Synthesis and structures of bimetallic silicon-containing imido alkylidene complexes of tungsten (R′O)2(ArN)Wdouble bond; length as m-dashCH–SiR2–CHdouble bond; length as m-dashW(NAr)(OR′)2 (R = Me, Ph) and (R′O)2(ArN)Wdouble bond; length as m-dashCH–SiMe

Bimetallic alkylidene complexes of tungsten (R′O)2(ArN)Wdouble bond; length as m-dashCH–SiR2–CHdouble bond; length as m-dashW(NAr)(OR′)2 (R = Me (1), Ph (2)) and (R′O)2(ArN)Wdouble bond; length as m-dashCH–SiMe2SiMe2–CHdouble bond; length as m-dashW(NAr)(OR′)2 (3) (Ar = View the MathML source2,6–Pr2iC6H3; R′ = CMe2CF3) have been prepared by the reactions of divinyl silicon reagents R2Si(CHdouble bond; length as m-dashCH2)2 with known alkylidene compounds R′′–CHdouble bond; length as m-dashMo(NAr)(OR′)2. (R′′ = But, PhMe2C) Complexes 1–3 were structurally characterized. Ring opening metathesis polymerization (ROMP) of cyclooctene using compounds 1–3 as initiators led to the formation of high molecular weight polyoctenamers with predominant trans-units content in the case of 1 and 3 and predominant cis-units content in the case of 2.