Polynuclear catalysis: Enhancement of enchainment cooperativity between different single-site olefin polymerization catalysts by ion pairing with a binuclear cocatalyst

Graham P. Abramo, Liting Li, Tobin J. Marks

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85 Citations (Scopus)


A new multicenter ethylene polymerization process is described whereby two different single-site catalysts, one competent for producing vinyl-terminated oligomers or macromonomers and one competent for producing high-molecular weight ethylene-α-olefin copolymers, are held in close spatial proximity via ion-pairing with a dianionic binuclear bis-borate cocatalyst. Ethylene polymerizations mediated by stoichiometrically appropriate quantities of Me2Si(tBuN)(η5-3-ethylindenyl)ZrMe2 and Me2Si(tBuN)(η5-C5Me4)TiMe2 activated by the bis-borate cocatalyst [Ph3C+]2[1,4-(C6F5)3BC6F4B(C6F5)3-2] yield a more homogeneous polyethylene product when compared to control polymerizations using the mononuclear activator [Ph3C+][B(C6F5)4-]. The bulk and spectroscopic properties of the polymer produced using the binuclear activator are consistent with highly branched polyethylene.

Original languageEnglish
Pages (from-to)13966-13967
Number of pages2
JournalJournal of the American Chemical Society
Issue number47
Publication statusPublished - Nov 27 2002


ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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