Intrigued by the unexpected room‐temperature dual visible/near‐infrared (NIR) luminescence observed for fast‐relaxing erbium complexes embedded in triple‐stranded helicates, in this contribution, we explore a series of six tridentate N‐donor receptors L4–L9 with variable aromaticities and alkyl substituents to extricate the stereoelectronic features responsible for such scarce optical signatures. Detailed solid‐state (X‐ray diffraction, differential scanning calorimetry, optical spectroscopy) and solution (speciations and thermodynamic stabilities, spectrophotometry, NMR and optical spectroscopy) studies of mononuclear unsaturated [Er(Lk)₂]³⁺ and saturated triple‐helical [Er(Lk)₃]³⁺ model complexes reveal that the stereoelectronic changes induced by the organic ligands affect inter‐ and intramolecular interactions to such an extent that 1) melting temperatures in solids, 2) the affinity for trivalent erbium in solution, and 3) optical properties in luminescent complexes can be rationally varied and controlled. With this toolkit in hand, mononuclear erbium complexes with low stabilities displaying only NIR emission can be transformed into molecular‐based dual Er‐centered visible/NIR emitters operating at room temperature in both solid and solution states.

中文翻译：

---

Dual（III）配合物对双可见/近红外发光的热力学编程

通过快速松弛嵌入在三链helicates铒复合物，在这方面的贡献双可见/近红外（NIR）荧光观察意想不到室温感兴趣，我们探索出一系列的六个三齿N-供体的受体L4 - L9与可变的芳香性和烷基取代基，以消除造成这种稀缺光学信号的立体电子特征。单核不饱和[Er（L k）₂ ] ³⁺和饱和三重核素的详细固态（X射线衍射，差示扫描量热法，光谱学）和溶液（形态和热力学稳定性，分光光度法，NMR和光谱学）研究螺旋[Er（Lk） ₃ ] ³⁺模型配合物表明，有机配体引起的立体电子变化会影响分子间和分子间的相互作用，其程度为1）固体中的熔化温度，2）对溶液中三价的亲和力和3）光学上的发光络合物的性质可以合理地改变和控制。使用此工具包，可以将仅显示NIR发射的低稳定性的单核complex络合物转换为在室温下以固态和溶液态运行的基于分子的以Er为中心的可见/ NIR双发射体。