8-Hydroxyquinoline salt of pyrazine-2,3,5,6-tetracarboxylic acid [HQ]2[H2pztc]· 2H2O （1） was prepared and characterized by single-crystal X-ray diffraction, NMR, IR, TGA, elemental analysis and fluorescent measurements. Compound 1 crystallizes in orthorhombic, space group Pbcn with a = 9.953（3）, b = 15.966（3）, c = 16.081（5） A, V = 2555.5（13） A3, Z = 4, μ = 0.122 mm^-1, Dc = 1.514 Mg/m3, T= 296（2） K, C26H22N4O12, Mr = 582.48, F（000） = 1208, S = 1.006, R = 0.0448 and wR = 0.1149. Compound 1 has a three-dimensional （3D） network, in which pyra- zine-2,3,5,6-tetracarboxylic acids build up two-dimensional （2D） sheets and 8-hydroxyquinoline cations and water molecules act as pillars to connect the 2D sheets into an extended 3D network through strong intermolecular hydrogen bonding and π…π stacking interactions. Especially, a very short O-H…O hydrogen bond （O…O 2.470（2） A） between two neighboring [H2pztc] anions was observed.
