| abstract |
Catalysts for the polymerization of olefins contain units of formula (I) wherein: each R is independently selected from a C1 to C10 aliphatic or cycloaliphatic group or a C6 to C18 aryl, aralkyl, or alkaryl; each R2 is independently selected from hydride, R, and Q radicals wherein at least one R2 is Q; Q has the general formula: LMpL'rXp-r-1, wherein L is a monoanionic aromatic ancillary ligand pi-bonded to M and covalently bonded to Si; L' is a monoanionic aromatic ancillary ligand pi-bondned to M and optionally bonded to L through a covalent bridging group; M is a metal selected from Groups 3-10 of the Periodic Table or lanthanides; X is independently selected from a hydride radical, halide radical, hydrocarbyl radical, halocarbyl radical, silahydrocarbyl, alkoxy radical, aryloxy radical, alkylsulfonate radical, arylesulfonate radical or (R)2N- radical; or two X groups are joined with M to form a metallacycle, silametallacycle or pi-diene metallacycle moiety; p is the valence of M; r is 0 or 1; and n is an integer between about 10 and about 500. |