Bis(9-amino-acridinium) bis-(pyridine-2,6-dicarboxyl-ato)cuprate(II) trihydrate

The asymmetric unit of the title compound, (C(13)H(11)N(2))(2)[Cu(C(7)H(3)NO(4))(2)]·3H(2)O, consists of one [Cu(pydc)(2)](2-) dianion (pydc is pyridine-2,6-dicarboxyl-ate), two 9-amino-acridinum monocations and three uncoordinated water mol-ecules. The Cu(II) atom is coordinated by two pydc dianions acting as tridentate ligands, and forming five-membered chelate rings with copper(II) as the central atom. The Cu(II) atom is surrounded by four O atoms in the equatorial plane and two pyridine N atoms in axial positions, resulting in a distorted octa-hedral coordination geometry. In the crystal, there are two types of O-H⋯O and N-H⋯O hydrogen-bonding synthons linking the anionic and cationic fragments and the water mol-ecules, namely R(4) (4)(16), and R(4) (2)(8). There are also weak C-H⋯O hydrogen bonds, π-π stacking inter-actions [the shortest centroid-centroid distance is 3.350 (2) Å], and a C-O⋯π inter-action [O⋯centroid distance = 3.564 (2) Å], which connect the various components into a three-dimensional network.