Experimental

R factor = 0.033; wR factor = 0.087; data-to-parameter ratio = 14.2. The asymmetric unit of the title co-crystal adduct, C6H4O2C6F4I2, comprises a half-molecule each of cyclo-hexa-2,5-diene-1,4-dione and 1,2,4,5-tetrafluoro-3,6-diiodo-benzene. The C6F4I2 molecule is almost planar (r.m.s. deviation = 0.0062 Å). In the crystal, the components are connected through O I halogen bonds [3.017 (11) Å], leading to the formation of wavelike chains along the a axis. The crystal packing also features C—H F interactions. Related literature For related studies on co-crystal formation, see: Bhogala &amp