Poly[[(µ4-benzene-1,3,5-tri-carboxyl-ato-κ(4) O (1):O (1'):O (2):O (3))bis-(2,2-bi-pyridine-κ(2) N,N')(µ2-hydroxido)dicopper(II)] trihydrate].

In the title two-dimensional coordination polymer, {[Cu2(C9H3O6)(OH)(C10H8N2)2]·3H2O} n , each of the two independent Cu(II) atoms is coordinated by a bridging OH group, two O atoms from two benzene-1,3,5-tri-carboxyl-ate (L) ligands and two N atoms from a 2,2- bi-pyridine (bipy) ligand in a distorted square-pyramidal geometry. Each L ligand coordinates four Cu(II) atoms, thus forming a polymeric layer parallel to the bc plane with bipy molecules protruding up and down. The lattice water mol-ecules involved in O-H⋯· O hydrogen bonding are situated in the inner part of each layer. The crystal packing is consolidated by π-π inter-actions between the aromatic rings of bipy ligands from neigbouring layers [inter-centroid distance = 3.762 (3) Å].