Synthesis, crystal structure and luminescent properties of a dysprosium coordinaation polymer based on pyridine-2, 6-dicarboxylic acid

2-D layered Dy coordination polymer [Dy (PDA) (HPDA)]_n (1) (H₂PDA=pyridine-2, 6-dicarboxylic acid) with (4.8²) topological network was synthesized under hydrothermal conditions and was characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. X-ray diffraction analysis reveals that compound 1 is monoclinic, space group P2 (1)/c. In the structure of compound 1, metal-centered Dy is connected via O atoms of H₂PDA ligands to form a (4.8²) topology network. The 3-D supramolecular structure of 1 is constructed through π-π stacking interactions between the adjacent layers. The luminescence properties of 1 were determined by UV-Vis and fluorescence spectrum in solid state at room temperature. The H₂PDA and 1 exhibit the similar broad maximum absorption peak at 280 nm, which are attributed to ligand-centered π-π* transition. The fluorescence emission band based on ligand-center and characteristic emission of Dy³⁺ at the same maximum excitation wavelength of 280 nm were observed in 1. The fluorescence decay curve of complex 1 indicated that the processes of decay consists of two components, of which corresponding lifetimes τ₁=3.61 μs and τ₂=12.81 μs.