Poly[[bis­{μ(3)-2-[(3,5-dimethyl-1H-pyrazol-1-yl)(phen­yl)meth­yl]propane­dioato}tetra­sodium(I)] 7.5-hydrate]

The asymmetric unit of the title polymer, {[Na(4)(C(15)H(14)N(2)O(4))(2)]·7.5H(2)O}(n), contains two 2-[(3,5-dimethyl-1H-pyrazol-1-yl)(phen­yl)meth­yl]propane­dioate (ppmp) anions, eight water mol­ecules (one located on a twofold rotation axis) and five sodium cations (one located on an inversion center and the other one located on a twofold rotation axis). The carboxyl­ate groups of the ppmp anions and the water mol­ecules bridge the Na cations, forming a two-dimensional polymeric structure. In the structure there are two types of coordination environment around the metal cations: one Na cation is coordinated by five O atoms in a distorted square-pyramidal geometry while the other four Na cations are coordinated by six O atoms in a distorted octa­hedral geometry. Extensive O—H⋯O and O—H⋯N hydrogen bonding is present in the crystal structure. The H atoms of one methyl group of the ppmp anion are disordered equally over two positions.