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

In the structure of triiodomesitylene (1,3,5-triiodo-2,4,6-trimethylbenzene ), C9H9I3, at 293 K, the benzene ring is found to be significantly distorte d from ideal D-6h symmetry; the average endocyclic angles facing the I atom s and the methyl groups are 123.8 (3) and 116.2 (3)degrees, respectively. T he angle between the normal to the molecular plane and the normal to the (1 00) plane is 5.1 degrees. No disorder was detected at 293 K. The thermal mo tion was investigated by a rigid-body motion tensor analysis. Intra- and in termolecular contacts are described and topological differences compared wi th the isomorphous compounds trichloromesitylene and tribromomesitylene are discussed.