Homolysis of the Eu-N Bond. Synthesis, Structural Characterization, and Catalytic Activity of Novel Europium(II) Complexes
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- 作者：Shaowu Wang ; Shuangliu Zhou ; Enhong Sheng ; Meihua Xie ; Kehua Zhang ; Lin Cheng ; Yan Feng ; Lili Mao ; and Zixiang Huang
- 刊名：Organometallics
- 出版年：2003
- 出版时间：August 18, 2003
- 年：2003
- 卷：22
- 期：17
- 页码：3546 - 3552
- 全文大小：142K
- 年卷期：v.22,no.17(August 18, 2003)
- ISSN：1520-6041
文摘
Two new indene compounds, C9H7CH2SiMe2NC4H8 (1) and C9H6-1-Me-3-CH2SiMe2NC4H8(2), were synthesized by the reaction of C9H6RLi (R = H, Me) with ClCH2SiMe2Cl, followedby treatment with lithium pyrrolidinide C4H8NLi. The interaction of [(Me3Si)2N]3Eu(
-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene produced, after workup, a novel triple-deckersandwich tetranuclear europium(II) compound, [{
:5:51-(C9H5CH2SiMe2NC4H8)2}Eu2(-Cl)]2[-3:5:1:3:5:1-(C9H5CH2SiMe2NC4H8)2]·C7H8·(C6H6)0.5 (3), with a coupled indenyl ligandthrough tandem silylamine elimination, reduction of Eu3+ to Eu2+, and the C-C couplingreactions. To probe the formation pathway of complex 3, the interaction of C9H6-1-Me-3-CH2SiMe2NC4H8 (3) with [(Me3Si)2N]3Eu(-Cl)Li(THF)3 was studied. Treatment of [(Me3Si)2N]3Eu(-Cl)Li(THF)3 with 2 equiv of 2 in refluxing toluene temperature or at 60 
Cproduced, after workup, a monomeric europium(II) complex, (5:1-C9H5-1-Me-3-CH2SiMe2NC4H8)2Eu (4), via tandem silylamine elimination/homolysis of the Eu-N bond reactions.The formation pathway for complex 3 was proposed. All the compounds were fullycharacterized by spectroscopic methods and elemental analyses, and the structures ofcomplexes 3 and 4 were additionally determined by single-crystal X-ray diffraction analyses.It was found that complexes 3 and 4 can function as single-component MMA polymerizationinitiators, which represent the first examples of europium(II) complexes as single-componentMMA polymerization catalysts. The solvents and temperature effects' on the activities ofthe catalysts were also discussed.
-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene produced, after workup, a novel triple-deckersandwich tetranuclear europium(II) compound, [{:5:51-(C9H5CH2SiMe2NC4H8)2}Eu2(-Cl)]2[-3:5:1:3:5:1-(C9H5CH2SiMe2NC4H8)2]·C7H8·(C6H6)0.5 (3), with a coupled indenyl ligandthrough tandem silylamine elimination, reduction of Eu3+ to Eu2+, and the C-C couplingreactions. To probe the formation pathway of complex 3, the interaction of C9H6-1-Me-3-CH2SiMe2NC4H8 (3) with [(Me3Si)2N]3Eu(-Cl)Li(THF)3 was studied. Treatment of [(Me3Si)2N]3Eu(-Cl)Li(THF)3 with 2 equiv of 2 in refluxing toluene temperature or at 60 Cproduced, after workup, a monomeric europium(II) complex, (5:1-C9H5-1-Me-3-CH2SiMe2NC4H8)2Eu (4), via tandem silylamine elimination/homolysis of the Eu-N bond reactions.The formation pathway for complex 3 was proposed. All the compounds were fullycharacterized by spectroscopic methods and elemental analyses, and the structures ofcomplexes 3 and 4 were additionally determined by single-crystal X-ray diffraction analyses.It was found that complexes 3 and 4 can function as single-component MMA polymerizationinitiators, which represent the first examples of europium(II) complexes as single-componentMMA polymerization catalysts. The solvents and temperature effects' on the activities ofthe catalysts were also discussed.