New organo-Lewis acids. Tris({beta}-perfluoronaphthyl)borane (PNB) as a highly active cocatalyst for metallocene-mediated Ziegler-Natta {alpha}-olefin polymerization
- Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry
Tris({beta}-perfluoronaphthyl)borane (B(C{sub 10}F{sub 7}){sub 3}, PNB) is synthesized from {beta}-perfluoronaphthyllithium and BCl{sub 3} to serve as a new strong organo-Lewis acid cocatalyst. PNB efficiently activates a variety of group 4 dimethyl complexes to form highly active homogeneous Ziegler-Natta olefin polymerization catalysts. Reaction of PNB with rac-Me{sub 2}Si(Ind){sub 2}ZrMe{sub 2} and CGCMMe{sub 2} (M = Zr, Ti; CGC = Me{sub 2}Si({eta}{sup 5}-Me{sub 4}C{sub 5})({sup t}BuN)) (1:1 molar ratio) rapidly produces the base-free cationic complexes rac-Me{sub 2}Si(Ind){sub 2}ZrMe{sup +}MePNB{sup {minus}} (1) and CGCMMe{sup +}MePNB{sup {minus}} (M = Zr, 2; Ti, 3), respectively. The {mu}-methyl dinuclear cationic complex [(CGCTiMe){sub 2}({mu}-Me)]{sup +}MePNB{sup {minus}} (4) is formed when 2:1 CGCTiMe{sub 2}:PNB stoichiometry is employed. In the case of group 4 dimethyl zirconocenes, L{sub 2}ZrMe{sub 2} (L = {eta}{sup 5}-C{sub 5}H{sub 5}, Cp; {eta}{sup 5}-1,2-Me{sub 2}C{sub 5}H{sub 3}, Cp{double_prime}), reaction in a 1:1 metallocene:PNB ratio affords cationic complexes L{sub 2}ZrMe{sup +}MePNB{sup {minus}} (L = Cp, 5; Cp{double_prime}, 6), while the reaction with a 1:2 molar ratio affords dinuclear {mu}-methyl cationic complexes [(L{sub 2}ZrMe){sub 2}({mu}-Me)]{sup +}MePNB{sup {minus}} (L = Cp, 7; Cp{double_prime}, 8). In both reactions, {mu}-F dinuclear cationic complexes [(L{sub 2}ZrMe){sub 2}({mu}F)]{sup +}MePNB{sup {minus}} (L = Cp, 9; Cp{double_prime}, 10) are formed as byproducts. (C{sub 6}F{sub 5}){sub 3}BNCCH{sub 3} and PNBNCCH{sub 3} were synthesized and characterized.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG02-86ER13511
- OSTI ID:
- 655337
- Journal Information:
- Organometallics, Vol. 17, Issue 18; Other Information: PBD: 31 Aug 1998
- Country of Publication:
- United States
- Language:
- English
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