[Aqua­bis­(nitrato-κO)copper(II)]-μ-{bis­[5-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl]selenide}-[diaqua­(nitrato-κO)copper(II)] nitrate monohydrate

In the title binuclear complex, [Cu(2)(NO(3))(3)(C(18)H(16)N(6)Se)(H(2)O)(3)]NO(3)·H(2)O, the Cu(II) ions are penta­coordinated in a tetra­gonal–pyramidal geometry. In both cases, the equatorial planes are formed by a chelating pyrazole-pyridine group, a water mol­ecule and a nitrate O atom, whereas the apical positions are occupied by a water mol­ecule for one Cu(II) ion and a nitrate O atom for the other. The organic selenide ligand adopts a trans configuration with respect to the C–Se–C plane. Numerous inter­molecular O—H⋯O and N—H⋯O hydrogen bonds between the coordinating and lattice water mol­ecules, nitrate anions and pyrazole groups are observed. π–π stacking inter­actions between the pyridine rings [averaged centroid–centroid distance = 3.652 (5) Å] are also present. The lattice water molecule is equally disordered over two sets of sites.