Poly[[mu2-aqua-bis[(1,10-phenanthroline)nickel(II)]]-di-mu2,mu4-5-nitro-1,3-benzenedicarboxylato].

The reaction of Ni(CH(3)COO)(2).4H(2)O, 5-nitro-1,3-benzenedicarboxylic acid (H(2)nmbdc), 1,10-phenanthroline and water under hydrothermal conditions yields the first reported two-dimensional nickel coordination polymer with water- and carboxylate-bridged dimeric units, viz. [Ni(2)(C(8)H(3)NO(6))(2)(C(12)H(8)N(2))(2)(H(2)O)](n). The coordination polyhedron of the Ni(II) ion in the title structure is an octahedron defined by an N(2)O(4) donor set. The water molecule is positioned on a mirror plane and the 5-nitro-1,3-benzenedicarboxylate group is located on a twofold axis. Two types of nmbdc(2-) coordination mode are observed: one is a bis-monodentate mode, mu(2)-nmbdc(2-), and the other is a bis-bridging mode, mu(4)-nmbdc(2-). The dimeric unit in the title compound is similar to the structural moiety in urease. In the two-dimensional framework in the title compound, strong stacking interactions between benzene rings (mu(2)-nmbdc(2-) and mu(4)-nmbdc(2-)) and 1,10-phenanthroline ligands are observed.