The hetero‐tetranuclear Cu²⁺/Ca²⁺/Ca²⁺/Cu²⁺ complex obtained with the N,N’‐bis((3‐hydroxy‐4‐pyron‐2‐yl)methyl)‐N,N’‐dimethylethylendiamine (Malten) ligand has been studied in solid and solution states as scaffold to bind anions. Three crystal structures showing the same metal ions sequence have been examined; they display a tetracharged complex cation neutralized by four monocharged anions. The anions play two different roles: as coordinated (two ClO₄⁻, Cl⁻ or NO₃⁻) or ancillary (two ClO₄⁻) guests. The tetranuclear scaffold hosts two anions also in aqueous and ethanol solutions. Spectrophotometric studies in ethanol allowed to determine the addition constant values for Cl⁻ and Br⁻ (Log K _1‐2 =4.43(4), 4.39(3) for Cl⁻, 3.80(3), 3.54(2) for Br⁻) while the others, although bound, showed lower affinity for the scaffold. Both the crystals and the solutions change their color depending on the added anion, namely pink, dark green or blue in the presence of ClO₄⁻, Cl⁻ or NO₃⁻, respectively, thus the presence of the different anions is visible to the naked eye. The hetero‐tetranuclear Cu²⁺/Ca²⁺/Ca²⁺/Cu²⁺ complex is a versatile architecture to be used as scaffold for anion binding.

中文翻译：

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基于Malten配体的杂四核Cu2 + / Ca2 + / Ca2 + / Cu2 +结构：用于阴离子结合的支架。

与N，N'-双（（3-羟基-4-吡喃-2-基）甲基）N，N'获得的杂四核Cu ²⁺ / Ca ²⁺ / Ca ²⁺ / Cu ²⁺复合物‐二甲基乙基己二胺（Malten）配体已在固溶和溶液状态下作为结合阴离子的支架进行了研究。已经检验了显示相同金属离子序列的三个晶体结构。它们显示出被四个单电荷阴离子中和的四电荷复合阳离子。阴离子扮演两个不同的角色：为协调（二CLO ₄ ^- ，氯^-或NO ₃ ^- ）或配套（二CLO ₄ ^-）客人。四核支架在水溶液和乙醇溶液中也带有两个阴离子。在乙醇光度法研究允许确定用于氯加入恒定值^-和Br ^- （登录ķ _1-2 = 4.43（4），4.39（3），用于氯^-，3.80（3），3.54（2）溴^- ）而其他尽管绑定，但显示对支架的亲和力较低。两个晶体和溶液改变取决于加入阴离子，即粉红色，深绿色或蓝色中CLO的存在下它们的颜色₄ ^- ，氯^-或NO ₃ ^-因此，肉眼可见不同阴离子的存在。杂四核Cu ²⁺ / Ca ²⁺ / Ca ²⁺ / Cu ²⁺络合物是一种通用的体系结构，可用作阴离子结合的支架。