Chiral Memory of Additive-Induced Handedness in Supramolecular Nanotubes from Achiral Monomers

We report additive-induced chiral memory in supramolecular nanotubes formed from an achiral 9,10-diphenylanthracene dyad bearing pyridyl recognition sites. The achiral dyad self-assembled into nanotubes in nonpolar solvent, and pre- assembly addition of enantiomeric α-methoxyphenylacetic acids induced mirror-image circular dichroism signals. In contrast, post-assembly addition to preformed nanotubes produced no chiroptical response. FT-IR spectroscopy and a phenyl analogue control confirmed that transient pyridine–carboxylic acid hydrogen bonding before aggregation is essential for induction of a handedness bias. The nanotubes retained the induced CD response even after most of the chiral additive was removed by filtration and washing. These results establish a removable-additive approach for programming chiral supramolecular nanotubes from achiral monomers.