Poly­[[di­aqua­tris(μ6‐benzene‐1,2,4,5‐tetra­carboxyl­ato)­tris(μ2‐4,4′‐bi­pyridine)­hexacopper(II)] dihydrate]

The hydro­thermal reaction of an aqueous solution of Cu(CH₃COO)₂·H₂O, 1,2,4,5‐benzene­tetra­carboxylic acid and 4,4′‐bi­pyridine gave rise to the interesting title three‐dimensional polymer {Cu₆(btec)₃(4,4′‐bpy)₃(H₂O)₂]·2H₂O}_n (btec is 1,2,4,5‐benzene­tetra­carboxyl­ate, C₁₀H₂O₈^4?, and 4,4′‐bpy is 4,4′‐bi­pyridine, C₁₀H₈N₂), in which each btec ligand links six copper(II) cations into a lamellar Cu₆(btec)₃(H₂O)₂]_n sub­polymer framework. There are two distinct diamine units and two distinct carboxylate units, with one of each lying across an inversion centre.