title: 4,4'-Bipyridinium bis-(oxalato-κO,O)cuprate(II): an ion-pair complex.
abstract: The title compound, (C(10)H(10)N(2))[Cu(C(2)O(4))(2)] or (4,4'-H(2)bpy)[Cu(ox)(2)] (bpy is 4,4'-bipyridine and ox is oxalate), is an ion-pair complex comprising a protonated 4,4'-bipyridinium dication and a square-planar dioxalatocopper(II) dianion. In the centrosymmetric dianion, the Cu(II) centre is coordinated by four O atoms from the two dicrete oxalate ligands [Cu-O = 1.9245 (19) and 1.9252 (17) Å], while the planar dications are also centrosymmetric. Inter-species N-H⋯O hydrogen bonds link the cations and anions into one-dimensional chains and, together with weak intra-ion C-H⋯O inter-actions, give a two-dimensional sheet structure.
authors.forename: Lai-Jun
authors.initials: LJ
authors.lastname: Zhang
authors.forename: Xing-Can
authors.initials: XC
authors.lastname: Shen
authors.forename: Hong
authors.initials: H
authors.lastname: Liang