Understanding the reactivity of [W=NAr(CH2tBu)2(=CHtBu)] (Ar=2,6-iPrC6H3)with silica partially dehydroxylated at low temperatures through a combined use of molecular and surface organometallic chemistry

Reaction of [W=NAr(CH(2)tBu)(2)(=CHtBu)] (At = 2,6-iPrC(6)H(3)) with silica partially dehydoxylated at 200 degrees C does not lead only to the expected bisgrafted [( SiO)(2)W=NAr(=CHtBu)] species, but also surface reaction intermediates such as [(SiO)(2)W=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. (c) 2006 Elsevier B.V. All rights reserved.