Catalyst/cocatalyst nuclearity effects in single-site olefin polymerization. Significantly enhanced 1-octene and isobutene comonomer enchainment in ethylene polymerizations mediated by binuclear catalysts and cocatalysts

Hongbo Li, Liting Li, Tobin J. Marks, Louise Liable-Sands, Arnold L. Rheingold

Research output: Contribution to journalArticle

117 Citations (Scopus)


This Communication describes the implementation of a new binuclear homometallic organotitanium "constrained geometry catalyst" (CGC), (μ-CH2CH2-3,3′){ (η5-indenyl )[1-Me2Si (tBuN)](TiMe2)}2[EBICGC(TiMe2)2; Ti2], together with the bifunctional activators (Ph3C+)2[1,4-(C6F5)3BC6F4B(C6F5)3]2- (B2) and new bisborane 1,4-(C6F5)2BC6F4B(C6F5)2 (BN2) in ethylene + α-olefin copolymerization processes. Specifically examined are the comonomers 1-octene and poorly responsive isobutene. Large increases in comonomer enchainment efficiency into the polyethylene microstructure are observed versus the corresponding mononuclear catalyst [1-Me2Si(3-ethylindenyl)(tBuN)]TiMe2 (Ti1) + Ph3C+B(C6F5)4- (B1) or B(C6F5)3 (BN) under identical polymerization conditions. In ethylene + 1-octene copolymerization, 11 times more 1-octene incorporation is observed for Ti2 + B2 vs Ti1 + B1. In ethylene + isobutene copolymerization, 5 times more isobutene incorporation is observed for Ti2 + BN2 vs Ti1 + BN.

Original languageEnglish
Pages (from-to)10788-10789
Number of pages2
JournalJournal of the American Chemical Society
Issue number36
Publication statusPublished - Sep 10 2003


ASJC Scopus subject areas

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

Cite this