Ferrocene-based olefin polymerization catalysts: Activation, structure, and intermediates

被引:56
作者
Shafir, A
Arnold, J [1 ]
机构
[1] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA
[2] Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA
关键词
D O I
10.1021/om020780f
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
This paper describes abstraction of a benzyl group from the Zr dibenzyl complex 1,1'-Fc-(NSiMe3)(2)]ZrBn2 (1) using B(C6F5)(3) and [Ph3C][B(C6F5)(4)] (TB). In both cases, clean formation of the corresponding cationic monobenzyl species LZrBn+ (L = 1,1'-Fc(NSiMe3)(2)(2-)) was observed by NMR spectroscopy. In the case of [LZrBn][BnB(C6F5)(3)] (2), an X-ray crystal structure determination confirmed an eta(6) coordination of the borate benzyl group to the cationic Zr center. Reaction of this complex with 1 equiv Of C2H2 or RCCR (R = Me, Ph) proceeded with rapid single insertion of the olefin or acetylene into the Zr-carbon sigma-bond. With ethylene or 2-butyne further insertions occur more slowly and longer chains were obtained upon addition of more monomer. Activation of 1 with TB leads to an active ethylene polymerization catalyst, producing 102 g of PE mmol(-1) atm(-1) h(-1). Compound 2 reacted with CH2Cl2 to form the dimeric [LZrCl2](2), which was characterized crystallographically.
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页码:567 / 575
页数:9
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