Trithia­cyanuric acid: a second triclinic polymorph

The title compound, C(3)H(3)N(3)S(3), is a triclinic modification. The other reported modification crystallizes with just one mol-ecule 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, mol-ecules are linked by strong intra-molecular N-H⋯S hydrogen bonds with set graph-motif R(2) (2)(8). In both mol-ecules, 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 inter-actions are not observed. In the solid state, the mol-ecules exist in the thione form. The mol-ecular and supra-molecular properties are similar in both polymorphs.