(dicarbonyl)(cyclopentadienyl)(2,4-dimethylpentadienyl)titanium | 172221-08-8

• 英文名称: (dicarbonyl)(cyclopentadienyl)(2,4-dimethylpentadienyl)titanium
• CAS: 172221-08-8
• 化学式: C₁₄H₁₆O₂Ti
• 分子量: 264.16
• InChiKey: XOEBHVVSVQQCMB-UHFFFAOYSA-N

反应信息

• 作为反应物：
  描述：

  (dicarbonyl)(cyclopentadienyl)(2,4-dimethylpentadienyl)titanium 以 正己烷 为溶剂， 以97%的产率得到(carbonyl)(cyclopentadienyl)(2,4-dimethylpentadienyl)titanium
  参考文献：
  名称：

  Pentadienyl as a Stronger Binding but More Reactive Ligand Than Cyclopentadienyl: Syntheses, Reactions, and Molecular Orbital Studies of Half-Open Titanocenes

  摘要：

  The reactions of Ti(C5H5)Cl-2(PR(3)) complexes (R = Me, Et) with 2 equiv of a potassium pentadienide such as KC5H7 or K(2,4-C7H11) (C7H11 = dimethylpentadienyl) lead to the formation of diamagnetic 16 electron half-open titanocenes as monophosphine adducts. A single-crystal X-ray diffraction study of Ti(C5H5)(2,4-C7H11)(PEt(3)) revealed that the Ti-C bond lengths for the open dienyl ligand were much shorter than those for the C5H5 ligand, 2.240(3) vs 2.346(4) Angstrom, indicative of stronger Ti-C7H11 bonding. Reaction of this complex with CH3CN leads to loss of the PEt(3) ligand and coupling to the 2,4-C7H11 ligand. Thus, the C7H11 ligand is not only more strongly bound than C5H5, it is also more reactive. A structural determination of this complex confirmed the mode of coupling and revealed that a dimeric species was formed. The phosphine ligands in the various complexes may readily be replaced by P(OMe)(3) or P(OEt)(3). The Ti(C5H5)(2,4-C7H11)(PEt(3)) complex also reacts with CO, leading to a thermally unstable monocarbonyl and a thermally unstable dicarbonyl. While spectroscopic data revealed a symmetric structure for the monocarbonyl, the dicarbonyl complex is clearly unsymmetric. Molecular orbital calculations provide confirmation of stronger titanium-pentadienyl bonding and also the fact that the pentadienyl ligands serve as much better electron accepters than cyclopentadienyl. To a large extent these may both be attributed to significant delta bonding interactions between titanium d(xy) and pentadienyl pi(4)* orbitals.

  DOI：

  10.1021/om00011a023
• 作为产物：
  描述：

  (cyclopentadienyl)Ti(dimethylpentadienide)(PEt3) 、 一氧化碳 以 正戊烷 为溶剂， 以61%的产率得到(dicarbonyl)(cyclopentadienyl)(2,4-dimethylpentadienyl)titanium
  参考文献：
  名称：

  Pentadienyl as a Stronger Binding but More Reactive Ligand Than Cyclopentadienyl: Syntheses, Reactions, and Molecular Orbital Studies of Half-Open Titanocenes

  摘要：

  The reactions of Ti(C5H5)Cl-2(PR(3)) complexes (R = Me, Et) with 2 equiv of a potassium pentadienide such as KC5H7 or K(2,4-C7H11) (C7H11 = dimethylpentadienyl) lead to the formation of diamagnetic 16 electron half-open titanocenes as monophosphine adducts. A single-crystal X-ray diffraction study of Ti(C5H5)(2,4-C7H11)(PEt(3)) revealed that the Ti-C bond lengths for the open dienyl ligand were much shorter than those for the C5H5 ligand, 2.240(3) vs 2.346(4) Angstrom, indicative of stronger Ti-C7H11 bonding. Reaction of this complex with CH3CN leads to loss of the PEt(3) ligand and coupling to the 2,4-C7H11 ligand. Thus, the C7H11 ligand is not only more strongly bound than C5H5, it is also more reactive. A structural determination of this complex confirmed the mode of coupling and revealed that a dimeric species was formed. The phosphine ligands in the various complexes may readily be replaced by P(OMe)(3) or P(OEt)(3). The Ti(C5H5)(2,4-C7H11)(PEt(3)) complex also reacts with CO, leading to a thermally unstable monocarbonyl and a thermally unstable dicarbonyl. While spectroscopic data revealed a symmetric structure for the monocarbonyl, the dicarbonyl complex is clearly unsymmetric. Molecular orbital calculations provide confirmation of stronger titanium-pentadienyl bonding and also the fact that the pentadienyl ligands serve as much better electron accepters than cyclopentadienyl. To a large extent these may both be attributed to significant delta bonding interactions between titanium d(xy) and pentadienyl pi(4)* orbitals.

  DOI：

  10.1021/om00011a023