Generalized Synthesis of Calixarene-Based High-Nuclearity M4n Nanocages (M = Ni or Co; n = 2–6)

A family of high-nuclearity M4n (M = Ni or Co, n = 2–6) coordination nanocages constructed by M4–calix­[4]­arene molecular building blocks (MBBs) with inorganic phosphate or organic phosphonate ligands have been isolated by solvothermal syntheses and characterized by single-crystal X-ray diffraction. This family can be divided into five structural types with an increase in the number of M4–calix­[4]­arene MBBs, including Ni8 (1 and 2, n = 2), M12 (M = Ni (3) and Co (4), n = 3), M16 (M = Ni (5) and Co (6), n = 4), Co20 (7, n = 5), and Co24 (8, n = 6) coordination nanocages. Structural analyses reveal that the metallic cores of 1 and 2 are arranged in chair conformation, while compounds 3–6 with closed-shell structures, where their ports are sealed by sodium ions, present the first examples of 2p-3d heterometallic metal–calixarene nanocages to our knowledge. The novel helmet-like Co20 (7) is the only one in this family with an open-shell structure, which can be thought of as a truncated octahedral Co24 (8) nanocage cutting one face. Furthermore, the magnetic behaviors of 1–8 have been investigated, suggesting the existence of strong antiferromagnetic interactions between magnetic centers for all title coordination cages.由M4-杯[4]芳烃分子构建单元（MBB）构建的高核性M4n（M为Ni或Co，n为2至6）配位纳米笼家族，该家族通过溶剂热合成法获得，并通过单晶X射线衍射进行了表征。此家族可根据M4-杯[4]芳烃MBB数量的增加分为五种结构类型，包括Ni8（1和2，n=2）、M12（M=Ni（3）和Co（4），n=3）、M16（M=Ni（5）和Co（6），n=4）、Co20（7，n=5）和Co24（8，n=6）配位纳米笼。结构分析揭示了1和2的金属核以椅式构象排列，而3至6的闭壳结构，其中其端口被钠离子密封，据我们所知，是首次出现的2p-3d异金属金属-杯芳烃纳米笼。新颖的盔式Co20（7）是本家族中唯一具有开壳结构的纳米笼，可以视为截顶八面体Co24（8）纳米笼切割一个面。此外，对1至8的磁性进行了研究，表明所有标题配位笼的磁性中心之间存在强烈的反铁磁性相互作用。