Trithiacyanuric acid: A second triclinic polymorph

Abstract

The title compound, C3H3N3S3, is a triclinic modification. The other reported modification crystallizes with just one molecule in the asymmetric unit, [Guo et al. (2006). Cryst. Growth Des. 6, 846-848] and was solved by power X-ray diffraction data. The present modification has Z′ = 2. In the crystal, molecules are linked by strong intramolecular N-H⋯S hydrogen bonds with set graph-motif R 22(8). In both molecules, all of the N atoms and two of the S atoms are involved in hydrogen bonding, with an average H⋯S distance of 2.58 Å and N-H⋯S angles in the range 163-167°. π-π stacking interactions are not observed. In the solid state, the molecules exist in the thione form. The molecular and supramolecular properties are similar in both polymorphs.