A 10-nm-sized multicompartment cuboctahedron and its 2D hierarchical arrays observed by cryo-EM

Summary

Quantitative self-assembly of three-dimensional (3D) giant molecules (>10 nm in diameter) with well-defined geometry remains an outstanding synthetic challenge. Here, we report the rational construction of a 10-nm-sized cuboctahedron using dynamic heteroleptic complexation and multivalent ligand design. The obtained molecular cuboctahedron contains a double-layered multicompartment structure, reminiscent of a self-balanced cable-strut tensile architecture. Its precisely designed shape and size lead to the hierarchical self-assembly into ordered square arrays with a lattice constant of 7.9 nm. Additionally, the local structures, such as dislocations and grain boundaries of packing domains, are also recognized by cryogenic electron microscopy (cryo-EM), which interrupt the regular patterns of square lattices and then result in the oblique arrays. The observed assembly of the giant cuboctahedra into supramolecular arrays provides a foundation for the bottom-up development of uniform two-dimensional (2D) materials.