S. Anbarasu

2-Amino-5-nitro-pyridinium hydrogen oxalate.

In the cation of the title molecular salt, C5H6N3O2 +·C2HO4 −, the dihedral angle between the aromatic ring and the nitro group is 3.5 (3)°; in the anion, the dihedral angle between the CO2 and CO2H planes is 10.5 (2)°. In the crystal, the anions are linked into [100] chains by O—H⋯O hydrogen bonds. The cations cross-link the chains by way of N—H⋯O hydrogen bonds and the structure is consolidated by C—H⋯O interactions.

Crystal structure of 2-amino-5-nitro­pyridinium sulfamate

The title molecular salt, obtained by the reaction of sulfamic acid with 2-amino-5-nitropyridine, is the result of a proton transfer from sulfamic acid to the N atom of the pyridine ring. In the crystal, the cations and anions are linked by a number of N—H⋯O and N—H⋯N hydrogen bonds, forming sheets lying parallel to (100).