bis(2-(3,5-di-tert-butylphenyl)indenyl)zirconium dibenzyl | 696614-54-7

• 英文名称: bis(2-(3,5-di-tert-butylphenyl)indenyl)zirconium dibenzyl
• CAS: 696614-54-7
• 化学式: C₆₀H₆₈Zr
• 分子量: 880.424
• InChiKey: UOLPQENMARQDEX-UHFFFAOYSA-N

反应信息

• 作为产物：
  描述：

  bis(2-(3,5-di-tert-butylphenyl)indenyl)zirconium dichloride 、 苄基氯化镁 以 四氢呋喃 为溶剂， 以15%的产率得到bis(2-(3,5-di-tert-butylphenyl)indenyl)zirconium dibenzyl
  参考文献：
  名称：

  Effects of Ligand Substitutions on the Rotation Rate of Indenyl Ligands in Bis(2-arylindenyl)zirconocenes by NMR Line-Shape Analysis and Relaxation in the Rotating Frame

  摘要：

  Unbridged bis(2-arylindenyl)metallocene complexes, such as bis(2-phenylindenyl)zirconium dichloride (1a), when treated with appropriate activators are active catalyst precursors for the production of elastomeric polypropylene. The proposed mechanism for polymerization involves isomerization of the catalyst between geometries of differing stereoselectivity on a time scale slower than polymer chain growth. As the rotation of the 2-arylindenyl ligand is proposed to result in the different catalyst geometries, the rate at which this rotation occurs is of interest for the interpretation of the behavior of these complexes. A series of zirconocenes {bis(2-phenylindenyl)zirconium dimethyl (1b), bis(2-phenylindenyl)zirconium dibenzyl (1c), bis(2-(3,5-di-tert-butylphenyl)indenyl)zirconium dimethyl (2b), and bis(243,5-di-tert-butylphenyl)indenyl) zirconium dibenzyl (2c)}, varying both in the indenyl ligand framework and the sigma-ligand, has been synthesized. The rotation rates of the methyl-substituted metallocenes are too fast to be determined by standard NMR techniques such as EXSY, line-shape analysis, or magnetization transfer experiments. On-resonance spin-lattice relaxation in the rotating frame (T-1p) has been used to determine the rate of rotation of the aryl ligands in 1b, 1c, and 2b and allowed comparison with the rates obtained for the benzylated species by line-shape analysis. The nature of both the pi and the sigma ligand systems affects the rate, with sterically bulky substituents resulting in slower rotation. The effect of the a ligand is substantially stronger than that of the pi ligand.

  DOI：

  10.1021/om034166v