Titanium and Zirconium Permethylpentalene Complexes, Pn*MCpRX, as Ethylene Polymerization Catalysts

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• 作者：Duncan A. X. Fraser ; Zoë R. Turner ; Jean-Charles Buffet ; Dermot O’Hare
• 刊名：Organometallics
• 出版年：2016
• 出版时间：August 22, 2016
• 年：2016
• 卷：35
• 期：16
• 页码：2664-2674
• 全文大小：616K
• 年卷期：0
• ISSN：1520-6041

文摘

A family of group 4 permethylpentalene complexes, Pn*MCp^RX (M = Ti, Zr; Cp^R = Cp, Cp^Me, Cp^tBu, Cp^nBu, Cp^Me₃, Ind; X = Cl, Me), has been synthesized and fully characterized by multinuclear NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction studies. These complexes were immobilized on an insoluble polymethylaluminoxane (sMAO), MAO-modified silica (ssMAO), and a MAO-modified layered double hydroxide (LDH-MAO). The effect of substitution around the Cp ligand was examined in relation to their performance (activity, M_w, PDI, polymer morphology) for ethylene polymerization measured both in solution and in slurry phase. Maximum solution-phase activities of 3585 kg/mol·h·bar were recorded at modest [Zr]:[Al] ratios of 1:250. These were compared to the activities recorded using the equivalent solid-supported complexes, and it was observed that sMAO was a superior support material with average increases in activity of 5.3 and 2.3 times relative to ssMAO and LDH-MAO, respectively. Most striking was the observation that slurry-phase ethylene polymerization activities using equivalent precatalysts supported on sMAO showed enhanced performance compared to the solution phase up to a maximum of 4486 kg/mol·h·bar.