Butane-1,4-diammonium bis(pyridine-2,6-dicarboxylato) cuprate(II) trihydrate

In the title compound, (C4H14N2)[Cu(C7H3NO4)(2)]center dot 3H(2)O or (bdaH(2))[Cu(pydc)(2)]center dot 3H(2)O ( where bda is butane-1,4-diamine and pydcH(2) is pyridine-2,6-dicarboxylic acid), the Cu II atom is coordinated by four O atoms [Cu-O = 2.0557 ( 16) 2.3194 ( 16) A] and two N atoms [Cu-N = 1.9185 ( 18) and 1.9638 ( 18) A] from two chelating rings of the pydc(2-) anion, which act as tridentate ligands. The geometry of the resulting CuN2O4 coordination can be described as distorted octahedral. The the two pydc(2-) fragments are almost perpendicular to one another [77.51 (11)degrees]. To balance the charges, two centrosymmetric protonated butane-1,4-diammonium, (bdaH(2))(2+) cations are present. In the crystal structure, extensive O-H center dot center dot center dot O, N-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds [ D center dot center dot center dot A = 2.720 ( 2)-3.446 ( 3) A], ion pairing, C-O center dot center dot center dot pi [ O center dot center dot center dot pi = 3.099 ( 2) A] and pi-pi stacking interactions between the pydc(2-) rings [centroid-centroid distance = 3.5334 ( 15) A] contribute to the formation of a three-dimensional supramolecular structure.