4-(Pyrimidin-2-yl)piperazin-1-ium (E)-3-carb­oxy­prop-2-enoate

In the cation of the title salt, C(8)H(13)N(4) (+)·C(4)H(3)O(4) (−), the piperazinium ring adopts a slightly distorteded chair conformation. In the crystal, a single strong O—H⋯O inter­molecular hydrogen bond links the anions, forming chains along the c-axis direction. The chains of anions are linked by the cations, via N—H⋯O hydrogen bonds, forming sheets parallel to (100). These layers are linked by weak C—H⋯O hydrogen bonds, forming a three-dimensional structure. In addition, there are weak π–π inter­actions [centroid–centroid distance = 3.820 (9) Å] present involving inversion-related pyrimidine rings.