Establishing a Hierarchy of Halogen Bonding by Engineering Crystals without Disorder

It
has been shown, using a foundation of new structural data, that
the relative strength and capability of iodo- and bromo-based molecules
to act as halogen-bond donors in a competitive supramolecular arena
accurately reflect a ranking of halogen-bond donors based upon electrostatic
molecular potentials. Furthermore, to obtain the critical structural
information, a protocol (comprising a lowering of molecular symmetry
and the addition of strong and directional hydrogen bonds) for engineering
crystals without positional disorder was successfully developed.