Figure 6:

Solid-state structures of a) TPyE and b) [TPyE]²⁺2[I]⁻ viewed down the C(1)-C(2) bond. This shows that in TPyE the nitrogen atoms in the heterocyclic rings are approximately eclipsed, whereas in [TPyE]²⁺2[I]⁻ they are approximately staggered. This is reflected in the angles formed by the planes defined by N(1)-C(1)-C(2)-N(2) and N(3)-C(2)-C(1)-N(4). Hydrogen atoms and iodide anions omitted for clarity.