A one pot reaction of Cu(NO3)2, malonate dianion (mal) and 1,2-bis(4-pyridyl)ethane (bpe) leads to a novel 3D open framework, [{Cu3(mal)2(bpe)3(H2O)2}(NO3)2(H2O)2]n (1), composed of Cu–malonate layers pillared by bidentate bpe ligands encapsulating NO3− and water molecules in bidirectional intersecting channels; the framework's secondary building unit comprises unprecedented two hexa- and four penta-coordinate copper(II) nodes which are 6- and 4-connecting, respectively, and the magnetic properties of the complex show the highest overall ferromagnetic interaction (J = 22 cm−1) of the previously reported syn–anti carboxylate bridged complexes.
