trans-Diaquabis(3-hydroxybenzoato-kappaO1)bis(nicotinamide-kappaN1)copper(II).

The title compound, [Cu(C(7)H(5)O(3))(2)(C(6)H(6)N(2)O)(2)(H(2)O)(2)], is a two-dimensional hydrogen-bonded supramolecular complex. The Cu(II) ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridine N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N-H...O and O-H...O hydrogen bonds produce R(2)(2)(4), R(2)(2)(8) and R(2)(2)(15) rings which lead to one-dimensional polymeric chains. An extensive two-dimensional network of N-H...O and O-H...O hydrogen bonds and C-H...pi interactions are responsible for crystal stabilization.