title: 4,4'-Bipyridinium bis-(2-carboxy-pyridine-3-carboxyl-ate).
abstract: The title salt, C(10)H(10)N(2) (2+)·2C(7)H(4)NO(4) (-) or (4,4'-bpyH(2))(py-2,3-dcH)(2), prepared by the reaction between pyridine-2,3-dicarboxylic acid (py-2,3-dcH(2)) and 4,4'-bipyridine (4,4'-bpy), consists of two anions and one centrosymmetric dication. In the crystal, there are two strong O-H⋯O hydrogen bonds involving the two carboxyl-ate groups, with an O⋯O distance of 2.478 (1) Å, and an N-H⋯N hydrogen bond between the anion and cation, with an N⋯N distance of 2.743 (1) Å. These inter-actions, along with other O-H⋯O and C-H⋯O hydrogen bonds, π-π stacking [centroid-centroid distances 3.621 (7) and 3.612 (7) Å] and ion pairing, lead to the formation of the three-dimensional structure.
authors.forename: Janet
authors.initials: J
authors.lastname: Soleimannejad
authors.forename: Hossein
authors.initials: H
authors.lastname: Aghabozorg
authors.forename: Ali
authors.initials: A
authors.lastname: Morsali
authors.forename: Foruzan
authors.initials: F
authors.lastname: Hemmati
authors.forename: Faranak
authors.initials: F
authors.lastname: Manteghi