catena-Poly[[[aqua(7-hydroxy-2H-1-benzopyran-2-one)sodium]-di-μ-aqua] 2-oxo-2H-1-benzopyran-7-olate monohydrate]

The asymmetric unit of the title compound, {[Na(C9H 6O3)(H2O)3](C9H 5O3)·H2O}n , contains two crystallographically independent Na atoms, two 7-hydroxy-coumarin ligands, six coordinated water molecules, two 7-hydroxy-coumarin anions and two uncoordinated water molecules. Both Na atoms exhibit a distorted octa-hedral coordination geometry and are coordinated by five water O atoms and the terminal O atom from a 7-hydroxy-coumarin ligand. Four of the water molecules are bridging, whereas the fifth is terminal. Na-O bond distances are in the range 2.288 (2)-2.539 (2) Å. In the chains, extending parallel to [100], adjacent Na atoms are separated by 3.60613 (7) Å. The uncoordinated water molecules and 7-hydroxy-coumarin phenolate anions are located between the chains and are hydrogen bonded to the chains.