带有蒽桥双官能醇盐配体的双核半二茂钛配合物：乙烯与1-辛烯或降冰片烯共聚的前所未有的协同作用,Macromolecules

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带有蒽桥双官能醇盐配体的双核半二茂钛配合物：乙烯与1-辛烯或降冰片烯共聚的前所未有的协同作用
Macromolecules ( IF 5.1 ) Pub Date : 2023-12-27 , DOI: 10.1021/acs.macromol.3c02385
Ze Liu ₁ , Yukai Gong ₁ , Jinbo Zhang ₁ , Shaofeng Liu ₁ , Zhibo Li _{1,

2}

Affiliation

合成了带有蒽桥双官能醇盐配体（ LH ₂ ）的双核半二茂钛配合物Ti ₂，并通过NMR光谱和单晶X射线衍射对其进行了充分表征，显示两个Ti中心之间的间距为7.433 Å。还制备了单核配合物Me ₅ CpTiMe ₂ -(OC ₆ H ₃ –2,6- ⁱ Pr ₂ ) ( Ti ₁ )用于对照实验。_{在[Ph 3} C][B(C ₆ F ₅ ) ₄ ]作为助催化剂存在下， Ti ₂对乙烯均聚表现出高活性和热稳定性，类似于Ti ₁。对于乙烯/1-辛烯共聚，Ti ₂^{在 120 °C 时表现出 112800 kg(polymer)·mol –1} (Ti)·h ^–1的极高活性，几乎是乙烯均聚的两倍，显示出显着的积极效果用于共聚。对于乙烯/降冰片烯（NBE）共聚，值得注意的是，Ti ₂_{在 4 atm C 2} H _{4下表现出 9180 kg(polymer)·mol}^–1 (Ti)·h ^–1的活性，其中 [NBE] = 2 M制得聚(乙烯-共-NBE)共聚物，其M _w为168×10 ⁴ g·mol ^–1，NBE掺入量为30.1 mol%，分别是Ti ₁的15.3倍、1.2倍和2.6倍。在其他相同的条件下。为了研究可能的双核协同作用，利用密度泛函理论对[Ph ₃ C][B(C ₆ F ₅ ) ₄ ]和B(C ₆ F ₅ ) _3对双核Ti ₂的活化进行了研究。（DFT）并为这两种情况提供了一种不寻常的 μ-Me 桥接双核单阳离子物种，揭示了Ti ₂中的两个 Ti 中心可能与（共）单体或增长链相互作用，从而导致协同催化。

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Dinuclear Half-Titanocene Complex Bearing an Anthracene-Bridged Bifunctional Alkoxide Ligand: Unprecedented Cooperativity toward Copolymerization of Ethylene with 1-Octene or Norbornene

Dinuclear half-titanocene complex Ti₂ bearing an anthracene-bridged bifunctional alkoxide ligand (LH₂) has been synthesized and fully characterized by NMR spectroscopy and single-crystal X-ray diffraction, displaying a separation of 7.433 Å between two Ti centers. The mononuclear complex Me₅CpTiMe₂-(OC₆H₃–2,6-ⁱPr₂) (Ti₁) was also prepared for control experiments. In the presence of [Ph₃C][B(C₆F₅)₄] as a cocatalyst, Ti₂ shows high activity and thermal stability toward ethylene homopolymerization, similar to those of Ti₁. For ethylene/1-octene copolymerization, Ti₂ exhibits an extremely high activity of 112800 kg(polymer)·mol^–1(Ti)·h^–1 at 120 °C that is almost twice that for ethylene homopolymerization, revealing a dramatically positive effect for copolymerization. For ethylene/norbornene (NBE) copolymerization, it is remarkable that Ti₂ shows an activity of 9180 kg(polymer)·mol^–1(Ti)·h^–1 with [NBE] = 2 M under 4 atm of C₂H₄ and produces the poly(ethylene-co-NBE) copolymer with an M_w of 168 × 10⁴ g·mol^–1 and an NBE incorporation of 30.1 mol %, which are 15.3×, 1.2×, and 2.6× those by Ti₁ under otherwise identical conditions. In order to study the possible dinuclear cooperativity, the activations of dinuclear Ti₂ by [Ph₃C][B(C₆F₅)₄] and B(C₆F₅)₃ have been carried out and studied by density functional theory (DFT) and afford an unusual μ-Me bridging dinuclear monocationic species for both cases, revealing that two Ti centers in Ti₂ that can possibly interact together with a (co)monomer or propagation chain could lead to synergetic catalysis.

更新日期：2023-12-27

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