2,4-Dinitro-1-naphthol.

In the title compound, C(10)H(6)N(2)O(5), the two fused rings are almost co-planar, with an r.m.s. deviation of 0.0163 Å. The nitro groups are oriented at dihedral angles of 2.62 (11) and 44.69 (11)° with respect to the plane of the parent fused rings. Intra-molecular O-H⋯O and C-H⋯O hydrogen bonds complete S(6) ring motifs. In the crystal, mol-ecules are linked into chains along [101] by inter-molecular O-H⋯O hydrogen bonds. π-π inter-actions [centroid-centroid distances = 3.6296 (15), 3.8104 (15) and 3.6513 (14) Å] might play a role in stabilizing the structure.