Synthesis, structures and luminescence of two lanthanide coordination polymers based on 2,4-pyridinedicarboxylic acid

Two Lanthanide coordination polymers [(H3O)Eu-3(PDA)6](2-)center dot 2H(3)O(+)center dot 12H(2)O (1) and [Tb-3(PDA)(4)(HO)(H2O)2]center dot 2H(2)O (2) (H(2)PDA = 2,4-pyridinedicarboxylic acid), have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, XRD as well as single-crystal X-ray diffraction. Both complexes are crystallized in the tetragonal system, P4(1)2(1)2 space group, but they have different three-dimensional coordination frameworks. 2,4-PDA(2-) ligand exhibits mu(4)-(kappa N-5,O-2:O-2':O-4:O-4(')), mu(4)-(kappa N-5,O-2:O-2,O-2':O-4:O-4') and mu(1)-(kappa N-5,O-2) coordination modes in the complexes. Both of them can be simplified to a new topology, with the Schlafli symbol of {3(6).4(16).5(6)} The luminescence properties for the two complexes were determined with solid samples. Complexes 1 and 2 show typical red and bright-green luminescence of Eu-III and Tb-III, respectively.