Cyanine dyes: synergistic action of hydrogen, halogen and chalcogen bonds allows discrete I42− anions in crystals

Abstract

In crystals of a benzoselenazole dye, a network of hydrogen bonds with the dye cations locks two iodide anions at a distance allowing for an iodine molecule to be pinned at either ends via two halogen bonds. I₄²⁻ supramolecular anions are formed as discrete species that lie in the confined space defined by cation molecules.