Received 3 April 2009
The structure of the title compound, C8H8I2, conforms closely to the mm2 symmetry expected for the free molecule and is the first reported structure of a diiododimethylbenzene. Repulsion by neighboring I atoms and the neighboring methyl groups opposite to them results in a slight elongation of the molecule along the approximate twofold rotation axis that bisects the ring between the two I atoms. In the extended structure, the molecules form inversion-related pairs which are organized in approximately hexagonal close-packed layers and the layers then stacked so that molecules in neighboring layers abut head-to-tail in a manner that optimizes dipole-dipole interactions.
For the synthesis see: Suzuki (1988). For the structure of 1,2-diiodo-4,5-dimethoxybenzene, see: Cukiernik et al. (2008). For methods of iodinating substituted benzenes, see: Hathaway et al. (2007). For related work on diacetylenes, see: Hathaway (1988); Hathaway & Scates (1997).
Data collection: COLLECT (Hooft, 1998); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: IS2407 ).
The authors thank the National Science Foundation DUE CCLI-A&I program (grant No. 9951348) and Southeast Missouri State University for funding the X-ray diffraction facility.
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