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Novel monocyclopentadienyl zirconium and hafnium trialkoxide complexes: Syntheses and catalytic properties for olefin polymerization
Author(s) -
Hsiao TingJui,
Tsai JingCherng
Publication year - 2010
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.31731
Subject(s) - methylaluminoxane , zirconium , cyclopentadienyl complex , hafnium , catalysis , ethylene , olefin fiber , polymer chemistry , polymerization , magnesium , ligand (biochemistry) , copolymer , chemistry , olefin polymerization , materials science , inorganic chemistry , metallocene , organic chemistry , polymer , biochemistry , receptor
Monocyclopentadienyl trialkoxy compounds of zirconium and hafnium [CpZr(OR) 3 and CpHf(OR) 3 ], which cannot be prepared by earlier methods, are synthesized in situ by reacting bis(cyclopentadienyl) magnesium with zirconium tetraalkoxides [Zr(OR) 4 ] and with hafnium tetraalkoxides [Hf(OR) 4 ], respectively. The generation of CpZr(OR) 3 and CpHf(OR) 3 compounds involves a highly effective cyclopentadienyl ligand (Cp) transfer reaction from the Cp ligand of bis(cyclopentadienyl) magnesium to Group 4 metal alkoxides. The utilization of CpZr(OR) 3 and CpHf(OR) 3 compounds as catalyst precursors for mediating α‐olefin polymerizations was carefully investigated. Results show that highly active catalysts can be generated by reacting these mono‐Cp Zr and Hf alkoxides with methylaluminoxane. The resulting active CpZr(OR) 3 /MAO and CpHf (OR) 3 /MAO catalysts induce ethylene polymerization and ethylene/propylene copolymerization with high activity (e.g., 1820 kg PE/mole of catalyst‐h). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010