The reaction of magnesium(II) nitrate hexahydrate with the proton-transfer compound (pipzH2)(pydc) [pipz is piperazine and pydcH2 is pyridine-2,6-dicarboxylic acid] in aqueous solution leads to the formation of the title compound, [Mg(C7H3O4)(H2O)3]2H2O. The piperazinium cation is not incorporated in this crystal structure. The MgII atom has a distorted octahedral coordination environment. There are many intermolecular O—H O hydrogen bonds involving the (pydc)2 species and water molecules in the crystal structure
