Diaquatetrakis(pyridine-2,6-dicarboxylato-kappa2O2,O6)tetrakis(micro-pyridine-3,5-dicarboxylic acid-kappa2N:O)tetracopper(II): a copper complex with tetrameric molecular units.

Crystals of the title tetramer, [Cu4(C7H3NO4)4-(C7H5NO4)4(H2O)2], were synthesized hydrothermally at 433 K. The triclinic structure consists of tetrameric molecular species, which interact via strong hydrogen bonds. The Cu(II) ions are distributed equally between one square-pyramidal site and one octahedral site distorted by the Jahn-Teller effect.