The dinuclear complexes [Ni(µ-Cl)(4,5-dihydro-4,4-dimethyloxazol-2-yl)methanol}]2Cl214 and [Ni(µ-Cl)(pyridin-2-yl)methanol}]2Cl216 have been synthesized in high yields by reaction of NiCl2 with 2 mol. equiv. of the ligands 4,5-dihydro-4,4-dimethyloxazol-2-yl)methanol 13 or (pyridin-2-yl)methanol 15, respectively. The reaction of NiCl2 with 3 mol. equiv. of 15 afforded in high yield the mononuclear, octahedral mer-[Ni(pyridin-2-yl)methanol}3Cl2] complex 18. The reaction of 16 with NaH led to the deprotonation of one of the pyridine alcohol ligands to form [Ni(pyridin-2-yl)methanol}(pyridin-2-yl)methanolate}Cl] 21 in which the metal is coordinated by one pyridine alcohol and one pyridine alcoholate ligand. The crystal structures of the dinuclear, chloride-bridged octahedral complexes in 14·C6H12 and in 16·3CH2Cl2 and of the mononuclear, octahedral complex 18 in 18·CH2Cl2 have been determined by X-ray diffraction. In the latter case, intermolecular OH⋯Cl bonding interactions generate a centrosymmetric pseudo-dimer. Complexes 14, 16 and 21 have been tested in ethylene oligomerization with AlEtCl2 (Al/Ni ratios of 2, 4 or 6) or MAO (50, 100 or 200 equiv.) as co-catalysts under 10 bar of ethylene and yielded mostly dimers and trimers. Complex 16 in the presence of 6 equiv. of AlEtCl2 proved to be the most active system with a turnover frequency (TOF) up to 187 500 C2H4 (mol Ni h)−1. Complex 16 with 200 equiv. of MAO was also the most active, with TOF up to 104 300 C2H4 (mol Ni h)−1 under 30 bar of ethylene.
通过将 NiCl2 与 2 摩尔当量的
配体 4,5-二氢-4,4-二甲基
恶唑-2-基
甲醇 13 或 (
吡啶-2-基)
甲醇 15 反应,高产率地合成了双核配合物 [Ni(µ-Cl)(4,5- 二氢-4,4-二甲基
恶唑-2-基)
甲醇}]2Cl214 和 [Ni(µ-Cl)(
吡啶-2-基)
甲醇}]2Cl216。当量的
配体 4,5-二氢-4,4-二甲基
恶唑-2-基)
甲醇 13 或(
吡啶-2-基)
甲醇 15 反应,高产率合成了 NiCl2。NiCl2 与 3 摩尔当量的 15 反应后,高产率地得到了单核八面体 mer-[Ni(pyridin-2-yl)methanol}3Cl2] 复合物 18。16 与 NaH 反应后,其中一个
吡啶醇配位体发生去质子化反应,生成[Ni(
吡啶-2-基)
甲醇}(
吡啶-2-基)
甲醇酸酯}Cl] 21,其中
金属由一个
吡啶醇和一个
吡啶醇酸酯配位体配位。X 射线衍射测定了 14-
C6H12 和 16-3 中的双核
氯桥八面体配合物以及 18-
CH2Cl2 中的单核八面体配合物 18 的晶体结构。在后一种情况下,分子间的 OH⋯Cl 键相互作用产生了一个中心对称的假二聚体。络合物 14、16 和 21 在 10 巴
乙烯条件下,以 AlEtCl2(铝/
镍比率为 2、4 或 6)或 MAO(50、100 或 200 等量)为助催化剂,进行了
乙烯低聚试验,结果大部分是二聚体和三聚体。事实证明,在 6 等量 AlEtCl2 存在下的络合物 16 是最活跃的体系,其翻转频率 (TOF) 高达 187 500
C2H4(mol Ni h)-1。含有 200 等量 MAO 的络合物 16 也是最活跃的,在 30 巴
乙烯条件下,其 TOF 高达 104 300 (mol Ni h)-1。