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

Abstract

In the title compound, (C4H14N2)[Cu(C7H3NO4)2]·3H2O or (bdaH2)[Cu(pydc)2]·3H2O (where bda is butane-1,4-diamine and pydcH2 is pyridine-2,6-dicarboxylic acid), the CuII atom is coordinated by four O atoms [Cu—O = 2.0557 (16)–2.3194 (16) Å] and two N atoms [Cu—N = 1.9185 (18) and 1.9638 (18) Å] from two chelating rings of the pydc2− anions, which act as tridentate ligands. The geometry of the resulting CuN2O4 coordination can be described as distorted octahedral. The the two pydc2− fragments are almost perpendicular to one another [77.51 (11)°]. To balance the charges, two centrosymmetric protonated butane-1,4-diammonium, (bdaH2)2+ cations are present. In the crystal structure, extensive O—H...O, N—H...O and C—H...O hydrogen bonds [D...A = 2.720 (2)–3.446 (3) Å], ion pairing, C—O...π [O...π = 3.099 (2) Å] and π–π stacking interactions between the pydc2− rings [centroid–centroid distance = 3.5334 (15) Å] contribute to the formation of a three-dimensional supramolecular structure.