Nuclearity and cooperativity effects in binuclear catalysts and cocatalysts for olefin polymerization
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Edited by Jack Halpern, University of Chicago, Chicago, IL, and approved June 15, 2006 (received for review April 26, 2006)
Abstract
A series of bimetallic organo-group 4 “constrained geometry” catalysts and binuclear bisborane and bisborate cocatalysts have been synthesized to probe catalyst center–catalyst center cooperativity effects on olefin enchainment in homogenous olefin polymerization and copolymerization processes. Significant nuclearity effects are found versus mononuclear controls, and the effect can be correlated with metal–metal approach distances and ion pairing effects. Novel polymer structures can be obtained by using such binuclear catalyst/cocatalyst systems.
Footnotes
- *To whom correspondence should be addressed. E-mail: t-marks{at}northwestern.edu
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Author contributions: H.L. and T.J.M. designed research, performed research, analyzed data, and wrote the paper.
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Conflict of interest statement: No conflicts declared.
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This article is a PNAS direct submission.
- Abbreviations:
- CGC,
- constrained geometry catalyst.
- © 2006 by The National Academy of Sciences of the USA
