Poly[[Diaqua-Mu(3)-Malonato-Iron(Ii)] Monohydrate]

The title coordination polymer, [[Fe(C4H4O5)(H2O)(2)]center dot H2O](n), was obtained by the hydrothermal reaction of FeSO4 with malic acid in alkaline aqueous solution. Each Fe-II atom is coordinated by four O atoms from three malate ligands and two water molecules, and displays a distorted octahedral geometry. The polychelated malate ligands bridge Fe ions to form corrugated layers; these layers are further assembled by intermolecular O-H center dot center dot center dot O hydrogen-bonding interactions to form a three-dimensional supramolecular network, with channels running along the b axis in which the uncoordinated water molecules are located. The solvent water molecule is disordered over two positions, with occupancy ratios of 0.78/0.22.