bis(1,2-dimethylcyclopentadienyl)hafnium(IV) methyl methyltris(pentafluorophenyl)borate | 163363-50-6

• 英文名称: bis(1,2-dimethylcyclopentadienyl)hafnium(IV) methyl methyltris(pentafluorophenyl)borate
• CAS: 163363-50-6
• 化学式: C₁₅H₂₁Hf*C₁₉H₃BF₁₅
• 分子量: 906.842
• InChiKey: JTPWDYKFAPSVHJ-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：

  bis(1,2-dimethylcyclopentadienyl)methyl(neopentyl)hafnium(IV) 、 三(五氟苯基)硼烷 以 氘代甲苯 为溶剂， 生成 bis(1,2-dimethylcyclopentadienyl)hafnium(IV) methyl methyltris(pentafluorophenyl)borate
  参考文献：
  名称：

  Metal-Alkyl Group Effects on the Thermodynamic Stability and Stereochemical Mobility of B(C₆F₅)₃-Derived Zr and Hf Metallocenium Ion-Pairs

  摘要：

  This paper reports significant dependence of ion-pair formation energetics and stereomutation rates upon the metal-bound alkyl substituent (R) and the solvent dielectric constant in the metallocenium series (1,2-Me2Cp)(2)MR+ MeB(C6F5)(3)(-) where R = Me, (CH2Bu)-Bu-t, CH2TMS, CH(TMS)(2), and M = Zr and Hf, as determined by reaction titration calorimetry and dynamic NMR spectroscopy. For the ion-pair forming reaction, (1,2 Me2Cp)(2)M(R)Me + B(C6F5)(3) --> (1,2-Me2Cp)(2)MR+ MeB(C6F5)(3)(-), enthalpies in toluene solution at 25 degreesC for M = Zr and R = Me, CH2TMS, and CH(TMS)(2) are -24.6(0.8), -22.6(1.0), and -59.2(1.4) kcal/mol, respectively. Corresponding values for M = Hf and R = Me and CH2TMS are -20.8(0.5) and -31.1(1.6) kcal/mol, respectively. DeltaH double dagger (reorg) values for the reorganization process that interchanges the ion-pair enantiotopic sites for M = Zr and R = Me, (CH2Bu)-Bu-t, CH2TMS, and CH(TMS)(2) are 22(1), 18(1), 17(1), and 9(2) kcal/mol, respectively. Corresponding DeltaH double dagger (reorg) values for M = Hf and R = Me, (CH2Bu)-Bu-t, and CH2TMS are >24, 12(3), and 15(2) kcal/mol, respectively. DeltaH double dagger (reorg) values are highest in low dielectric constant solvents such as C6D12 Activation parameters for beta -Me elimination in the complexes (1,2-Me2Cp)(2)(MCH2Bu+)-Bu-t MeB(C6F5)(3)(-) for M = Zr and Hf are found to be DeltaH double dagger (beta -Me) = 22.5(0.9) and 17.3(0.9) kcal/mol, and DeltaS double dagger (beta -Me) = 4.3(3.3) and -11.9(3.4) cal/mol(.)K, respectively.

  DOI：

  10.1021/ja000810a

文献信息

• Highly Electrophilic Olefin Polymerization Catalysts. Quantitative Reaction Coordinates for Fluoroarylborane/Alumoxane Methide Abstraction and Ion-Pair Reorganization in Group 4 Metallocene and “Constrained Geometry” Catalysts
  作者：Paul A. Deck、Colin L. Beswick、Tobin J. Marks

  DOI：10.1021/ja972912f

  日期：1998.3.1

  Reaction enthalpies of group 4 metallocenes having the general formula L2M(CH3)2 (L = Cp, 1,2-Me2Cp, Me5Cp; L2 = Me2Si(Me4Cp)(tBuN); M = Ti, Zr, and Hf) with the strong organo-Lewis acid B(C6F5)3 were measured using batch titration calorimetry in toluene. Methide abstraction to form the corresponding L2MCH3+CH3B(C6F5)3- contact ion pairs is highly exothermic in all cases. Exothermicity increases with

  具有通式 L2M(CH3)2 (L = Cp, 1,2-Me2Cp, Me5Cp; L2 = Me2Si(Me4Cp)(tBuN); M = Ti、Zr 和 Hf) 的第 4 族金属茂的反应焓与强有机路易斯酸 B(C6F5)3 在甲苯中使用分批滴定量热法测量。在所有情况下，形成相应的 L2MCH3+ B( )3- 接触离子对的甲基化物提取都是高度放热的。放热性随着 Cp 甲基取代基的增加而增加：对于 M = Zr，ΔH = -23.1(3)、-24.3(4) 和 -36.7(5) kcal mol-1，分别为 L = Cp、Me2Cp 和 Me5Cp。对于 M = Hf 和 L = 1,2-Me2Cp，ΔH = -20.8(5) kcal mol-1。“受限几何”配合物 (L2 = Me2Si(Me4Cp)(tBuN)) 表现出类似的放热性，对于 M = Ti，ΔH = -22.6(2)、-23