Spontaneous chiral self-assembly of CdSe@CdS nanorods

The enantiomeric excess phenomenon in spontaneous chiral symmetry breaking (SCSB) is a crucial issue in the origin of homochirality in nature, whereas chiral inorganic compounds have long been reckoned as racemates. Here, we report the SCSB in the self-assembly of cadmium chalcogenide nanorods, leading to chiral biases away from the racemate. In the presence of achiral organics, helical CdSe@CdS nanorods (HCCNs) with unidirectionally rotated crystal lattices along the rod axis were stochastically formed on the epitaxial interface of the {111}cub/{0001} hex planes. The stability of helical dislocation structures, as supported by a theoretical analysis of their binding energies, suggested the possibility of the emergence of helical structures in an achiral environment. Hierarchical chiral films induced by simple solvent evaporation self-assembly of HCCNs exhibited spontaneous enantiomeric excess between batches, which was speculated to be originated from the enantiomeric excess seed assembly that induce one-handedness dominated system based on the majority rules.