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

Abstract

Superb control over the helical chirality of highly-entangled (M ₃L ₂) _n polyhedra (M = Cu( i), Ag( i); n = 2,4,8) was achieved via multiplication of weak chiral inductions by side chains accumulated on the huge polyhedral surfaces.

Abstract

Superb control over the helical chirality of discrete (M ₃L 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 ₃L 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.