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 = 0.012Å). An intramolecular C - HO hydrogen bond occurs in the anion. In the crystal, N - HO hydrogen bonds and a weak C - HO interaction between the cations and anions form two sets of R 22(8) graph-set ring motifs. Intermolecular O - HO hydrogen bonds between these lead to a criss-cross pattern along the b axis. In addition to the classical hydrogen bonds, a weak C - Hπ(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). © Yamuna et al. 2014.