4,4′-Bipyridine-1,1′-diium 2,3,5,6-tetrabromoterephthalate dihydrate

The title compound, C10H10N22+center dot C8Br4O42-center dot 2H(2)O, consists of a tetrabromoterephthalate dianion, a 4,4'-bipyridinium dication and two solvent water molecules. Crystallographic inversion centers are situated at the center of the aromatic ring of the dianion as well as at the midpoint of the carbon-carbon bond connecting the pyridine rings in the dication. In the crystal, intermolecular N-H center dot center dot center dot O hydrogen-bonding interactions between tetrabromoterephthalate dianions and protonated 4,4'-bipyridinium dications result in the formation of a chain-like structure. Further O-H center dot center dot center dot O hydrogen bonds between carboxylate O atoms and water molecules lead to the formation of a two-dimensional network in the crystal structure.