New Organo-Lewis Acids. Tris(β-perfluoronaphthyl)borane (PNB) as a Highly Active Cocatalyst for Metallocene-Mediated Ziegler−Natta α-Olefin Polymerization
作者:Liting Li、Tobin J. Marks
DOI:10.1021/om980229b
日期:1998.8.1
NB- (4) is formed when a 2:1 CGCTiMe2:PNB stoichiometry is employed. In the case of group 4 dimethyl zirconocenes, L2ZrMe2 (L = η5-C5H5, Cp; η5-1,2-Me2C5H3, Cp‘‘), reaction in a 1:1 metallocene:PNB ratio affords cationic complexes L2ZrMe+MePNB- (L = Cp, 5; Cp‘‘, 6), while the reaction with a 1:2 molar ratio affords dinuclear μ-methyl cationic complexes [(L2ZrMe)2(μ-Me)]+MePNB- (L = Cp, 7; Cp‘‘, 8)
三(β-全氟萘基)硼烷(B(C 10 F 7)3,PNB)是由β-全氟萘基锂和BCl 3合成的,用作新型强有机路易斯酸助催化剂。PNB有效地活化了各种第4组二甲基配合物,从而形成了高活性的均相齐格勒-纳塔烯烃聚合催化剂。与PNB的反应外消旋-Me 2的Si(茚基)2 ZrMe 2和CGCMMe 2(M =锆,钛; CGC =我2的Si(η 5 -Me 4 Ç 5)(吨BUN))(1:1分摩尔比)迅速产生游离碱阳离子络合物外消旋-Me 2的Si(茚基)2 ZrMe + MePNB - (1)和CGCMMe + MePNB -(M =锆,2 ;钛,3) , 分别。μ-甲基双核的阳离子配合物[(CGCTiMe)2(μ-Me)中] + MePNB - (4)被形成时,一个2:1 CGCTiMe 2:PNB化学计量使用。在组4二甲基二茂锆的情况下,L 2 ZrMe 2(L =η 5 -C 5 H ^5,Cp;