μ-4,4'-Diazenediyldiphthalato-κO:O-bis-[penta-aqua-manganese(II)] tetra-hydrate.

The dinuclear complex in the title compound, [Mn(2)(C(16)H(6)N(2)O(8))(H(2)O)(10)]·4H(2)O, lies on an inversion center. Two delocalized carboxyl-ate groups are each connected in a monodentate fashion to two similar penta-aqua-manganese units, whereas the other two localized carboxyl-ate groups are uncoordinated. The metal ion has octa-hedral coordination, with the O atom of a carboxyl-ate group and three coordinated water mol-ecules forming the equatorial plane [Mn-O(COO) = 2.143 (4) Å] and two water mol-ecules occupying the axial positions. The architecture is further consolidated by extensive hydrogen bonds for which coordinated water mol-ecules serve as donors or acceptors.