Developing discrete radical organometallic nanocages is essential for fabricating functional materials. In this study, we construct a series of poly-NHC-based (NHC = N-heterocyclic carbene) organometallic nanocages 3a–3c with different sizes by employing redox-active bis(triarylamine) derivatives with different π-conjugated spacers as building blocks. The varied sizes of nanocages 3a–3c modulate the distance of the redox-active centers and reversibly convert them to radical nanocages 3a²⁺–3c²⁺ through chemical and electrochemical oxidation. Radical nanocages 3a²⁺–3c²⁺ display clear bond and angle alteration and retention of their three-dimensional topologies. This work not only merely proves that these nanocages are excellent stimulus-responsive materials but also opens a door to the rational design of novel radical organometallic nanocages.

Bottom-up construction of highly complex architecture from simple components remains one of the long-standing challenges in chemistry. Herein two supramolecular isomers based on large trigonal prismatic Pd₃L¹₆ building block are reported. Significantly, they can be controllably obtained by adjusting the solute concentration during crystal growth. Specifically, the square shape crystals, α-[Pd₃L¹₆](PF₆)₁₂ in the cubic system with $I\overline{4}3m$ space group, can be isolated from a high-concentration solution of Pd₃L¹₆. Interestingly, a mesoporous cage assembled from eight Pd₃L¹₆ units with a diameter of 24 Å is observed in the crystal structure. For the low-concentration solution of Pd₃L¹₆, the rectangular shape crystals β-[Pd₃L¹₆](PF₆)₁₂ are obtained, which crystallize in the hexagonal system with P6₃/m space group, and display two-dimension packing pattern and one-dimension mesoporous channels (diameter ca. 22 Å) along the c axis. Moreover, the two supramolecular isomers were used as nanoporous reactors to induce the specific formation of polyiodides with different compositions and shapes as evidenced from single crystal X-ray diffraction studies. These findings provide a reference in targeting functional crystalline mesoporous supramolecular materials from a single complex building unit.