What is the shape of a more flexible salamo-type ligand? Unexpectedly single crystals of the ligand and a uncommon tetranuclear chloride-bridged complex with Ni(II) [Ni(L)(Cl)(OMe)(MeOH)] were acquired. Single-crystal X-ray analyzes revealed the true structure of the ligand to be a twisted rectilinear shape, with a unique structure providing a diverse coordination environment for the metal ions. The involvement of halogens in the bridging is uncommon, and Single-crystal X-ray analysis of the complex showed that each deprotonated methoxy group bridges three Ni(II) metals, and then three Ni(II) metals are bridged by two chloride ions, each chloride ion bridges two Ni(II) metals. At this point the geometries of all four Ni(II) atoms adopt 6-coordinated octahedral configurations. It was demonstrated in UV–visible titration test that the metal-to-ligand ratios in solution and the structure of the complex obtained by single-crystal X-ray analysis are consistent. The properties were predicted analytically by DFT theory calculations and the UV–vis absorption spectra obtained by TD-DFT theory calculations in general coincide with the test results. The weak interactions in the complex were analyzed by cell freedom, Hirshfed surface analysis, ESP and IRI calculations. Finally, the fluorescence properties were explored in detail.

中文翻译：

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更灵活的萨拉莫型配体及其罕见的四核氯桥镍（II）络合物的结构、荧光和理论研究


更灵活的萨拉莫型配体的形状是什么？出乎意料地获得了配体的单晶和罕见的四核氯桥配合物 Ni(II) [Ni(L)(Cl)(OMe)(MeOH)]。单晶X射线分析揭示了配体的真实结构是扭曲的直线形状，其独特的结构为金属离子提供了多样化的配位环境。卤素参与桥联的情况并不常见，配合物的单晶 X 射线分析表明，每个去质子化的甲氧基桥联三个 Ni(II) 金属，然后三个 Ni(II) 金属通过两个氯离子桥联，每个氯离子桥接两个 Ni(II) 金属。此时，所有四个 Ni(II) 原子的几何形状均采用 6 配位八面体构型。紫外可见滴定测试表明，溶液中金属与配体的比例与单晶X射线分析得到的配合物结构是一致的。通过DFT理论计算对这些性能进行了分析预测，并且通过TD-DFT理论计算获得的紫外-可见吸收光谱与测试结果基本一致。通过细胞自由度、Hirshfed 表面分析、ESP 和 IRI 计算分析了复合物中的弱相互作用。最后，详细探讨了荧光特性。