Retracted: Poly[diaqua­di-μ₃-malonato-μ-pyrazine-dinickel(II)]

The title compound, [Ni₂(C₃H₂O₄)₂(C₄H₄N₂)(H₂O)₂]_n, has been prepared from the hydro­thermal reaction of nickel(II) chloride, malonic acid and pyrazine. The Ni^II atoms are linked via coordinated malonates, forming a two-dimensional network with cavities of 6.14 × 5.60 Å. These sheet structures are further connected into a three-dimensional network by bridging pyrazine ligands which have inversion symmetry, the mean distance between the layers being 7.39 Å. The coordination geometry around the Ni^II atom is a tetra­gonally elongated octa­hedron, with pyrazine N and aqua O atoms at the apical positions.