An M60L60 metal-peptide capsid with a 60-crossing woven network

Abstract

Controlling topologies of highly entangled molecular strands from scratch has long been challenging. For its realization, repeated cycles of prediction, considering the geometrical constraints behind molecular self-assembly, and synthetic trial-and-error are crucial. Here, we report the chemical construction of an unexplored topological molecule—a dodecahedral link with 60 crossings. This structure, predicted through theoretical considerations, represents an advancement from previous tetrahedral and cubic links. The resulting capsid-like structure, measuring 6.3 nm in size, has an M 60 L 60 composition (M, metal; L, ligand), formed through the folding and assembly of 60 trivalent Cu + ions and 60 tritopic pentapeptide ligands. This entangled topological framework formed a 4.0 nm-sized inner cavity (∼34,000 Å 3 ). The 60-crossing dodecahedral link topology was, in another way using both knot and graph theories, also characterized as a Goldberg T = 3 polyhedron ( T , triangulation number) consisting of trefoil knot panels, providing a new roadmap to further giant capsid structures.