Nuclearity and cooperativity effects in binuclear catalysts and cocatalysts for olefin polymerization

  1. Hongbo Li and
  2. Tobin J. Marks*
  1. Department of Chemistry, Northwestern University, Evanston, IL 60208-3113

  1. Edited by Jack Halpern, University of Chicago, Chicago, IL, and approved June 15, 2006 (received for review April 26, 2006)

  1. Fig. 1.
    View larger version:
    Fig. 1.

    Generalized structural motif for constrained geometry polymerization catalysts.


  2. Fig. 2.
    View larger version:
    Fig. 2.

    Binuclear and mononuclear constrained geometry catalysts and compound labeling scheme.


  3. Fig. 3.
    View larger version:
    Fig. 3.

    Synthetic routes to binuclear CGCs.


  4. Fig. 4.
    View larger version:
    Fig. 4.

    Molecular structure of ethylene-bridged EBICGC[Zr(NMe2)2]2. Thermal ellipsoids are drawn at the 50% probability level. A single enantiomer is shown for each complex.


  5. Fig. 5.
    View larger version:
    Fig. 5.

    Molecular structures of methylene-bridged MBICGC[Zr(NMe2)2]2. Thermal ellipsoids are drawn at the 50% probability level. A single enantiomer is shown for each complex.


  6. Fig. 6.
    View larger version:
    Fig. 6.

    Mononuclear and binuclear bisborane and bisborate cocatalysts.


  7. Fig. 7.
    View larger version:
    Fig. 7.

    Synthetic pathway to binuclear bisborane cocatalyst BN2.


  8. Fig. 8.
    View larger version:
    Fig. 8.

    Molecular structure of the mononuclear ion pair [1-Me2Si(3-ethylindenyl)(tBuN)]TiMe+MeB(C6F5)3 −. Thermal ellipsoids are drawn at the 50% probability level.


  9. Fig. 9.
    View larger version:
    Fig. 9.

    Molecular structure and atom numbering scheme for [(C5H5)2ZrMe+]2{Me21,4C6F4[B(C6F5)2]2}2−. Thermal ellipsoids are drawn at the 50% probability level.


  10. Fig. 10.
    View larger version:
    Fig. 10.

    Catalyst/cocatalyst nuclearity matrix for group 4 CGC-type catalysts.


  11. Fig. 11.
    View larger version:
    Fig. 11.

    Proposed pathways for branch formation facilitated by binuclear group 4 CGCs. P,P′ = polymeryl fragment.


  12. Fig. 12.
    View larger version:
    Fig. 12.

    Possible agostic C–H bonding interactions in bimetallic catalysts.


  13. Fig. 13.
    View larger version:
    Fig. 13.

    Branch formation via B2 activated electrostatically organized heterobimetallic group 4 catalysts.


  14. Fig. 14.
    View larger version:
    Fig. 14.

    Gel permeation chromatography (A) and differential scanning calorimetry (B) comparisons of polyethylenes produced by using organozirconium and organotitanium CGCs in combination with either cocatalysts B2 or B1.


  15. Fig. 15.
    View larger version:
    Fig. 15.

    Crystal structure of heterobinuclear polymerization catalyst precursor Ti1Zr1(NMe2)4.


  16. Fig. 16.
    View larger version:
    Fig. 16.

    Novel polyolefin copolymer structures synthesized with binuclear CGCTi-catalysts.


  17. Fig. 17.
    View larger version:
    Fig. 17.

    Possible catalyst–arene Ti-system interactions in styrene polymerization catalysis. P = polymer.


  18. Fig. 18.
    View larger version:
    Fig. 18.

    Binuclear polymerization catalyst enchainment-altering interactions with styrene monomers.


Footnotes

  • *To whom correspondence should be addressed. E-mail: t-marks{at}northwestern.edu
« Previous | Next Article »Table of Contents

This Article

  1. Published online before print October 10, 2006, doi: 10.1073/pnas.0603396103 PNAS October 17, 2006 vol. 103 no. 42 15295-15302
  1. AbstractFree
  2. » Figures Only
  3. Full Text
  4. Full Text (PDF)
  5. Supporting Figures

Classifications

    • Polymerization Special Feature
    • Review
About Our New Site Design >>
Link: Advanced Search

This Week's Issue

  1. November 25, 2008, 105 (47)
  1. Current Issue
  1. Alert me to new issues of PNAS

Most