Synthesis, crystal structure and characterization of one-dimension complex constructed by terbium(III) and 2-iodobenzoate

The complex of [Tb(2-IBA)3(H2O)2]n (2-IBA=2-iodobenzoate)was prepared by solvent method from TbCl3·6H2O and 2-iodobenzoic acid. The crystal structure was determined with X-ray single-crystal diffraction. The X-ray diffraction analysis indicated that the title complex crystallized in triclinic crystal system and Pī space group. The Tb3+ ion was coordinated by six oxygen atoms from five 2-IBA ligands and two oxygen atoms from two water molecules, giving a distorted square-antiprism polyhedral geometry. The carboxyl groups were bonded to the Tb3+ ions with bidentate-bridging and bidentate-chelating coordination modes. The adjacent Tb3+ ions were linked by two bidentate-bridging 2-IBA ligands, forming 1-D chain structure. The fluorescence spectrum of the complex showed four main peaks at 489, 543, 587, and 618 nm, corresponding to 5D4→7FJ (J=6−3) transition emissions of the Tb3+ ion, respectively.