Crystal structures of 2,6-bis­[(1H-1,2,4-triazol-1-yl)meth­yl]pyridine and 1,1-[pyridine-2,6-diylbis(methyl­ene)]bis­(4-methyl-1H-1,2,4-triazol-4-ium) iodide triiodide

In the structures of the 2,6-bis­(1,2,4-triazoly-3-yl)methyl-substituted pyridine compound, C(11)H(11)N(7), (I) and the iodide triiodide salt, C(13)H(17)N(7) (2+)·I(−)·I(3) (−), (II), the dihedral angles between the two triazole rings and the pyridine ring are 66.4 (1) and 74.6 (1)° in (I), and 68.4 (2)° in (II), in which the dication lies across a crystallographic mirror plane. The overall packing structure for (I) is two-dimensional with the layers lying parallel to the (001) plane. In (II), the triiodide anion lies within the mirror plane, occupying the space between the two triazole substituent groups and was found to have minor disorder [occupancy ratio 0.9761 (9):0.0239 (9)]. The overall packing of structure (II) can be described as two-dimensional with the layers stacking parallel to the (001) plane. In the crystal, the predominant inter­molecular inter­actions in (I) and (II) involve the acidic hydrogen atom in the third position of the triazole ring, with either the triazole N-atom acceptor in weak C—H⋯N hydrogen bonds in (I), or with halide counter-ions through C—H⋯I inter­actions, in (II).