Abstract

A novel tetranuclear Ni(II) complex [Ni₄(L)₂(N₃)₄Cl(MeOH)₃]·CH₃COCH₃ is synthesized via a symmetrical salamo-based ligand H₂L, NiCl₂·6H₂O, and NaN₃. The structure is characterized by elemental analyses, IR and UV-Vis spectroscopy, and X-ray diffraction analysis. The X-ray crystal analysis shows that Ni(II) atoms in the Ni(II) complex have distorted octahedral geometries. It is the key factor that the ligand containing 3-position methoxy groups gives rise to the formation of the tetranuclear Ni(II) complex. When \(\text{NO}_{3}^{-}\) anions are used to bridge two Ni2 atoms, there are two symmetrical open cubic structures. The Ni(II) complex forms a 3D supramolecular structure through intermolecular hydrogen bond interactions. Using the Hirshfeld surface to clarify interactions between the molecules, the percentages of C–H/H–C, O–H/H–O, and H–H/H–H contacts are calculated as 19.0%, 15.3%, and 54.0%, respectively. Density functional theory (DFT) studies show that the stability of the Ni(II) complex is much higher than that of H₂L. The calculation of the fluorescence titration experiment can give K = 1.05·10⁸ M^–1, which further proves the stability of the Ni(II) complex.

中文翻译：

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采用两种开放立方结构的新型四核镍 (II) SALAMO 复合物：合成、表征、DFT 计算、Hirshfeld 分析和荧光特性

摘要

通过对称的萨拉莫基配体H ₂ L, NiCl ₂ ·6H ₂ O合成了新型四核Ni(II)配合物[Ni ₄ (L) ₂ (N ₃ ) ₄ Cl(MeOH) ₃ ]·CH ₃ COCH ₃ , 和 NaN ₃。通过元素分析、IR 和 UV-Vis 光谱以及 X 射线衍射分析表征了该结构。X 射线晶体分析表明 Ni(II) 复合物中的 Ni(II) 原子具有扭曲的八面体几何形状。含有3位甲氧基的配体是形成四核Ni(II)配合物的关键因素。当\(\text{NO}_{3}^{-}\)阴离子用于桥接两个Ni2原子，有两个对称的开放立方结构。Ni(II) 配合物通过分子间氢键相互作用形成 3D 超分子结构。使用 Hirshfeld 表面来阐明分子之间的相互作用，C–H/H–C、O–H/H–O 和 H–H/H–H 接触的百分比计算为 19.0%、15.3% 和 54.0 ％， 分别。密度泛函理论（DFT）研究表明，Ni(II)配合物的稳定性远高于H ₂ L。荧光滴定实验计算得出K = 1.05·10 ⁸  M ^–1，进一步证明Ni(II)配合物的稳定性。