A series of three-dimensional 3d–4f heterometallic coordination frameworks based on pyridinedicarboxylic acid

Four new 3d–4f heterometallic coordination polymers [Cu3Eu2(2,5-pydc)6(H2O)12]·4(H2O) (1), [Zn2Eu2(2,5-pydc)5(H2O)2]·3(H2O) (2), and [Co3Ln2(2,6-pydc)6(H2O)6]·4(H2O) (Ln = Eu, 3; Dy, 4) (H2pydc = pyridinedicarboxylic acid) have been synthesized and characterized. All of these compounds have extended 3D coordination frameworks containing supramolecular 1D channels, in which lattice water molecules are located. Hydrogen bonds stabilize the 3D frameworks. Additionally, a study of their fluorescence properties has indicated that compounds 1 and 2 show the characteristic transitions of Eu3+. Weak antiferromagnetic interactions are observed in compound 3.