A series of 1,2-bis(arylimino)acenaphthylidenes (L1âL5) and their corresponding 4,4â²-methylenebis(1-(2,6-diisopropylphenylimino)-2-(arylimino)acenaphthylene) derivatives (L6âL10) were synthesized and used to form mono-nuclear nickel bromides LnnNiBr2 (n = 1â5, Ni1âNi5) and bi-nuclear nickel halides LnnNi2X4 (n = 6â10: X = Br, Ni2-1âNi2-5; n = 4, X = Cl, Ni2-6). All the organic compounds were fully characterized by FT-IR spectra, NMR measurements and elemental analysis. The nickel complexes were characterized by FT-IR spectra and elemental analysis and the molecular structures of the representative complexes Ni1, Ni2-1 and Ni2-3 were confirmed by single-crystal X-ray diffraction. Upon activation with either Et2AlCl or MAO, all the nickel complex pre-catalysts exhibited high activity toward ethylene polymerization over the temperature range from ambient to 50 °C. In general, the bi-nuclear complexes showed a positive synergetic effect with higher activity than their mono nuclear analogs. The resultant polyethylene possessed higher molecular weight and a high degree of branching.
一系列1,2-双(芳基亚
氨基)
苊基(L1→L5)及其相应的4,4→-亚甲基双(1-(2,6-二异丙基苯基亚
氨基)-2-(芳基亚
氨基)
苊基)衍
生物(L6→ L10) 被合成并用于形成单核
溴化镍 LnnNiBr2 (n = 1–5, Ni1–Ni5) 和双核卤化
镍 LnnNi2X4 (n = 6–10: X = Br, Ni2-1â Ni2-5;n = 4,X = Cl,Ni2-6)。所有有机化合物均通过 FT-IR 光谱、NMR 测量和元素分析进行了全面表征。通过FT-IR光谱和元素分析对
镍配合物进行了表征,并通过单晶X射线衍射证实了代表性配合物Ni1、Ni2-1和Ni2-3的分子结构。用 Et2AlCl 或 MAO 活化后,所有
镍配合物预催化剂在环境温度至 50°C 的温度范围内都表现出对
乙烯聚合的高活性。一般来说,双核复合物表现出积极的协同效应,其活性比其单核类似物更高。所得聚
乙烯具有较高的分子量和高支化度。