Heavy-Atom Kinetic Isotope Effects, Cocatalysts, and the Propagation Transition State for Polymerization of 1-Hexene Using the rac-(C2H4(1-indenyl)2)ZrMe2 Catalyst Precursor
- 21 September 2002
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 124 (41) , 12062-12063
- https://doi.org/10.1021/ja026608k
Abstract
Using 13C NMR techniques, the 12C/13C kinetic isotope effects (KIEs) for the polymerization of 1-hexene catalyzed by rac-(C2H4(1-indenyl)2)ZrMe2 in the presence of four different cocatalysts (tris(pentfluorophenyl)borane, tris(pentafluorophenyl)alane, anilinium tetrakis(pentafluorophenyl)borate, and methylalumoxane) have been determined. All cocatalysts yield similar KIEs within experimental uncertainty, with values of 1.009(1) and 1.017(2) at C1 and C2, respectively. Ab initio DFT computational modeling of the polymerization KIE indicates that alkene binding to the catalyst must be reversible, with the majority of the KIE developing in the subsequent migratory insertion reaction.Keywords
This publication has 5 references indexed in Scilit:
- Ancillary Ligand and Olefin Substituent Effects on Olefin Dissociation for Cationic Zirconocene Complexes Bearing a Coordinated Pendant OlefinOrganometallics, 2001
- Cocatalysts for Metal-Catalyzed Olefin Polymerization: Activators, Activation Processes, and Structure−Activity RelationshipsChemical Reviews, 2000
- 13C Kinetic Isotope Effects for the Addition of Lithium Dibutylcuprate to Cyclohexenone. Reductive Elimination Is Rate-DeterminingJournal of the American Chemical Society, 1997
- High-Precision Simultaneous Determination of Multiple Small Kinetic Isotope Effects at Natural AbundanceJournal of the American Chemical Society, 1995
- Density-functional exchange-energy approximation with correct asymptotic behaviorPhysical Review A, 1988