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 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.

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.