title: Ethylene polymerization by 2-iminopyridylnickel halide complexes: synthesis, characterization and catalytic influence of the benzhydryl group.
abstract: A series of 2-(2-benzhydrylbenzenamino)pyridine ligands (L1–L13) was synthesized and used as bidentate N^N ligands with nickel halides to afford the corresponding nickel dihalide complexes L(2)Ni(2)Cl(4) C1–C13 and L(2)NiBr(2) D1–D13. All ligands and complexes were characterized by IR and NMR spectroscopy, and by elemental analysis. The molecular structures of the representative complexes C1·2CH(3)OH, C5·2H(2)O, D4, D7 and D9 were confirmed by single-crystal X-ray diffraction studies. Upon activation with either methylaluminoxane (MAO) or ethylaluminium sesquichloride (Et(3)Al(2)Cl(3), EASC), these nickel pre-catalysts exhibited high activities (up to the range of 10(7) g mol(-1) (Ni) h(-1)) towards ethylene polymerization, producing branched polyethylenes with narrow polydispersity.
authors.affiliation: Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. whsun@iccas.ac.cn
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Sun
authors.forename: Shengju
authors.initials: S
authors.lastname: Song
authors.forename: Baixiang
authors.initials: B
authors.lastname: Li
authors.forename: Carl
authors.initials: C
authors.lastname: Redshaw
authors.forename: Xiang
authors.initials: X
authors.lastname: Hao
authors.forename: Yue-Sheng
authors.initials: YS
authors.lastname: Li
authors.forename: Fosong
authors.initials: F
authors.lastname: Wang