The hydrochloride and hydrobromide salt forms of (S)-amphetamine

(S)-Amphetamine hydrochloride, C9H14ClN, has a Z′ = 6 structure with six independent cation, anion pairs. That these are indeed crystallographically independent is supported by different packing orientations of the cations and by observation of a wide range of cation conformations generated by rotation about the phenyl–CH2 bond. The supramolecular contacts about the anions also differ such that both a wide variation in the geometry of the three N–H···Cl hydrogen bonds formed by each chloride anion and differences in C–H···Cl contacts are apparent. (S)-Amphetamine hydrobromide, C9H14BrN, is broadly similar to the chloride in terms of cation conformation, the existance of three N–H···X hydrogen bond contacts per anion and the overall 2 dimensional hydrogen bonded sheet motif. However, only the chloride structure features organic bilayers and Z′ > 1.