Chiral and achiral crystals, charge‐assisted hydrogen‐bond patterns and self‐organization of selected solid diaminium thiosulfates

A series of diaminium thiosulfates, derivatives of diamines: NH 2 CH 2 CH(CH 3 )NH 2 (1) and NH 2 (CH 2 ) n NH 2 , n = 3–6 [(2)–(5)] and thiosulfuric acid were prepared and their structures determined by single‐crystal X‐ray diffraction analysis. Compounds (1), (2) and (4) turned out to be hydrates. The crystal structure of 1,2‐propylenediaminium thiosulfate is chiral and exhibits spontaneous resolution. Crystals for both enantiomers [(1 a ) and (1 b )] were obtained with high enantiometric excess and examined. An extended network of strong, charge‐assisted hydrogen bonding of the + N—H…O − type (also O—H…O and O—H…S for hydrates) is most likely the main factor defining crystal packing and the variable conformation of the cations. The formation of chiral hydrogen‐bond motifs – distorted cubans – seems to induce the formation of chiral solid‐state structure from achiral components in the case of (4). Diaminium thiosulfates with an odd number of C atoms in the alkyl chain [compounds (1), (2) and (4)] form three‐dimensional supramolecular networks, while in the case of diaminium salts with an even number of C atoms [(3) and (5)], two‐dimensional layers of hydrogen‐bond domains are observed. The aminium thiosulfates were also characterized by elemental analysis, NMR and Fourier transform (FT)–IR spectroscopy. The conformations of α,ω‐alkyldiaminium cations in the solid state are discussed and rationalized by DFT calculations.