Diaquabis(dihydrogen 3-azaniumyl-1-hydroxypropylidene-1,1-diphosphonato-κ 2 O , O ′)cobalt(II)

The asymmetric unit of title compound, [Co(C3H10NO7P2)2(H2O)2], contains one half-molecule of the complex. The CoII atom is located on an inversion centre and displays a distorted octahedral coordination geometry defined by four O atoms of two 3-azaniumyl-1-hydroxypropylidene-1,1-bisphosphonato ligands in the equatorial plane and two water molecules located in axial positions. The ligand molecules, which exist in a zwitterionic state, form two six-membered chelate rings with chair conformations. In the crystal, molecules are interlinked by O—H...O and N—H...O hydrogen bonds, forming a three-dimensional supramolecular structure.