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(C(9)H(6)O(3))(H(2)O)(3)](C(9)H(5)O(3))·H(2)O}(n), contains two crystallographically independent Na atoms, two 7-hy­droxy­coumarin ligands, six coordinated water mol­ecules, two 7-hy­droxy­coumarin anions and two uncoordinated water mol­ecules. Both Na atoms exhibit a distorted octa­hedral coordination geometry and are coordinated by five water O atoms and the terminal O atom from a 7-hy­droxy­coumarin 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-hy­droxy­coumarin phenolate anions are located between the chains and are hydrogen bonded to the chains.