By employment of a tripodal phosphoric carboxylate ligand, tris(4-carboxylphenyl)phosphine oxide (H3TPO), two novel porous metal–organic frameworks, namely, [Zn4(μ3-OH)2(TPO)2(H2O)2] (1) and [Zn6(μ6-O)(TPO)2](NO3)4·3H2O (2), have been synthesized by solvothermal methods. Complexes 1 and 2 exhibit three-dimensional microporous frameworks with flu and pyr topologies and possess rare butterfly-shaped Zn4(μ3-OH)2(CO2)6 and octahedral Zn6(μ6-O)(CO2)6 secondary building units, respectively. Large cavities and one-dimensional channels are observed in these two frameworks. Gas-sorption measurements indicate that complex 2 has a good H2 uptake capacity of 171.9 cm3 g–1 (1.53 wt %) at 77 K and 1.08 bar, and its ideal adsorbed solution theory calculation predicts highly selective adsorption of CO2 over N2 and CH4. Furthermore, complexes 1 and 2 exhibit excellent blue emission at room temperature.

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.

A enneanuclear nanocage, [Ni9(HL)6(Pz)6](PzH)3(ClO4)3(H2O)24 (1), has been synthesized by coordination-driven face-directed self-assembly of octahedral Ni(II) ions and asymmetric hydrazone ligands with addition of pyrazole in ethanol solution. Compound 1 with hexahedral nanocage structure has been characterized by elemental analysis, FT-IR, TGA, ESI-MS, and X-ray diffraction analysis. Furthermore, variable-temperature magnetic studies for compound 1 have also been reported.