Hafnium, bis(1,3,5,7-cyclooctatetraene)- | 39292-59-6

• 英文名称: Hafnium, bis(1,3,5,7-cyclooctatetraene)-
• 英文别名: {Hf(η8-C8H8)(η4-C8H8)}
• CAS: 39292-59-6
• 化学式: C₁₆H₁₆Hf
• 分子量: 386.793
• InChiKey: HFBFXAUPEZGMCL-NWLKIXJSSA-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

• 作为反应物：
  描述：

  氯化铪(IV)四氢呋喃络合物 、 Hafnium, bis(1,3,5,7-cyclooctatetraene)- 以 四氢呋喃 为溶剂， 以60%的产率得到{Hf(η8-C8H8)Cl2(tetrahydrofuran)}
  参考文献：
  名称：

  Improved synthesis and structure of solvated and unsolvated forms of cyclooctatetraene-zirconium and -hafnium dichloride

  摘要：

  An improved synthesis for [M(eta-8-C8H8)Cl2(thf)] (M = Zr or Hf) and their unsolvated forms [M(eta-8-C8H8)Cl2] has been developed based on a ligand redistribution reaction between [M(eta-8-C8H8)(eta-4-C8H8)] and [MCl4(thf)2] (thf = tetrahydrofuran). This reaction was proven to be valuable also in the case of substituted cyclooctatetraenes, as shown in the synthesis of [{Zr[eta-8-C8H6(SiMe3)2]Cl}2(mu-Cl)2]. Crystallographic details: [Hf(eta-8-C8H8)Cl2(thf)], space group Cmca, a = 12.308(1), b = 12.005(1), c = 17.470(2) angstrom, alpha = beta = gamma = 90-degrees, Z = 8, and R = 0.032 for 771 independent observed reflections; [{Zr[eta-8-C8H6(SiMe3)2]Cl}2(mu-Cl)2], space group C222(1), a = 10.498(1), b = 23.253(2), c = 15.830(1) angstrom, alpha = beta = gamma = 90-degrees, Z = 4 and R = 0.048 for 3121 independent observed reflections.

  DOI：

  10.1039/dt9910003093
• 作为产物：
  描述：

  氯化铪(IV)四氢呋喃络合物 、 1,3,5,7-cycloocatetraene 在 Mg 作用下， 以 四氢呋喃 为溶剂， 以50%的产率得到Hafnium, bis(1,3,5,7-cyclooctatetraene)-
  参考文献：
  名称：

  双（环辛酸酯基）锆：x射线晶体结构，溶液和固态NMR光谱

  摘要：

  The structure of bis(cyclooctatetraenyl)zirconium, Zr(C8H8)2, has been investigated by variable-temperature solution and solid-state NMR spectroscopy and by X-ray crystallography. The solution H-1 and C-13 NMR data show that all 16 protons and all 16 carbon atoms are equivalent on the NMR time scale even at -100-degrees-C. No line broadening due to decoalescence of a fluxional process was noted, and the spectra are thus consistent with the original proposal that Zr(C8H8)2 adopts a symmetric sandwich structure. However, the CPMAS C-13 NMR spectrum contains two resonances and the X-ray crystallographic results unambiguously reveal a structure with one eta-8- and one eta-4-C8H8 ring. The exchange barrier for the fluxional process that makes the two C8H8 rings equivalent has been estimated to be < 7.5 kcal mol-1 in solution and > 13.5 kcal mol-1 in the solid state. A second fluxional process which involves 1,2-shifts of the eta-4-C8H8 ring has a much lower barrier that has been estimated to be < 5.5 kcal mol-1 in the solid state. Neither electronic nor steric factors clearly favor the asymmetric structure over the symmetric sandwich alternative. Similar conclusions are drawn for the structure of the hafnium analogue Hf(C8H8)2. Crystal data for Zr(C8H8)2 at -75-degrees-C: monoclinic; space group Pn; a = 7.049 (5), b = 7.695 (4), c = 11.217 (10) angstrom; beta = 95.08 (7)-degrees; V = 606 (1) angstrom 3; Z = 2; R(F) = 0.054; R(wF) = 0.057 for 153 variables and 1023 independent reflections with I > 2.58-sigma-(I).

  DOI：

  10.1021/om00053a053

文献信息

• Bis(cyclooctatetraene) derivatives of zirconium(<scp>IV</scp>) and hafnium(<scp>IV</scp>): syntheses and Lewis base adducts. Crystal structures of [Zr(η⁸-C₈H₈)(η⁴-C₈H₈)], [Hf{η⁸-C₈H₆(SiMe₃)₂}{η⁴-C₈H₆(SiMe₃)₂}], [Zr(η⁸-C₈H₈)(η⁴-C₈H₈)(NH₃)] and [Zr(η⁸-C₈H₈)(η⁴-C₈H₈)(CNBu^t)]
  作者：Pietro Berno、Carlo Floriani、Angiola Chiesi-Villa、Corrado Rizzoli

  DOI：10.1039/dt9910003085

  日期：——

  The syntheses of [M(eta-8-C8H8)(eta-4-C8H8)] (M = Zr, 2 or Hf, 3) and [Meta-8-C8H6(SiMe3)2}eta-4-C8H6(SiMe3)2}] (M = Zr, 4 or Hf, 5) are reported. The eta-8 and eta-4 bonding modes for C8H8 were established in the solid state by X-ray analyses, while in solution a single C8H8 environment was observed by H-1 NMR spectroscopy even at low temperature in accord with fluxional behaviour for these compounds. Complexes 2-5 behave as Lewis acids toward tetrahydrofuran, NH3 and Bu(t)NC and the adducts [Zr(eta-8-C8H8)(eta-4-C8H8)(NH3)] 6 and [M(eta-8-C8H8)(eta-4-C8H8)(CNBu(t))] (M = Zr, 7 or Hf, 8) have been isolated and characterized by X-ray analysis. Crystallographic details: 2, monoclinic, space group P2(1)/c, a = 13.754(1), b = 7.798(1), c = 12.753(1) angstrom, beta = 114.02(1)-degrees, Z = 4 and R = 0.037 for 1267 independent observed reflections; 5, orthorhombic, space group Pca2(1), a = 14.418(1), b = 11.285(1), c = 18.898(1) angstrom, Z = 4 and R = 0.036 for 2239 independent observed reflections; 6, orthorhombic, space group P2(1)2(1)2(1), a = 9.815(1), b = 14.129(2), c = 9.561(1) angstrom, Z = 4 and R = 0.022 for 1556 independent observed reflections; 7, triclinic, space group P1BAR, a = 11.172(1), b = 13.469(1), c = 14.303(1) angstrom, alpha = 62.80(1), beta = 78.01(1), gamma = 77.26(1)-degrees, Z = 4 and R = 0.028 for 2994 independent observed reflections.