2,2′-(Piperazine-1,4-diium-1,4-di­yl)diacetate dihydrate.

The asymmetric unit of the title compound, C8H14N2O4·2H2O, contains one water mol­ecule and one half-mol­ecule of piperazine-1,4-diacetic acid in salt form. Intra­molecular N—H⋯O and O—H⋯O and inter­molecular O—H⋯O hydrogen bonds are involved in the crystal packing. In the centrosymmetric title compound, the six-membered piperazine ring is in a standard chair form, and the two acetates are mutually trans. The 2,2′-(piperazine-1,4-diyl)diacetic acid and water molecules are connected through a complex pattern of hydrogen-bonding interactions, resulting in a three-dimensional network. [ABSTRACT FROM AUTHOR]