Acta Cryst. (2011). E67, o2684-o2685 [ doi:10.1107/S1600536811037329 ]
Abstract: The absolute structure of the title compound, [H3N-(CH2)7-NH2]I, has been determined from the diffraction experiment, the Flack parameter refining to -0.02 (2). In the crystal, adjacent symmetry-related cations are connected by head-to-tail R'H2N+-HNH2R hydrogen bonds, forming chains along . The remaining four H atoms attached to the amino and the azanium group form weak hydrogen bonds to neighbouring iodide anions, producing a three-dimensional hydrogen-bonded network. The amino group and the aliphatic chain of the 7-aminoheptylazanium cation show an exact all-trans conformation, within experimental uncertainties. The azanium group, to fulfill the needs of hydrogen bonding, is twisted out of the plane defined by the C atoms of the aliphatic chain, the C-C-C-N torsion angle being -65.4 (4)°.
Online 17 September 2011
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