Molecular and crystal structures of bis-tetrazolate ammonium salt and bis-tetrazole monohydrate

The title compounds bis-tetrazolate ammonium salt (I) and bis-tetrazole monohydrate (II) are synthesized and studied by single crystal and powder X-ray diffraction, IR and elemental analyses. Compound I crystallizes in the monoclinic space group C2/m, a = 8.8862(17) Å, b = 11.2334(21) Å, c = 3.7269(7) Å, β = 99.4(6)°, V = 367.03 ų (12), Z = 2. Compound II crystallizes in the monoclinic space group P2₁/c, a = 5.1701(9) Å, b = 4.7506(8) Å, c = 15.2197(24) Å, β = 107.2(7)°, V = 357.09(10) ų, Z = 2. In the structure of I, both ammonium cation and bis-tetrazolate counter-anion are located on twofold crystallographic axes, moreover, the bis-tetrazolate anion has a mirror plane passing through the ’C1-C1a bond. In the crystal structure of (II), the bis-tetrazole molecule sits on the twofold axis (bisecting the C1-C1a bond), whereas the solvent water molecule occupies a general position. In the crystal structure of (I), the molecules are packed via N-H…N intermolecular interactions. In the crystal structure of (II), the molecules are packed via N-H…O and O-H…O intermolecular interactions. In addition, the crystal packing of both structures is further strengthened by π-π stacking interactions.