Abstract
Reaction of [W
NAr(CH
2
tBu)
2(
CH
tBu)] (Ar
=
2,6-
iPrC
6H
3) with silica dehydroxylated at 200
°C does not lead only to the expected digrafted carbene species but also to the monografted carbene complex and to a bis-neopentyl surface species.
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.