The title structure, C10H9N2+.I-3(-), consists of 2-(2-pyridyl)pyridin
ium cations and near-symmetric essentially linear triiodide anions [I-
I = 2.902(1) and 2.920(1) Angstrom, and I-I-I = 177.88(5)degrees]. The
cation has a syn configuration, with an intramolecular N-H ... N hydr
ogen bond: H-N2 and H ... N1 = 1.13(11) and 1.83(10) Angstrom, respect
ively, and N2-H ... N1 = 124(8)degrees, The two heterocyclic rings are
not coplanar, the angle between the rings being 9.6 (8)degrees.