3,6-Diaza-octane-1,8-diaminium diiodide.
The asymmetric unit of the title salt, C(6)H(20)N(4) (2+)·2I(-), comprises half a 3,6-diaza-octane-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 inter-molecular inter-actions: two H atoms of the ammonium group form inter-actions with two I(-) anions and the H atom of the secondary amine forms a weak inter-action 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.
Department of Chemistry, University of Pretoria, Private Bag X20, Hatfield 0028,  South Africa.
Ignacy
I
Cukrowski
Adedapo S
AS
Adeyinka
David C
DC
Liles