Controlled self-assembly of a giant isohedral triakis tetrahedron

Polyhedra have long appeared throughout art and design for their aesthetic topological features and, more recently, have found versatile roles in supramolecular chemistry and organized materials. Non-regular convex tetrahedra with positive augmentations of a regular tetrahedron, for example an isohedral triakis tetrahedron, have rarely been explored in synthetic chemistry. Herein, we report the synthesis of a giant triakis tetrahedron through multi-component self-assembly from four umbrella-shaped hexa-armed organic terpyridine ligands and six pre-organized cadmium-containing building blocks. Hexafunctionalized tribenzotriquinacene cavitands serve as the scaffold for the formation of the triakis tetrahedron. The convex vertices derived from rhomboid panels form four trigonal-pyramidal cages based on regular tetrahedral faces. Characterization with multiple types of nuclear magnetic resonance spectroscopy, mass spectrometry, atomic resolution microscopy, and X-ray scattering provide crucial structural information on the triakis tetrahedron. The triakis tetrahedron is applied in the photo-driven degradation of a sulfur mustard mimic. The principles developed herein enhance the possible topological diversity of supramolecular coordination polyhedra.