Experimental

R factor = 0.039; wR factor = 0.122; data-to-parameter ratio = 24.3. In the crystal structure of the title compound, C27H39N2 +I3, the imidazolidinium ring is perpendicular to a mirror plane which bisects the cation. The dihedral angle between the imidazolidinium ring and the benzene ring is 89.0 (2). The triiodide anion also lies on a mirror plane and is almost linear with an I—I—I bond angle of 178.309 (18). Related literature For a related structure with a 1,3-(2,6-diisopropylphenyl)-imidazolidinium unit, see: Giffin et al. (2010). For its synthesis, see: Llewellyn et al. (2006)