Pyridinium and 1,2-diazinium salts of chloranilic acid

The crystal structures of two salts of chloranilic acid (2,5-dichloro-3,6- dihydroxy-p-benzoquinone), namely pyridinium chloranilate monohydrate, C₅H₆N⁺·-C₆HCl ₂O^-₄·H₂O, (I), and bis(1,2-diazinium) chloranilate, 2C₄H₅N⁺₂·C₆Cl ₂O^2-₄, (II), have been determined at room temperature. In (I) and (II), the cations and anions are held together by N - H⋯O hydrogen bonds with short N⋯O distances of 2.670 (4) Å in (I) and 2.582 (3) Å in (II). The H atom in the hydrogen bond in (I) was located at the N-atom site [N - H = 1.09(5) and H⋯O = 1.70 (5) Å], while that in (II) was found near the center of N⋯O [N⋯H = 1.32 (5) and H⋯O = 1.28 (5) Å].