1H-Pyrazol-2-ium hydrogen oxalate.
In the title compound, C(3)H(5)N(2) (+)·C(2)HO(4) (-), the anions form centrosymmetric dimers through cyclic O-H⋯O hydrogen-bonding associations [graph set R(2) (2)(10)]. These dimers are then linked through a cyclic R(4) (2)(10) N-H⋯O hydrogen-bonding association involving two cations and the carboxyl O-atom acceptors of separate anions, giving chain structures extending across the (111) plane.
Ordered Matter Science Research Center, College of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189,  People's Republic of China.
Chun-Hua
CH
Yu
Run-Qiang
RQ
Zhu