Disodium diaqua­bis­(methyl­enedi­phos­pho­nato-κ(2) O,O′)cobaltate(II) dihydrate

In the title compound, Na(2)[Co(CH(4)O(6)P(2))(2)(H(2)O)(2)]·2H(2)O, the asymmetric unit is composed of one methyl­enediphospho­nate ligand and one water mol­ecule, which both are coordinated to a Co(II) atom, as well as a non-coordinated water mol­ecule and a sodium cation. The Co(II) atom occupies a special position on a crystallographic inversion centre. The slightly distorted Co(II)O(6) octa­hedral coordination environment is composed of two bidentate methyl­enediphospho­nate ligands and two coordinated water mol­ecules in trans positions. The sodium ion is octa­hedrally coordinated to six O atoms with Na—O distances ranging from 2.3149 (12) to 2.6243 (12) Å. An extensive three-dimensional network of inter­molecular as well as intra­molecular O—H⋯O and C—H⋯O hydrogen bonding inter­acions is present.