Powder diffraction crystal structure analysis using derivative difference minimization: example of the potassium salt of 1-(tetrazol-5-yl)-2-nitroguanidine.

The crystal structure of the potassium salt of 1-(tetrazol-5-yl)-2-nitroguanidine [K(C2H3N8O2)] was solved and refined from X-ray powder diffraction data by applying the derivative difference minimization (DDM) method. The compound is of interest as an energetic substance. The structure model was found from a Patterson search.

1,2-dinitroguanidine.

The title compound, CH(3)N(5)O(4), is almost planar, and the conformation is fixed by two intramolecular N-H...

2-nitrimino-1-nitroimidazolidine.

The molecule of the title compound, C(3)H(5)N(5)O(4), has a planar geometry. Due to the presence of a second nitro group, the lengths of the two conjugated C--N bonds are different. Nevertheless, the conjugation of the nitrimine group spreads to the nitramine group.

1-Amino-2-nitraminoethane.

The molecule of title compound, C(2)H(7)N(3)O(2), has a zwitterionic structure. All non-H atoms, apart from the terminal N atom of the NH(3) group, lie in the same plane, with a maximum deviation of 0.056 (1) A for the amine N atom of the nitramine group, whereas the deviation of the terminal N atom of the NH(3) group from the same plane is 1.

5-Nitro-2-nitromethyl-2H-1,2,3,4-tetrazole.

The molecule of the title compound, C(2)H(2)N(6)O(4), consists of three planar fragments, namely a tetrazole ring, a nitromethyl group and a nitro group. The nitro group and the tetrazole cycle are arranged in the same plane, but the planar nitromethyl group is located nearly orthogonal to this plane. The molecules are packed in the crystal via van der Waals interactions.

Nitroguanyl azide.

Crystals of the title compound, nitrocarbamimidoyl azide, CH(2)N(6)O(2), consist of two symmetry-independent molecules and the structure is stabilized by intra- and intermolecular hydrogen bonds. The molecule possesses a nitrimine structure.

3-Nitro-1-nitromethyl-1H-1,2,4-triazole.

The title compound, C(3)H(3)N(5)O(4), consists of three planar fragments twisted in relation to each other, namely a triazole ring, a nitromethylene group and a nitro group. Molecular conformation analysis shows that the first stage of thermal decomposition is a breakage of the H(2)C-NO(2) bond. There are essential conformational differences in the molecule in comparison with semi-empirical calculations.