Wikipedia
Hexaiodobenzene
Hexaiodobenzene is a chemical compound with the formula CI. Structurally, it is a derivative of benzene, in which all hydrogen atoms are replaced by iodine atoms. It forms orange crystals that are poorly soluble in all solvents.
The compound was first prepared by iodination of benzoic acid in the presence of hot fuming sulfuric acid. It adopts the expected structure with a central C6 ring.