5-Amino-1H-pyrazol-2-ium hydrogen succinate.

In the cation of the title salt, C3H6N3 (+)·C4H5O4 (-), the protonated pyrazolium ring is planar (r.m.s. deviation = 0.012†à ). An intra-molecular C-H⋯O hydrogen bond occurs in the anion. In the crystal, N-H⋯O hydrogen bonds and a weak C-H⋯O inter-action between the cations and anions form two sets of R 2 (2)(8) graph-set ring motifs. Inter-molecular O-H⋯O hydrogen bonds between these lead to a criss-cross pattern along the b axis. In addition to the classical hydrogen bonds, a weak C-H⋯π(pyrazolium) inter-action is observed and contributes to crystal packing. All of these inter-actions link the mol-ecules into a two-dimensional supra-molecular framework parallel to (10-1).