We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Zirconium complexes bearing bis(phenoxy-imine) ligands with bulky o-bis(aryl)methyl-substituted aniline groups: synthesis, characterization and ethylene polymerization behavior.
- Authors
Li, Aike; Ma, Haiyan; Huang, Jiling
- Abstract
A series of bis(phenoxy-imine) zirconium complexes bearing bulky o-bis(aryl)methyl-substituted aryl groups on the aniline moiety have been synthesized, characterized and tested as catalyst precursors for ethylene polymerization. 1H NMR spectroscopy suggests that these complexes exist as a single chiral C2-symmetric isomer in the solution. X-ray crystallographic analysis of the resulting biszwitterionic-type adduct complex C1 · 2HCl reveals that the phenoxy-imine groups function as a monodentate phenoxy ligand and the oxygen atoms are oriented trans to each other at the central metal atom. Using modified methylaluminoxane (MMAO) as co-catalyst, C1 · 2HCl, C2-C6 exclusively produce linear aluminium-terminated polyethylenes (Al-PEs) with high activity (up to 16.89 × 106 g PE (mol Zr h)−1, suggesting that chain transfer to aluminum is the predominant termination mechanism. It is noteworthy that the introduction of an excessively bulky o-bis(aryl)methyl substituent adjacent to the imine-N produces low molecular-weight Al-PEs ( Mv 1.6-10.1 × 103) due to the enhanced rate of chain transfer to alkylaluminium groups during polymerization. Copyright © 2013 John Wiley & Sons, Ltd.
- Publication
Applied Organometallic Chemistry, 2013, Vol 27, Issue 6, p341
- ISSN
0268-2605
- Publication type
Article
- DOI
10.1002/aoc.2984