5627246 Supported metallocene complexes having heterofunctional groups in the cyclopentadienyl system as catalyst systems

“Bound but Not Gagged”Immobilizing Single-Site α-Olefin Polymerization Catalysts

“…Brintzinger and co-workers reported the pretreatment of dehydroxylated silica with 4-ClCH 2 C 6 H 4 Si(OMe) 3 yielding a silica that quarternizes the amino group(s) in Me 2 Si(2-NMe 2 −Ind) 2 ZrCl 2 to form an ionic metallocene, which was active in the polymerization of propylene in combination with MAO …”

“…Brintzinger and co-workers reported the pretreatment of dehydroxylated silica with 4-ClCH 2 C 6 H 4 Si-(OMe) 3 yielding a silica that quarternizes the amino group(s) in Me 2 Si(2-NMe 2 -Ind) 2 ZrCl 2 to form an ionic metallocene, which was active in the polymerization of propylene in combination with MAO. 369 Perhaps the most unusual example of a reactive tethering is the use of the thallium cyclopentadienyl salts. Lee and co-workers reacted the thallium salt, TlCp-L-CpZr(Ind)Cl 2 (L ) hexamethyltrisiloxane or pentamethylene) with a p-tosylated silica surface, eliminating thallium tosylate to form a silicasubstituted cyclopentadiene tether (Scheme 27).…”

Heterogeneous Single-Site Catalysts for Olefin Polymerization

“…Partially hydroxylated silica substituted with ClCH 2 PhSi(OMe) 3 quaternizes the amino groups in Me 2 Si(2-Me 2 NInd) 2 ZrCl 2 yielding an ionic metallocene procatalyst which is active in propylene polymerization when contacted with MAO (Scheme ) 10 …”

“…149 Partially hydroxylated silica substituted with ClCH 2 -PhSi(OMe) 3 quaternizes the amino groups in Me 2 Si-(2-Me 2 NInd) 2 ZrCl 2 yielding an ionic metallocene procatalyst which is active in propylene polymerization when contacted with MAO (Scheme 10). 150 Ansa-metallocenes tethered to a silica surface through the bridging group have been prepared by reacting ClMeSi(Cp) 2 MCl 2 (M ) Zr, Hf) with partially dehydroxylated silica, either by itself 151 or modified by agents such as (MeO) 3 Si(CH 2 ) 3 NH 2 . 152 The catalyst activity in ethylene-1-hexene copolymerization is reduced by about 75% over the homogeneous variant.…”