Crystal structures of the three closely related compounds: Bis[(1H-Tetrazol-5-yl)methyl]-nitramide, triaminoguanidinium 5-({[(1H-Tetrazol-5-yl)methyl](nitro)amino}methyl)tetrazol-1-ide, and diammonium bis[(tetrazol-1-id-5-yl)methyl]-nitramide monohydrate

In the molecule of neutral bis[(1H-Tetrazol-5-yl)methyl]nitramide, (I), C₄H₆N₁₀O₂, there are two intramolecular N-H·O hydrogen bonds. In the crystal, N-H·N hydrogen bonds link molecules, forming a two-dimensional network parallel to (201) and weak C-H·O, C-H·N hydrogen bonds, and intermolecular φ φstacking completes the three-dimensional network. The anion in the molecular salt, triaminoguanidinium 5-({[(1H-Tetrazol-5-yl)methyl]( nitro)amino}methyl)tetrazol-1-ide, (II), CH₉N₆ +-C⁴H₅N_10O^2-, displays intramolecular φ-φ stacking and in the crystal, N-H·N and N-H·O hydrogen bonds link the components of the structure, forming a three-dimensional network. In the crystal of diammonium bis[(tetrazol-1-id-5-yl)methyl]nitramide monohydrate, (III), 2NH₄+C⁴H₄N₁₀O₂ ^2-H₂O, O-H·N, N-H·N, and N-H·O hydrogen bonds link the components of the structure into a threedimensional network. In addition, there is intermolecular φ-φ stacking. In all three structures, the central N atom of the nitramide is mainly sp²-hybridized. Bond lengths indicate delocalization of charges on the tetrazole rings for all three compounds. Compound (II) was found to be a non-merohedral twin and was solved and refined in the major component.