catena-Poly[[[tetra­aqua­magnesium]-trans-μ-[(piperazine-1,4-diium-1,4-di­yl)bis­(methyl­ene)]di­phospho­nato] hemihydrate]

The structure of the title polymer, }[Mg(C(6)H(14)N(2)O(6)P(2))(H(2)O)(4)]·0.5H(2)O}(n), is based on centrosymmetric MgO(6) octahedra, which are linked by [(piperazine-1,4-diium-1,4-di­yl)bis­(methyl­ene)]di­phospho­nate ligands, forming chains parallel to [1-1-1]. These chains are connected via hydrogen bonds primarily formed between the phospho­nate groups and water mol­ecules. The latter constitute four of the corners of the MgO(6) polyhedra and bind to the O atoms of the phospho­nate groups of neighbouring chains. The lattice water molecule is disordered around an inversion centre, exhibiting an occupancy of 0.25.