[Cp2Zr(η3-CH2C(CH2CHMe2)CH2)][B(C6F5)4] | 1048008-88-3

• 英文名称: [Cp2Zr(η3-CH2C(CH2CHMe2)CH2)][B(C6F5)4]
• 英文别名: [Cp₂Zr(η³-CH₂C(CH₂CHMe₂)CH₂)][B(C₆F₅)₄]
• CAS: 1048008-88-3
• 化学式: C₁₇H₂₃Zr*C₂₄BF₂₀
• 分子量: 997.637
• InChiKey: NYBHRELWGFPGJX-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
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• 重原子数：
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• 可旋转键数：
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• 环数：
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• sp3杂化的碳原子比例：
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• 拓扑面积：
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• 氢给体数：
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• 氢受体数：
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反应信息

• 作为产物：
  描述：

  methylzirconocenium tetrakis(pentafluorophenyl)borate 、 2,4-二甲基-1-戊烯 生成 [Cp2Zr(η3-CH2C(CH2CHMe2)CH2)][B(C6F5)4]
  参考文献：
  名称：

  Observation of zirconium allyl species formed during zirconocene-catalyzed propene polymerization and mechanistic insights

  摘要：

  Oligomeric Cp2Zr+-allyl species were detected in reaction mixtures of either [Cp2ZrMe][MeB(C6F5)(3)] or [Cp2ZrMe][B(C6F5)(4)] with propylene by a combination of H-1 NMR spectroscopy and electrospray ionization (tandem) mass spectrometry techniques. Conjointly, the data imply that formation of Cp2Zr+-allyl species occurs via (re)coordination of alkene (propylene and vinylidene end groups of unsaturated polymer chains, respectively) to Cp2Zr+R (R = CH3, H, polymeryl), followed by intramolecular proton transfer from C gamma to R and release of RH. Analysis of the olefinic region of the H-1 NMR spectra of the reaction mixture obtained from [Cp2ZrMe][MeB(C6F5)(3)] and propylene reveals the presence of a triplet resonance at delta similar to 5.2, which was attributed to the unprecedented 3-propenyl end group. A plausible mechanism for the origin of the 3-propenyl end groups is discussed. Additionally, a mechanism for incorporation of stereodefects into stereoregular polymers is also discussed. The cationic Cp2Zr+-allyl intermediates formed during polymerization may contribute to catalyst deactivation. (C) 2014 Elsevier Inc. All rights reserved.

  DOI：

  10.1016/j.jcat.2014.12.004

文献信息

• Detection of an η-Alkene Intermediate of the Type [Cp₂Zr(Me)(η¹-alkene)]⁺:  The Role of Such Species in Metallocene Catalyst Deactivation to Allylic Species
  作者：Mihaela Vatamanu、Goran Stojcevic、Michael C. Baird

  DOI：10.1021/ja0742683

  日期：2008.1.1

  the unprecedented alkyl η1-alkene complex [Cp2Zr(Me)(η1-CH2CMeCH2CHMe2)]+, in which C(2) is essentially carbocationic and the C(1)−C(2) bond order is sufficiently low that rotation about it occurs. The hydrogen atoms of the methyl group on C(2) are sufficiently acidic that proton transfer to the Zr−Me group occurs to generate the allylic product. It seems likely that the chemistry described here provides

  锆茂络合物 [Cp2ZrMe]+ 与 2,4-二甲基-1-戊烯反应生成甲烷和烯丙基络合物 [Cp2Zr(η3- C( CHMe2)CH2)]+。该反应涉及作为中间体的前所未有的烷基 η1-烯烃复合物 [Cp2Zr(Me)(η1- CMe CHMe2)]+，其中 C(2) 基本上是碳正离子且 C(1)-C(2) 键顺序足够围绕它发生旋转的低点。C(2) 上甲基的氢原子具有足够的酸性，以致于发生质子转移到 Zr-Me 基团以生成烯丙基产物。似乎这里描述的化学反应为丙烯聚合催化剂的失活提供了一个基本原理，因为链转移的正常产物，具有亚乙烯基端基的聚合物，应该以相同的方式形成烯丙基物种。