dimethylbis(η5-tetramethyl(trimethylsilyl)cyclopentadienyl)titanium(IV) | 944272-14-4

• 英文名称: dimethylbis(η5-tetramethyl(trimethylsilyl)cyclopentadienyl)titanium(IV)
• 英文别名: [Ti(η5-C5Me4SiMe3)2Me2]
• CAS: 944272-14-4
• 化学式: C₂₆H₄₈Si₂Ti
• 分子量: 464.718
• InChiKey: PMKKEGYUQSSRRU-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
  None
• 可旋转键数：
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• 环数：
  None
• sp3杂化的碳原子比例：
  None
• 拓扑面积：
  None
• 氢给体数：
  None
• 氢受体数：
  None

反应信息

• 作为反应物：
  描述：

  dimethylbis(η5-tetramethyl(trimethylsilyl)cyclopentadienyl)titanium(IV) 以 甲苯 为溶剂， 以76%的产率得到[Ti(II)(η5-tetramethyl(trimethylsilyl)cyclopentadienyl)(η6:η1-C5Me3(CH2)(SiMe2CH2))]
  参考文献：
  名称：

  Effect of the Trimethylsilyl Substituent on the Reactivity of Permethyltitanocene

  摘要：

  The presence of a trimethylsilyl substituent in place of one of the methyl groups of each of the cyclopentadienyl ligands of decamethyltitanocene enhances the thermal stability of the resulting complex, [Ti-II{eta(5)-C5Me4(SiMe3)}(2)] (1), and controls the products formed in thermolysis of its methyl derivatives. Titanocene 1 was found to be stable in toluene solution up to 90 degrees C, while under vacuum at 140 degrees C it liberated hydrogen to give the asymmetrical doubly tucked-in titanocene [Ti-II{eta(3):eta(4)-C5Me2(SiMe3)(CH2)(2)}{eta(5)-C5Me4(SiMe3)}] (3). The mono- and dimethyl derivatives of 1, the complexes [(TiMe)-Me-III{eta(5)-C5Me4(SiMe3)}(2)] (5) and [(TiMe2)-Me-IV{eta(5)-C5Me4(SiMe3)}(2)] (6), undergo thermolysis at lower temperature than do the corresponding permethyltitanocene derivatives and eliminate hydrogen from their trimethylsilyl group. Thus, the known [Ti-III{eta(5):eta(1)-C5Me4(SiMe2CH2)}{eta(5)-C5Me4(SiMe3)}] (4) was obtained from 5, and compound 6 afforded [Ti-II{eta(6):eta(1)-C5Me3(CH2)(SiMe2CH2)}{eta(5)-C5Me4(SiMe3)}] (7) at only 90 degrees C, both with liberation of methane. Crystal structures of 3, 5, and 7 were determined. DFT calculations for titanocene 1 revealed that the metal-cyclopentadienyl bonding is accomplished via a three-center-four-electron orbital interaction. An auxiliary long-range Si-C bond interaction with the Ti center was also established, providing a reason for the enhanced thermal stability of 1. The molecular orbitals participating in the exo methylene-titanium bonds for 3 and 7 are also three-centered and are compatible with the assignment of their activated ligands to eta(3):eta(4)-allyldiene and eta(6)-fulvene structures, respectively. Qualitatively, the much higher thermal stability of 3 and 7 compared to that of 1 is due to the exploitation of four d orbitals in the bonding molecular orbitals for 3 and 7 versus only two d orbitals for 1.

  DOI：

  10.1021/om070159l
• 作为产物：
  描述：

  [TiCl2(η5-C5Me4SiMe3)2] 、 甲基锂 以 正己烷 为溶剂， 以87%的产率得到dimethylbis(η5-tetramethyl(trimethylsilyl)cyclopentadienyl)titanium(IV)
  参考文献：
  名称：

  Effect of the Trimethylsilyl Substituent on the Reactivity of Permethyltitanocene

  摘要：

  The presence of a trimethylsilyl substituent in place of one of the methyl groups of each of the cyclopentadienyl ligands of decamethyltitanocene enhances the thermal stability of the resulting complex, [Ti-II{eta(5)-C5Me4(SiMe3)}(2)] (1), and controls the products formed in thermolysis of its methyl derivatives. Titanocene 1 was found to be stable in toluene solution up to 90 degrees C, while under vacuum at 140 degrees C it liberated hydrogen to give the asymmetrical doubly tucked-in titanocene [Ti-II{eta(3):eta(4)-C5Me2(SiMe3)(CH2)(2)}{eta(5)-C5Me4(SiMe3)}] (3). The mono- and dimethyl derivatives of 1, the complexes [(TiMe)-Me-III{eta(5)-C5Me4(SiMe3)}(2)] (5) and [(TiMe2)-Me-IV{eta(5)-C5Me4(SiMe3)}(2)] (6), undergo thermolysis at lower temperature than do the corresponding permethyltitanocene derivatives and eliminate hydrogen from their trimethylsilyl group. Thus, the known [Ti-III{eta(5):eta(1)-C5Me4(SiMe2CH2)}{eta(5)-C5Me4(SiMe3)}] (4) was obtained from 5, and compound 6 afforded [Ti-II{eta(6):eta(1)-C5Me3(CH2)(SiMe2CH2)}{eta(5)-C5Me4(SiMe3)}] (7) at only 90 degrees C, both with liberation of methane. Crystal structures of 3, 5, and 7 were determined. DFT calculations for titanocene 1 revealed that the metal-cyclopentadienyl bonding is accomplished via a three-center-four-electron orbital interaction. An auxiliary long-range Si-C bond interaction with the Ti center was also established, providing a reason for the enhanced thermal stability of 1. The molecular orbitals participating in the exo methylene-titanium bonds for 3 and 7 are also three-centered and are compatible with the assignment of their activated ligands to eta(3):eta(4)-allyldiene and eta(6)-fulvene structures, respectively. Qualitatively, the much higher thermal stability of 3 and 7 compared to that of 1 is due to the exploitation of four d orbitals in the bonding molecular orbitals for 3 and 7 versus only two d orbitals for 1.

  DOI：

  10.1021/om070159l