LAUSR

Reaction kinetics drives chiral nanocrystal formation from helically bonded tellurium atoms A glove fits only one of our hands because the mirror images of gloves (and our hands) cannot be superimposed. Molecules or crystals that have this property are said to be chiral. Since the work of Pasteur on the separation of the sodium ammonium salts of racemic tartaric acid into right- and left-handed crystals (1), how and whether molecular chirality is necessary for formation of chiral crystals has been explored. Even atoms such as tellurium (Te) (2) can form chiral crystals because their chemical bonding can create helices (see the figure, top) that are right- or left-handed, although such helices can also pack to form achiral crystals. On page 729 of this issue, Ben-Moshe et al. (3) explored what determines the formation of chiral Te nanocrystals through controlled colloidal synthesis and advanced electron microscopy. Chiral crystals grew at medium supersaturation, apparently driven by screw dislocations in the crystal nuclei.