Lawrence Berkeley National Laboratory

The reaction of [W(=NAr)(=CHtBu)(CH2tBu)2] (1; Ar = 2,6-iPrC6H3) with a silica partially dehydroxylated at 700oC, SiO2-(700), gives syn-[(_SiO)W(=NAr)(=CHtBu)(CH2tBu)] (2) as a major surface species, which was fully characterized by mass balance analysis, IR, NMR, EXAFS, and DFT periodic calculations. Similarly, complex 1 reacts with [(c-C5H9)7Si7O12SiOH] to give [(SiO)W(=NAr)(=CHtBu)(CH2tBu)] (2m), which shows similar spectroscopic properties. Surface complex 2 is a highly active propene metathesis catalyst, which can achieve a TON of 16000 within 100 h, with only a slow deactivation.