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

Abstract

In the title compound, Na 2[Co(CH 4O 6P 2) 2(H 2O) 2]·2H 2O, the asymmetric unit is composed of one methyl-enediphospho-nate 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 IIO6 octa-hedral coordination environment is composed of two bidentate methyl-enediphospho-nate ligands and two coordinated water molecules in trans positions. The sodium ion is octa-hedrally 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 intra-molecular O-H⋯O and C-H⋯O hydrogen bonding inter-acions is present.