Zirconium(IV) complexes having a rigid 1,8-naphthalene diamide versus a flexible 1,3-propylene diamide for olefin polymerization
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- Title
- Zirconium(IV) complexes having a rigid 1,8-naphthalene diamide versus a flexible 1,3-propylene diamide for olefin polymerization
- Authors
- Lee, CH; La, YH; Park, JW
- Date Issued
- 2000-02-07
- Publisher
- AMER CHEMICAL SOC
- Abstract
- Structure and chemical properties of zirconium(IV) complexes containing a rigid naphthalene diamide ligand ([1,8-C10H6(NSiMe3)(2)](2-)) or flexible propylene diamide ligands ([1,3-C3H6(NR)(2)](2-), R = SiMe3, Si(i-Pr)(3)) are described. The reaction of 1,8-C10H6(NHSiMe3)(2) with Zr(NMe2)(4) in refluxing toluene yields [1,8-C10H6(NSiMe3)(2)]Zr(NMe2)(2) (1), and the product 1 is converted to [1,8-C10H6(NSiMe3)(2)]ZrCl2 (2) in a moderate isolation yield by the treatment with excess ClSiMe3. X-ray crystallographic analysis establishes that 2 forms a dimer associated through two chloride bridges in the solid state and has a highly puckered six-membered ring with a small N-Zr-N bite angle (91.05 degrees). The reaction of 1,3-C3H6(NHR)(2) (R = SiMe3, Si(i-Pr)(3)) with Zr(NMe2)(4) also affords [1,3-C3H6(NR)(2)]Zr(NMe2)(2). Treatment of the amide complex with excess ClSiMe3 results in [1,3-C3H6(NR)(2)]ZrCl2 (4, R = SiMe3; 5, R Si(i-Pr)(3)) in a facile manner. The crystal structure of 5 shows that the molecule is monomeric, featuring a mirror plane that passes the zirconium atom and two chloride atoms, and the chelate and the metal form a boatlike six-membered ring with a large N-Zr-N angle (104.31 degrees). While these zirconium(IV) diamide complexes (2, 4, and 5) exhibit moderate ethylene polymerization activity (10-90 kg of PE/(mol(cat).atm.h)) in the presence of methylalumoxane, the diamide dimethyl compound [1,3-C3C6(NSi(i-Pr)(3))(2)]ZrMe2 (6) shows a high activity (300 kg of PE/(mol(cat).atm.h)) for the ethylene polymerization when it is activated with Ph3CB(C6F5)(4).
- Keywords
- GROUP-4 METAL-COMPLEXES; ETHYLENE POLYMERIZATION; ALKYL DERIVATIVES; LIVING POLYMERIZATION; MOLECULAR-STRUCTURES; AMINE ELIMINATION; ALPHA-OLEFINS; LIGANDS; CATALYSTS; REACTIVITY
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/20125
- DOI
- 10.1021/om990360z
- ISSN
- 0276-7333
- Article Type
- Article
- Citation
- ORGANOMETALLICS, vol. 19, no. 3, page. 344 - 351, 2000-02-07
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- There are no files associated with this item.
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