Determined the type of halogen bonds in a polypeptoid crystal by atomic-scale imaging and validated the observations by simulations on the same scale.
Significance and Impact
Traditional knowledge of the geometry of noncovalent interactions (e.g., hydrogen and halogen bonds) is based on indirect experiments such as spectroscopy. In this study, the geometric arrangement of neighboring halogen atoms in a model soft material is obtained directly by atomic-scale cryogenic electron microscopy.
- Atomic-scale cryo-TEM imaging of a series of polypeptoids.
- Images agree with simulations only when the σ-hole (a small positive patch) on Br atom is accounted for.