1,3,5-Triiodo-2,4,6-trimethylbenzene at 293 K.

In the structure of triiodomesitylene (1,3,5-triiodo-2,4,6-trimethylbenzene), C(9)H(9)I(3), at 293 K, the benzene ring is found to be significantly distorted from ideal D(6h) symmetry; the average endocyclic angles facing the I atoms and the methyl groups are 123.8 (3) and 116.2 (3) degrees, respectively. The angle between the normal to the molecular plane and the normal to the (100) plane is 5.1 degrees. No disorder was detected at 293 K. The thermal motion was investigated by a rigid-body motion tensor analysis. Intra- and intermolecular contacts are described and topological differences compared with the isomorphous compounds trichloromesitylene and tribromomesitylene are discussed.