Synthesis, crystal structure and fluorescence property of 1-D europium complex with 2,3-difluorobenzoate

A new chain europium complex [Eu(2,3-DFBA)3·(H2O)2]n (2,3-DFBA=2,3-difluorobenzoate) was synthesized by solvent method. X-ray single-crystal diffraction analysis revealed that Eu3+ ions were linked through 2,3-DFBA groups via alternate bidentate-bridging and tridentate chelating-bridging coordination modes to form a one-dimensional (1-D) polymeric chain. Each Eu3+ ion is eight-coordinated by six O atoms of five 2,3-DFBA ligands and two water molecules. The abundant hydrogen bonds between chains resulted in a two-dimensional (2-D) network structure. The titled complex crystallizes in monoclinic system, space group P21/c, with a=0.79977(2) nm, b=2.99156(7) nm, c=0.93260(2) nm, and β=100.691(1)°. The complex exhibited strong red fluorescence under ultraviolet light, and the 5D0 → 7Fj (j=0∼4) transitions of Eu3+ ion were observed in its emission spectrum.