Crystal structure and thermal behaviour of pyridinium styphnate

In the crystal structure of the title mol­ecular salt, C(5)H(6)N(+)·C(6)H(2)N(3)O(8) (−) (systematic name: pyridinium 3-hy­droxy-2,4,6-tri­nitro­phenolate), the pyridin­ium cation and the 3-hy­droxy-2,4,6-tri­nitro­phenolate anion are linked through bifurcated N—H⋯(O,O) hydrogen bonds, forming an R (1) (2)(6) ring motif. The nitro group para with respect to phenolate ion forms an intra­molecular hydrogen bond with the adjacent phenolic –OH group, which results in an S(6) ring motif. The nitro group flanked by the phenolate ion and the phenolic –OH group deviates noticeably from the benzene ring, subtending a dihedral angle of 89.2 (4)°. The other two nitro groups deviate only slightly from the plane of the benzene ring, making dihedral angles of 2.8 (4) and 3.4 (3)°. In the crystal, the 3-hy­droxy-2,4,6-tri­nitro­phenolate anions are linked through O—H⋯O hydrogen bonds, forming chains along [100]. These anionic chains, to which the cations are attached, are linked via C—H⋯O hydrogen bonds, forming a three-dimensional structure. Impact friction sensitivity tests and TGA/DTA studies on the title mol­ecular salt imply that it is an insensitive high-energy-density material.