Poly[piperazinediium [aquabis(μ-pyridine-2,5-dicarboxylato)zincate] dihydrate]

Abstract

The polymeric title compound, {(C4H12N2)[Zn(C7H3NO4)2(H2O)]·2H2O}n, was obtained by the reaction of zinc(II) nitrate hexahydrate with the proton-transfer compound (pipzH2)(py-2,5-dc) (where pipz is piperazine and py-2,5-dcH2 is pyridine-2,5-dicarboxylic acid) in aqueous solution. Each ZnII atom is coordinated in a distorted octahedral geometry by four O atoms and two N atoms from one water molecule and two (py-2,5-dc)2– ligands, which also act as bridging ligands between ZnII atoms. π–π Stacking interactions 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.