Series of 2-R₁-6-(1-R₂-4,5-diphenyl-1H-imidazol-2-yl)pyridine (R₁ = R₂ = H, L1; R₁ = Me, R₂ = H, L2; R₁ = H, R₂ = Me, L3; R₁ = R₂ = Me, L4), 2-(6-R₁-pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole (R₁ = H, L5; R₁ = Me, L6) and 2-(pyridin-2-yl)phenanthro[9,10-d]oxazole (L7) were synthesized and used to prepare their corresponding dihalonickel complexes (C1–C9). All organic compounds and nickel complexes were characterized by elemental and spectroscopic analyses. Molecular structures of C1, C4, C5 and C8 were confirmed by the single-crystal X-ray diffraction analysis. The single-crystal X-ray analysis revealed complex C1 as a distorted octahedral geometry, complex C4 as a distorted square pyramidal geometry, complex C5 as a distorted trigonal bipyramidal configuration, and complex C8 as a tetrahedral geometry. Upon activation with methylaluminoxane (MAO), the nickel complexes showed good activity towards norbornene polymerization through main additional and minor ring-opening metathesis. The reaction parameters such as norbornene concentration, reaction temperature and different coordinate environments caused by the ligands affected their catalytic performances.

中文翻译：

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带有2-（咪唑-2-基）吡啶或2-（吡啶-2-基）菲并咪唑/恶唑的镍（II）配合物的合成，表征及其降冰片烯的聚合

2-R ₁ -6-（1-R ₂ -4,5-二苯基-1H-咪唑-2-基）吡啶系列（R ₁  = R ₂  = H，L1 ; R ₁  = Me，R ₂  = H ，L2 ; R ₁  = H，R ₂  = Me，L3 ; R ₁  = R ₂  = Me，L4），2-（6-R _1-吡啶-2-基）-1H-菲[9,10-d ]咪唑（R ₁  = H，L5 ; R ₁  = Me，L6）和2-（吡啶-2-基）菲[9,10-d]恶唑（L7）被合成并用于制备其相应的二卤代酮复合物（C1 - C9）。所有有机化合物和镍络合物均通过元素分析和光谱分析进行表征。通过单晶X射线衍射分析确认了C1，C4，C5和C8的分子结构。单晶X射线分析显示，复合物C1为扭曲的八面体几何形状，复合物C4为扭曲的四棱锥几何形状，复合物C5为扭曲的三角双锥体结构，复合物C8作为四面体的几何形状。在用甲基铝氧烷（MAO）活化后，镍络合物通过主要的开环和次要开环复分解反应，对降冰片烯聚合反应显示出良好的活性。配体引起的降冰片烯浓度，反应温度和不同的配位环境等反应参数影响了它们的催化性能。