Bis(μ-5-carboxyl-ato-1-carboxyl-ato-methyl-2-oxidopyridinium)-κO:O;κO:O-[diaqua-(phenan-throline-κN,N')manganese(II)] dihydrate.

The centrosymmetric binuclear title complex, [Mn(2)(C(8)H(5)NO(5))(2)(C(12)H(8)N(2))(2)(H(2)O)(4)]·2H(2)O, was obtained by the reaction of manganese chloride with 5-carb-oxy-1-carboxy-methyl-2-oxidopyridinium and 1,10-phenanthroline. The Mn(II) atom is coordinated by two N atoms from the 1,10-phenanthroline ligand, two O atoms from two 5-carboxyl-ato-1-carboxyl-atomethyl-2-oxidopyridinium ligands and two water mol-ecules, leading to a distorted octahedral MnN(2)O(4) environment. Inter-molecular O-H⋯O hydrogen bonds link neighbouring mol-ecules into a layer structure parallel to (001).