N-(5-Amino-1H-tetrazol-1-yl)formamide

In the title compound, C2H4N6O, the planar [maximum deviation = 0.006 (2) Å] aminotetrazole group makes a dihedral angle of 83.65 (8)° with the formamide unit. In the crystal structure, intermolecular N—H⋯N, N—H⋯O and C—H⋯N hydrogen bonds are responsible for the formation of a three-dimensional network.

In the title compound, C 2 H 4 N 6 O, the planar [maximum deviation = 0.006 (2) Å ] aminotetrazole group makes a dihedral angle of 83.65 (8) with the formamide unit. In the crystal structure, intermolecular N-HÁ Á ÁN, N-HÁ Á ÁO and C-HÁ Á ÁN hydrogen bonds are responsible for the formation of a three-dimensional network.

Structure Reports Online
The molecular structure of the title compound is presented in Fig. 1. The aminotetrazole group is essentially planar and makes a dihedral angle of 83.65 (8)° with the formamide unit. The bond distances and bond angels in the title compound are similar to the corresponding distances and angles reported by He et al. (2009). In the crystal structure, the molecules are linked to each other via intermolecular N-H···N, N-H···O and C-H···N hydrogen bonds (Table 1), forming a threedimensional network structure.

Experimental
Diamino-tetrazole (10 mmol) was dissolved in 10 ml formic acid, 0.3 g sodium formate was added to the above mixture and reacted under refluxing, use TLC to control the reaction process. After cooling, the crude product precipitated and was filtered. The purity of the compound was checked by its melting point. of methanol (20 ml) and acetone (10 ml) and the solution was kept at room temperature to give suitable crystals for X-ray structure determination.

Refinement
Amino H atoms were located in a difference Fourier maps and were refined isotropically. Other H-atoms were placed in calculated positions with C-H = 0.98 Å, and refined in riding mode with U iso (H) = 1.2U eq (C).
In the absence of significant anomalous dispersion effects, the Friedel pairs were averaged. Fig. 1. The molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.