Olefin Binding in a Binuclear Iridium Complex as a Function of Fluorine Substitution: Ethylene to Tetrafluoroethylene
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- 作者：Dusan Ristic-Petrovic ; D. Jason Anderson ; Jeffrey R. Torkelson ; Robert McDonald ; and Martin Cowie
- 刊名：Organometallics
- 出版年：2003
- 出版时间：November 10, 2003
- 年：2003
- 卷：22
- 期：23
- 页码：4647 - 4657
- 全文大小：149K
- 年卷期：v.22,no.23(November 10, 2003)
- ISSN：1520-6041
文摘
The reactions of the diiridium methyl complex [Ir2(CH3)(CO)(
-CO)(dppm)2][CF3SO3] (1)with ethylene, fluoroethylene, Z-1,2-difluoroethylene, 1,1-difluoroethylene, trifluoroethylene,and tetrafluoroethylene have been investigated. Reaction of 1 with ethylene at -78 
C yields[Ir2H(
2-C2H4)(CO)2(-CH2)(dppm)2][CF3SO3] (2a), resulting from C-H activation of themethyl group induced by ethylene coordination, whereas reaction at higher temperaturesyields the simple ethylene adduct [Ir2(CH3)(CO)(2-C2H4)(-CO)(dppm)2][CF3SO3] (2b).Reactions of 1 with fluoroethylene and Z-1,2-difluoroethylene yield only the olefin adductsanalogous to 2b. At -78 C reaction with 1,1-difluoroethylene yields the methylene-bridgedhydride product [Ir2H(2-C2F2H2)(CO)2(-CH2)(dppm)2][CF3SO3] (5a), which upon warming,yields first the olefin adduct [Ir2(CH3)(CO)(2-C2F2H2)(-CO)(dppm)2][CF3SO3] (5b) followedby the olefin-bridged product [Ir2(CH3)(CO)2(-C2F2H2)(dppm)2][CF3SO3] (5c). Trifluoro- andtetrafluoroethylene yield only the olefin-bridged products [Ir2(CH3)(CO)2(-olefin)(dppm)2][CF3SO3] (olefin = C2F3H (6), C2F4 (7)). The structure of the tetrafluoroethylene-bridged,tricarbonyl species [Ir2(CH3)(CO)3(-C2F4)(dppm)2][CF3SO3] (8), determined by X-ray techniques, is reported.
-CO)(dppm)2][CF3SO3] (1)with ethylene, fluoroethylene, Z-1,2-difluoroethylene, 1,1-difluoroethylene, trifluoroethylene,and tetrafluoroethylene have been investigated. Reaction of 1 with ethylene at -78 C yields[Ir2H(2-C2H4)(CO)2(-CH2)(dppm)2][CF3SO3] (2a), resulting from C-H activation of themethyl group induced by ethylene coordination, whereas reaction at higher temperaturesyields the simple ethylene adduct [Ir2(CH3)(CO)(2-C2H4)(-CO)(dppm)2][CF3SO3] (2b).Reactions of 1 with fluoroethylene and Z-1,2-difluoroethylene yield only the olefin adductsanalogous to 2b. At -78 C reaction with 1,1-difluoroethylene yields the methylene-bridgedhydride product [Ir2H(2-C2F2H2)(CO)2(-CH2)(dppm)2][CF3SO3] (5a), which upon warming,yields first the olefin adduct [Ir2(CH3)(CO)(2-C2F2H2)(-CO)(dppm)2][CF3SO3] (5b) followedby the olefin-bridged product [Ir2(CH3)(CO)2(-C2F2H2)(dppm)2][CF3SO3] (5c). Trifluoro- andtetrafluoroethylene yield only the olefin-bridged products [Ir2(CH3)(CO)2(-olefin)(dppm)2][CF3SO3] (olefin = C2F3H (6), C2F4 (7)). The structure of the tetrafluoroethylene-bridged,tricarbonyl species [Ir2(CH3)(CO)3(-C2F4)(dppm)2][CF3SO3] (8), determined by X-ray techniques, is reported.