Poly[[[diaquazinc(II)]-bis(mu(2)-3-cyano-4-dicyanomethylene-5-oxo-4,5-dihydro-1H-pyrrol-2-olato-kappa(2)N3:N3')] dihydrate].

The coordination of the 3-cyano-4-dicyanomethylene-5-oxo-4,5-dihydro-1H-pyrrol-2-olate anion to Zn(II), the apical sites of which are occupied by two water molecules, results in the formation of two-dimensional layers of the title coordination polymer, {[Zn(C8HN4O2)2(H2O)2].2H2O}n, in which the Zn(II) cations lie on inversion centres in space group C2/c, with water ligands in the apical sites of octahedral geometry. Hydrogen bonds between coordinated and lattice water molecules, and pi-pi stacking interactions between the anions link adjacent layers into a continuous framework.