Ethyl­enedi­ammonium sodium tetra­kis­[bis­(ethyl­enedi­amine-κ(2) N,N′)(oxalato-κ(2) O (1),O (2))cobalt(III)] [penta­hydrogen di(phosphato­octa­deca­tungstate)] tetra­deca­hydrate

The title compound, Na(C(2)H(10)N(2))[Co(C(2)O(4))(C(2)H(8)N(2))(2)](4)[H(5)(P(2)W(18)O(62))(2)]·14H(2)O, prepared under hydro­thermal conditions, consists of two Dawson-type [P(2)W(18)O(62)](6−) anions, four isolated [Co(en)(2)(ox)](+) cations (en = ethyl­enedi­amine and ox = oxalate), one Na(+) cation, one [H(2)en](2+) cation, and a number of ordered (14) and disordered solvent water mol­ecules. The [P(2)W(18)O(62)](6−) polyoxidometalate anion has site symmetry 1 and contains two structurally distinct types of W atoms: viz. six W atoms on vertical pseudo-mirror planes grouped in two sets of three, and 12 equatorial W atoms that do not lie in the pseudo-mirror planes grouped in two sets of six. In each [Co(en)(2)(ox)](+) cation, the Co(III) ion is coordinated by four N atoms from two en ligands and two O atoms from the ox ligands, completing a distorted octa­hedral structure. The sodium cation lies on an inversion centre and additionally links the complex cations and anions. In the crystal, the various units are linked by N—H⋯O and O—H⋯O hydrogen bonds, which together with C—H⋯O hydrogen bonds form a three-dimensional structure. The contribution of a region of disordered electron density, possibly highly disordered solvent water mol­ecules, to the scattering was removed with the SQUEEZE option of PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155]. To equilibrate the charges five H(+) ions have been added to the polyoxidometalate. These H(+) ions and the disordered solvent contribution were not included in the reported mol­ecular weight and density.