The combination of strong coordination bonds and hydrogen bonding interactions were used to generate a series of supramolecular coordination materials (SCMs), which was achieved by reacting a bis-pyridyl amide ligand, namely N-(4-pyridyl)nicotinamide (4PNA) with copper(II), zinc(II), and cadmium(II) benzoates. The SCMs were structurally characterized using X-ray diffraction and the key intermolecular interactions were identified via Hirshfeld surface analysis. The role of solvent molecules on the supramolecular architecture was analyzed by synthesizing the SCMs in different solvents/solvent mixtures. A solvent-mediated solid-state structural transformation was observed in copper(II) SCMs and we were able to isolate the intermediate form of the crystal-to-crystal transformation process. The luminescence experiments revealed that complexation enhanced the fluorescence properties of 4PNA in the zinc(II) and cadmium(II) SCMs, but a reverse phenomenon was observed in the copper(II) SCMs. This work demonstrated the tuning of supramolecular assembly in coordination compounds as a function of solvents for generating SCMs with diverse properties.

中文翻译：

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超分子配位化合物的固态结构转变和光致发光性质

强配位键和氢键相互作用的组合被用来生成一系列超分子配位材料（SCM），这是通过使双吡啶酰胺配体（即N-（4-吡啶基）烟酰胺（4PNA）与铜（II），锌（II）和镉镉（II）。使用X射线衍射对SCM进行结构表征，并通过Hirshfeld表面分析确定关键的分子间相互作用。通过在不同溶剂/溶剂混合物中合成SCM，分析了溶剂分子在超分子体系中的作用。在铜（II）SCM中观察到溶剂介导的固态结构转变，并且我们能够分离出晶体到晶体转变过程的中间形式。发光实验表明，络合作用增强了锌（II）和镉（II）SCM中4PNA的荧光特性，但在铜（II）SCM中观察到了相反的现象。