Hexaiodobenzene is an aryl iodide and a six-substituted iodobenzene with the formula C6I6. Structurally, it is a derivative of benzene, in which all hydrogen atoms are replaced by iodine atoms. It forms orange crystals[1] that are poorly soluble in all solvents. It adopts the expected structure with a central C6 ring.[3]
Hexaiodobenzene forms orange needles that are practically insoluble in water, but sparingly soluble in N-methyl-2-pyrrolidone and dimethyl sulfoxide. It melts at 430 °C, but also already begins to show some decomposition at 370 °C, forming I2.[1]
Crystallographic properties
The crystals are monoclinic and pseudohexagonal, with centrosymmetric C6I6 units. The carbon atoms lie in a plane with C–C distances about 141 pm, while the nearby iodine atoms show very small displacements (about 4 pm) above and below the ring. The shortest intermolecular distance, 376 pm, is notably short compared to twice the Van der Waals radius, which is 430 pm.[2] The structure is retained at high pressures up to 9.7 GPa.[6]
References
^ abcdMattern, Daniell Lewis (1983). "Periodination of benzene with periodate/Iodide". The Journal of Organic Chemistry. 48 (24): 4772–4773. doi:10.1021/jo00172a063.