A New Heteroatom Coordination Promoted Homolysis of the Yb-N Bond. Synthesis and Structural Characterization of a New Class of Ytterbium(II) and Ytterbium(III) Complexes with Amido and Indenyl Ligands
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- 作者：Enhong Sheng ; Shaowu Wang ; Gaosheng Yang ; Shuangliu Zhou ; Lin Cheng ; Kehua Zhang ; and Zixiang Huang
- 刊名：Organometallics
- 出版年：2003
- 出版时间：February 17, 2003
- 年：2003
- 卷：22
- 期：4
- 页码：684 - 692
- 全文大小：205K
- 年卷期：v.22,no.4(February 17, 2003)
- ISSN：1520-6041
文摘
Reaction of Me2Si(Me2NCH2CH2C9H6)Cl with 1 equiv of t-BuNHLi yielded Me2Si(Me2NCH2CH2C9H6)(t-BuNH) (1). Treatment of Me2NCH2CH2C9H7 with 1 equiv of n-BuLi,followed by reaction with an excess of Me3SiCl, produced Me2NCH2CH2C9H6SiMe3 (2) in79% yield. Interaction of YbCl3 with 3 equiv of (Me3Si)2NLi in THF, after workup, producedthe tetracoordinate ytterbium(III) amide [(Me3Si)2N]3YbIII(
-Cl)Li(THF)3 (3) in 85% yield.Treatment of 3 with 2 equiv of 1 gave the ytterbium(II) complex [
5:1-Me2Si(Me2NCH2CH2C9H5)(t-BuNH)]2YbII (4) in 58% yield via a reductive reaction. To get some insight intothe reaction, several reactions were initiated to study the effects of the t-BuNH group, silylgroup, and N,N-dimethylaminoethyl group of the indene compounds, effects of coordinateClLi(THF)3 in 3, and temperature effect on the reductive reaction. Treatment of 3 with 2equiv of 2 afforded (5:1-Me2NCH2CH2C9H5SiMe3)2YbII (5) in 52% yield. Interaction of 3with 2 equiv of Me2NCH2CH2C9H7 produced a ytterbium(II) complex (5:1-Me2NCH2CH2C9H6)2YbII (6) in 63% yield. Treatment of the ytterbium(III) complex [(Me3Si)2N]3YbIIIwith 2 equiv of Me2NCH2CH2C9H7 also afforded the ytterbium(II) complex (5:1-Me2NCH2CH2C9H6)2YbII (6) in 62% yield, which provides an alternate method for the preparation of6. Treatment of 3 with 2 equiv of indene(C9H8) produced the ytterbium(III) complex (5-C9H7)2YbIIIN(SiMe3)2 (7). Treatment of 3 with 1 equiv of 1,2-bis(indenyl)ethane also producedthe ytterbium(III) complex meso-[ethylenebis(5-indenyl)ytterbiumIII bis(trimethylsily)amide((EBI)YbIIIN(SiMe3)2) (8). All the compounds were fully characterized by spectroscopicmethods and elemental analyses. Complexes 3, 4, 5, 6, and 8 were additionally characterizedby a single-crystal X-ray diffraction study. The formation pathway for the ytterbium(II)complexes is proposed. The study showed that ytterbuim(II) complexes 4, 5, and 6 canfunction as single-component MMA polymerization catalysts with good activity.
-Cl)Li(THF)3 (3) in 85% yield.Treatment of 3 with 2 equiv of 1 gave the ytterbium(II) complex [5:1-Me2Si(Me2NCH2CH2C9H5)(t-BuNH)]2YbII (4) in 58% yield via a reductive reaction. To get some insight intothe reaction, several reactions were initiated to study the effects of the t-BuNH group, silylgroup, and N,N-dimethylaminoethyl group of the indene compounds, effects of coordinateClLi(THF)3 in 3, and temperature effect on the reductive reaction. Treatment of 3 with 2equiv of 2 afforded (5:1-Me2NCH2CH2C9H5SiMe3)2YbII (5) in 52% yield. Interaction of 3with 2 equiv of Me2NCH2CH2C9H7 produced a ytterbium(II) complex (5:1-Me2NCH2CH2C9H6)2YbII (6) in 63% yield. Treatment of the ytterbium(III) complex [(Me3Si)2N]3YbIIIwith 2 equiv of Me2NCH2CH2C9H7 also afforded the ytterbium(II) complex (5:1-Me2NCH2CH2C9H6)2YbII (6) in 62% yield, which provides an alternate method for the preparation of6. Treatment of 3 with 2 equiv of indene(C9H8) produced the ytterbium(III) complex (5-C9H7)2YbIIIN(SiMe3)2 (7). Treatment of 3 with 1 equiv of 1,2-bis(indenyl)ethane also producedthe ytterbium(III) complex meso-[ethylenebis(5-indenyl)ytterbiumIII bis(trimethylsily)amide((EBI)YbIIIN(SiMe3)2) (8). All the compounds were fully characterized by spectroscopicmethods and elemental analyses. Complexes 3, 4, 5, 6, and 8 were additionally characterizedby a single-crystal X-ray diffraction study. The formation pathway for the ytterbium(II)complexes is proposed. The study showed that ytterbuim(II) complexes 4, 5, and 6 canfunction as single-component MMA polymerization catalysts with good activity.