Emergence of hierarchical structural complexities in nanoparticles and their assembly

Probing packing rules The crystals of a well-defined ligand-covered gold nanoparticle can reveal how packing into a lattice happens. Zeng et al. synthesized nanoparticles with a 246-atom gold core surrounded by 80 4-methylbenzenethiol ligands. These nearly spherical nanoparticles did not pack into a cubic arrangement but instead formed a lower-symmetry monoclinic structure. A hierarchy of interparticle ligand interactions controlled the packing, including sets of chiral packing arrangements that reversed between layers. Science , this issue p. 1580