Dissipative Formation of Covalent Basket Cages

Abstract Living systems use chemical fuels to transiently assemble functional structures. As a step toward constructing abiotic mimics of such structures, we herein describe dissipative formation of covalent basket cage CBC 5 by reversible imine condensation of cup‐shaped aldehyde 2 (i.e., basket) with trivalent aromatic amine 4 . This nanosized [4+4] cage ( V =5 nm 3 , M w =6150 Da) has shape of a truncated tetrahedron with four baskets at its vertices and four aromatic amines forming the faces. Importantly, tris ‐aldehyde basket 2 and aliphatic tris ‐amine 7 undergo condensation to give small [1+1] cage 6 . The imine metathesis of 6 and aromatic tris ‐amine 4 into CBC 5 was optimized to bias the equilibrium favouring 6 . Addition of tribromoacetic acid (TBA) as a chemical fuel perturbs this equilibrium to result in the transient formation of CBC 5 , with subsequent consumption of TBA via decarboxylation driving the system back to the starting state.