Memory of macromolecular helicity assisted by interaction with achiral small molecules

The helicity of biological macromolecules such as DNA and proteins is largely governed by the homochirality of their components (D-sugars and L-amino acids). In polymer and supramolecular chemistry, control of helicity is an attractive goal because of possible applications in materials science, chemical sensing and enantioselective catalysis(1-13). We reported recently that macromolecular helicity can be induced in a polymer by an optically active amine(14). Here we show that this helicity can be 'memorized' when the amine is replaced by various achiral amines. Although the maintenance of helicity in the polymer is not perfect, it can 'repair' itself over time. Small structural changes in the achiral amines influence the efficiency of helicity retention markedly.