Abstract:
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.