Occurrence of Chiral Nanostructures Induced by Multiple Hydrogen Bonds

Developing artificial systems to
mimic the emergence of chirality
is of vital importance in better understanding the mysterious origin
of natural homochirality and guiding the design of advanced chiroptical
materials. Herein, we present a DNA-inspired control over the emergence
of supramolecular nanoscale chirality in multiple hydrogen-bonded
self-assemblies. N-Terminated aromatic amino acids
bearing serine and aromatic domains could self-assemble into lamellar
microsheets without nanoscale chirality, ascribed to their pronounced
molecular stacking preference on two-dimensional orientations. Significantly,
when achiral bipyridine-, melamine-, and imidazole-based molecular
binders that could potentially form hydrogen-bonded complexes with
these aromatic amino acids were introduced, the induced chiral nanostructures
from the resulting coassemblies were observed. Melamine and its derivatives
presented an excellent capability to generate ordered supramolecular
structures and induce the nanoscale chirality. Assisted by the key
duplex hydrogen bonds between the melamine core and serine segments,
chiral nanotubes and ribbons were obtained. This study reveals that
multiple hydrogen bonds are the prerequisite for inducing the emergence
of chiral nanostructures from integrated coassemblies.