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sp 3 ‐C 1 ‐Bridged 1,3‐Me 2 Cp/Amido Titanium and Zirconium Complexes and Their Reactivities towards Ethylene Polymerization
Author(s) -
Kim Tae Ho,
Won Young Chul,
Lee Bun Yeoul,
Shin Dong Mok,
Chung Young Keun
Publication year - 2004
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200300703
Subject(s) - chemistry , zirconium , dimer , nucleophile , medicinal chemistry , aqueous solution , ethylene , stereochemistry , crystallography , inorganic chemistry , catalysis , organic chemistry
sp 3 ‐C 1 ‐Bridged Cp/amido titanium and zirconium complexes are synthesized by using novel fulvenes that have substituents in the 1‐, 4‐, and 6‐positions only. Thus, the nucleophilic attack of lithium tert ‐butylamide on 1,4‐dimethyl‐6‐phenylfulvene, 6‐(2‐furyl)‐1,4‐dimethylfulvene and 6‐cyclohexyl‐1,4‐dimethylfulvene, and subsequent aqueous workup, yields t BuN(H)−CHR−C 5 H 3 Me 2 (R = phenyl, 6 ; R = 2‐furyl, 7 ; R = cyclohexyl, 8 ) in 80, 88, and 60% yields, respectively. The reactions of the ligands with M(NMe 2 ) 4 (M = Ti or Zr) afford the desired bis(dimethylamido) complexes, which can be transformed by treatment with Me 2 SiCl 2 to the dichloride complexes, (1,3‐Me 2 C 5 H 2 −CHR−N t Bu−κ N )MCl 2 (M = Ti, R = phenyl, 10 ; M = Zr, R = phenyl, 11 ; M = Ti, R = 2‐furyl, 13 ; M = Zr, R = 2‐furyl, 14 ; M = Zr, R = cyclohexyl, 15 ). Complex 10 is very sensitive towards water, such that an oxo‐bridged dimer, (1,3‐Me 2 C 5 H 2 −CHPh−NH t Bu)ZrCl 2 −μO−ZrCl 2 (1,3‐Me 2 C 5 H 2 −CHPh−NH t Bu) ( 12 ), is easily formed by the abstraction of water from the solvents. The solid structures of (1,3‐Me 2 C 5 H 2 −CHPh−N t Bu−κ N )Zr(NMe 2 ) 2 , 10 , 11 , and 12 have been determined by X‐ray crystallography. The complexes are active towards the polymerization of ethylene when activated with MAO. The activities are rather low and the molecular weight distributions are broad ( M w / M n = 10−36). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)