Remote Control of the Planar Chirality in Peptide-Bound Metallomacrocycles and Dynamic-to-Static Planar Chirality Control Triggered by Solvent-Induced 310-to-α-Helix Transitions

The dynamic planar chirality in a peptide-bound Ni-II-salphen-based macrocycle can be remotely controlled. First, a right-handed (P)-3(10)-helix is induced in the dynamic helical oligopeptides by a chiral amino acid residue far from the macrocyclic framework. The induced planar chirality remains dynamic in chloroform and acetonitrile, but is almost completely locked in fluoroalcohols as a result of the solvent-induced transition of the peptide chains from a 3(10)-helix to a wider a-helix, which freezes the rotation of the pendant peptide units around the macrocycle.