Pyrazinediium bis(3-carboxy-4-hydroxybenzenesulfonate) dihydrate

Abstract

Pyrazine and 5-sulfosalicylic acid crystallize from a methanol solution containing water as the title salt, C4H6N22+·2C7H5O6S−·2H2O. The pyrazinediium cation sits on an inversion center. The component ions and water molecules are linked by intermolecular O—H...O, N—H...O and C—H...O hydrogen bonds into layers running parallel to the (10overline{2}) plane.