Rendon, NuriaBerthoud, RomainBlanc, FredericGajan, DavidMaishal, TarunBasset, Jean-MarieCoperet, ChristopheLesage, AnneEmsley, LyndonMarinescu, Smaranda C.Singh, RojendraSchrock, Richard R.2015-01-082015-01-082015-01-08200910.1002/chem.200802465https://infoscience.epfl.ch/handle/20.500.14299/110043WOS:000266292200016The monosiloxy surface complexes [( SiO)Mo( NAr)(=CHC-Me(2)R')(OR)] (R' = Me or Ph: OR = OtBu, OCMe(CF(3))(2) or OAr) are obtained by grafting onto SiO(2-(700)) either symmetric Mo-alkylidene derivatives [Mo( NAr)(=CHCMe(2)R')(OR)(2)] Or asymmetric derivatives, that is, with two different pendant ligands, one amido and one alkoxy/aryloxy, [Mo( NAr)(=CHCMe(2)R')(OR)(NC(6)H(8))]. ne formation of these complexes was confirmed by mass-balance analysis, and infrared (IR) and NMR spectroscopies. These systems are highly efficient catalyst precursors for the metathesis of acyclic alkenes; the best results were seen when OR = OCMe-(CF(3))(2). Nevertheless, they display poor performances in ring-closing metathesis, possibly due to the rigidity of the metal center (as evidenced by NMR spectroscopy), which therefore slows the rate of the metathesis.metathesissilica supportssolid-state NMR spectroscopysurface chemistrymolybdenumtext::journal::journal article::research article