Tetra-aqua-(2,2'-bipyridine-κN,N')manganese(II) di-μ-aqua-bis-[aqua-(2,2'-bipyridine-κN,N')(5-sulfonatoisophthalato-κO)manganate(II)] tetra-hydrate.

The crystal structure of the title salt, [Mn(C(10)H(8)N(2))(H(2)O)(4)][Mn(2)(C(8)H(3)O(7)S)(2)(C(10)H(8)N(2))(2)(H(2)O)(4)]·4H(2)O, consists of mononuclear manganese(II) cations, dinuclear manganate(II) dianions and uncoordinated water mol-ecules. The dianion is located about an inversion center; the Mn(II) atom is coordinated by a 2,2'-bipyridine ligand, a sulfonatoisophthalate group, a water mol-ecule along with two bridging water mol-ecules in an octa-hedral geometry. The cation lies on a twofold rotation axis; the Mn(II) atom is coordinated by four water mol-ecules and a chelating 2,2'-bipyridine ligand in a distorted octa-hedral geometry. A partially overlapped arrangement between the bipyridine ligands and the aromatic ring of the sulfoisophthalate group of adjacent anions is observed; the distance (3.357†à ) indicates π-π stacking. Hydrogen bonds, with the water mol-ecules serving as hydrogen-bond donors, lead to a three-dimensional network architecture.