Abstract:

Four one-dimensional(1D) Ln(Ⅲ) coordination polymers[Eu₂(C₉H₇O₂)₆(C₉H₇O₂H)(C₂H₅OH)]n(1)，[Sm(C₉H₇O₂)₃]n(2)，[Tb(C₉H₇O₂)₃]n(3)and [Gd(C₉H₇O₂)₃]n(4)(C₉H₈O₂=cinnamate acid) were synthesized by hydrothermal method, and their structures were determined by single-crystal X-ray diffraction. The Ln(Ⅲ) ions were nine-coordinated in these four complexes, and the bridging ligands were all cinnamate groups. However, the coordination environments of the central Ln(Ⅲ) ions were appreciably different. The complexes were characterized by IR, UV-Vis-NIR and fluorescence spectroscopy. The study on luminescent property in the visible region reveals that complex 1 emits red light, complexes 2 and 3 emit green light, but complex 4 emits feeblish blue light. In addition, the influence of the cinnamic ligand with softness and rigidity on the construction of coordination polymers and the luminescence of Ln(Ⅲ) ions was discussed.

Key words: Ln(Ⅲ)coordination complex, Crystal structures, Luminescence property