[(C2H4(η5-C9H6)2)Zr(CH3)(THF)] | 863590-22-1

• 英文名称: [(C2H4(η5-C9H6)2)Zr(CH3)(THF)]
• CAS: 863590-22-1
• 化学式: C₁₉H₃BF₁₅*C₂₅H₂₇OZr
• 分子量: 961.733
• InChiKey: YODIGRXJWQYMOE-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：

  四氢呋喃 、 rac-(ethylenebis(indenyl))ZrMe(MeB(C6F5)3) 以 四氢呋喃 为溶剂， 生成 [(C2H4(η5-C9H6)2)Zr(CH3)(THF)]
  参考文献：
  名称：

  B(C₆F₅)₃- vs Al(C₆F₅)₃-Derived Metallocenium Ion Pairs. Structural, Thermochemical, and Structural Dynamic Divergences

  摘要：

  The thermodynamic and structural characteristics of Al(C6F5)(3)-derived vs B(C6F5)(3)-derived group 4 metallocenium ion pairs are quantified. Reaction of 1.0 equiv of B(C6F5)(3) or 1.0 or 2.0 equiv of Al(C6F5)(3) with raC-C2H4(eta(5)-Ind)(2)Zr(CH3)(2) (rac-(EBI)Zr(CH3)(2)) yields rac-(EBI)Zr(CH3)+H3CB(C6F5)(3)(-) (1a), rac-(EBI)Zr(CH3)+H3CAl(C6F5)(3)(-) (1b), and rac-(EBI)Zr2+[(HCAl)-C-3(C6F5)(3)](-)(2) (1c), respectively. X-ray crystallographic analysis of 1b indicates the H3CAl(C6F5)(3)(-) anion coordinates to the metal center via a bridging methyl in a manner similar to B(C6F5)3-derived metallocenium ion pairs. However, the Zr-(CH3)(bridging) and Al(CH3)(bridging) bond lengths of 1b (2.505(4) angstrom and 2.026(4) angstrom, respectively) indicate the methyl group is less completely abstracted in 1b than in typical B(C6F5)(3)-derived ion pairs. Ion pair formation enthalpies (Delta H-ipf) determined by isoperibol solution calorimetry in toluene from the neutral precursors are -21.9(6) kcal mol(-1) (1a), -14.0(15) kcal mol(-1) (1b), and -2.1 (1) kcal mol(-1) (1b -> 1c), indicating Al(C6F5)(3) to have significantly less methide affinity than B(C6F5)(3). Analogous experiments with Me2Si(eta(5)-Me4C5)(t-BuN)Ti(CH3)(2) indicate a similar trend. Furthermore, kinetic parameters for ion pair epimerization by cocatalyst exchange (ce) and anion exchange (ae), determined by line-broadening in VT NMR spectra over the range 25-75 degrees C, are Delta H-ce(double dagger) = 22(1) kcal mol(-1), S-ce(double dagger) = 8.2(4) eu, Delta H-ae(double dagger) = 14(2) kcal mol(-1), and Delta S-ae(double dagger) = -15(2) eu for 1a. Line broadening for 1b is not detectable until just below the temperature where decomposition becomes significant (similar to 75-80 degrees C), but estimation of the activation parameters at 72 degrees C gives Delta H-ce(double dagger) approximate to 22 kcal mol(-1) and Delta H-ae(double dagger) approximate to 16 kcal mol(-1), consistent with the bridging methide being more strongly bound to the zirconocenium center than in 1a.

  DOI：

  10.1021/ja0429622