Tetra-aqua-{5-[(pyridin-2-yl-methyl-idene)amino]benzene-1,3-dicarboxyl-ato-κ(2)N,N'}nickel(II) tetra-hydrate.

The title structure, [Ni(C(14)H(8)N(2)O(4))(H(2)O)(4)]·4H(2)O, contains a mononuclear Ni(II) complex formed by a chelating bidentate Schiff base and by four Ni-bonded water mol-ecules. The Ni(II) atom is in a distorted octa-hedral coordination by two N atoms in a cis disposition [Ni-N = 2.0753 (16) and 2.1048 (16) Å] and by four water O atoms [Ni-O = 2.0500 (15)-2.0822 (15) Å]. The crystal structure is completed by four further non-coordinating water mol-ecules and all constituents are linked in a three-dimensional manner by an extensive system of 16 O-H⋯O hydrogen bonds.