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

Abstract

In the cation of the title salt, C3H6N3+·C4H5O4−, the protonated pyrazolium ring is planar (r.m.s. deviation = 0.012 Å). An intramolecular C—H...O hydrogen bond occurs in the anion. In the crystal, N—H...O hydrogen bonds and a weak C—H...O interaction between the cations and anions form two sets ofR22(8) graph-set ring motifs. Intermolecular O—H...O hydrogen bonds between these lead to a criss-cross pattern along thebaxis. In addition to the classical hydrogen bonds, a weak C—H...π(pyrazolium) interaction is observed and contributes to crystal packing. All of these interactions link the molecules into a two-dimensional supramolecular framework parallel to (10-1).