Understanding the reactivity of [W [dbnd]NAr(CH 2tBu) 2( [dbnd]CH tBu)] (Ar = 2,6- iPrC 6H 3) with silica partially dehydroxylated at low temperatures through a combined use of molecular and surface organometallic chemistry

Abstract

Reaction of [W NAr(CH 2 tBu) 2( CH tBu)] (Ar = 2,6- iPrC 6H 3) with silica partially dehydoxylated at 200 °C does not lead only to the expected bisgrafted [( SiO) 2W NAr( CH tBu)] species, but also surface reaction intermediates such as [( SiO) 2W NAr(CH 2 tBu) 2]. All these species were characterized by infrared spectroscopy, 1D and 2D solid state NMR, elemental analysis and molecular models obtained by using silsesquioxanes. While a mixture of several surface species, the resulting material displays high activity in the olefin metathesis.