Amplification of weak chiral inductions for excellent control over the helical orientation of discrete topologically chiral (M 3 L 2 ) n polyhedra.

Superb control over the helical chirality of discrete (M 3 L 2 ) n polyhedra ( n = 2,4,8, M = Cu I or Ag I ) created from the self-assembly of propeller-shaped ligands (L) equipped with chiral side chains is demonstrated here. Almost perfect chiral induction (>99 : 1) of the helical orientation of the framework was achieved for the largest (M 3 L 2 ) 8 cube with 48 small chiral side chains (diameter: ∼5 nm), while no or moderate chiral induction was observed for smaller polyhedra ( n = 2, 4). Thus, amplification of the weak chiral inductions of each ligand unit is an efficient way to control the chirality of large discrete nanostructures with high structural complexity.