Fluorosilyl-Substituted Cyclopentadienyltitanium(IV) Complexes: Synthesis, Structure, and Styrene Polymerization Behavior
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- 作者：Milan Erben ; Jan Merna ; So
//pubs.acs.org/images/entities/ncaron.gif" border="0">a Hermanová ; Ivana Cí ; sa
- 刊名：Organometallics
- 出版年：2007
- 出版时间：May 7, 2007
- 年：2007
- 卷：26
- 期：10
- 页码：2735 - 2741
- 全文大小：146K
- 年卷期：v.26,no.10(May 7, 2007)
- ISSN：1520-6041
文摘
The synthesis and characterization of new halo-silyl-substituted titanium(IV) derivatives [TiCl3(
5-C5H4SiCl3)] (9), [TiCl3(5-C5H4SiMe2F)] (10), [TiCl3(5-C5H4SiMeF2)] (11), [TiCl3(5-C5H4SiF3)] (12),and [TiF3(5-C5H4SiMe2F)] (13) are reported. The reaction of lithiated trimethylsilylcyclopentadienidewith Me2SiCl2, MeSiCl3, or SiCl4 gave chlorosilyl(trimethylsilyl)cyclopentadienes that were fluorinatedwith Me3SnF to yield fluorosilyl derivatives C5H4(SiMe2F)SiMe3 (4), C5H4(SiMeF2)SiMe3 (5), and C5H4(SiF3)SiMe3 (6), respectively. Addition of disilylated compounds 4-6 to a solution of TiCl4 gave therespective half-sandwich titanium complexes 10-12, which could be alternatively prepared by selectivefluorination of the corresponding chlorosilyl-substituted cyclopentadienyltitanium(IV) trichlorides withMe3SnF. Completely fluorinated [TiF3(C5H4SiMe2F)] (13) was prepared from [TiCl3(C5H4SiMe2Cl)] (7)and 4 equiv of Me3SnF. The molecular structures of the pentameric 13 and the monomeric 10 weredetermined by X-ray diffraction analysis. The 47,49Ti NMR and UV-vis spectroscopy showed the electron-releasing nature of the SiMe2Cl, SiMe2F, SiMeCl2, and SiMeF2 substituents, whereas SiCl3 and SiF3groups had electron-withdrawing properties. The catalytic behavior of these half-sandwich titaniumcompounds in styrene polymerization was studied in the presence of excess methylaluminoxane.
5-C5H4SiCl3)] (9), [TiCl3(5-C5H4SiMe2F)] (10), [TiCl3(5-C5H4SiMeF2)] (11), [TiCl3(5-C5H4SiF3)] (12),and [TiF3(5-C5H4SiMe2F)] (13) are reported. The reaction of lithiated trimethylsilylcyclopentadienidewith Me2SiCl2, MeSiCl3, or SiCl4 gave chlorosilyl(trimethylsilyl)cyclopentadienes that were fluorinatedwith Me3SnF to yield fluorosilyl derivatives C5H4(SiMe2F)SiMe3 (4), C5H4(SiMeF2)SiMe3 (5), and C5H4(SiF3)SiMe3 (6), respectively. Addition of disilylated compounds 4-6 to a solution of TiCl4 gave therespective half-sandwich titanium complexes 10-12, which could be alternatively prepared by selectivefluorination of the corresponding chlorosilyl-substituted cyclopentadienyltitanium(IV) trichlorides withMe3SnF. Completely fluorinated [TiF3(C5H4SiMe2F)] (13) was prepared from [TiCl3(C5H4SiMe2Cl)] (7)and 4 equiv of Me3SnF. The molecular structures of the pentameric 13 and the monomeric 10 weredetermined by X-ray diffraction analysis. The 47,49Ti NMR and UV-vis spectroscopy showed the electron-releasing nature of the SiMe2Cl, SiMe2F, SiMeCl2, and SiMeF2 substituents, whereas SiCl3 and SiF3groups had electron-withdrawing properties. The catalytic behavior of these half-sandwich titaniumcompounds in styrene polymerization was studied in the presence of excess methylaluminoxane.