Hexa-aqua-zinc(II) dinitrate bis-[5-(pyridinium-3-yl)tetra-zol-1-ide].

Hexa-aqua-zinc(II) dinitrate 5-(pyridinium-3-yl)tetra-zol-1-ide, [Zn(H2O)6](NO3)2·2C6H5N5, crystallizes in the space group P . The asymmetric unit contains one zwitterionic 5-(pyridinium-3-yl)tetra-zol-1-ide mol-ecule, one NO3- anion and one half of a [Zn(H2O)6]2+ cation ( symmetry). The pyridinium and tetra-zolide rings in the zwitterion are nearly coplanar, with a dihedral angle of 5.4 (2)°. Several O-H⋯N and N-H⋯O hydrogen-bonding inter-actions exist between the [Zn(H2O)6]2+ cation and the N atoms of the tetra-zolide ring, and between the nitrate anions and the N-H groups of the pyridinium ring, respectively, giving rise to a three-dimensional network. The 5-(pyridinium-3-yl)tetra-zol-1-ide mol-ecules show parallel-displaced π-π stacking inter-actions; the centroid-centroid distance between adjacent tetra-zolide rings is 3.6298 (6) Å and that between the pyridinium and tetra-zolide rings is 3.6120 (5) Å.