title: 2-Amino-pyridin-1-ium triiodide.
abstract: The asymmetric unit of the title compound, C5H7N2 (+.)I3 (-), consists of one 2-amino-pyridin-1-ium cation (apyH(+)) and one triiodide anion, both located in general postions. The apyH(+) cation is planar within the experimental uncertainties. The short N-C distance [1.328 (5) Å] of the exocyclic NH2 group is typical for the imino-form of protonated 2-amino-pyridines. Consequently, the bond lengths within the six-membered ring vary significantly. The geometric parameters of the triiodide anion are in the typical range, with bond lengths of 2.8966 (3) and 2.9389 (3) Å and a bond angle of 176.02 (1)°. In the crystal, N-H ⋯ I hydrogen bonds connect adjacent ions into screwed chains along the b-axis direction. These chains are twisted pairwise into rectangular rods. The pyridinium moieties of neighbouring rods are arranged parallel to each other with a plane-to-plane distance of 3.423 (5) Å.
authors.affiliation: Institut für Anorganische Chemie und Strukturchemie, Lehrstuhl II: Material- und Strukturforschung, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany.
authors.forename: Guido J
authors.initials: GJ
authors.lastname: Reiss
authors.forename: Peer B
authors.initials: PB
authors.lastname: Leske
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