Synthesis, characterization and ethylene polymerization of 1-(2,6-dimethyl-4-fluorenylphenylimino)-2-aryliminoacenaphthylnickel bromides

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• 作者：Venkataramana Katla^a ; Erlin Yue^a ; Natesan Mannangatti Rajendran^a ; Tongling Liang^a ; Wen-Hua Sun^a ; ^b ; ^{whsun@iccas.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Acenaphthylene ligand ; Ni(II) complex ; Ethylene polymerization ; Lesser branched polyethylene
• 刊名：Comptes Rendus Chimie
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：19
• 期：5
• 页码：604-613
• 全文大小：1181 K

文摘

A series of 1-(2,6-dimethyl-4-fluorenylphenylimino)-2-aryliminoacenaphthylene compounds (aryl = 2,6-di(Me)Ph (L1), 2,6-di(Et)Ph (L2), 2,6-di(i-Pr)Ph (L3), 2,4,6-tri(Me)Ph (L4), 2,6-di(Et)-4-MePh (L5)) was prepared and used to form their corresponding dibromonickel complexes (D1–D5). Both L1–L5 and D1–D5 were fully characterized by FT-IR and elemental analysis as well as NMR measurements in the case of ligands L1–L5. The molecular structure of the representative complex D5 was confirmed by single crystal X-ray diffraction revealing a distorted trigonal bipyramidal geometry around the nickel center. On activation with either ethylaluminium sesquichloride (Et₃Al₂Cl₃, EASC) or methylaluminoxane (MAO), all nickel complexes exhibited high activities up to 9.82 × 10⁶ g of PE (mol of Ni)⁻¹ h⁻¹ for ethylene polymerization. In comparison with the polyethylenes obtained with related Ni pre-catalysts, the polyethylenes obtained in this work possessed relatively higher molecular weights and lower levels of branching, highlighting the significant influence of the remote fluorenyl substituent.