Living Ziegler-Natta polymerization by early transition metals: synthesis and evaluation of cationic zirconium alkyl complexes bearing beta-hydrogens as models for propagating centers

Journal of the American Chemical Society
Matthew B HarneyLawrence R Sita

Abstract

The synthesis and characterization of a series of cationic zirconium and hafnium complexes with alkyl substituents bearing beta-hydrogens of general formula {(eta(5)-C5Me5)MR[N(Et)C(Me)N(t-Bu)]}[B(C6F5)4] [M = Zr; R = Et, n-Pr, i-Pr, n-Bu, i-Bu, and 2-ethylbutyl (5a-f) and M = Hf; R = i-Bu and t-Bu (6 and 7, respectively)] is described, including several isotopically labeled derivatives. The ability of these complexes to serve as model complexes for the living Ziegler-Natta polymerization of olefins that can be effected using the initiator 2a (R = Me in 5) has been addressed. The results obtained shed additional light on the steric and electronic factors that can contribute to the living character of a Ziegler-Natta polymerization based on an early transition metal initiator.

References

Dec 26, 2001·Chemical Reviews·A K RappéC J Casewit
Feb 22, 2003·Angewandte Chemie·Pierre JanvierJieping Zhu

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Citations

Oct 10, 2006·Dalton Transactions : an International Journal of Inorganic Chemistry·Dae June JoeBun Yeoul Lee
Aug 9, 2008·Dalton Transactions : an International Journal of Inorganic Chemistry·Cristina E PetrisorTomás Cuenca
Apr 10, 2014·Macromolecular Rapid Communications·Jun ZhengJidong Zhang
Dec 22, 2009·Dalton Transactions : an International Journal of Inorganic Chemistry·Daisuke Takeuchi

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