N (1),N (1)-Dimethyl­propane-1,2-diaminium bis­(6-carb­oxy­pyridine-2-carboxyl­ate) monohydrate

The asymmetric unit of the title proton-transfer compound, C(5)H(16)N(2) (2+)·2C(7)H(4)NO(4) (−)·H(2)O, consists of two mono-deproton­ated pyridine-2,6-dicarb­oxy­lic acid mol­ecules as anions, viz. (py-2,6-dcH)(−), one diprotonated N (1),N (1)-dimethyl­propane-1,2-diamine mol­ecule as a cation, viz. (dmpdaH(2))(2+), and one water mol­ecule. The crystal packing shows extensive O—H⋯O, N—H⋯O, N—H⋯N and O—H⋯N and weak inter­molecular C—H⋯O hydrogen bonds. These inter­actions link the (dmpdaH(2))(2+) cation, the (py-2,6-dcH)(−) anions and water mol­ecule and play an important role in the stabilization of crystal packing.