Poly[[diaquabis(μ3-maleato-κ4O1:O1′,O4:O4′)dicopper(II)] trihydrate]

In the title compound, {[Cu2(C4H2O4)2(H2O)2]·3H2O}n, CuII ions with square-pyramidal coordination are bridged by exotridentate maleate dianions into [Cu2(maleate)2(H2O)2]n layers coincident with the bc crystal plane. The interlamellar regions contain hydrogen-bonded cyclic water hexamers which facilitate layer stacking into a pseudo-three-dimensional crystal structure. The water hexamers themselves are formed by the operation of crystallographic inversion centers on sets of three crystallographically distinct water molecules of hydration