Hydrogen-bonded network in the salt 4-methyl-1H-imidazol-3-ium picrate.

In the title molecular salt, C4H7N2 (+)·C6H2N3O7 (-), the phenolic proton of the starting picric acid has been transferred to the imidazole N atom. The nitro groups are twisted away from the benzene ring plane, making dihedral angles of 12.8 (2), 9.2 (4) and 29.3 (2)°. In the crystal, the component ions are linked into chains along [010] via N-H⋯O and bifurcated N-H⋯(O,O) hydrogen bonds. These chains are further linked by weak C-H⋯O hydrogen bonds into a three-dimensional network. The complex three-dimensional network can be topologically simplified into a 4-connected uninodal net with the point symbol {4.8(5)}.

Hydrogen bonding in the crystal structure of the molecular salt of pyrazole-pyrazolium picrate.

The asymmetric unit of the title organic salt [systematic name: 1H-pyrazol-2-ium 2,4,6-tri-nitro-phenolate-1H-pyrazole (1/1)], H(C3H4N2)2 (+)·C6H2N3O7 (-), consists of one picrate anion and one hydrogen-bonded dimer of a pyrazolium monocation. The H atom involved in the dimer N-H⋯N hydrogen bond is disordered over both symmetry-unique pyrazole mol-ecules with occupancies of 0.52 (5) and 0.48 (5). In the crystal, the component ions are linked into chains along [100] by two different bifurcated N-H⋯(O,O) hydrogen bonds. In addition, weak C-H⋯O hydrogen bonds link inversion-related chains, forming columns along [100].