[mu]-4,4'-Bipyridine-[kappa]²N:N'-bis­[tetra­aqua­(4,4'-bipyridine-[kappa]N)diman­gan­ese(II)] bis­(4-amino­benzoate) bis­(perchlorate)-4,4'-bipyridine-water (1/2/4): a supra­molecular system constructed by [pi]-[pi] and hydrogen-bond inter­actions

The title dinuclear manganese compound, [Mn₂(C₁₀H₈N₂)₃(H₂O)₈](C₇H₆NO₂)₂(ClO₄)₂·2C₁₀H₈N₂·4H₂O, (I), has an inversion center located midway between the Mn^II ions. Each Mn^II ion has a distorted octa­hedral coordination environment, defined by two mutually cis N atoms from two different 4,4'-bipyridine (4,4'-bipy) ligands and four O atoms from four water mol­ecules. The asymmetric unit contains cationic [Mn(4,4'-bipy)_1.5(H₂O)₄]²⁺, one isolated 4,4'-bipy mol­ecule, one 4-amino­benzoate ion, one disordered perchlorate ion and two uncoordinated water mol­ecules. In the dinuclear manganese cationic unit, one 4,4'-bipy acts as a bidentate bridging ligand between two Mn^II ions, while the other two act only as monodentate terminal ligands, giving rise to a `Z-type' [Mn₂(4,4'-bipy)₃(H₂O)₈] host unit. These host units are linked to each other via face-to-face [pi]-[pi] stacking inter­actions between monodentate terminal 4,4'-bipy ligands, generating a zigzag chain. The corners of these chains, defined by Mn(OH)₄ units, are surrounded by the solvent water mol­ecules and the carboxyl­ate O atoms of the 4-amino­benzoate ions, and all of these are connected to each other via strong O-H...O hydrogen-bond inter­actions, leading to a three-dimensional grid network with a large cavity running along the b axis of the unit cell. The isolated 4,4'-bipy mol­ecules, the 4-amino­benzoate and perchlorate anions and the water mol­ecules are encapsulated in the cavities by numerous hydrogen-bond inter­actions.