Two derivatives of 1,5-disubstituted tetrazoles: 1-(4-nitrophenyl)-1H-tetrazol-5-amine and {(E)-[1-(4-ethoxyphenyl)-1H-tetrazol-5-yl]iminomethyl}dimethylamine.

The geometric features of 1-(4-nitrophenyl)-1H-tetrazol-5-amine, C(7)H(6)N(6)O(2), correspond to the presence of the essential interaction of the 5-amino group lone pair with the pi system of the tetrazole ring. Intermolecular N-H..

Two derivatives of 5-aminotetrazole: 5-amino-1-phenyltetrazole and 5-amino-1-(1-naphthyl)tetrazole.

In the molecules of 5-amino-1-phenyltetrazole, C(7)H(7)N(5), (I), and 5-amino-1-(1-naphthyl)tetrazole, C(11)H(9)N(5), (II), the tetrazole rings and aryl fragments are not coplanar; corresponding dihedral angles are 50.58 (5) and 45.19 (7) degrees for the two independent molecules of (I), and 64.