Bis(9-aminoacridinium) bis(pyridine-2,6- dicarboxylato)zincate(II) trihydrate

R factor = 0.032; wR factor = 0.091; data-to-parameter ratio = 13.8. In the title compound, (C13H11N2)2[Zn(C7H3NO4)2]3H2O, the ZnII ion is six-coordinated with the N4O2 donor set being a distorted octahedron through two almost perpendicular (r.m.s. deviation of ligand atoms from the mean plane is 0.057 Å) tridentate pyridine-2,6-dicarboxylate ligands [dihedral angle between the ligands = 86.06 (4)]. The charge is compensated by two 9-aminoacridinium cations protonated on the ring N atom. A variety of intermolecular contacts, such as ion–ion, N—H O and O—H O hydrogen bonds, and – stacking [centroid–centroid distances = 3.4907 (9)–4.1128 (8) Å], between cations and between anions, play important roles in the formation of the three-dimensional network. Related literature For the behaviour of 9-aminoacridine in coordination compounds see: Derikvand et al. (2010); Eshtiagh-Hosseini, Mirzaei, Eydizadeh et al. (2011). For a brief review of the pyridinedicarboxylate family of ligands, see: Mirzaei et al