Na₂Co(H₂PO₄)₄·4H₂O

Abstract

In the title compound, disodium cobalt tetrakis­(dihydrogen­phosphate) tetrahydrate, the CoII ion lies on an inversion centre and is octahedrally surrounded by two water molecules and four H2PO4 groups to give a cobalt complex anion of the form [Co(H2PO4)4(OH2)]2−. The three-dimensional framework results from hydrogen bonding between the anions. The relationship with the structures of Co(H2PO4)2·2H2O and K2CoP4O12·5H2O is discussed.