) , Iker Del rosal (3) , Laurent Maron (3) , M. Taoufik (2) , Régis M. Gauvin (1) , Laurent Delevoye (1)

1 UCCS - Unité de Catalyse et Chimie du Solide - UMR 8181
2 C2P2 - Laboratoire de Chimie, Catalyse, Polymères et Procédés, R 5265
3 LPCNO - Laboratoire de physique et chimie des nano-objets

The DFS enhancement method as applied to 17O MAS NMR was critically assessed, first on NaPO3, a simple binary glass system, and in a second step, on a series of catalysis-related organometallic molecules and materials. The robustness of DFS was investigated for the wide range of anisotropic parameters (quadrupolar coupling and chemical shift anisotropy) encountered in these samples. Emphasis has been put on the variation of signal enhancements with respect to the DFS final sweep frequency, pulse amplitude and pulse duration, while line shape distortion issues were also addressed. Finally, the robustness of DFS enhancement of the 17O MAS NMR signal is shown through its successful application to silica-supported olefin metathesis catalysts.

Domaines: Chimie; Catalyse; Chimie inorganique

D. Grekov, Y. Bouhoute, Iker Del rosal, Laurent Maron, M. Taoufik, et al.. 17 O MAS NMR studies of oxo-based olefin metathesis catalysts: a critical assessment of signal enhancement methods. Physical Chemistry Chemical Physics, 2016, 18 (40), pp.28157-28163. ⟨10.1039/C6CP04667C⟩. ⟨hal-01968823⟩