Cukrowski, IgnacyAdeyinka, Adedapo S.Liles, David C.2013-03-202013-03-202012-07-02Cukrowski, I, Adeyinka, AS & Liles, DC 2012, '3,6-Diazaoctane-1,8-diaminium diiodide', Acta Crystallographica Section E-Structure Reports Online, vol. E68, no. o2387, pp. sup-1-5.1600-5368 (online)10.1107/S1600536812030127http://hdl.handle.net/2263/21196Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: JJ2132).The asymmetric unit of the title salt, C6H20N4 2+ 2I , comprises half a 3,6-diazaoctane-1,8-diaminium dication plus an I anion. The dications are symmetrical and lie across crystallographic centres of inversion. In the crystal, the ions form a network involving mainly weak N—H I intermolecular interactions: two H atoms of the ammonium group form interactions with two I anions and the H atom of the secondary amine forms a weak interaction with a third I cation. The third ammonium H atom is hydrogen bonded to a secondary amine of an adjacent cation. The backbone of the cation does not form a uniformly trans chain, but is ‘kinked’ [C—N—C—C torsion angle = 71.5 (2) ], probably to accommodate the direct hydrogen bond between the ammonium group and the secondary amine in an adjacent cation.enInternational Union of CrystallographySingle-crystal X-ray studyT = 180 KMean (C–C) = 0.002 AR factor = 0.023wR factor = 0.053Data-to-parameter ratio = 39.3CrystalsCrystallographyAminesArticle