title: Poly[piperazinediium [aqua-bis(μ-pyridine-2,5-dicarboxyl-ato)zincate] dihydrate].
abstract: The polymeric title compound, {(C(4)H(12)N(2))[Zn(C(7)H(3)NO(4))(2)(H(2)O)]·2H(2)O}(n), was obtained by the reaction of zinc(II) nitrate hexa-hydrate with the proton-transfer compound (pipzH(2))(py-2,5-dc) (where pipz is piperazine and py-2,5-dcH(2) is pyridine-2,5-dicarboxylic acid) in aqueous solution. Each Zn(II) atom is coordinated in a distorted octa-hedral geometry by four O atoms and two N atoms from one water mol-ecule and two (py-2,5-dc)(2-) ligands, which also act as bridging ligands between Zn(II) atoms. π-π Stacking inter-actions between two aromatic rings of (py-2,5-dc)(2-) fragments, with centroid-centroid distances of 3.4747 (7) and 3.7081 (7) Å are observed. The crystal structure is stabilized by O-H⋯O and N-H⋯O hydrogen bonds.
authors.affiliation: Faculty of Chemistry, Teacher Training University, 49 Mofateh Avenue 15614, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Aghabozorg
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Derikvand
authors.forename: Andya
authors.initials: A
authors.lastname: Nemati
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Bahrami
authors.forename: Jafar
authors.initials: J
authors.lastname: Attar Gharamaleki