Bis[[(6-carb­oxy­pyridazine-3-carboxyl­ato-κ(2) N (2),O (3))lithium]-μ-penta­hydrogen­dioxy­gen(1+)]

The structure of the title compound, [Li(C(6)H(3)N(2)O(4))(2)(H(5)O(2))], is composed of centrosymmetric monomers in which an Li(I) ion is chelated by two N,O-bonding groups donated by two ligands. The Li(I) ion and both ligand mol­ecules are coplanar [r.m.s. deviation 0.0047 (2) Å] and water O atoms are in the axial positions. The second carboxyl group of each ligand remains protonated. An additional H atom, located between adjacent coordinated water mol­ecules and observed on Fourier maps, maintains the charge balance within the monomers and bridges them by short symmetric hydrogen bonds of 2.518 (3) Å to form catenated ribbons. The monomers also inter­act via hydrogen bonds in which water and carboxyl O atoms act as donors.