Expected and unexpected products of reactions of 2-hydrazinylbenzothiazole with 3-nitrobenzenesulfonyl chloride in different solvents

The syntheses and crystal structures of 2-[2-(propan-2-ylidene)hydrazinyl]-1,3-benzothiazol-3-ium 3-nitrobenzenesulfonate (C10H12N2S+·C6H4NO5S−), (I), 2-[2-(3-nitrobenzenesulfonyl)hydrazinyl]-1,3-benzothiazole (C13H10N4O4S2), (II) and 2-[2-(3-nitrobenzenesulfonyl)hydrazinyl]-1,3-benzothiazol-3-ium 3-nitrobenzenesulfonate (C13H11N4O4S2+·C6H4NO5S−), (III) are reported. Salt (I) arose from an unexpected reaction of 2-hydrazinylbenzothiazole with the acetone solvent in the presence of 3-nitrobenzenesulfonyl chloride, whereas (II) and (III) were recovered from the equivalent reaction carried out in methanol. The crystal of (I) features ion pairs linked by pairs of N—H...Os (s = sulfonate) hydrogen bonds; adjacent cations interact by way of short π–π stacking interactions between the thiazole rings [centroid–centroid separation = 3.4274 (18) Å]. In (II), which crystallizes with two neutral molecules in the asymmetric unit, the molecules are linked by N—H...N and N—H...On (n = nitro) hydrogen bonds to generate [\overline{1}1\overline{1}] chains, which are cross-linked by C—H...O and π–π stacking interactions. The crystal of (III) features centrosymmetric tetramers (two cations and two anions) linked by cooperative N—H...O hydrogen bonds; C—H...O and π–π interactions occur between tetramers.