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
文摘
The synthesis and full characterization of a well-defined silica-supported 鈮i鈥揙鈥揥(Me)5 species is reported. Under an inert atmosphere, it is a stable material at moderate temperature, whereas the homoleptic parent complex decomposes above 鈭?0 掳C, demonstrating the stabilizing effect of immobilization of the molecular complex. Above 70 掳C the grafted complex converts into the two methylidyne surface complexes [(鈮iO鈭?W(鈮H)Me2] and [(鈮iO鈭?2W(鈮H)Me]. All of these silica-supported complexes are active precursors for propane metathesis reactions.