Figure 3.

Tubular (and space-filling) representations of the solid-state superstructures revealing the angle and distance between adjacent dications for 3²⁺ (a and b), 6²⁺ (c and d), and 7²⁺ (e and f). All three dications display an ABAB stacking motif in the solid state as a result of the increased steric interactions provided by the substituents in the 2 and 9 positions of the diazaperopyrenium dication. For the numbering of the positions on the dication, please refer to the general structural formula in Figure 1.